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ELEMENTS  OF  CHEMISTRY 


AND 


DENTAL    MATERIA    MEDICA 


BY 

J.    S.    CASSIDY,    D.D.S.,    M.D 

Pkofessok  of  Chemistry  and  Materia  Medica  in  Ohio  College  of 

Dental  Surgery 


CINCINNATI 
ROBERT    CLARKE    &    CO 

1893 


COPYKIGHT,     1892, 

By  JAMES  S.  CASSIDY. 


TO 

ELIZA   GUYTOE", 

IN     LOVINO    APPRECIATION    OF    HER 

CHRISTIAN  FORTITUDE 

AND 

EXCEEDING   PATIENCE 

UNDER    MANY    TRYINO    CIRCUMSTANCES, 

Stbis  ^ook  is  ^ffettionattlg  ^nstribtb, 

BY    HER   HUSBAND, 

THE  AUTHOR. 


"  •"■>   *".. 


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PREFACE. 


The  labor  involved  in  the  preparation  of  the  fol- 
lowing pages,  was  assumed  at  the  solicitation  of 
members  of  my  classes;  and  also  for  the  purpose 
of  testing  the  comparative  value,  to  Dental  Stu- 
dents, of  the  two  approved  didactic  methods  of 
teaching  Chemistry  and  Materia  Medica,  i,  e.,  by 

Lectures  and  quiz,  and  by  Recitation  from  approved 
Text-books,  in  connection  with  suggestive  experi- 
ments. 

The  author  lays  no  claim  to  originality  of  style, 
or  system,  in  presenting  the  subjects.  The  sub- 
jects themselves,  with  few  exceptions,  are  not  elas- 
tic, and  admit  of  only  slight  variations  from  the 
usual  accepted  phraseology. 

Division  of  the  volume  into  Three  Parts  was 
made,  with  a  view  to  the  convenience  of  the  three 
graded  classes,  which  now  obtain,  as  required  by 
the  Association  of  Dental  Faculties. 

The  space  given  to  the  consideration  of  Chemi- 
cal Philosophy,  and  Compound  Radicals,  as  well  as 
that  occupied  by  the  few  simple  rules  to  be  observed 
in    Prescription  writing,  Hud  the  approximate  re- 


vi  Preface. 

lations  between  the  Metric,  and  Apothecaries  sys- 
tems, of  weights  and  measures,  will,  not,  I  trust, 
he  regarded  as  superfluous;  for  dental  students,  as 
well  as  those  of  medicine,  are  often  sadly  deficient 
in  a  clear  knowledge  of  those  important  accom- 
plishments. 

It  may  appear  on  first  sight,  that  our  Materia 
Medica  is  too  limited,  and  overshadowed  by  the 
governing  science  of  Chemistry;  but  the  combina- 
tion of  these  two  branches  of  our  curriculum,  as 
herein  presented — which  I  believe  is  unique,  and 
to  the  advantage  of  the  student — necessarily  pre- 
vents the  complete  exposition  of  at  least  those 
drugs  which  are  unessential  in  dental  practice. 

Description  of  the  work  performed  by  the  class, 
in  our  Chemical  Laboratory,  on  Qualitative  Analy- 
sis, lias  been  omitted,  inasmuch  as  a  monograph  on 
that  subject,  will  probably  soon  be  forthcoming. 

I  have,  of  necessity,  borrowed  freely  from  the 
authorities  consulted,  to  all  of  whom  it  would  be 
impossible  to  give  individual  credit.  Of  these^ 
however,  we  must  not  forget  the  collective  credit 
due  to  various  dental,  medical,  and  scientific  jour- 
nals, and  in  especial  manner  to  Fowne's,  Atfield's, 
Clark's,  Appleton's,  Mitchell's  Dental,  Roscoe's, 
Crooke's,  ai'Ui/:Barket!^;/<vhen:dstry ;  Miller's  Mi- 
crobes, and  Biddre^s, Polter^^,  (jforgas.'. Dental,  Bar- 


Preface.  vii 

tholow's,  Farquharson's,  and  Waring's  Materia 
Medica.  To  tliem,  and  many  other  friends,  who 
have  assisted  to  render  my  task  a  labor  of  love,  I 
hereby  extend  my  grateful  acknowledgments. 

J.  S.  CASSIDY, 

1555  Madison  Avenue,  Covington,  Ky.,  December  15,  1892. 


Note. — By  kindly  referring  to  the  Index,  the  reader  will 
observe  a  slight  departure  from  the  usual  orthography  of  cer- 
tain words.  Thus  will  be  found  Chlori>2,  lodni,  Glycerin, 
Cocam,  Oxid,  SuJfur,  etc. 

This  innovation  is  in  accord  with  the  recent  official  report  of 
a  Committee  of  the  Chemical  Section  of  the  American  Associ- 
ation for  the  Ads^ancement  of  Science,  and  will  probably  be 
generally  adopted  in  the  very  near  future.  J,  S.  C. 


»-      »w 

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INORGANIC   CHEMISTRY. 


PAR^T    FIRST. 


CHAPTER   I. 
PHYSICS. 

Matter  and  Force  are  involved  in  the  consider- 
ation of  all  natural  phenomena. 

Matter,  substance,  of  which  the  physical  uni- 
verse is  composed. 

Force,  modes  of  motion  by  which  are  manifested 
heat,  light,  magnetism,  and  electricity;  also  motor, 
or  mechanical  motion.  All  of  these  are  inter-con- 
vertible. 

Specific  gravity.  Special  kinds  of  matter,  as 
water,  chloroform,  gold,  etc.,  differ  from  each  other 
in  Aveight;  or  equal  bulks  of  them  are  not  affected 
equally  by  the  attraction  of  gravitation.  They 
differ  therefore  in  specific  gravity,  or  in  the  force 
with  which  they  fall  to  the  earth. 

The  specific  gravity  of  any  substance  is  its  loeight 
compared  with  the  weight  of  an  equal  bulk  of  the  stand- 
dard  substance  reckoned  as  unity. 

In  the  case  of  all  solids  and  liquids,  distilled 
water  at  a  temperature  of  4°C.  (39°F.),  is  the  stand- 

(1) 


2  ^       Inorganic  Chemistiy. 

ard  of  unity.  A  given  temperature  is  necessary, 
inasmuch  as  change,  in  this  respect,  either  in- 
creases or  decreases  the  volume.  The  specific 
gravity  of  any  liquid  is  ascerfained  by  dividing  its 
weight,  at  the  standard  temperature,  by  the  weight 
of  an  equal  bulk  of  water.  The  quotient  will  be 
greater  or  less  than  unity,  according  as  the  weight 
of  the  liquid  in  question,  is  greater  or  less  than 
that  of  the  standard. 

The  specific  gravity  of  a  solid  is  obtained  by  the 
same  rule,  viz.,  divide  the  weight  of  the  solid  by 
the  weight  of  the  same  bulk  of  the  standard 
(water).  If  the  solid  be  heavier  than  water,  it  is 
first  weighed  in  air,  then  in  water;  it  thus  weighs 
less  in  water  than  in  air,  and  the  loss  in  weight 
expresses  the  weight  of  its  own  bulk  of  the  liquid. 
Its  weight  in  air  is  divided  by  the  amount  it  loses 
by  immersion  in  water;  the  quotient  will  be  the 
specific  gravity  of  the  solid. 

When  the  solid  body  is  soluble  in  water,  then 
some  non-solvent  liquid,  the  specific  gravity  of 
which  is  known,  is  taken  as  a  substitute. 

In  determining  the  specific  gravity  of  a  solid 
lighter  than  water,  various  methods  are  employed. 
A  piece  of  metal,  for  instance,  may  be  attached 
to  overcome  the  buoyancy  of  the  light  body,  and 
mathematical  results  thus  obtained. 


Physics.  S 

A  sufficiently  exact  key  to  the  general  doctrine . 
of  the  e([uilibrium  of  floating  bodies  is  afl:brded  by 
the  theorem  of  Archimedes. 

A  solid  of  less  specific  gravity  than  the  liquid  in 
which  it  is  placed  will  float.  It  displaces,  at  the 
same  time,  a  quantity  of  liquid  exactly  equal  to  its 
own  weight.  Thus,  a  solid  possessing  one-half  the 
specific  gravity  of  water,  if  placed  in  that  liquid, 
will  sink  one-half  its  bulk,  the  weight  of  the  water 
displaced,  l)eing  equal  to  the  weight  in  air  of  the 
floating  body. 

It  is  on  this  principle  that  instruments  known 
as  hydrometers,  urinometers,  etc.,  are  constructed, 
by  which  a  graduated  stem,  made  of  glass  or 
metal,  floats  in  the  liquid  to  be  tested.  If  the 
liquid  be  heavier  than  unity,  the  stem  will  be 
raised  accordingly,  and  vice  versa,  with  liquids 
lighter  than  water.  The  specific  gravity  of  the 
rKpiid  will  he  indicated  by  the  coincidence  of 
its  surface  with  the  figures  on  the  graduated 
scale. 

The  specific  weights  of  gases  are  obtained  by 
dividing  their  weight  by  an  equal  volume  of  air. 
In  many  cases  hydrogen  is  taken  as  the  standard 
of  unity  for  gases.  The  term  dejisitij,  when  ap- 
jdiod  to  a  gas,  implies  that  hydroiren  is  reckoned 
as  unity,  and  when  the  term  specific  gravity  is  em- 


4  Inorganic  Chemistry. 

ployed  with  reference  to  the  same,  or  some  other 
gas,  it  is  understood  that  air  is  the  standard  of 
unity. 

PROPERTIES    OF    GASES. 

G-ases  or  vapors,  whether  simple  or  compound, 
are  obviously  affected  by  the  attraction  of  gravita- 
tion, in  common  with  other  forms  of  matter. 

The  atmosphere  is  the  familiar  prototype  of 
gases  in  general,  and  serves  to  exhibit  certain  phe- 
nomena pertaining  to  all  of  them ;  one  of  which 
is  the  property  of  elasticity. 

Air  contained  in  a  cylinder,  in  which  works  an 
air-tight  piston  suffers  condensation,  if  the  piston 
be  pressed  down  ;  whereas,  if  the  pressure  be  less- 
ened by  raising  the  piston,  the  air  will  expand  and 
completely  fill  the  enlarged  space  in  the  cylinder. 

The  volume  of  a  given  weight  of  gas  depends 
on  the  pressure  :  the  relation  being  expressed  by 
the  law  of  Mariotte,  "  The  volume  of  a  gas  is  in- 
versely as  the  pressure ;  the  density  and  elastic 
force  are  directly  as  the  pressure  and  inversely  as 
the  volume."  Thus,  100  cubic  inches  of  gas  at  the 
ordinary  pressure,  will  expand  to  200  cubic  inches, 
if  the  pressure  be  reduced  one-half,  and  shrink  to 
a  volume  of  50  cubic  inches  if  the  pressure  be 
doubled. 

The   atmosphere   is  the  ocean  of  gaseous  matter 
surrounding  the  earth  and  held  to  the  latter  by  the 


Physics.  5 

attraction  of  gravitation.  Its  weight,  or  density, 
is  therefore  greater  at  the  sea  level,  than  at  high 
elevations;  the  density  decreasing  uniformly  as 
we  ascend. 

Instruments  to  indicate  changes  in  the  weight, 
or  pressure  of  the  atmosphere  at  different  eleva- 
tions, or  temporary  changes  in  the  pressure  at  a 
given  elevation,  are  called  barometers. 

The  mercurial  barometer  is  constructed  by  filling 
completely,  a  glass  tube  about  35  inches  long  with 
clean,  dry  mercury,  and  the  open  end  of  the  tube 
inverted  in  a  reservoir  of  mercury.  It  will  then 
be  seen  that  the  mercurial  column  will  descend  in 
the  tube — leaving  an  empty  space  above — until  it 
reaches  a  position  about  30  inches  above  the  sur- 
face of  the  mercury  in  the  reservoir,  at  which  point 
it  remains  balanced  by  the  pressure  of  the  atmos- 
phere. Now,  if  such  a  column  of  mercury,  having 
an  area  of  1  inch,  be  weighed,  it  will  be  found  to 
weigh  between  14  and  15  lbs.,  proving  that  the 
pressure  of  the  atmosphere  is  nearly  15  lbs.  on 
every  inch  of  the  earth's  surface. 

The  diffusive  poicer  of  gases,  depends  on  their  rel- 
ative densities;  the  rule  being  that  "  the  diffusive 
power  of  a  gas  is  inversely  as  the  square  root  of  its 
density."  If  a  vessel  be  divided  in  two  equal  com- 
partments by  a  thin,   dry  partition  of  plaster  of 


6  Inorganic  Chemistry. 

paris,  and  the  two  compartments  filled  with  differ- 
ent gases,  incapable  of  acting  chemically  on  each 
other  at  ordinary  temperatures,  it  will  be  found  that 
diffusion  into  each  other  will  take  place  according 
to  the  above  rule. 

If  one  compartment  be  filled  with  H,  and  the 
other  with  0,  4  cubic  inches  of  H  will  pass 
through  the  porous  plaster  of  paris  diaphragm,  to 
the  oxygen  side,  while  1  cubic  inch  of  0  will  pass 
to  the  11  side.  The  densities  of  these  two  gases 
are  as  1  to  16;  their  relative  rates  of  dift'usion,  are 
inversely  as  the  square  roots  of  these  numbers,  or 
as  4  to  1. 

The  inherent  diffusive  power  of  gases,  whereby 
the  atmosphere  absorbs  them,  prevents  the  accu- 
mulation of  poisonous  vapors  in  confined  localities, 
their  wide  dissemination  permitting  the  atmospheric 
ozone  to  destroy  them  easily ;  or  they  become  so  at- 
tenuated in  the  air,  as  is  the  case  with  carbon-diox- 
ide, ammonia,  etc.,  that  they  exert  no  appreciable 
influence  on  the  health  of  the  animal  kingdom. 
Certain  gases,  though  comparatively  dense,  diffuse 
most  readily  through  wet  membranes  on  account  of 
■  their  great  solubility ;  as  in  the  process  of  animal 
respiration,  the  CO2,  which  is  freely  soluble  in 
water,  escapes  easily  thus  dissolved,  through  the 
wet  membranes  of  the  lungs. 


Effects  of  Heat. 


CHAPTER  II. 

EFFECTS  OF  HEAT. 

One  of  the  most  general  eiFects  produced  on 
matter,  by  increasing  temperature,  is  expansion. 
If  a  metallic  bar  be  fitted  accurately  to  a  guage 
when  cold,  and  then  slightly  heated,  it  will  be 
found  too  long  to  enter  the  gauge.  This  is  due  to 
the  heat  overcoming  to  that  extent  the  attraction 
of  cohesion  existing  between  the  molecules  of  the 
bar.  If  the  heat  be  continued,  the  molecules  may 
be  driven  so  far  apart,  that  the  metal  will  assume 
the  liquid  state;  and,  finally,  the  metal  may  be 
made  to  volatilize,  or  become  gaseous,  in  which 
condition,  the  molecules  are  widely  separated.  By 
abstracting  the  heat,  or  allowing  the  mass  to  cool, 
contraction  takes  place  ;  the  space  between  the  mol- 
ecules is  lessened,  the  metallic  vapor  changes  again 
to  a  liquid,  and  this  back  to  the  original  solid  con- 
dition. The  expansibility  of  most  solids  varies 
with  the  increment  of  heat,  zinc,  lead,  silver,  cop- 
per, gold,  soft  iron,  tempered  steel,  untempered 
steel,  common  white  glass,  platinum  and  flint  glass, 
expand  in  the  order  named. 


8  Inorganic  Chemistry. 

It  is  seen  that  glass  and  platinum  expand  and 
contract,  nearly  alike,  and  porcelain,  whose  nature 
and  expansive  power  approximates  the  former  ma- 
terial, permits  fusion  with  platinum  in  the  manu- 
facture of  artificial  teeth,  Logan  crowns,  etc.,  with- 
out the  danger  of  fracture,  by  excessive  changes  in 
temperature. 

Liquids  not  only  differ  in  dilation  by  equal 
amounts  of  heat,  but  they  differ  greatly  in  their 
rate  of  expansion,  by  increasing  temperature. 

Mercury  expands  more  uniformly  between  0°C, 
and  100°C,  than  other  liquids,  and  for  this  reason 
it  is  employed  in  the  construction  of  thermome- 
ters, instruments  for  measuring  changes  in  tem- 
perature. A  glass  tube  closed  at  one  end  and 
blown  to  a  bulb,  the  other  end  left  open  and  drawn 
to  a  point,  is  partially  filled  \vith  mercury.  The 
bulb  is  carefully  heated,  by  which  the  air  is  driven 
out,  the  tube  being  completely  filled  with  the  ex- 
panded mercury ;  the  open  end  is  then  hermetically 
sealed,  and  on  cooling,  the  mercury  contracts, 
leaving  an  empty  space  above.  The  height  of  the 
mercurial  column  is  marked  on  the  glass,  at  two 
fixed  points.  These  two  points  are  found  at  the 
boiling  temperature  of  water,  the  barometric  pres- 
sure being  noted,  and  at  the  freezing  of  water, 
which  is  constant.     Between  these  two  marks,  the 


Effects  of  Heat.  9 

tube  is  divided  into  an  arbitrary  number  of  degrees, 
the  scale  continuing  above  and  below  each  mark 
respectively,  to  indicate  temperatures  above  and 
below  the  boiling  and  freezing  points  of  water. 
The  Raumer  scale  is  divided  into  80  degrees;  the 
boiling  point  at  80°,  the  freezing  point  at  0°.  Fah- 
renheit's scale  contains  180  degrees,  but  he  placed 
his  0°,  32  degrees  below  the  freezing  point;  conse- 
quently the  boiling  point  is  expressed  by  Fahren- 
heit at  212°.  According  to  the  centegrade  ther- 
mometer, the  freezing  of  water  is* indicated  by  0°, 
and  the  boiling  point  by  100°.  The  graduation  of 
the  latter  instrument  is  considered  the  most  ra- 
tional. It  is  adopted  by  nearly  all  scientific  bodies. 
Fresh  water  when  subjected  to  the  freezing  pro- 
cess continues  to  contract  in  volume  until  it  reaches 
a  temperature  of  4°C,  (-SO^F) — its  point  of  maxi- 
mum density.  On  further  cooling  it  expands,  until 
the  freezing  temperature  is  reached,  0°C,  (32°F.) 
In  the  immediate  act  of  solidifying,  great  enlarge- 
ment takes  place  :  ice  is  therefore  formed  on  the 
surface,  being  lighter  than  the  liquid  water  beneath. 
On  melting,  the  reverse  takes  place;  the  volume 
contracting  until  the  temperature  of  4°C  is  reached, 
after  which  expansion  proceeds  with  increasing 
heat.  In  regard  to  the  expansion  of  gases  by  heat, 
the  following  statement  will  suffice : 


10  Inorganic  Chemistry. 

I.  All  gases  or  vapors  when  remote  from  their 
condensing  points,  expand  nearly  alike  for  equal 
increments  of  heat. 

II.  The  rate  of  expansion  is  uniform  for  all  de- 
grees of  heat. 

III.  The  rate  of  expansion  is  not  altered  by  a 
change  in  the  state  of  compression  or  elastic  force 
of  the  gas  itself. 

IV.  The  actual  amount  of  expansion  is  equal  to 


1 1 


3QQQ  of  the  volume  of  the  gas  at  0°C,  for  each 
degree  of  that  scale :  3,000  volumes  of  gas  at  0°C 
become  3,011  at  1°C,  3,022  volumes  at  2°C,  etc. 


CONDUCTION    OF    HEAT. 

The  power  of  conducting  heat  varies  greatly  with 
different  bodies.  If  rods  of  the  same  size  of  differ- 
ent solids  have  each  one  extremity  heated  equally, 
the  other  extremities  will  become  heated  in  the 
ratio  of  the  conducting  power  of  the  material. 

The  metals  as  a  class  are  the  best  conductors  of 
heat  (and  electricity),  silver  being  first.  Rating 
the  conducting  power  for  silver  at  1,000  that  of 

Copper  is 736 

Gold  is 532 

Tin  is 145 

Iron  is  119 


Effects  of  Heat.  11 

Lead  is 85 

Platinum  is 84 

Normal  Moist  Dentine  is 15 

Gold,  and  mercurial  alloys  of  copper,  and  of  silver 
and  tin — known  as  amalgams — are  much  better  con- 
ductors of  heat  than  tooth  structure,  and  to  that 
extent,  at  least,  are  objectionable  materials  for  fill- 
ing cavities  in  teeth.  Tn  sudden  thermal  changes 
in  the  mouth,  heat  is  conducted  by  them  so  rapidly 
to  or  from  the  dental  pulp,  as  to  endanger  the  com- 
fort and  life  of  that  organ. 

Various  other  solids,  mainly  non-metallic,  such 
as  glass,  wood,  vulcanite,  gutta-percha,  zinc  ox- 
ide cements,  etc.,  are  poor  conductors.  The  last 
two  substances  are  frequently  employed  singly  and 
sometimes  in  union,  as  a  protecting  covering  to 
the  pulp,  before  applying  the  metallic  tilling. 

Liquids  and  gases  are  classed  as  non-conductors 
of  heat;  their  increase  in  temperature  is  due  to 
convection,  or  the  circulation  of  their  particles 
within  the  mass.  Those  particles  nearest  to  the 
source  of  artificial  heat  move  away,  giving  place 
to  others  of  lower  temperature,  until  all  the  par- 
ticles acted  upon  are  involved  in  the  heating 
process. 


12  Inorganic  Chemistry. 


CHAPTEK  III. 

SPECIFIC   HEAT. 

Equal  weights  of  different  substances  require 
different  amounts  of  beat  to  raise  tbem  a  given 
temperature.  If  1  lb.  of  water  at  40°C.,  and  1  lb. 
of  water  at  10°C.,  be  mixed,  the  mixture  will  pos- 
sess the  mean  temperature  of  both,  or  25°C.  If  1 
lb.  of  mercury  at  40°C.  be  mixed  with  1  lb.  of  mer- 
cury at  10°C.,  the  mixture  will  also  possess  a  tem- 
perature the  mean  of  40  and  10,  or  25°C.  IsTow,  if 
1  lb.  of  water,  at  40°C.,  be  mixed  with  1  lb.  of  mer- 
cury at  10°C.,  the  temperature  will  not  be  25°C.,  but 
will  be  39°C.  The  lb.  of  water  at  40°C.  loses  but 
1°  in  cooling  from  40°  to  39°,  while  it  raises  its  own 
weight  of  mercury  29°,  from  10°  to  39°  ;  the  specific 
heat,  i.  e.,  calorific  capacity  of  water  is,  therefore, 
29  times  greater  than  mercury.  The  amount  of 
heat  sufficient  to  raise  a  given  weight  of  water 
through  a  given  range  of  temperature,  referred 
relatively  to  the  amount  of  heat  required  to  raise 
equal  weights  of  the  different  substances  through 
the  same  range  of  temperature,  implies  tlie  spe- 
cific   heats — capacities    for   heat — of    the    various 


Specific  Heat.  13 

substances.  The  specific  beat  of  water  is  greater 
tlian  that  of  any  other  substance,  excepting  hy- 
drogen. Taking  water  as  unity — 1,000 — the  ca- 
pacity for  heat,  of  an  equal  weight  of  hydrogen, 
is  expressed  by  3.490,  and  gold  by  0.324. 

But  if,  instead  of  equal  weights,  quantities  pro- 
portional to  the  atomic  weights  of  elements  be 
taken,  there  will  be  found  a  remarkable  relation, 
viz :  "  The  atomic  weights  of  the  various  elements 
are  inversely  proportional  to  the  specific  heats,  so 
that  the  product  of  the  specific  heats  into  the 
atomic  weights  is  approximately  a  constant  num- 
ber. The  same  quantity  of  heat  will  produce  a 
given  change  of  temperature  in  7  grains  of  Li.,  56 
of  Fe,  108  of  Ag,  197  of  Au,  etc.  These  numbers 
represent  the  atomic  weights  of  the  elements 
named.  In  other  words,  the  atoms  of  the  several 
elements  have  equal  capacities  for  heat. 

Latent  Heat. —  Whenever  a  solid  melts  or  fuses 
a  certain  amount  of  sensible  heat  disappears  and 
remains  latent  in  the  liquid. 

One  lb.  of  powdered  ice  or  snow,  at  0°C.,  placed 
in  1  11).  of  water  at  70C.  will  melt;  the  tempera- 
ture, however,  will  not  be  35°C. — the  mean  of  70° 
and  0° — but  will  be  reduced  to  0°C.  by  the  melting 
of  the  ice,  showing  that  70°C.  of  heat  have  been 


14  Inorganic  Chemistry. 


absorbed    in    the    chanofe    of    state    from    solid   to 


liquid. 

1  lb.  of  water  at  70°C. 
1  lb.  of  ice  at  0°C. 

This  heat  of  fluidity  is  set  free,  when  the  water 
again  freezes;  for,  although  the  temperature  of  the 
surrounding  medium  may  be  much  lower  than  the 
freezing  point  of  water,  so  much  latent  heat  is  set 
free  by  the  change  of  state  from  liquid  to  solid,  as 
to  keep  the  temperature  up  to  0°C. 

This  law  of  sensible  heat  becoming  latent,  when- 
ever any  solid  becomes  a  liquid,  also  applies  to 
solids  and  liquids  becoming  gases,  a  certain  amount 
of  heat  disappears  and  remains  latent  in  the  gas; 
and  heat,  to  an  exactly  corresponding  amount  is 
set  free,  when  the  gas  again  assumes  the  liquid 
state. 

A  pound  of  water  at  lOO^C.  mixed  with  a  pound 
of  w^ater  at  0°C.,  will  occasion  a  temperature  in  the 
mixture  of  50°C.,  but  a  pound  of  steam  at  100°C., 
if  condensed  to  a  liquid  in  water  at  0°C.,  will, 
by  giving  up  its  latent  heat,  confer  a  temper- 
ature equal  to  its  own  of  100°C.  on  5.4  pounds  of 
water  at  0°C.  It  follows,  that  temperature  is  less- 
ened by  change  of  state  from  solid  to  liquid,  and 
from  liquid  to  vapor.  Fahrenheit  mixed  powdered 
ice  and  salt :  the  mixture  became  liquid  and  re- 


Specific  Heat.  15 

duced  the  temperature  32°F.  (by  his  scale)  below 
the  freezing  point  of  water.  He  supposed  this  to 
be  the  greatest  absence  of  heat  that  could  be  arti- 
ficially produced,  and  named  the  point  zero  (0°F.) 

Ordinary  chemical  action  always  occasions  a  rise 
in  temperature ;  but  mere  solutions  generally  lower 
the  temperature  because  of  the  amount  of  heat  ab- 
sorbed overcoming  the  heat  developed  by  weak 
chemical  affinities.  This  is  the  principle  of  frigo- 
rilic  mixtures,  such  as  powered  calcium  chloride 
and  snow;  ammonium  nitrate  and  water,  etc. 

The  great  reduction  of  temperature  occasioned 
by  the  rapid  evaporation  of  highly  volatile  liquids, 
such  as  ethyl  chloride,  ethyl  oxide,  etc.,  is  due  to 
the  heat  absorbed  and  which  remains  latent  in  the 
escaping  vapor.  In  minor  surgical  operations, 
some  of  these  highly  volatile  liquids  are  applied 
to  the  part,  in  the  form  of  a  spray,  to  obtund 
sensibility. 

Water  evaporates  at  all  temperatures,  and,  as 
with  other  liquids,  its  evaporation  is  increased  by 
increase  of  heat.  'When  the  boiling  point  is 
reached  there  is  visible  formation  in  the  body  of 
the  liquid  of  bubbles  of  gas,  which  ascend  to  the 
surface  and  escape  into  the  atmosphere  as  vapor, 
carrying  the  latent  heat  with  them,  thus  prevent- 
ing the  liquid  from  assuming  a  higher  tempera- 


16 


Inorganic  Chemistry. 


tare.  Water  (or  otlier  liquid)  boils,  when  the 
elasticity  of  its  vapor  is  able  to  overcome  the  pres- 
sure upon  it. 

At  the  sea  level  water  boils  at  100°G.,  (212°F.), 
but,  at  higher  elevations,  as  on  mountain  tops,  ebul- 
lition takes  place  at  a  lower  temperature,  because 
of  the  lessened  pressure,  or  weight  of  the  atmos- 
phere. If  water  be  made  to  boil  in  a  partially 
filled  flask,  the  vessel  then  tightly  corked  and  re- 
moved from  the  source  of  heat,  the  boiling  of  the 
water  will  soon  cease  by  the  pressure  of  its  own 
inclosed  vapor.  By  applying  to  the  surface  of  the 
vessel  a  wet  sponge,  which  condenses  the  vapor 
and  thus  diminishes  the  pressure,  ebullition  again 
takes  place;  and  this  repeatedly,  until  the  water  in 
the  flask  is  reduced  to  a  common  temperature. 


Distillation,  17 


CHAPTER  IV. 

DISTILLATION. 

The  object  of  distillation  is  either  to  separate 
different  substances  which  rise  in  vapor,  at  differ- 
ent temperatures,  from  a  composite  liquid,  or  to 
part  volatile  liquids  from  substances  that  do  not 
volatilize.  When  the  process  applies  to  solid 
bodies  passing  directly  to  the  gaseous  state  and 
back  again  to  the  solid  form, it  is  called  sublimation. 

Liquids  evaporate  at  temperatures  below  the  boil- 
ing points,  and  the  vapors  thus  escaping,  as  in  the 
case  of  water  from  the  ocean  and  from  the  general 
surface  of  the  earth,  are  virtually  distilled. 

Vapor  of  water  exists  in  the  atmosphere  at  all 
times  and  in  all  situations.  If  the  aqueous  vapor 
he  in  condition  of  greatest  possible  density  for  the 
temperature,  or  as  is  often  but  incorrectly  ex- 
pressed, the  air  be  saturated  with  vapor  of  water, 
the  slightest  reduction  of  temperature  will  cause 
the  deposition  of  a  portion  in  the  liquid  form.  If, 
however,  the  vapor  of  water  be  below  the  point  of 
maximum  density,  that  is,  in  an  expanded  condi: 
tion,  which    is   generally  the  case,  a  considerable 


18  Inorganic  Chemistry. 

fall  of  temperature  may  occur  before  the  dew. point, 
or  liquefaction  commences.  The  resemblance  be- 
tween vapors,  and  what  are  ordinarily  known  as 
gases  suggested  means  by  which  all  of  the  latter 
class  have  been  converted  into  liquids,  by  the  influ- 
ence of  cold  combined  with  pressure.  Thus,  chlo- 
rine gas  at  a  pressure  of  4  atmospheres  and  a  tem- 
perature of  15.5°C.,  and  nitrous  oxide  gas  at  a 
pressure  of  50  atmospheres  and  a  temperature  of 
7.2°C.,  are  condensed  to  the  liquid  state. 

Nature  of  Heat. — Although  the  sources  of  heat 
are  numerous,  such  as  the  sun  itself,  the  interior 
of  the  earth,  mechanical  motion  (the  latter  includ- 
ing percussion,  friction  and  condensation),  electric 
excitation  and  chemical  action,  a  rise  in  tempera- 
ture is  caused  in  all  cases  by  increased  motions  in- 
duced in  the  particles  of  matter  involved  in  its 
development.  It  is  probable  that  absolute  zero  or 
perfect  absence  of  molecular  motion,  does  not  ex- 
ist. That  matter  changing  from  the  gaseous  to 
the  liquid,  and  on  to  the  solid  state,  is  owing  to  a 
lessening  in  the  molecular  and  atomic  motion,  con- 
sequent on  the  withdrawal  of  a  corresponding 
equivalent  of  heat,  and  vice  versa. 

Light.— Rays  of  light,  the  effect  of  undulating 
motion,  projected  from  a  luminous  body,  either  ce- 
lestial or  terrestrial,  while  passing  through  homo- 


Distillation. 


19 


geneous  diaphanous  media,  travel  in  straight  lines, 
and  with  great  velocity.  If,  however,  the  media 
through  which  the  light  passes,  should  vary  in 
density,  the  ray  of  light  will  be  changed  in  direc- 
iion,  will  he  bent  from  a  continuous  straight  line ; 
in  short,  refracted.  The  rale  of  simple  refractio.n 
of  light  is  stated  thus:  lohen  a  ray  of  light  loasses 
from  a  rare  through  a  denser  medium,  it  is  bent  toward, 
a  line  draivn  perpendicular  to  the  surface  of  the  lat- 
ter, and  when  passing  from  a  dense  to  a  rarer  me- 
dium it  is  bent  from  the  perpendicular  line,  and 
takes  a  direction  parallel  with  a  continuation  of  its 
former  course,  provided  the  medium  be  the  same 
before  and  after  refraction. 


f 

I 
/A 

// 
// 
/  / 
/    / 

B/  / 

/C 

Tf  the  incident  ray  of  light,  /,  fall  upon  the  plate 
ghiss,  A,  at  the  angle  shown,  then  instead  of  pass- 
ing straight  through  tlu;  glass  to  J3,  it  will  be  bent 
toward   the    perpendicular  line    P  to    C,  and    on 


20 


Inorganic  Chemistry. 


emerging  again  into  the  air  at  C,  it  will  be  bent 
from  the  perpendicular  line,  assuming  a  direction 
parallel  to  its  former  course.  It  is  upon  this  prin- 
ciple that  prisms  and  lenses  depend.  Convex  sur- 
faces converging  the  refracted  rays,  and  concave 
separating  them  more  widely.  In  case  the  refract- 
ing substances  should  be  prismatic  in  form  instead 
of  possessing  parallel  sides  like  plate  glass,  the  ray 
of  light  will  be  refracted  as  described,  and  also  de- 
composed into  colors  of  different  refrangibility. 
(See  spectrum  analysis.) 


If  a  ray  of  sunlight  A  be  admitted  into  a  dark 
room  and  allowed  to  pass  through  a  glass  prism 
at  jB,  the  light  is  refracted;  and  if  thrown  on  a 
white  screen  (7,  it  will  be  seen  to  consist  of  several 
colors,  which  form  what  is  known  as  the  solar 
spectrum,  and  also  as  the  primary  colors.  These 
colors  and  their  various  shades  are  dependent  on 


I 


Dislillation.  21 

mathematical  perception.  The  red  color  is  dis- 
tingiiished  as  such,  because  the  vibrations  of  light, 
producing  it  are  received  by  the  retina  of  the  eye, 
at  the  rate,  in  round  numbers,  of  about  450  mil- 
lion million  times  a  second,  and  the  violet  at  about 
785  million  million  times  a  second.  The  interme- 
diate colors  and  the  infinite  number  of  tints  ac- 
companying them  are  due  to  the  variations  in  the 
number  of  vibrations  received  by  the  normal  hu- 
man retina.  Hence,  color-blindness  is  owing  to 
the  inability  of  the  retina  to  receive  a  given  num- 
ber of  vibrations  within  a  given  time.  The  solar 
spectrum  is  often  divided  into  three  different  parts  ; 
the  most  refrangible  colors  are  known  as  the  blue 
rays,  the  richest  in  chemical  influence;  the  least  re- 
frangible, or  red,  the  heat  rays,  and  the  intermedi- 
ate colors,  the  light  rays.  An  invisible  ray,  more 
refrangible  than  the  violet,  is  richer  in  actinic 
power  than  the  latter,  and  a  ray,  also  invisible,  less 
refrangible  than  any,  possesses  greater  heating 
power  than  the  red. 

Reflection  of  Light. — When  a  ray  of  light  falls 
upon  surfaces,  it  is  either  absorbed  and  thus  it 
more  or  less  disappears;  or,  it  suffers  reflection  and 
thus  assumes  a  new  direction.  The  law  of  the  re- 
flection of  light  is  simply  stated. 


22 


Inorganic  Chemistry. 


When  a  ray  of  light,  J,  falls  upon  a  polished 
surface,  A,  at  a  certain  angle,  it  is  reflected  in  the 
direction  of  R,  which  makes  an  angle  with  the  per- 
pendicular line,  P,  equal  to  the  angle  of  incidence. 
In  other  words,  the  angles  of  incidence  and  reflec- 
tion are  equal. 

R  P  I 


Almost  all  things  upon  the  general  surface  of 
the  earth,  incline  toward  each  other  at  promiscu- 
ous angles,  and  so  reflect  the  liglit  diffused.  It  is 
by  means  of  this  diffused  reflected  ligiit  that  we 
are  enabled  to  perceive  objects  distinctly.  The 
color  of  an  object  is  due  to  its  ability  to  reflect  the 
special  rays  or  combination  of  them,  by  which  it 
is  distinguished.  A  white  object  reflects  all  the 
rays  of  light  that  fall  upon  it,  while  black  absorbs 
all,  and  reflects  none. 

Radiant  Heat. — A  few  salient  features  of  ra- 
diant heat  may  be  properly  considered  as  an  ac- 
companiment to  our  studies  of  the  nature  of  light. 

When  a  hot  body  has  its  source  of  heat  with- 
drawn, it  begins  to  cool  immediately.  It  loses 
heat  in  three  ways. 


Distillation.  28 

1st.  By  conduction ;  by  means  of  the  support 
upon  which  it  rests. 

2nd.  By  convection ;  the  particles  of  air  sur- 
rounding the  heated  body,  move  away,  carrying 
their  modicum  of  heat  with  them,  and  giving  place 
to  other,  colder,  particles  of  air,  which  also  become 
heated  and  move  away,  and  so  on,  all  in  accordance 
with  the  law  of  hydrostatics. 

3rd.  By  radiation ;  a  portion  of  heat  escapes  by 
vibration  in  all  directions  from  the  heated  body. 
It  meets  with  no  interference  from  the  air,  and  suf- 
fers absorption  and  reflection,  by  surrounding  bod- 
ies, like  rays  of  light. 

In  fixct,  radiant  heat  resembles  light  in  many  re- 
spects ;  it  travels  with  great  velocity  ;  it  is  reflected 
from  surfaces ;  it  enters  and  traverses  certain 
media,  undergoing  at  the  same  time  refraction,  ab- 
sorption, and  polarization,  obeying  in  these  re- 
spects the  same  laws  which  regulate  the  corres- 
ponding phenomena  of  light.  Polished  concave 
surfaces  will  therefore  reflect  and  concentrate  the 
heat  rays  to  a  focus,  while  convex  surfaces  will 
cause  them  to  diverge.  Smooth,  bright  surfaces 
reflect  nearly  all  the  heat  that  falls  upon  them,  and 
thus  reniain  cool;  dark,  rough  surfaces,  on  the 
contrary,  soon  become  heated,  by  absorbing  the  ra- 
diant heat,  and  reflecting  scarcely  any.     Good  re- 


24  Inorganic  Chemistry. 

flectors  are  poor  absorbers  of  heat,  and  vice  versa. 
The  power  of  absorbing  and  of  radiating  heat,  is 
in  direct  proportion.  The  surface  \^ihich  absorbs 
heat  most  perfectly,  will  when  heated,  also  radiate 
most  perfectly.  If  two  vessels  of  equal  size  and 
material,  one  having  a  polished  w^hite  surface,  the 
other  a  dark,  rough  surface,  be  filled  with  hot 
water,  the  rate  of  cooling  by  radiation  will  be  un- 
equal ;  the  water  in  the  latter  vessel  will  lose  its 
heat  more  rapidly  than  that  in  the  one  wdth  the 
polished  surface.  Hence,  the  dental  pulp  when 
protected  by  a  highly  polished  filling  is  not  so 
much  affected  by  thermal  changes,  as  it  would  be  in 
case  the  surface  of  the  filling  is  roughly  finished. 
On  this  principle  also, investments  of  artificial  teeth 
should  be  smoothly  finished  in  order  to  prevent  un- 
due radiation  of  heat  from  the  surface  during  the 
process  of  soldering.  At  the  same  time,  much  heat 
will  be  economized,  if  the  blow-pipe  flame  be 
thrown  in  such  direction  as  to  compel  the  reflected 
heat  to  strike  only  some  part  of  the  investment. 


Constitution  of  Matter.  26 


CHAPTER  Y. 

CONSTITUTION  OP  MATTEK. 

All  kinds  of  matter  may  be  divided  into  single  or 
elementary  and  compound  forms.  A  compound  con- 
sists of  two  or  more  elements  united  together  in 
certain  proportions.  An  acquaintance  therefore 
with  the  names  of  the  several  elements  symbolized 
by  certain  letters,  and  their  atomic  weights,  or  pro- 
portions in  which  they  unite  to  form  compounds,  is 
necessary^  to  the  beginning  of  chemical  studies. 
The  following  table  is  presented  for  this  purpose  : 

CONSTITUTION    OF    MATTER. 
NAME.  SYMBOL.     -  ATOMIC  WEIGHT. 

Aluminum Al 27 

Arsenic .*.... As 75 

Antimony Sb.  (Stibium) 120 

Boron B 11 

Bromine Br 80 

Barium Ba 137 

Bismuth Bi 208 

Carbon C 12 

Chlorine CI 35-5 

Calcium Ca 40 

3 


26  Inorganic  Chemistry. 

NAME.  SYMBOL.  ATOMIC  WEIGHT. 

Chromium Cr 52 

Cobalt Co 59 

Copper Cu.  (Cuprum) 63-3 

Colurabium Cb 94 

Cadmium Cd 112 

Caesium Cs 133 

Cerium , Ce 141 

Didymium Di 142-3 

Decipium Dp 

Erbium Er 166 

Flourine F 19 

Glucinum Gl 9 

Gallium Ga 69 

Gold Au.  (Aurum) 196-5 

Hydrogen H.  = 1 

Iron Fe.  (Ferrum) 56 

Indium In 113-6 

Iodine 1 127 

Iridium Ir 193 

Lithi  u  m Li 7 

Lanthanum La 138-2 

Lead Pb.  (Plumbum) 207 

Magnesium Mg 24 

Manganese Mn 55 

Molybdenum Mo 96 

Mercury Hg.  (Hydrargyrum).. 200 

Nitrogen    N 14 


Constitution  of  Matter.  27 

NAME.  SYMBOL.  ATOMIC  WEIGHT. 

Nickel Ni 58 

Oxygen O 16 

Osmium Os  198 

Phosphorus P 31 

Potassium K.  (Kalium) 39 

Platinum Pt 195 

Kubidium Rb 85-5 

Ruthenium.  Ru 104 

Rhodium Rh 104 

Sodium Na.  (Natrium) 23 

Silicon Si 28 

Sulphur S 32 

Scandium Sc 44 

Selenium Se 79 

Strontium Sr 87-5 

Silver Ag.  (Argeutum) 108 

Titanium Ti 48 

Tin Sn.  (Stannum) 118 

Tellurium Te 126 

Terbium Tb 

Tantalum Ta 182-6 

Tungsten W.  (Wolfram) 184 

Thulium Tm 

Thallium Tl 204 

Thorium Th 232 

Uranium U 239 

Vanadium V 51-5 


28  Inorganic  Chemistry, 

NAME.  SYMBOL.  ATOMIC  WEIGHT. 

Yttrium  Yt 89 

Ytterbium   Yb 173 

Zinc Zn 65 

Zirconium Zr 90 

For  convenience  of  description,  matter  is  divided 
into  three  physical  conditions ;  namely,  Solids,  Li- 
quids and  Gases. 

Gold  and  marble  are  examples  of  solids  ;  ordinary 
water  and  the  oils,  of  liquids;  and  the  atmosphere 
and  nitrous  oxide,  of  gases. 

Each  of  these  physical  conditions  is  sub-divided 
into  masses y  molecules  and  atoms. 

A  mass  of  matter  is  any  quantity  of  matter  ap- 
preciable to  the  senses.  A  molecule  is  the  smallest 
particle  of  matter  that  can  exist  without  losing 
its  identity.  An  atom  is  the  still  smaller  particle 
of  matter  obtained  by  division  of  a  molecule.  The 
earth  and  a  grain  of  sand  are  equally  masses  of 
matter.  The  molecules  of  marble,  consisting  of 
the  metal  calcium,  and  the  non-metal  carbon,  and 
the  gas  oxygen  ;  and  the  molecule  of  nitrous  oxide, 
composed  of  the  two  gasses,  nitrogen  and  oxygen, 
may  be  split  up  by  chemical  means  into  their  con- 
stituent atoms.  From  the  molecule  of  marble  the 
individual  atoms  of  calcium,  carbon,  and  oxygen; 


Constitution  of  Matter.  29 

and  from  the  molecule  of  nitrous  oxide,  nitrogen 
and  oxygen  can  be  obtained. 

The  atoms  of  calcium,  carbon,  and  oxygen,  in 
marble ;  and  of  nitrogen,  and  oxygen,  in  nitrous 
oxide,  can  not  be  further  separated  into  simpler 
forms.     An  atom  itself  is  indivisible. 

Chemical  action  involves  the  play  of  selective 
affinities  at  given  temperatures,  between  the  con- 
stituent atoms  only,  of  the  acting  substances. 

The  force  of  attraction  exerted  on  the  above  three 
divisions  of  matter  is  threefold. 

The  attraction  of  gravitation  between  masses  of 
matter.  The  earth  and  other  planets  are  held  to 
the  sun,  and  the  grain  of  sand  to  the  earth,  by 
the  attraction  of  gravitation.  The  attraction  be- 
tween homogeneous  molecules,  as  those  of  marble, 
gold,  etc.,  is  called  cohesion,  while  that  which  holds 
the  atoms  together  to  form  the  molecule  is  called 
chemism,  chemical  attraction  or  chemical  affinity. 
The  latter  form  of  attraction  is  considered  as 
closely  allied  to  the  electric  condition.  As  a  class, 
the  atoms  of  the  non-metallic  elements,  as  oxygen, 
sulphur,  iodine,  etc.,  are  electro-negative,  those  of 
the  metallic  elements,  like  silver,  calcium  and  po- 
tassium, are  electro-positive.  These  two  classes 
are  strongly  attractive  toward  each  other,  while 
the  atoms  of  those  elements  intermediate  between 


30  Inorganic  Chemistry. 

the  non-metallic  and    metallic   elements,  such   as 
arsenic,  antimony,  etc.,  will  combine  readily  with 
the  atoms  of  either  the  negative  or  positive  kind. 
A  molecule  may  he  defined  as  consisting  of  a 
definite    number  of   atoms.      A  simple   molecule 
being  made  up  of  atoms  of  the  same  kind,  as,  for 
example,  a  molecule  of  hydrogen,  H-H;   or  of 
oxygen,  0=0  ;  or  of  ozone,  ^^    A  compound 
molecule  contains  two  or  more  atoms  of  different 
kinds,  as  water  H,0,  or  marble  CaCO,.     These 
facts  are  ascertained  by  analysis  and  synthesis. 

Analysis,  which  separates  the  constituent  ele- 
ments in  compounds,  and  synthesis,  which  recom- 
bines  the  elements  to  form  compounds.  From  a 
mass  oi  simple  molecules  only  simple  matter  comes, 
but  from  a  mass  of  compound  molecules,  simple 
matter  is  obtained. 

From  a  mass  of  gold  nothing  but  gold  can  be 
obtained.  Gold  is,  therefore,  a  simple  form  of 
matter,  or  is  an  element.  Water  H,0,  on  the 
contrary,  is  a  compound,  because  by  analysis  it 
gives  np  two  diflierent  substances,  hydrogen  and 
oxygen ;  but  all  efforts  to  divide  either  hydrogen  or 
oxygen  into  simpler  forms  fail ;  they  still  remain 
hydrogen  and  oxygen.  They  are,  therefore,  each 
elementary. 


Notation  and  Nomenclature.  31 


CHAPTER  YL 

CHEMICAL  NOTATION  AND  NOMENCLATUEE. 

The  letters,  symbols — H,  0,  or  IN",  etc.,  in  the 
table,  on  p.  26,  27,  not  only  indicate  the  presence 
of  hydrogen,  oxygen,  nitrogen,  etc.,  respectively, 
but  also  certain  quantities  by  weight  of  each,  pro- 
portional to  their  atomic  weight. 

Thus,  the  letter  H  symbolizes  hydrogen,  and  at 
the  same  time  indicates  1  part  by  weight  of  hy- 
drogen. Hydrogen  being  the  lightest  substance 
known,  the  weight  of  its  atom  is  taken  as  unity. 
The  letter  0,  one  atom,  or  16  parts  by  weight  of 
oxygen.  The  letter  N,  one  atom,  or  14  parts  by 
weight  of  nitrogen,  etc. 

Combination  between  elements  to  form  com- 
pound molecules — which  latter  suggest  a  propor- 
tional weight  of  a  mass  of  the  given  compound — 
is  represented  by  placing  the  symbols  in  immediate 
juxtaposition.  Thus,  HCl  is  a  compound-mole- 
cule— consisting  of  one  atom,  or  1  part  by  weight 
of  hydrogen,  united  to  one  atom,  or  35 — 5  parts 
by  weight  of  chlorine.  When  there  are  more  than 
one  atom  of  a  certain  element  forming  the  mole- 


32  Inorganic  Chemistry. 

cule,  the  appropriate  figure  is  placed   to  the  right 
and  a  little   below  the  symbol.     The  molecule  of 
water  contains  two  atoms  of  hydrogen  and  one  of 
oxygen  ;  the  formula  for  water  is,  therefore,  II2O. 
The  formula  of  peroxide  of  hydrogen,  which  con- 
tains  two  atoms  of  hydrogen    and  two   atoms  of 
oxygen  is  written  H2O2.     When  it  is  necessary  to 
multiply  the  molecule  itself,  the  figure  is  placed  to 
the  left,  and  on  a  line  with  the  first  symbol.     The 
formula    2H2O,   means    two    molecules   of   water. 
Sometimes  when   the   molecule  is  somewhat  com- 
plicated, it  is  inclosed  in   brackets,  and  if  multi- 
plied, the  figure  is  placed  either  to  the  left  and  on 
a  line,  or  to  the  right  and  a  little  below.     Thus, 
3(ISrH4Cl)  or  (NH4C1)3  represents  three  molecules 
of  a  certain    compound,  each  molecule  containing 
4  atoms  of  hydrogen,  1   atom  of  nitrogen,  and  1 
atom  of  chlorine.     These  few  examples  will  suffice 
for  similar  explanation  of  all  other  formulae. 

In  chemical  changes  every  atom  of  each  element 
involved,  must  be  accounted  for.  This  is  done  by 
placing  the  formulae  of  the  reacting  bodies  first, 
with  a  plus  mark  between  them,  followed  by  a  sign 
of  equality  and  then  the  formulae  of  the  bodies 
produced  by  the  change,  with  a  plus  mark  be- 
tween them.  All  of  which  constitutes  a  chemical 
equation : 


Notation  and  Nomenclature.  33 

2IIC1   +  Na2C03  =  2:N'aCl  +  ll^O  +  CO2 

Hydroj^en        Sodium  Sodium  Hydrogeu       Carbon 

Chloride.         Carbonate.       •       Chloride.  Monoxide.      Dioxide. 

The  above  equation  is  also  an  illustration  of 
wliat  is  termed  double  decomposition  and  recom- 
position.  Two  molecules  of  hydrogen  chloride,  and 
one  molecule  of  sodium  carbonate  react  upon  each 
other  by  means  of  the  mutual  affinities  between 
their  atoms.  The  2  atoms  of  hydrogen  take  one 
atom  from  the  3  atoms  of  oxygen,  forming  a  mole- 
cule of  water,  (H2O.)  The  2  atoms  of  chlorine  set 
free,  unite  with  the  2  atoms  of  Xa  forming  2  mole- 
cules of  common  salt,  (2  NaCl,)  and  the  remaining 
group,  CO2  escapes  as  a  molecule  of  carbonic  acid 
gas.  Heat  alone  is  oftentimes  a  most  important 
factor  in  causing  chemical  decomposition  and  re- 
composition.  If  a  salt  known  as  ammonium  ni- 
trate be  placed  in  a  flask  and  heated  sufficiently, 
an  interchange  of  the  atoms  of  the  constituent  ele- 
ments will  take  place,  according  to  the  following 
equation  : 

NII4XO3    +    Heat    =    2H2O    +    :N'20 

Ammonium  Hydrogen  Nitrous 

Nitrate.  Monoxide.  Oxide. 

It  will  be  noticed  by  referring  to  the  compounds 
in  the  preceding  equations,  that  their  names  sug- 
gest their  composition.  When  a  compound  mole- 
cule is  composed  of  only  two  elements  its  chemical 
name    always    ends    in    ide^  as,  hydrogen  chloridCy 


84  Inorganic  Chemistry. 

meaning,  evidently,  a  combination  of  H  and  CI, 
(IICl ;)  hydrogen  monoxide,  of  H  and  0,  (HgO;) 
sodium  c\\\oYide,  of  ^a  and  CI,  (NaCl ;)  Yiiirous 
oxide,  of  ]^  and  0,  (Ng^O  The  most  highly  elec- 
tro-positive element  in  the  formulae  (a  question  to 
be  studied  later),  is  generally  placed  first,  a  rule, 
however,  sometimes  departed  from,  in  order  to 
better  explain  the  relations  between  the  elements 
in  the  group.  In  ammonium  nitrate,  the  H,  al- 
though electro-positive,  follows  negative  ^,  thus, 
NH4NO3,  because  we  can  better  realize  the  relation 
that  really  exists  between  the  two  radicals  NH^ 
and  isTOg,  which  form  the  molecule  in  question. 

By  referring  to  the  few  preceding  formulae  we 
preceive  the  rule  is  observed,  H  is  electro-positive 
to  CI ;  Na  to  C  and  0 ;  ISTa  to  CI ;  H  to  0 ;  and 
C  to  0. 

In  naming  the  compounds  of  inorganic  chemis- 
try, we  shall  employ  the  full  name  of  the  positive 
element,  preferring  the  noun  to  the  adjective,  as 
more  euphonious.  Where  the  compound  is  made 
up  of  elements  which  unite  with  each  other  in  only 
one  proportion,  that  is,  form  but  one  compound,  the 
final  syllables  in  the  names  of  the  electro-negative 
elements  are  changed  into  ide.  H  and  CI  unite  with 
each  other  only  in  this  proportion,  H^Cl^^"^; 
hence  the  name  of  such  compound  is  hydrogen  chlo- 


Notation  and  Nomenclature.  35 

ride.  K  and  I  form  but  one  compound,  KI,  its 
name  is  evidently  potassium,  iodide,  etc.  When  two 
elements  unite  with  each  other  in  iiiore  than  one 
proportion,  the  distinctions  are  made  by  employ- 
ing the  Greek  numerals,  mon,  di,  iri,  etc.,  to  indi- 
cate the  number  of  atoms  or  radicles  in  the  mole- 
cule. H  and  0  form  two  compounds,  H2O  and 
II2O2 ;  the  first  formula  ma}'  be  called  hydrogen 
monoxide,  the  second  hydrogen  dioxide,  signifying 
one  atom  of  oxygen  and  two  atoms  of  oxygen  re- 
spectively. The  binary  compounds  of  IS'  and  O 
furnish  perhaps  the  best .  example  of  these  disr 
tinctions; 

N^O       N2O2       N2O3       N^O,       N2O5 

Nitrogen       Nitrogen  Nitrogen  Nitrogen         Nitrogen 

Monoxide.    Dioxide.  Trioxide.         Tetroxide.     Pentoxide. 

The  name  alone,  therefore,  indicates  the  number  of 
O  atoms  in  each  molecule ;  and  they  are  all  equally 
(imitrogen  oxides. 

There  are  also  different  terminations  in  the 
name  of  the  positive  element,  to  indicate  the  least 
or  greatest  relative  proportion  of  the  negative  ele- 
ment in  the  series.  In  these  nitrogen  oxides,  for 
instance,  the  lowest  or  mon  (one)  oxide  is  most  fre- 
quently called  wiivous  oxide,  and  the  highest,  or 
pent  (five)  oxide  is  known  as  wiiric  oxide.  The 
prefix  hyper  (reduced  sometimes  to  per)  meaning 
above,  is  found  coiivea(eiil':tc/^pivly  to  the  name  of 


•  •  • 
•  •  • 

•  •  • 


3^  Inorganic  Cheynistry, 

a  compound  containing  more  of  tlie  negative  ele- 
ment than  exists  in  a  previously  named  compound 
of  the  same  elements.  Thus  nitrogen  dioxide 
might  be  named  as  hypermtrous  oxide.  The  prefix 
hjpoy  meaning  under,  might,  on  tlie  same  principle, 
be  applied  to  nitrogen  tetroxide,  and  the  latter 
named  hypomtric  oxide.  These  rules  apply  to  any 
series  of  compounds  made  up  of  the  same  two 
elements. 


etc       '•t  *-    c  C  {    c  c 


Notation  and  Nomenclature.  37 


CHAPTER  VII. 

NOMENCLATURE. 

The  names  of  compounds  more  complicated  in 
the  number  of  their  elements  than  those  men- 
tioned in  the  preceding  chapter,  are,  in  inorganic 
chemistry,  derived  mainly,  from  their  composition. 
Let  it  be  understood  that  all  acids  contain  H. 
Nitric  acid,  as  its  name  implies,  contains  IST.  If 
there  be  at  least  three  elements  in  the  molecules  of 
acids,  a  fact  which  usually  obtains,  we  are  safe  in 
assuming  that  0  is  the  other  element,  unless  the 
name  of  the  acid  is  otherwise  distinguished.  We 
have,  therefore,  in  the  above  acid,  H  and  IST  and  O. 
It  remains  only  to  correctly  formulate  the  number 
of  atoms  of  each,  to  the  molecule,  and  we  accept 
the  proof  of  analysis  and  the  process  known  as 
equivalent  substitution  for  this  fact.  The  formula 
of  nitnc  acid  is  thus  ascertained  to  be  HNO3. 

Then,  there  is  another  oxy-acid  of  nitrogen ;  it 
is  named  mtvoiis  acid — IINO2 — because  it  contains 
less  negative  0  than  nitric  acid. 

The  names  of  the  other  acids  are  derived  in  the 
same  way.  Sulph,unV.P;Cid,  is  formulated  II2SO4; 
sulphuroi^s    acid,  :|J.jS0;]V. /^^'^.If^^^v  acid,    HCIO3 ; 


38  Inorganic  Chemistry. 

chloro?^5  acid,  HCIO2  ;  and  A]/j90-chlorous  acid, 
HCIO,  etc. 

Acids  are  classed  as  electro-negative,  in  contra- 
distinction to  a  class  of  compounds  called  bases. 
The  latter  are  electro-positive,  and  many  of  them 
are  also  known  as  alkalies ;  they  are  the  opposite  of 
acids. 

These  two  classes  have  a  strong  love  for  each 
other,  and  combine  to  form  another  class  of  com- 
pounds, which  have  received  the  general  name  of 
salts. 

Our  conception  of  chemical  salts,  may  be  confined 
for  the  present,  to  the  simple  statement  that  they 
are,  usually  solid,  neutral  substances,  produced  by 
the  union  of  acids  with  alkalies  (or  bases),  and 
named  accordingly. 

If  nitric  acid  be  brought  in  contact  with  the  al- 
kali— or  base — sodium  oxide,  neutral  bodies  will 
result,  as  will  be  seen  by  the  following  equation : 

I^aO    +    HXO3    =   H2O    -f    :N'a^"03 

Sodium  Nitric  Water.  Sodium 

Oxide.  Acid.  Nitrate. 

The  origin  of  the  names  of  the  first  three  com- 
pounds has  already  been  explained ;  the  last  sub- 
stance, it  will  be  noticed,  receives  its  name  by 
applying  the  full  name  of  the  basic  sodium,  and 
changing  the  final  ic  in  the  name  of  the  acid  to  ate. 
The  name  derived  t'^^sy.  ,is;  sodium   mivate.     All 


Notation  and  Nomenclature.  39 

salts  of  nitric  acid  are  nitrates.  Salts  of  nitro?<5 
acid  are  named  nitrites.  In  the  same  way,  all  salts 
produced  by  the  union  of  sulphuric  acid  with  a  base 
are  named  sulphates.  Sulphurous  acid  produces 
salts  called  sulphi7c5,  etc.  The  names  of  all  salts 
whose  acids  contain  more  than  two  elements  to  the 
molecule,  such  as  H^Og,  terminate  in  either  ate  or 
ite;  w^hile  the  names  of  salts  derived  from  acids 
whose  molecules  contain  only  two  elements,  end  in 
ide.  For  instance,  hydrochloric  acid — HCl — bi- 
nary,  because  made  up  of  only  two  elements,  acting 
on  the  basic  metal  sodium,  IN'a,  produces  a  binary 
salt  whose  name  should  end  in  ide^  as  will  be  seen 
by  the  following  reaction  : 

:N'a     +     HCl     ==     H     +     KaCl 

Sodium.  Hydro-chloric    Hydrogen.    Sodium 

Acid.  Chloride. 

In  brief,  inorganic  salts,  whose  molecules  contain 
three  or  more  elements,  have  names  which  end  in 
either  ate  or  ite,  and  salts  containing  but  two  elements 
have  names  ending  in  ide.  The  reaction  between 
an  acid  and  a  metallic  base,  usually  consists  in  the 
metal  taking  the  place  of  the  H  in  the  molecule  of 
acid,  thus : 

f     2H 

Hydrogen. 


Zn 

+ 

II^SO,     = 

=     ZnSO^ 

Zinc. 

Sulphuric 

Zinc. 

Acid. 

Sulphate 

When  the  oxide  of  the  metal  is  employed,  then,  in- 


•  •  • 


40 


Inorganic  Chemistry. 


stead  of  the  II  escaping  free  as  a  gas,  it  will  unite 
with  the  0  of  the  base  to  form  water. 

ZnO     +       H2SO4    =    ZnSO^     +     H^O 

Zinc  Sulphuric  Zinc  Water, 

Oxide.  Acid,  Sulphate. 

Chemical  compounds  are  definite  in  their  nature, 
constant  in  the  ratio  of  their  elements.  They  fur- 
nish no  evidence,  in  physical  or  chemical  proper- 
ties, of  their  composition,  except  by  analysis.  I^ot 
so  with  mere  mixtures,  water  and  alcohol  may  be 
mixed  in  any  proportion,  the  mixture  exhibiting 
properties  intermediate  between  those  of  its  con- 
stituents, showing  regular  gradation  according  to 
the  relative  amount  of  water  and  alcohol  that  may 
be  mixed  together.  A  mass  of  pure  water  is  a 
chemical  compound,  it  is  rendered  appreciable  by 
our  senses,  by  the  union  of  a  great  number  of 
molecules  of  like  construction ;  that  is,  they  are 
formed  by  the  same  kind  and  number  of  atoms ; 
two  atoms  of  H,  and  one  atom  of  0,=Il20;  and 
inasmuch  as  the  individual  atom  has  its  own  fixed 
and  unchangeable  weight,  it  follows  that  the  mass 
of  matter,  made  up  of  homogeneous  molecules, 
each  having  the  same  kind  and  number  of  atoms, 
must  be  definite  in  its  nature  and  constant  in  the 
ratio  of  its  elements. 

When  two  or  more  compounds  are  made  up  of  the 
same  elements  then.  ^?  ^'^^  Ucn4  imperceptibly  into  each 


Notation  and  Nomenclature.  41 

other ^  as  in  the  case  of  mixtures.  Even  though 
their  molecules  may  differ  in  constitution,  by  only 
one  atom  of  the  same  element,  their  chemical 
nature  is  divided  by  a  sharp  line  of  demarcation; 
they  are  separated,  as  it  were,  by  an  impassable 
gulf;  and  the  compounds  themselves  show  no 
properties  that  would  leave  us  to  suspect  the 
presence  of  their  constituent  elements.  Their 
composition  is  ascertained  by  analysis,  and  proven 
by  synthesis.  Carbon-monoxide,  CO,  and  car- 
bon-dioxide, CO2,  differ  only  by  one  atom  of  O, 
and  yet  they  are  not  at  all  alike,  chemically.  The 
first  is  lighter  than  air,  it  is  highly  combustible, 
and  is  not  absorbed  by  a  solution  of  potash.  The 
second  is  heavier  than  air,  it  is  not  a  combustible, 
and  is  readily  absorbed  by  a  solution  of  potash, 
and  neither  indicates,  in  the  slightest  degree,  that 
it  is  really  a  compound  of  C  and  0.  One  more  ex- 
ample of,  perhaps,  more  familiar  substances,  may 
better  explain  the  foregoing  statement.  Mercury 
and  chlorine  form  two  compounds;  mercuric  chlo- 
ride (HgCl2),  is  soluble  in  water;  it  is  a  strong 
corrosive  poison,  one  centigram  (1-6  grain)  might 
prove  a  dangerous  dose  to  an  adult.  Mercurous 
chloride  (IIg2Cl2)  is  not  soluble  in  water;  it  is  a 
comparatively  mild  medicine,  one  hundred  centi- 
grams (15  grains)  Jiii^K^^  fl^b  t'a,k^'>l'"\yithout  danger. 

?•. 

•    ••••••••«.       »      ».'      '      >      '•, 

•••     •••    •••••       *    .»    '  '      '      '  >    ,  , ,  •  I 

'.*  ''•  ;..  '...',,/'>' ' . 


•  .•-  ••.  ,•,  •  . 


•  ••» 

•  •  ,  •»  » 

•  •  * 

•  •  * 


42  Inorganic  Chemistry. 

They  are  commonly  named,  corrosive  sublimate 
and  calomel,  respectively.  Their  molecules  differ, 
as  you  perceive,  by  only  one  atom  of  Hg,  and  they 
exhibit  no  properties  by  which  we  could  suppose 
that  mercury  and  chlorine  are  the  elements  in  their 
composition. 

We  shall  consider  other  important  facts  in  chemi- 
cal philosophy  after  we  become  acquainted  with 
t'he  principal  non-metallic  or  electro-negative  ele- 
ments. These,  as  a  class,  are  more  important,  from 
a  chemical  standpoint,  than  are  the  metallic  ele- 
ments, inasumuch  as  one  at  least,  of  the  former,  is 
a  necessary  constituent  of  all  chemical  compounds. 
Theirintroduction,  together  with  the  leading  com- 
pounds which  they  form  with  each  other,  will  be 
in  the  order  best  adapted,  we  think,  to  promote  an 
intimate  and  pleasant  acquaintance  with  them. 


Oxygen.  43 


CHAPTER  VIII. 

OXYGEN. 

Symbol,  0.     At.  wt.  IB.     Sp.  gr.  1.1056. 

Oxygen  is  a  colorless,  tasteless,  and  odorless  gas. 
It  is  the  most  abundant  of  the  elements.  It  exists 
free  in  the  atmosphere,  of  which  it  forms  about 
one-fifth  part,  and  of  which  it.  is  the  active  ele- 
ment. Combined  with  other  elements,  it  consti- 
tutes about  one-half  the  weight  of  the  solid  crust 
of  the  earth,  and  eight- ninths  of  the  weight  of 
water.  It  is  also  found  as  an  important  element 
of  animal  and  vegetable  tissues. 

Oxygen  was  discovered  by  Priestly  and  Scheele 
in  1774,  independently  of  each  other.  It  can  be 
obtained  from  any  of  its  compounds,  but  only  those 
which  can  give  it  up  cheaply  and  in  large  volume 
are  the  ones  employed  for  such  purposes. 

The  favorite  method  is  to  heat  the  salt,  potas- 
sium chlorate,  in  a  retort,  and  collect  the  escaping 
gas  over  water.  We  do  not  regard  a  detailed  de- 
scription of  experiments  necessary  here,  inasmuch 
as  they  are  fully  explained  by  the  teacher. 

KCIO3     +     Heat     =     KCl       -f      30 

Potassium  Potassium  Oxygen. 

Chlorate.  Chloride. 


44  Inorganic  Chemistry. 

All  the  0  in  the  salt  is  thus  driven  off  by  the 
heat,  leaving  a  residue  in  the  retort  composed  of 
K  and  CI.  If  three-fourths,  by  weight,  of  potas- 
sium chlorate  be  mixed  with  one-fourth  of  an 
oxide,  such  as  ferric  oxide,  cupric  oxide, -or  better, 
manganese  dioxide  (MnOg),  decomposition  will  re- 
sult at  a  lower  temperature,  although  either  of  the 
latter  substances  does  not  itself  suffer  decomposi- 
tion. Its  influence  is  said  to  be  due  to  catalytic 
action  (?);  a  question  not  fully  understood. 

Oxygen  combines,  either  directly  or  indirectly, 
with  all  the  other  elements,  except  fluorine,  to  form 
binary  compounds;  (i.  e.,  H2O,  CaO,  AU2O3,  etc.). 

When  a  stngle  element  unites  with  O,  it  is  said 
to  be  oxidized,  and  the  process  is  called  oxidation. 

Oxidation,  like  other  chemical  action,  always  de- 
velops heat.  When  heat  and  light  are  both  devel- 
oped by  the  process,  the  body  is  said  to  burn.  The 
process  of  combustion  will  be  sufiiciently  described 
in  connection  with  the  element  carbon.  Ordina- 
rily, when  a  body  burns,  its  elements  are  simply 
uniting  rapidly  with  the  O  of  the  air.  Bodies 
which  burn  in  the  air  do  so  with  much  greater 
energy  in  oxygen  alone.  If  pieces  of  burning 
charcoal  or  sulphur,  or  phosphorus,  be  placed  in  a 
jar  of  oxygen,  the  immediate  rapid  increase  in  the 
amount   of    heat   and   light   is   remarkable.     If  a 


Oxygen.  45 

candle  with  a  glowing  wick  be  plunged  into  a  ves- 
sel full  of  oxygen,  the  candle  will  at  once  burst  into 
a  flame.  Certain  substances,  which  do  not  ordina- 
rily burn  in  the  air,  will  do  so  readily  in  oxygen. 
A  thin  piece  of  iron  or  steel,  such  as  the  rubber 
saw  of  the  dental  labratory  or  a  broken  watch- 
spring,  its  surface  previously  brightened  by  sand 
paper,  and  having  attached  to  the  lower  end  a  bit 
of  burning  match,  or  spunk,  or  sulphur,  placed 
thus  in  a  jar  of  pure  oxygen^  will  become  ignited, 
and  evolve  exceedingly  brilliant  corruscations  of 
heat  and  light. 

The  oxygen  of  the  air,  although  weakened  by  its 
mixture  with  nitrogen  and  other  gases,  is  the  sup- 
porter of  ordinary  combustion.  It  is  also  the  sup- 
porter of  animal  respiration;  we  inhale  it  with 
every  breath,  and  alternately  exhale  the  products 
which  are  formed  by  it  in  the  body  and  which  are 
carried,  by  the  venous  circulation,  to  the  lungs,  to 
be  expelled. 

The  name  oxygen,  from  tw^o  Greek  words, 
meaning  a  generator  of  acids,  was  given  it  by  La- 
voisier, in  1778,  who  was  the  first  to  describe  the 
important  part  which  oxygen  plays  in  the  field  of 
natural  phenomena. 

It  is  a  necessary  element  in  the  formation  of 
nearly  all  acids.     If  we  examine  with  litmus  test 


46  Inorganic  Chemistry. 

paper,  the  jars  in  which  were  burned  the  sulphur 
or  phosphorus,  we  will  detect  an  acid  reaction : 
not  sa  the  contents  of  the  jar  in  which  the  iron 
burned;  the  latter  fact  indicating  that  all  oxides 
are  not  of  an  acid  nature.  It  is  only  some  of  the 
oxides  of  the  non-metallic  elements,  or  those  of 
the  metallic  elements  bordering  on  the  non-metal- 
lic, which  are  classed  as  acid. 

These  oxides  of  the  more  highly  electro-positive 
of  the  metals,  such  as  barium,  potassium,  etc.,  are 
always  basic  or  the  opposite  of  acid.  Barium  oxide 
and  sulphuric  oxide  will  combine  directly  under 
the  influence  of  heat,  and  thus  form  the  salt 
known  as  barium  sulphate. 

BaO     +     SO3     =     BaSO^ 

Barium  Sulphuric  Barium 

Oxide.  Oxide.  Sulphate. 

The  acid  oxides  unite  with  water  to  form  acids, 

as: 

SO3     +     H2O     =    H2SO4 

Sulphuric  Water.  Sulphuric 

Oxide.  Acid. 

Basic  oxides  react  with  acids  to  form  correspond- 
ing salts,  as  : 

CaO     +     H2SO4     ==     CaSO^     +     H2O 

Calcium  Sulphuric  Calcium  Water. 

Oxide.  Acid.  Sulphate. 

There  is  a  third  class  of  oxides  called  neutral^  of 
which  water  is  a  good  example.  They  are  neither 
acid  nor  basic,  but  some  of  them  may  act  in  either 


Oxygen.  47 

capacity,  according  to  circumstances.  When  cal- 
cium oxide,  which  is  strongly  basic,  is  mixed  with 
water,  the  latter  acts  as  an  acid  oxide,  resulting  in 
the  production  of  the  salt  caled  calcium  hydrate, 
or  hydroxide. 

CaO       +       H2O      =       Ca(H0)2 

Calcium  Water.  Calcium  Hydrate, 

Oxide. 

It  will  be  seen,  on  the  contrary,  by  referring  to 
the  proper  equation  preceding,  that  water  acting 
on  SO 3  takes  the  part  of  a  basic  oxide,  in  forming 
the  molecule  of  sulphuric  acid,  or  hydrogen-sul- 
phate (H2SO4). 

Ozone. — When  an  element  is  capable  of  existing 
in  more  than  one  state  it  is  called  allotropic.  Oxy- 
gen is  an  allotropic  element.  It  exists  in  a  passive 
and  in  an  active  state.  Passive  oxygen  is  the  kind 
we  have  been  studying.  Active  oxygen  is  named 
ozone.  The  latter  substance  is  far  more  energetic 
as  an  oxidizing  agent  than  ordinary  oxygen.  It  is 
the  great  natural  disinfectant,  destroying  by  oxi- 
dation the  infectious  matter  that  appertains  to  the 
metamorphosis  of  animal  and  vegetable  tissues. 
Ozone  is  developed  in  a  variety  of  ways : 

Ist.  By  heat;  as  when  platinum  wire  is  merely 
heated  in  the  air. 

2nd.  By  light;  as  when  CO2  is  decomposed  by 
living  plants,  by  the  aid  of  sunlight ;  and  when 


48  Inorganic  Chemistry. 

essential  oils  are  exposed  to  sunlight  and  summer 
temperature. 

3d.  By  electricity;  as  when  the  silent  electric 
discharge  takes  place  in  the  air,  or  in  oxygen  gas, 
and  by  electrolysis  of  water. 

4th.  By  slow  oxidation  ;  as  when  a  clean  stick  of 
phosphorus  is  partially  exposed  to  the  air,  or 
when  a  strongly  heated  glass  rod  is  placed  in  va- 
por of  common  ether. 

5th.  By  rapid  combustion;  as  when  a  vigorous 
blast  of  air  forces  the  top  of  a  Bunsen  flame  into 
a  large  beaker,  the  contents  of  the  beaker  will  give 
the  ozone  reaction. 

A  good  test  for  the  presence  of  ozone  is  paper 
moistened  with  dilute  solution  of  potassium  iodide 
(KI)  and  starch.  The  ozone,  by  uniting  with  the 
potassium,  sets  the  iodine  free,  which  turns  the 
starch  to  a  deep  blue  color. 

Ozone  is  an  irritating  poison  to  animal  tissues, 
if  inhaled  in  quantity.  Unlike  ordinary  oxygen, 
ozone  has  a  decided  odor,  hence  its  name,  which 
means  to  smell.  It  is  one-half  as  heavy  again  as 
oxygen ;  its  density  being  24,  and  that  of  the  lat- 
ter 16.  In  fine,  ozone  is  oxygen  modified  into  a 
condition  of  intense  activity.  All  its  combina- 
tions with  other  individual  elements  produce  only 
oxides. 


Hydrogen.  49 


CHAPTER  IX. 

HYDROGEN. 

Symbol  H.     At.  wt.  1.     Sp.  gr.  0.0693. 

Hydrogen  is  a  colorless  gas,  without  taste  or 
smell.  It  is  the  lightest  body  known,  being  about 
foui'teen  and  a  half  times  lighter  than  air.  The 
spectroscope  shows  that  hydrogen  is  a  constituent 
of  the  sun,  the  fixed  stars  and,  largely  of  the  celes- 
tial nebulae.     It  is  found  occluded  in  meteoric  iron. 

Hydrogen  is  found  free  in  volcanic  gases.  Com- 
bined with  oxygen,  it  forms  the  compound  water ; 
hence  its  name,  given  it  by  Lavoisier,  signifying 
'^  generator  of  water."  It  is  an  important  element 
of  animal  and  vegetable  tissues,  and  of  mineral 
oils. 

Hydrogen   was  known  in  the  sixteenth  century, 

but  was  first  accurately  described  by  Cavendish  in 

1766.     It  can  be  obtained  from  its  compounds  by 

various  methods,  but  is  usually  prepared  by  action 

of  zinc,  on  dilute  sulphuric  acid,  or  hydro-chloric 

acid. 

Zn     -t-     2IIC1     =     ZnCl2     -h     2H 

Zinc.  ir.Vflrochloric        Zinc;  Hydrogen. 

Acid.  Chloride. 

The   gas    may  be  collected  over  water  or  by  dis- 
5 


50  Inorganic  Chemistry, 

placement  of  air.  Although  hydrogen  is  the 
lightest  substance  known,  it  is  undoubtedly  the 
vapor  of  a  highly  volatile  metal.  We  describe  it 
thus  early,  in  connection  with  the  non-metals,  be- 
cause of  the  wonderfully  important  place  it  holds 
in  the  family  of  elements.  On  account  of  the  high 
diffusive  power  and  combustibility  of  hydrogen, 
great  precaution  should  be  observed  in  experi- 
menting with  the  gas,  in  order  to  avoid  the  danger 
of  explosion.  Heated  to  a  temperature  of  about 
500°C.  (982°F.),  it  unites  with  oxygen  :  the  union 
of  these  gases  developing  the  highest  temperature 
produced  by  chemical  action.  One  gram  of  hydro- 
gen in  oxidizing,  or  burning,  will  raise  the  tempe- 
rature of  34,462  grams  of  water  from  0°  to  1°  ;  that 
is  equal  to  34,472  heat  units.  The  compound  which 
it  forms  by  direct  union  with  oxygen  is  water 
(H2O),  the  molecule  of  which  contains  two  parts 
by  weight,  or  two  atoms  of  hydrogen,  and  sixteen 
parts  by  weight,  or  one  atom  of  oxygen.  The  mol- 
ecular weight  of  any  substance  is  the  sum  of  the 
atomic  weights^  and  inasmuch  as  the  two  atoms  of 
hydrogen  weigh  two,  and  the  one  atom  of  oxygen 
weighs  sixteen,  the  molecular  weight  of  water 
must  be  2  +  16  =  18. 

Water  is  the  most  abundant  of  chemical   com- 
pounds.    Notwithstanding  its  neutral  nature,  being 


Hydrogen.  51 

neither  acid  nor  alkali,  it  is  a  very  active  substance, 
clieniically.  It  leads  all  other  liquids  as  a  solvent. 
With  but  few  exceptions,  solids  will  dissolve  more 
easily  in  warm  than  in  cold  water,  while  certain 
gases,  as  0,  N2O,  CO2,  etc.,  are  more  soluble  in 
cold  water  than  in  warm. 

Pure  water  is  tasteless,  ordorless,  and,  when  in 
small  quantity,  colorless.  It  exists  in  certain  com- 
pounds as  w^ater  of  crystallization,  enabling  them  to 
assume  a  definite  crystalline  form,  as,  natural  gyp- 
sum, blue-stone,  etc.  When  sufficiently  heated, 
this  water  is  driven  out,  and  the  substance  loses  its 
crystalline  form,  but  will  take  up  water  again  most 
readily,  as  in  the  case  of  plaster  of  parfs. 

Oxygen  and  hydrogen  may  be  induced  to  unite 
in  the  proportion  of  two  atoms  of  each,  to  form 
hydrogen  dioxide  (H2O2),  commonly  called  perox- 
ide of  hydrogen.  It  may  be  prepared  by  acting 
on  barium  dioxide,  held  in  suspension  in  water,  by 
either  of  several  acids,  as  : 


Ba02 

+ 

Ha  CO J     = 

=:     BaCOg 

+ 

H.O^ 

Bftrium 

Carbonic 

Barium 

Hydrf)gen 

Dioxide. 

Acid, 

Carbonate. 

Dioxide. 

Approximately  pure,  peroxide  of  hydrogen  is 
colorless;  it  possesses,  however,  an  ozone-like  odor 
and  a  peculiar  metallic  taste.  It  is  never  used  in 
medicine,  or  the  arts,  in  the  undiluted  form,  but  is 
usually  held  in  solution  in  glycerine  or  water.     A 


52  Inorganic  Chemistry. 

"ten  volume  "  preparation  of  it  will  give  off  ten 
times  its  o^yn  volume  of  free  oxygen.  The  tem- 
perature of  summer  heat  will  cause  the  molecule 
(H2O2)  to  decompose,  one  of  the  O  atoms  escap- 
ing. The  solution  should,  therefore,  be  kept  in  a 
cool  place,  except  when  in  use. 

It  is  an  excellent  germicide  and  disinfectant,  de- 
stroying the  infectious  matter  by  the  activity  of 
the  nascent  oxygen  which  it  supplies. 

An  element  is  nascent  at  the  time  it  is  set  free 
from  combination,  and  is  then  more  anxious  to 
unite  with  other  bodies  than  when  it  is  in  its  ordi- 
nary state. 

A  trace  of  acid  (sulphuric  or  phosphoric)  is  us- 
ually found  with  the  peroxide  of  hydrogen  solu- 
tion, to  render  the  preparation  more  stable  ;  and- 
the  results  of  experiments  with  the  peroxide  on 
pus,  bone,  etc.,  are  often  misjudged  on  account  of 
the  acid  present. 


Chlorine.  53 


CHAPTER  X. 

CHLORINE. 

Symbol,  CI.     At.  wt.  35.5.     Sp.  gr.  2.46. 

Chlorine  was  discovered  by  Scheele,  in  1774.  Its 
elementary  character  was  proven  by  Dav}^  in  1810, 
who  gave  it  the  name  it  bears,  w^hich  signifies  its 
color,  ^'  greenish  yellow^ 

Chlorine  is  not  found  free  in  nature.  It  exists 
abundantly,  however,  in  combination  with  Na.,  Ca., 
K.,  and  Mg.,  in  sea  water,  and  saline  springs.  Vast 
deposits  of  solid  sodium  chloride,  or  common  salt, 
are  found  and  mined;  it  being  a  necessary  article 
of  every  day  use. 

Chlorine  is  usually  obtained  in  quantity  by  gently 
heating  together  certain  proportions,  indicated  by 
their  molecular  weights,  of  the  two  first  following 
compounds : 

iMn02     I    4IIC1  =^  2II2O  +  MnCl2  +  2CI2 

Manganese        Hydrochloric  Water  Manganese         Chlorine 

Dioxide.  Acid.  Chloride. 

It  may  also  be  obtained,  sufficiently  pure  for 
ordinary  experiment,  by  acting  on  common  bleach- 
ing powder  with  dilute  sulphuric  acid.  The  re- 
action of  these  substances,  being  rather  complica- 
ted, will  not  be  considered  at  this  time. 


54  Inorganic  Chemistry. 

Chlorine  is  a  greenish-yellow  gas,  of  an  intoler- 
able suffocating  odor  and  astringent  taste.  When 
subjected  to  a  cold  of  40°,  or  at  a  common  temper- 
ature, to  a  pressure  of  four  atmospheres — 60  pounds 
to  the  square  inch,  it  condenses  to  a  yellow  liquid 
of  sp.  gr.  1.38. 

Water  will  dissolve  nearly  three  times  its  own 
bulk  of  chlorine,  the  solution  acquiring  the  color 
and  odor  of  the  gas;  it  is  known  as  aqua  Mori, 
and  is  employed  to  advantage  in  practice,  as  a  dis- 
infectant, and  to  bleach  discolored  teeth.  Aqua 
chlori,  exposed  to  the  influence  of  light,  decom- 
poses according  to  the  following  equation : 

H2O,  2C1     =     2HC1     f       O 

Water.    Chlorine.  Hydrochloric  Oxygen. 

Acid. 

It  must,  therefore,  be  preserved  in  a  dark  place. 
Chlorine  acts  indirectly  as  a  bleaching  agent  and 
disinfectant  through  its  love  for  the  hydrogen  of 
water,  letting  the  0  go  free,  vide  the  above  equa- 
tion, which  latter  element,  in  its  nascent  state,  at- 
tacks the  coloring  matter,  or  infectious  matter,  as 
the  case  may  be,  forming  with  either,  new  com- 
pounds that  are  destitute  of  color,  or  free  from  the 
germs  of  disease.  Mineral  colors,  as  a  rule,  are 
not  affected  by  chlorine. 

The  affinities  of  chlorine  are  exerted  mainly 
toward  hydrogen  and   the  metals.      If  a   lighted 


Chlorine.  55 

candle,  the  combustible  elements  of  which  are  C 
and  H^  be  placed  in  a  jar  tilled  with  chlorine, 
dense  volumes  of  smoke  will  be  evolved,  owing  to 
the  chlorine  taking  up  with  the  H  of  the  candle, 
resulting  in  HCl,  and  the  rejection  of  the  C,  which 
escapes  as  smoke.  A  piece  of  tissue  paper  moist- 
ened with  warm  oil  of  turpentine,  and  thrust  into 
a  jar  of  chlorine,  shows  the  same  phenomenon. 
Finely  divided  arsenic,  or  antimony,  or  thin  leaves 
of  copper  or  bronze,  or  a  bit  of  phosphorus,  at 
ordinary  temperatures,  and  sodium,  at  a  higher 
temperature,  will  burn  in  chlorine,  forming  a  chlo- 
ride in  each  case.  A  mixture  of  hydrogen  and 
chlorine,  exposed  to  the  sunlight,  will  unite  with 
explosive  violence.  In  tine,  chlorine  unites,  either 
directly  or  indirectly,  with  all  the  elements,  form- 
ing a  chloride  with  each,  some  of  which,  however, 
are  very  unstable  compounds. 

Hydrogen  Chloride. —  Chlorine  and  hydrogen 
unite  with  each  other  in  but  one  proportion.  The 
compound  is  generally  called  hydrochloric  acid. 
It  is  a  colorless  gas,  of  a  pungent  odor,  is  irrespi- 
rable,  though  not  so  irritating  as  chlorine,  and  is 
noncombustiblc.  Its  specific  gravity  is  1.264,  its 
density  (II  as  unity)  is  18.25.  Subjected  to  cold 
and  pressure,  it  condenses  to  a  colorless  liquid,  of 
specific  gravity  1.27. 


56  Inorganic  Chemistry. 

Hydrochloric  acid  is  manufactured  on  a  large 
scale  by  heating  togetlier  quantities  of  common  salt 
(;N"aCl)  and  strong  sulphuric  acid,  as  indicated  by 
the  following  equation  : 

2:N'aCl  +  H2SO4  =  :^a2S04   +  21101 

Sodium  Sulphuric  Sodium  Hydrochloric 

Chloride.  Acid.  Sulphate.  Acid. 

The  gas  (HCl)  is  very  soluble  in  water.  A  given 
volume  of  wat'er  will  dissolve  450  volumes  of  the 
gas,  and  a  more  or  less  saturated  aqueous  solution 
becomes  the  hydrochloric  or  muriatic  acid  of  com- 
merce, possessing  the  same  acrid  and  acid  proper- 
ties of  the  gas  itself.  The  presence  of  the  w^ater, 
however,  is  not  expressed  in  the  reactions  of  the 
acid,  so  that  the  formula  HCl  means  either  the  gas 
alone,  or  its  solution  in  water. 

Hydrochloric  acid  is  an  important  substance.  It 
dissolves  many  of  the  metals,  such  as  aluminum, 
tin,  iron,  zinc,  etc.,  the  reaction  consisting  in  the 
metal  supplanting  the  H  of  the  acid,  resulting  in 
free  hydrogen  and  metallic  chlorides.  As  before 
alluded  to,  as  a  rule,  wnth  some  exceptions,  when- 
ever any  acid  attacks  a  metal,  a  quantity  of  H 
equivalent  to  the  metal  escapes  free,  the  metal 
uniting  with  the  residue  of  the  acid  to  form  a  salt 
of  the  metal  in  question,  as : 

2HC1     +     Fe     =     2H     +     FeCl2 

Hydrochloric        Iron.  Ferrous 

Acid.  Chloride. 


Chlorine.  57 

Hydrochloric  acid  is  therefore  the  type  of  all 
chlorides. 

It  is  one  of  the  solvents  in  the  gastric  juice,  and 
is  probably  developed  there  by  the  influence  of  a 
special  ferment^  which,  in  some  way  not  yet  under- 
stood, induces  the  CI  of  the  sodium  chloride,  one 
of  the  proximate  principles  of  the  body,  to  unite 
with  the  H  of  the  water  present,  or  some  other 
hydrogen  compound,  or  vice  versa.  The  child  of 
the  union  would,  of  course,  be  HCl. 

Dr.  George  Watt,  of  Ohio,  the  recognized  origi- 
nator of  the  chemical  (per  se)  theory  of  dental  de- 
cay, proposes  hydrochloric  acid  as  the  active  cause 
of  the  brown,  or  common  variety  of  decay  of  teeth. 

The  structure  of  a  tooth  is  generally  divided  into 
animal  (matrix)  and  mineral  portions  ;  the  latter 
consisting  mainly  of  calcium  phosphate  and  cal- 
cium carbonate. 

If  hydrochloric  acid  is  formed  in  the  mouth,  in 
accordance  with  the  afflnities  by  which  it  is  devel- 
oped in  the  gastric  juice,  a  chemical  analogy  by 
no  means  improbable,  the  nascent  individual  mole- 
cules of  the  acid  would  simultaneously  decompose 
the  calcium  carbonate,  and  dissolve  the  calcium 
phosphate. 


CaC03 

+ 

2IIC1     — 

CaCL, 

Calcium 
Carbonate. 

Hydrogen 
Chloride. 

Calcium 
Chloride 

58  Inorganic  Chemistry. 

The  calcium  phosphate  of  the  tooth,  although 
riot  entering  into  the  equation,  loses  its  structural 
integrity  by  solution,  and  the  animal  portion  more 
or  less  remains  in  situ. 

There  are  compounds  of  chlorine,  hydrogen,  and 
oxygen,  the  elements  we  have  especially  introduced 
thus  far,  which  are  worthy  of  some  consideration 
at  this  time.     They  are   all  acid  in  their  nature, 
and  may  be  regarded  as  oxides  of  HCl  : 
HCIO4,  Perchloric  acid. 
HCIO3,  Chloric  acid. 
HCIO2,  Chlorous  acid. 
HCIO,  Hypochlorous  acid. 

The  salts  of  these  acids  are  known,  seriatim,  as 
perchlorates,  chlorates,  chlorites,  and  hypochlo- 
rites. The  first  and  third  class  are  of  no  special 
interest,  but  the  chlorates  and  hypochlorites  are 
used  largely  as  important  agents  in  chemistry  and 
materia  medica ;  they  will  be  considered  later  on 
in  connection  with  certain  metals.  There  are  three 
oxides  of  chlorine,  CI2O,  CI2O2,  CI2O4,  which  are 
highly  explosive,  but  possess  no  other  interrst. 

Chlorine  is  the  principal  member  of  a  group  of 
elements  which  contains  also  iodine,  bromine,  flu- 
orine. They  are  all  called  halogen  elements,  because 
the  sea  is  the  principal  source  of  chlorine,  iodine, 


Chlorine.  59 

and  bromine ;  so  great  is  the  resemblance  to  each 
other,  in  their  chemical  nature,  that  a  description 
of  one,  as,  for  instance,  chlorine,  will  serve  in  a 
measure  for  that  of  the  others. 


60  Inorganic  Chemistry. 


CHAPTER  XI. 

IODINE. 

Symbol,  I.     At.  wt.  127.     Sp.  gr.  4.95. 

Iodine  is  obtained  from  the  ash  of  sea  weeds. 
It  is  a  dark  bluish  solid,  consisting  of  rhombic 
scales,  of  a  metallic  luster.  It  melts  at  107°  (225° 
F.),  and  boils  at  180°  (356°F.),  evolving  a  magnifi- 
cent violet  vapor,  of  specific  gravity  8.72. 

Iodine  requires  7,000  parts  of  water  to  dissolve 
it.  It  is  freely  soluble  in -an  aqueous  solution  of 
its  most  important  compound,  potassium  iodide, 
and  in  alcohol,  ether,  chloroform,  and  carbon  di- 
sulphide.  It  is  not  as  active,  chemically,  as  chlor- 
ine, though  it  combines  directly  with  most  of  the 
metals  forming  iodides.  It  strikes,  with  a  solution 
of  starch,  a  deep  blue  color,  so  intense  that  one 
part  of  iodine  in  300,000  of  water  can  be  detected 
by  the  starch  test. 

Iodine,  both  free  and  in  combination,  is  a  valu- 
able therapeutic  agent,*  as  a  resolvent  and  anti- 
septic; it  is  also  largely  used  in  photography. 

*Brief  allusion  to  medicinal  qualities,  while  considering  the 
non-metallic  elements,  is  excusable,  as  we  hope  to  deal  justly 
by  their  compounds  in  materia  medica. 


Bromine.  61 

BROMINE. 

Symbol,  Br.     At.  wt.  80.     Sp.  gr.  3.187. 

Bromine  is  prepared  from  sea  water  and  saline 
springs.  It  is  a  red-brown  liquid  of  disagreeable 
odor,  hence  its  name.  Heated  to  a  temperature 
of  63°  (145°F.),  it  boils,  yielding  a  deep  red  vapor, 
of  specific  gravity  5.5.  Cooled  to  —22°  (— 8°F.),  it 
becomes  a  crystalline  lead-gray  solid.  One  part  of 
bromine  requires  33  parts  of  water  to  dissolve  it. 
It  is  a  corrosive  poison ;  exerts  a  strong  bleaching 
power.  It  is,  chemically,  less  active  than  chlorine, 
but  more  so  than  iodine.  Some  of  the  metals  will 
burn  in  its  vapor,  producing  bromides.  It  is  used 
extensively  in  photography,  and  some  of  its  com- 
pounds are  of  therapeutic  value. 

FLUORINE. 

Symbol,  F.     At.  wt.  19.     Sp.  gr. . 

Fluorine  is  a  constituent  of  a  substance  known 
as  fluor  spar,  meaning,  I  flow,  because  this  com- 
pound— CaF2 — is  used  as  a  flux  in  the  reduction 
of  some  metals. 

Free  fluorine  (but  recently  isolated)  is  a  colorless 
gas,  of  pungent  odor,  and  exceedingly  corrosive. 


62  Inorganic  Chemistry. 

It  is  especially  distinguished  as  the  only  element 
which  refuses  to  unite  with  oxygen ;  and  although 
in  its  free,  and  therefore  inactive  state,  it  shows 
only  slight  affinity  toward  silicon,  the  latter  ele- 
ment is  violently  attacked  by  nascent  fluorine, 
which  is  developed  by  bringing  together  hydro- 
fluoric acid  and  a  silicon  compound,  such  as  glass. 
Hydrofluoric  acid,  HF,  is  usually  prepared  by  re- 
action of  calcium  fluoride  and  sulphuric  acid,  in  a 
vessel  of  platinum  or  lead. 

CaF2     4-    H2SO4    =    CaSo4   +    2HF 

Calcium  Sulphuric  Calcium  Hydrofluoric 

Fluoride.  Acid.  Sulphate.  Acid. 

This  acid,  when  pure,  is  a  colorless  gas,  but  in 
its  ordinary  condition  it  is  dissolved  in  water.  It 
is  of  peculiar  interest,  because  it  is  the  only  sub- 
stance that  freely  attacks  such  compounds  of  sili- 
con as  glass,  and  porcelain  teeth.  It  is  useful  in 
the  arts,  for  etching  on  glass. 

HALOGEN    ACIDS. 

The  analogy  between  the  halogen  elements, 
chlorine,  iodine,  bromine,  and  fluorine,  is  best  ex- 
emplified by  their  binary  hydrogen  compounds : 

Hydrochloric  acid HCl 

Hydriodic  acid HI 

Hydrobromic  acid HBr 

Hydrofluoric  acid HF 


Halogen,  63 

The  first  and  last  of  these  acids  have  already 
been  sufficiently  described.  The  second  (HI)  and 
third  (HBr)  are  also  pungent,  colorless  gases,  yqyj 
soluble  in  water,  and  are  used  in  practice  in  aque- 
ous solution.  They  are  the  prototypes  of  all 
iodides  and  bromides,  as  hydrochloric  and  hydro- 
fluoric acids  are  the  types  respectively  of  chlorides 
and  fluorides.  There  are  also  oxy  acids  of  iodine 
and  bromine  analogous  to  those  of  CI.  The  prin- 
cipal ones  have  the  formula  of  HIO3  and  HBrOg, 
corresponding  to  chloric  acid  HCIO3.  Their  salts 
are  called  iodates  and  bromates. 


64  Liorganic  Chemistry. 


CHAPTER  Xir. 
NITROGEN. 

Symbol,  K     At.  wt.  14.     Sp.  gr.  0.971. 

Nitrogen  is  a  colorless,  odorless,  and  tasteless 
gas.  It  was  discovered  by  Rutherford  in  1772, 
and  received  its  name  because  it  was  found  to  be  a 
necessary  constituent  of  niter. 

Nitrogen  and  oxygen  are  the  principal  compo- 
nents of  the  atmosphere;  four-iifths  of  nitrogen, 
and  one-fifth  of  oxygen.  Although  not  chemically 
combined,  their  intimate  mixture  in  the  above 
proportions  obtains  throughout,  the  nitrogen  serv- 
ing to  retard  within  reasonable  bounds  the  energy 
of  oxygen. 

If  a  piece  of  phosphorus  be.  burned  in  a  given 
volume  of  air,  confined  over  water,  the  phosphorus 
takes  up  all  the  oxygen,  the  water  rapidly  absorbs 
the  compound  so  formed,  and  the  nitrogen  remains 
alone,  comparatively  pure. 

Nitrogen  is  not  a  supporter  of  combustion,  nor 
of  respiration;  it  is,  in  fine,  remarkably  inert, 
showing  little  disposition  to  unite  directly  with 
other  elements,  although  its  compounds  are  nu- 
merous, and  some  of  them  of  exceeding  energy. 


Nitrogen.  6^5 

Besides  its  existence  in  the  atmosphere,  it  is  found 
\\\  nature  in  the  compounds  known  as  nitrates,  and 
in  ammonia,  and  is  also  an  essential  element  of 
certain  animal  and  vegetable  substances. 

Ammonia. — Ammonia  is  a  gaseous  compound  of 
nitrogen  and  hydrogen  (NHg).  It  is  formed  slowly 
at  common  temperatures,  by  putrefactive  decom- 
position of  animal  and  vegetable  substances  con- 
taining nitrogen;  more  rapidly  when  clippings  of 
horns,  hoofs,  or  hides,  or  other  animal  tissue,  are 
subjected  to  heat — hence  the  name  sometimes 
given  it  of  "spirits  of  hartshorn."  Many  of  its 
compounds  are  now  obtained  by  the  destructive 
distillation  of  coal,  in  the  manufacture  of  illumin- 
ating gas.  Ammonia  itself  is  prepared  by  gently 
heating  together  a  salt  known  as  "  sal  ammoniac," 
or  ammonium  chloride,  and  calcium  oxide  (quick- 
lime). 
(NH4CM)2     +    CaO    =     CaCl^   'H2O    +    2NH3 

Am.  chloride.  Calcium  Calcium      Water.  Ammonia. 

Oxide.  Chloride. 

Ammonia  is  a  colorless  gas,  of  specific  gravity 
0.59.  It  is  possessed  of  a  peculiar  pungent  odor, 
by  which  its  presence  may  be  detected.  Subjected 
to  a  pressure  of  a  hundred  pounds  to  the  square 
inch,  at  10°  (50°F.),  it  condenses  to  a  clear  liquid, 
of  specific  gravity  0.76.  The  liquid  ammonia  is 
highly  volatile,  and  in  passing  into  the  gaseous 
6 


66 


Inorganic  Chemistry. 


state,  by  removal  of  pressure,  it  absorbs  a  large 
amount  of  heat.  It  is  for  this  reason,  as  well  as 
its  cheapness,  that  ammonia  is  employed  in  the 
artificial  production  of  ice. 

Ammonia  gas  is  exceedingly  soluble  in  water ; 
one  volume  of  water  at  15°  (59°F.)  will  dissolve 
783  volumes  of  the  gas.  This  solution,  further  di- 
luted, is  the  well  known  ''  aqua  ammonia"  of  com- 
merce. It  evolves  the  gas  again  upon  iieating,  or 
on  exposure  to  the  air.  It  is  a  stimulant  when 
slightly  inhaled,  and  is  often  so  employed  in  non- 
complicated syncope. 

Ammonia,  whether  in  the  gaseous  form  or  in 
the  aqueous  solution,  is  strongly  alkaline;  it  unites 
with  and  neutralizes  the  strongest  acids,  forming 
with  them  compounds,  called  salts  of  ammonia. 
The  hydrogen  of  the  acid,  in  such  combination,  is 
not  driven  out,  but  seems  to  take  up  intimately 
with  the  ammonia  itself,  apparently  producing,  in 
the  reaction,  an  unsatisfied  group  (I^H4),  which 
has  received  the  name  of  ammomum.,  because  it 
acts  in  many  cases  like  an  atom  of  some  of  the 
metals.     Thus: 

OTI3     +     IICl     =     (:N'H4)C1, 

Ammonia.  Hydrochloric     Ammonium 

Acid,  Chloride. 

analogous  to  sodium  chloride,  IRaCl.  Ammonium 
chloride  was  first  prepared  by  the  Arabs  of  the 


Nitrogen,  67 

Libyan  deserts,  as  a  substitute  for  common  salt,  by 
heating  camel's  dung.  They  named  it  ''  sal  am- 
moniac"— salt  of  Ammon — in  honor  of  Jupiter 
Ammon,  whom  they  worshiped,  and  from  w^hich 
the  name  ammonia  is  derived.  Ammonium  iodide 
and  ammonium  bromide  are  analogous  salts. 

Nitrogen  and  oxygen  unite  wnth  each  other  in  five 
proportions.  Their  compounds  have  the  following 
names iind  formulas: 

Nitrogen  pentoxide  (or  miric  oxide) ^2^5 

Nitrogen  tetroxide ^2^4 

Nitrogen  trioxide ^2^3 

Nitrogen  dioxide ^2^2 

Nitrogen  monoxide  (or  mXvous  oxide).... N2O 
The  first  and  third  are  acid  oxides;  they  will 
combine  with  water  to  form  acids.  Nitric  oxide, 
sometimes  called  nitric  anhydride,  may  be  prepared 
by  action  of  chlorine  on  solution  of  silver  nitrate: 
2AgN03     +    2C1    =    2AgCl     +     0     +    l^^O, 

ArKeutura  Chlorine.         Argentum  Oxygen.       Nitric 

Nitrate.  Chloride.  Oxide. 

Nitric   oxide   is  a  colorless    crystalline  solid,  of 
unstable,  explosive   qualities.     It  reacts  energetic- 
ally with  water,  producing  nitric  acid  : 
N2O5      +      [1,0    =    2IINO3 

Nitric  oxide.  .V>»ter.  Nitric  acid. 

Nitric  acid  was  known  to  Geber  in  the  eighth 
century,  and  described  by  Raymond  Lully  in  1225. 
Cavendish,  in  1785,  first  determined  its  true  compo- 


68  Inorganic  Chemistry. 

sition.  It  is  formed  in  nature  in  various  ways  ;  by 
strong  electric  currents  passing  through  air;  by 
ozone  acting  upon  the  nitrogen,  or  the  ammonia  in 
the  air,  or  on  nitrogen  dioxide,  trioxide,  and  tetrox- 
ide,  in  the  presence  of  water. 

When  animal  or  vegetable  matters  containing 
nitrogen  decompose,  ammonia  is  produced,  and 
this  compound,  in  presence  of  weak  alkaline  bases, 
is  decomposed  by  nascent  oxygen,  or  by  ^  ozone, 
into  water  and  nitric  acid  : 

NH3     +     04     =     H2O     +     HNO3 

Ammonia.  Water.  Nitric  acid. 

A  process  of  manufacture,  following  these  lines, 
will  result  in  the  development  of  artificial  beds  of 
niter. 

In  the  arts,  however,  nitric  acid  is  always  pro- 
duced by  "heating  sulphuric  acid  with  either  potas- 
sium nitrate  or  sodium  nitrate. 

An  equation  will  best  explain  the  reaction  : 


KN03 

+ 

H,SO,     = 

=       HKSO4        + 

HNO3 

Potassium 

Sulphuric 

Hydropotassium 

Nitric 

Nitrate. 

Acid. 

Sulphate. 

Acid. 

Nitric  acid,  commercially  known  as  aqua  fortis, 
when  pure,  is  a  fuming,  colorless,  corrosive  liquid, 
having  a  specific  gravity  of  1.52 ;  chemically,  it  is 
an  exceedingly  energetic  body,  attacking  most  of 
the  metals,  and  forming  with  them  salts  called 
nitrates,  nearly  all  of  which  are  soluble  in  water. 


Nitrogen.  69 

xTitrogenous  animal  substances,  as  wool,  silk, 
and  parchment,  are  colored  a  deep  yellow  by  it. 
And  many  non-nitrogenous  substances,  as  cotton, 
sugar,  and  glycerine,  are  converted  into  explosive 
bodies  by- nitric  acid. 

By  virtue  of  its  oxidizing  power,  many  remark- 
able reactions  are  induced  to  take  place.  Gold  is 
not  affected  by  any  single  acid,  except  slightly  by 
selenic  acid,  but  if  the  two  acids,  hydrochloric  and 
nitric,  be  mixed  and  gently  heated,  the  nitric  acid 
will  give  up  enough  oxygen  to  oxidize  all  the 
hydrogen  of  both  acids,  setting  the  chlorine  free, 
which  latter  element,  in  its  nascent  state,  readily 
unites  with  the  gold  present,  forming  the  soluble 
AUCI3. 

9HC1  +  3HXO3  =  6H2O  +  3N0C1  +  2CI3. 

2Au  ^  2CI3  =  2AUCI3. 

The  XOCl  is  of  no  importance,  some  authorities 
claiming  that  the  residue  of  nitrogen  and  oxygen 
remain  together  as  3N0,  letting  all  the  -chlorine 
escape  to  the  gold. 

Nitric  acid  is  believed  by  many  experimenters  to 
be  the  cause  of  the  rapid,  or  white,  variety  of  decay 
of  teeth.  This  idea  does  not  conflict  in  the  least  with 
the  so  called  "germ  theory"  of  decay,  inasmuch  as 
the  ferment  of  nitric  acid  has  been  discovered  re- 
cently.    The   manner  of  its   formation  in  the  re- 


70  Inorganic  Chemistry. 

cesses  of  the  teeth,  as  described  by  Dr.  Watt,  is 
owing  to  the  decomposition  of  nitrogenous  sub- 
stances (putrefaction),  developing  simultaneously 
ammonia  and  nascent  oxygen,  which  immediately 
react  on  each  other,  resulting  in  the  oxidation  of 
the  hydrogen  and  nitrogen  into  nitric  acid.  The 
action  of  any  acid  on  the  tooth,  in  forming  caries, 
must  occur  at  the  place,  and  at  the  instant,  of  its 
development ;  that  is,  molecularly.  It  is  not  con- 
ceived that  caries  are  formed  only  by  a  general 
acid  nature  of  the  oral  fluid ;  on  the  contrary,  the 
latter  may  remain  neutral,  or  be  even  decidedl}^ 
alkaline.  The  favorite  trysting  place  of  the  fer- 
ments, in  dental  caries,  is  usually  a  quiet  nook, 
unfrequented  by  the  brush,  wdiere  the  cultures 
consisting  of  organized  debris,  are  changed  into 
simpler  bodies,  and  many  of  these,  ultimately,  into 
poisonous  ptomaines  and  acids. 

Little  need  be  said  of  the  dioxide,  trioxide,  and 
tetroxide  of  nitrogen.  The  dioxide  (N2O2)  is  able 
to  take  up  oxygen  from  the  air  and  is  thereby  con- 
verted into  the  tetroxide,  ^^2^4  5  ^^^^  latter  sub- 
stance is  a  good  oxidizing  agent,  as  we  shall  learn 
by  and  by.  The  trioxide  (IS'gOg)  is  the  anhydrous 
oxide  of  nitrous  acid,  as  the  pentoxide  (^2^5)  ^^^  of 
7iitric  acid ;  the  salts  of  nitrous  acid  are  called  ni- 
trites, as  those  of  nitric  acid  are  called  nitrates. 


Nitrogen.  71 

Nitrous  Oxide. — Or  nitrogen  monoxide.  Mole- 
cular formula,  XgO.     Sp.  gr.  1.527. 

Nitrous  oxide  was  discovered  by  Priestly  in  1776. 
Sir  Humphry  Davy,  in  1807,  described  its  exhilar- 
ating properties,  and  in  1845  Dr.  Horace  Wells,  aii 
American  dentist,  of  Hartford,  Conn.,  employed  it 
as  an  anaesthetic,  and  in  so  doing,  became  the  orig- 
inal, genuine  discover  of  ancesthesia. 

Nitrous  oxide  is  prepared  by  carefully  heating 
in  a  retort  the  salt  known  as  ammonium-nitrate. 
The  retort  is  connected  by  means  of  glass  and  rub- 
ber tubing  with  a  series  of  wash  bottles,  the  tube 
ending  in  a  receiver  placed  over  water  : 

NH4NO3     -f     Heat     =z     2H2O     +     N2O 

Am   Nitrate  Water.  Nitrous 

Oxide. 

The  wash  bottles  usually  contain  water,  potas- 
sium hydrate,  and  ferrous  sulphate;  these  sub- 
stances neutralize  any  traces  of  the  higher  oxides 
of  nitrogen  that  may  be  evolved,  and  which  other- 
wise would  pass  through  with  the  nitrous  oxide  into 
the  receiver. 

Nitrous  oxide  is  a  colorless,  odorless  gas,  with  a 
slightly  sweetish  taste.  Subjected  to  a  pressure  of 
45  atmospheres  at  0°  (32°F.),  it  condenses  to  a 
clear,  mobile  liquid  of  specific  gravity  0.9;  this 
liquid  freezes  into  a  snowlike  mass,  by  the  effect  of 
its  own  evaporation,  when  allowed  to  escape  freely 


72  Inorganic  Chemistry. 

into  the  air.  Its  boiling  point  is  — 88°(— 126°F.)  ; 
its  freezing  point  is  — 101°(— 150°F.). 

The  gas  is  quite  soluble  in  alkaline  solutions ;  it 
is  also  soluble  in  water;  more  so  in  cold  water  than 
in  warm  ;  100  volumes  at  IS*'  (60°F.)  will  dissolve  78 
volumes  of  the  gas.  It  possesses  decided  disin- 
fectant and  antiseptic  properties.  Impure  water, 
containing  much  organic  matter,  becomes  pure  and 
sweet,  and  remains  so  indefinitely,  after  dissolving 
even  a  small  quantity  of  the  gas. 

Kitrous  oxide  is  readil}^  decomposed  by  the  heat 
of  burning  bodies,  letting  its  oxygen  go  to  support 
the  combustion.  In  this  way  combustible  bodies 
will  burn  in  it,  much  like  we  saw  them  do  in  oxygen, 
with  greater  energy  than  in  the  air.  In  this  way, 
also,  it  supports  animal  respiration  to  a  certain 
point.  One  of  the  products  it  develops  in  the 
body  (CO 2)  can  not  escape,  as  in  ordinary  breath- 
ing; the  unavoidable  retention,  therefore,  of  this 
product,  in  the  central  and  other  capillaries,  in- 
duces more  or  less  asphyxia,  according  to  the 
quantity  and  rapidity  of  the  inhalation  of  the  un- 
mixed gas.* 

Nitrous  oxide  is  now  largely  supplied  to  the  pro- 
fession, condensed  to  the  liquid  state  in  metallic 
cylinders. 

*  The  possible  chemico-physiological  action  of  nitrous  oxide 
will  be  considered  with  the  compounds  of  iron. 


Sulphur.  73 


CHAPTER  XIII. 

SULPHUR. 

Symbol,  S.     At.  Wt.  32.     Sp,  gr.  2.04. 

Sulpliur  (brimstone)  has  been  known  from  the 
earliest  historic  ages.  It  is  found  free  in  certain 
volcanic  regions.  It  is  found  also  in  nature  in 
combination  with  other  elements,  as  iron,  copper, 
mercury,  zinc,  lead,  arsenic,  antimony,  and  hydro- 
gen. The  sulphides  are  important  natural  com- 
pounds, and  with  oxygen  and  certain  metals,  such 
as  calcium,  magnesium,  barium,  strontium,  and 
sodium,  it  is  found  in  the  class  of  salts  known  as 
sulphates.  Sulphur  is  an  essential  element  of  ani- 
mal bodies,  and  of  many  vegetables. 

It  is  a  yellow,  brittle  solid,  freely  soluble  in  car- 
bon disulphide,  but  not  in  water;  it  melts  at 
114°(237°F.),  and  boils  at  448°(824°F.) ;  it  is  taste- 
less and  odorless,  and  is  not  a  conductor  of  heat  or 
electricity. 

Sulphur  is  capable  of  crystallizing  in  two  distinct 
forms;  it  is,  therefore,  said  to  be  dimorphous.  The 
natural  crystals,  and  those  deposited  from  solu- 
tion of  the  element  in  carbon  disulphide,  are  rhom- 
bic octohedra,  while  melted  sulpliur,  if  allowed  to 
7 


74  Inorganic  Chemistry, 

cool  slowly,  will  assume  a  prismatic  form.  An 
amorphous  (non-crystalline)  variety  is  obtained  by 
pouring  melted  sulphur  into  cold  water. 

When  heated  in  the  air  to  260°(500°F.),  sulphur 
takes  fire,  and  burns  with  a  pale,  lambent  flame, 
forming  SOg  ;  and  certain  metals,  if  heated  in 
its  vapor,  will  burn  readily,  forming  sulphides.  It, 
therefore,  shows  an  aflinity  for  oxygen  and  various 
metals;  it  also  unites  directly  with  carbon. 

Dental  rubbers  contain  from  15  to  20  per  cent  of 
"  flowers  of  sulphur,"  which  enables  the  caoutchouc 
to  become  vulcanized  into  a  hard  material.  Sul- 
phur has  been  suggested  as  a  filling  for  root 
canals,  being  fused  therein  by  heated  instruments, 
and  for  setting  crowns. 

Sulphur  unites  with  oxygen  in  two  proportions. 
When  sulphur  is  burned  in  the  air,  or  in  oxygen, 
the  dioxide  (SO2)  is  formed;  this  substance  is  a 
good  disinfecting  and  bleaching  agent,  being  a  de- 
oxidizer,  able  to  take  away  oxygen  from  certain 
deoxidizable  bodies,  which  destroys  their  identity. 

Sulphur  dioxide  is  an  acid  oxide;  united  with 
water,  sulphurous  acid  is  the  result : 

SO2     +     H2O     =     H2SO3 

■    Sulphurous  acid. 

The  salts  of  this  acid  are  named  sulphites. 

The  other  oxide  of  sulphur  is  the  trioxide  (SO^) 


Sulphur.  75 

or  sulphuric  oxide.  It  is  usually  prepared  by  oxi- 
dizing sulphurous  oxide — the  dioxide  SO2.  Sul- 
phur trioxide  is  a  white  wax-like  solid,  of  a  silky, 
librous  appearance,  somewhat  resembling  asbestus. 
It  unites  with  water,  giving  rise  to  great  heat,  pro- 
ducing sulphuric  acid: 

SO3     +     H2O     =     H2SO4 

Sulphuric  Acid. 

Sulphuric  acid,  hydrogen  sulphate,  next  to  water 
itself,  is  perhaps  the  most  generally  useful  sub- 
stance in  chemistry:  it  occurs  free  in  the  waters  of 
certain  springs  and  rivers,  and  in  the  saliva  of  cer- 
tain mollusks,  and  is  the  type  of  all  sulphates. 

The  preparation  of  sulphuric  acid — also  known 
as  oil  of  vitriol — involves  several  simple  chemical 
reactions : 

1st.  The  burning  of  sulphur  in  the  air  to  obtain 
sulphurous  oxide  SOg. 

2d.  The  presence  of  nitric  acid  (2H]Sr03)  which 
supplies  nitrogen  tetroxide  ^2^4- 

3d.  The  latter  compound  gives  oxygen  to  the 
SO2,  changing  it  into  SO3,  and  is  itself  reduced  to 
nitrogen  dioxide  N2O2. 

4th.  Water,  heated  by  the  burning  sulphur, 
unites  with  the  SO3,  producing  sul[)liuric  acid. 

5th.  The  taking  up  of  oxygen  from  the  air  by 


76  Inorganic  Chemistry. 

the  uitrogen  dioxide,  which  thus  serves  as  a  carrier 
of  oxygen. 

The  whole  process  may  be  more  easily  under- 
stood by  referring  to  the  following  equations : 

S  H-  20  =  SO2. 

2SO2    +   N2O4    r=r  2SO3    -h   ^202- 
SO3    +    H2O  =  H2SO4. 

K2O2  -f  20  =  N2O,. 

Inasmuch  as  the  process  is  continuous  and  si- 
multaneous, from  the  burning  of  the  sulphur  to  the 
deposition  of  the  acid  on  the  floor  of  the  leaden 
chamber,  it  is  probable  that  other  and  complicated 
reactions  take  place.  The  above  explanation,  how- 
ever, is  the  one  generally  accepted  as  the  simplest 
view  that  can  be  taken  in  the  premises  and  is,  at 
least  approximately,  correct. 

Sulphuric  acid  is  a  colorless,  oily  liquid,  of  spe- 
citic  gravity  about  1.85.  Freezes  at  —  26°  (— 15°F.) 
and  boils  at  328°  (622°F.).  It  has  a  strong  aflanity 
for  many  of  the  metals.  It  is  always  thirsty  for 
water,  their  union  evolving  great  heat.  It  absorbs 
moisture  from  the  air  and  from  other  gases,  and  is 
therefore  often  used  as  a  drying  agent.  Its  general 
action  on  organic  matters  is  to  dehydrate  them, 
that  is,  to  take  from  their  substance  the  elements 
oxygen  and  hydrogen,  and  induce  them  to  combine 
to  form  water,  that  its  thirst  may  be  satisfied. 


Sulphur,  77 

Sulphuric  acid  is  more  than  likely  involved  in 
the  condition  known  as  "  black  decay  "  of  teeth. 
Its  production  in  situ  is  probably  due  to  the  energy 
of  nascent  oxygen  on  hydrogen  sulphide  (H2S), 
these  being  evolved  from  the  organized  debris  in 
contact  with  the  tooth,  Orud  which  is  said  to  un- 
dergo decomposition  by  the  influence  of  some  not 
yet  detected  special  form  of  bacteria. 

The  phenomena  of  "  black  decay  "  really  seem  to 
be  an  arrest  of  the  destructive  proceedings  of  some 
active  solvent,  previously  at  work.  Any  well- 
marked  specimen  of  this  form  of  caries  represents 
the  surface  of  the  cavity  of  a  dark  brown  or  black 
appearance,  hard,  and  sometimes  polished,  and 
which  is  comparatively  immune  from  further  decay. 
The  limiting  action  of  sulphuric  acid  on  tooth 
structure  explains  the  above  physical  characteris- 
tics. Its  molecules,  at  their  birth,  attack  the 
earthy  portion,  forming  insoluble  calcium  sulphate 
(CaSO^),  and  at  the  same  time  dehydrating  the 
animal  or  gelatinous  portion,  which  is  mainly  made 
up  of  carbon,  hydrogen,  and  oxygen ;  these  two 
latter  elements  are  withdrawn,  as  already  alluded 
to,  leaving  the  indestructible  carbon  as  a  residue, 
to  be  incorporated  with  the  insoluble  sulphate, 
producing  thus  a  protecting  covering  to  the  unaf- 


78  Inorganic  Chemistry. 

fected  parts  beneath  against  fnrther  inroads  both 
of  the  causing  agent  and  other  solvents. 

A  gaseous  compound  of  sulphur  and  hydrogen 
(sulphuretted  hydrogen,  dihydrogen  sulphide,  sul- 
phydric  acid,  etc.,  U2S),  is  found  in  nature,  and 
also  largely  employed  in  the  labratory  as  an  im- 
portant re-agent  in  classifying  the  metals,  according 
as  their  sulphides  are  either  soluble  or  insoluble  in 
acid  and  alkaline  solutions. 

Quite  a  number  of  oxygen  acids  of  sulphur  are 
known  as  thionic  acids;  their  molecules  contain  2 
atoms  of  H  and  6  of  0,  and  2,  3,  4,  and  5  atoms  of 
S,  respectively.  They  are,  however,  of  no  general 
or  special  interest  to  us. 

SELENIUM. 

Symbol,  Se.     At.  wt.  79.     Sp.  gr.  4.5. 

Selenium,  named  in  honor  of  the  moon,  belongs 
to  the  less  abundant  elements.  It  is  occasionally 
found  free,  but  generally  in  company  with  sulplwir, 
and  in  the  selenides  of  silver,  mercury,  lead,  and 
copper.  It  unites  with  hydrogen  to  form  a  gaseous 
compound  (H2Se),  analogous  to  sulphuretted  hy- 
drogen, of  an  extremely  nauseous  odor.  It  forms 
acids  corresponding  to  those  of  sulphur:  selenious 
acid  (HgSeOg),  and  selenic  acid  (H2Se04),  the  lat- 
ter being  the  only  single  acid  that  will  even  spar- 
ingly attack  gold. 


Tellurium.  79 

TELLURIUM. 

Symbol,  Te.     At.  wt.  128.     Sp.  gr.  6.2. 

Tellurium,  named  from  tellus,  the  earth,  is  a 
rarer  element  than  selenium.  It  occurs  free  in 
small  quantities,  and  in  the  tellurides  of  mercury, 
silver,  lead,  bismuth,  and  gold.  In  Colorado,  the 
tellurides  of  silver  and  gold  are  important  ores. 
Physically,  it  resembles  the  metals,  but  in  its  chem- 
ical nature,  it  is  closely  related  to  sulphur  and 
selenium. 

The  three  elements  form  similar  compounds — 
with  hydrogen  (Il2Te),  and  with  oxygen  (Te02Te 
O3),  and  corresponding  acids  (H2Te03,  Il2Te04). 


80  Inorganic  Chemistry, 


CHAPTER  XIY. 

PHOSPHORUS. 

Symbol,  P.     At.  wt.  31.     Sp.  gr.  183—214. 

Phosphorus  was  discovered  by  Brandt  in  1669. 
It  does  not  occur  free  in  nature,  but  exists  in  com- 
bination, generally  as  phosphates.  It  is  a  constit- 
uent of  teeth,  bones,  and  other  tissues,  and  is 
obtained  in  our  food,  mainly  from  the  seeds  of 
plants. 

Phosphorus  is  prepared  from  the  ash  of  bones 
by  treatment  with  sulphuric  acid  and  charcoal.  It 
is  a  yellow,  waxy,  translucent  solid,  easily  cut  with 
a  knife,  is  luminous  in  the  dark,  by  slow  oxida- 
tion. At  50°  (122°F.)  it  takes  fire,  and  burns  with 
great  brilliancy.  Its  field  of  energy  is  very  wide, 
as  it  combines  with  nearly  all  the  elements,  C  and 
^N"  being  exceptions.  It  is  soluble  in  carbon  disul- 
phide,  but  not  soluble  in  water,  in  which  it  must 
be  preserved.  As  phosphorus  is  an  active,  insidi- 
ous poison,  workmen  in  match  factories,  by  neg- 
lecting their  teeth,  are  often  afilicted  with  dental 
caries  and  necrosis  of  the  lower  jaw.  Oil  of  tur- 
pentine and  alkaline  mouth  washes  are  the  best 
antidotes. 


Phosphorus.  81 

Phosphorus,  heated  to  250°  (482°F.),  is  converted 
into  a  red  powder  of  sp.  gr.  214.  The  red  variety 
is  not  soluble  in  carbon  disulphide,  is  not  poison- 
ous, has  no  odor,  and  does  not  oxidize  in  the 
air,  and  will  not  take  lire  until  heated  to  260° 
(500°F.). 

There  are  two  oxides  of  phosphorus :  that  pro- 
duced by  oxidation,  phosphorous  oxide  (P2O3), 
and  that  produced  when  phosphorus  is  burned  in 
the  air  or  in  oxygen,  phosphoric  oxide  (P2O5). 
Phosphoric  oxide,  united  with  water,  forms  phos- 
phoric acid  : 

P2O5      +     3H2O     =:     2H3PO4 

There  are  several  kinds  of  phosphorus  acids, 
but  two  or  three  only  need  be  mentioned. 

Ordinary  phosphoric  acid  (H3PO4),  often  called 
orthophosphoric,  is  a  syrupy  liquid,  of  strong  acid 
properties;  its  salts  are  called  orthophosphates  (as 
bone  phosphate).  It  forms,  with  calcined  zinc  oxide 
(and  also  with  cupric  oxide),  a  coherent,  hard  ce- 
ment, used  as  a  temporary  tilling,  or  for  strength- 
ening frail  walls  in  cavities  of  teeth. 

As  phosphoric  acid  is  formulated  from  3  mole- 
cules of  water,  pyrophosphoric  acid  is  formulated 
from  2  molecules,  and  m(?^aphosphoric  acid  from  1 
molecule  of  water,  thus  : 

P2O5    -(    3II2O  =  2II3PO4,  phosphoric  acid; 


82  Inorganic  Chemistry. 

P2O5  -f  2H2O  =  H4P2O7,  pyrophosphoric 
acid; 

P2O5   +  H2O  =  2HPO3,  metaphosphoric  acid. 

The  salts  of  the  two  latter  are  called  pyrophos- 
phates and  metaphosphates,  respectively.  The 
meta  acid  is  also  known  as  glacial  phosphoric  acid. 
It  is  a  vitreous  solid,  readily  soluble  in  water;  will 
coagulate  albumen,  while  the  or^Ao  variety  will  not. 
By  the  addition  of  water  and  a  gentle  heat,  the 
glacial  is  converted  into  the  ordinary  so-called 
ortho-phosphoric  acid. 

Phosphorus  and  hydrogen  unite  indirectly,  pro- 
ducing a  compound  phosphine  (PH3),  correspond- 
ing with  ammonia  (I^Hg),  a  colorless  gas  of  garlic- 
like odor.  It  precipitates  several  metals  from 
solutions,  as  phosphides. 

Phosphine  is  usually  prepared  by  filling  a  flask 
nearly  full  of  an  aqueous  solution  of  caustic  pot- 
ash, to  which  are  added  a  few  bits  of  phosphorus. 
The  air  above  the  solution  in  the  flask  should  be 
driven  out  by  drops  of  ether  or  a  current  of  illu- 
minating gas. 
4P    +    3H2O    +    3KH0    =    3KPH2O2    +  PH3 

Pot.  Hydrate.       Pot.  Hypophosphite. 

The  PH3  is  adulterated  with  traces  of  P2H4, 
which,  on  escaping  from  the  tube  in  the  water  pan 
into  the  air,  causes  each  bubble  of  the  phosphine 


Phosphorus.  83 

to  ignite  with  a  brilliant  flash,  to  form  beautiful 
ascending  rings  of  smoke,  consisting  of  the  oxid- 
ized phosphorus  (P2O5). 

There  are  two  chlorides  of  phosphorus,  the  tri- 
chloride (PCI 3)  and  pentachloride  (PCI5).  The 
pentachloride  is  a  solid  substance,  and  is  formed  in 
the  experiment  showing  the  spontaneous  ignition 
of  phosphorus  in  chlorine  gas. 


84  Inorganic  Chemistry. 


CHAPTER  XV. 

CARBON. 

Symbol,  C.     At.  wt.  12.     Sp.  gr.  3-5,  2.15,  1-9. 

Carbon  is  remarkable  as  existing  in  nature  in 
three  distinct  allotropic  forms,  which  have  no 
physical  properties  in  common,  but  whose  chem- 
ical nature  is  the  same.  These  three  forms  are 
known  as  the  diamond,  graphite^  and  charcoal. 
Twelve  (12)  parts,  by  weight,  of  either  of  these 
varieties,  united  with  oxygen,  give  us  forty-foiu^ 
parts,  by  weight  of  the  same  compound  (CO2). 

Carbon  also  occurs  extensively  in  nature,  as  in 
the  carbonates,  of  which  limestone,  marble,  chalk, 
and  dolomite  are  examples.  It  is  the  characteristic 
element  of  animal  and  vegetable  life — all  organized 
tissues  contain  it — hence  organic  chemistry  treats 
only  of  carbon  in  its  relations  to  other  elements. 

The  DIAMOND  occurs  in  nature  in  crystals,  more 
or  less  perfect,  derived  from  the  regular  octa- 
hedron. It  is  the  hardest  substance  known,  and 
when  cut  and  polished  possesses  high  refractive 
and  dispersive  power  hence  its  use  as  a  costly 
gem.     When  diamond  is  heated  in  a  gas  incapable 


Carbon.  85 

of  acting  chemically  upon  it,  it  swells  into  a  black 
porous  mass  resembling  coke. 

Graphite,  or  plumbago,  also  known  as  black 
lead,  occurs  in  hexagonal  plates,  found  as  an  ir- 
regular vein  traversing  ancient  slate  beds.  It  is 
also  obtained  in  brilliant  scales  from  melted  cast- 
iron,  on  cooling.  Graphite  has  a  semi-metallic 
appearance,  an  unctuous  feel,  leaves  a  mark  when 
drawn  on  paper,  is  a  fairly  good  conductor  of  heat 
and  electricity  (which  the  diamond  is  not),  and  is 
used  in  the  making  of  lead-pencils  (therefore 
graphite),  stove  polish,  crucibles,  in  electrotyping, 
and  as  a  varnish  for  grains  of  gunpowder. 

An  impure,  quasi  graphite,  gas  carbon,  formed 
in  the  retorts  in  manufacturing  coal  gas,  is  used  in 
galvanic  batteries,  and  for  the  carbon  points  of  the 
arc  electric  light. 

Charcoal  includes  all  those  varieties  of  coal 
found  in  nature,  ordinary  charcoal  (of  either  ani- 
mal or  vegetable  origin),  coke,  and  lampblack. 

Coal  consists  of  the  remains  of  vegetable  matter 
that  once  flourished  on  the  earth's  surface,  and 
was  subjected  to  a  process  of  partial  combustion, 
much  like  that  by  which  common  charcoal  is  pre- 
pared ;  but  much  of  the  volatile  principles  yet  re- 
main, made  up  largely  of  hydrogen.  Cannel  and 
soft  coal  contain  the  most  hydrogen,  and  anthracite 


86  Inorganic  Chemistry. 

the  least.  The  elements,  oxygen,  sulphur,  and 
nitrogen,  are  also  found  in  coal,  in  varying  pro- 
portions; and  likewise  earthy  substances,  which 
form  the  ash. 

The  varieties  recognized  merely  as  charcoal  are 
produced  by  imperfect  combustion  of  wood,  bones, 
etc.  Nearly  all  the  volatile  principles  of  the  orig- 
inal substance  are  driven  out,  leaving  a  porous 
matrix.  The  ability  of  charcoal  to  absorb  certain 
gases  is  due  to  this  porosity.  ^N'oxious  gases,  such 
as  ammonia  and  sulphuretted  hydrogen,  are  ab- 
sorbed in  large  quantity  by  freshly  prepared  char- 
coal, which  are  condensed  within  its  pores  and 
oxidized  into  harmless  compounds  by  the  oxygen 
which  it  also  absorbs  at  the  same  time.  In  this 
way  charcoal  acts  as  a  disinfectant. 

Coke  is  the  residue  left  in  the  retorts  of  the  gas- 
works from  the  destructive  distillation  of  coal. 

Lampblack^  considered  as  the  purest  variety  of 
amorphous  carbon,  is  prepared  by  burning  resin, 
tar,  petroleum,  or  turpentine,  in  a  limited  supply 
of  air,  and  collecting  the  smoke  in  suitable  cham- 
bers, by  which  the  soot,  carbon,  is  deposited. 
Printer's  ink,  India  ink,  and  black  paint,  are  made 
from  lampblack. 

Combustion. — In  the  wide  sense  of  the  term, 
combustion  means  any  chemical  action  that  devel- 


Carbon.  87 

opes  heat  and  light.  Ordinarily,  however,  the 
meaning  is  restricted  to  the  burning  of  substances 
in  the  air  or  in  oxygen,  and  still  further  restricted 
by  the  understanding  that  the  elements  of  the 
burning  body  are  mainly  carbon  and  hydrogen. 
This  fact  obtains  in  the  burning  of  coal,  or  wood, 
or  candle,  or  coal  oil,  or  illuminating  gas;  and  the 
chemical  action,  briefly  stated,  consists  in  the 
union  of  these  elements,  C  and  H,  with  the  0  of 
the  air.  Sufficient  heat  must  be  applied  to  start 
the  process,  which  then  continues,  under  favorable 
conditions,  until  the  materials  involved  are  com- 
pletely oxidized.  An  equation  will  enable  us  to 
understand  fully,  the  general  reaction : 

C     -f     H2     +     30     =     H2O     4-     CO2 

Water.  Carbon  Dioxide. 

Common  combustion  may  therefore  be  defined 
as  "  consisting  of  the  union  of  the  elements  of  the 
burning  body  with  the  oxygen  of  the  air,  resulting 
in  the  formation  of  water  and  carbonic  acid  gas." 
The  earthy  constituents  of  the  wood  or  coal,  such 
as  potassium,  are  also  oxidized  at  the  same  time, 
forming  the  "  ash." 

Illuminating  gas,  manufactured  by  destructive 
distillation  of  bituminous  coal,  is  a  mixture  of  free 
h^^drogen,  methane,  ethene,  ethine,  and  traces  of 
CO,  CO2,  N,  and  II2S. 

Methane,  marsh  gas,  or  light  carburetted  hydro- 


88  Inorganic  Chemistry, 

gen,  CH4,  is  the  lightest  body  known  next  to  hydro- 
gen, its  specific  gravity  being  0.5576.  It  occurs  free 
in  nature,  being  produced  by  decomposition  of  veg- 
etable matter  confined  under  water,  and  may  be  col- 
lected by  filling  a  wide-mouthed  bottle  with  water 
and  holding  it  over  the  bubbles  which  rise  on  stir- 
ring with  a  stick  the  mud  at  the  bottom  of  marshy 
ponds — hence  its  name,  "  marsh  gas."  It  is  also 
the  "  fire  damp  "  of  the  miners. 

It  is  usually  prepared  in  the  laboratory  by  heat- 
ing sodium  acetate  and  sodium  hydrate. 

1^2iQ^11^0^   +  :N'aHO  =  1^2i^C0^  +  CH4 

Sodium  Sodium  Sodium  Methane. 

Acetate.  Hydrate.  Carbonate. 

Methane  is  a  colorless,  odorless  and  tasteless  gas, 
and  burns  in  the  air  with  a  faintly  luminous  flame. 

Ethene,  ethylene,  heavy  carburetted  hydrogen 
(^2^4);  produced  in  the  decomposition  of  many 
organic  bodies,  is  prepared  by  heating  alcohol  with 
strong  sulphuric  acid,  which  abstracts  the  ele- 
ments of  water,  thus : 

CJI.O     -    H,0    =     C,H, 

Alcohol.  Ethene. 

Ethene  is  a  colorless  gas,  much  heavier  than  me- 
thane, its  specific  gravity  being  0.978;  it  burns 
with  a  splendid  white  flame,  and  will  unite  with 
chlorine  (C2H3CI)  forming  an  oily  liquid  of  ethereal 
odor,  whence  the  name  sometimes  applied,  '' oli- 
fiant  gas." 


Carbon. 


89 


The  reader  will  kindly  appreciate  the  fact,  that 
these  two  gases,  CH^  and  C2  H^,  are  fair  examples 
of  the  hydrocarbons  that  take  active  part  with  the 
oxygen  of  the  air,  in  the  process  of  ordinary  com- 
bustion ;  and  that  the  products  are,  necessarily, 
water,  (H2O),  and  carbonic  acid  gas,  or  carbon - 
dioxide  (CO2). 

The  light  from  burning  oil,  or  candle,  or  illumin- 
ating gas,  or  at  the  cheerful  fireside,  or  the  open 
grate,  holding  either  wood  or  coal,  or  natural  or 
artificial  gas,  consists  substantially  of  the  same 
chemical  reaction,  i.  e.,  the  union  of  hydrogen  and 
carbon  with  atniospheric  oxygen. 

A  jlame^  therefore,  will  vary  in  physical  and 
chemical  properties,  according  to  the  relative  quan- 
tities of  either  the  less  or  more  dense  hydrocarbon 
compounds,  and  the  oxygen  involved  in  the  pro- 
cess. When  the  more  dense  or  heavy  gases  burn 
in  the  air,  the  light  evolved  is  superior  to  that 
given  ofl[*  by  the  less  dense  hydrocarbons,  owing  to 
the  difierence,  in  afiinity,  between  the  carbon  and 
hydrogen  of  the  burning  gases,  and  oxygen. 

Burning  gases,  containing  relatively  much  hy- 
drogen, give  oflT  greater  heat,  while  those  that  are 
relatively  rich  in  carbon  are  deficient  in  heating,  but 
correspondingly  rich  in  lighting  power. 

The  common,  everyday  hydrocarbon  flame,  is 
8 


90  Inorganic   Chemistry. 

divided,  for  convenience  of  description,  into  three 
parts : 

1st.  That  which  surrounds  the  wick  of  oil,  or 
candle,  or  jet  of  gas  burner,  the  zone  of  noncom- 
bustion. 

2d.  The  zone  of  incomplete  combustion,  where  hy- 
drogen mainly  oxidizes,  and  where  the  particles  of 
free  Carbon  are  brought  to  a  high  state  of  incan- 
descence, by  the  heat  developed  by  the  burning  hy- 
drogen, radiate  their  light — the  luminous  portion 
of  ;the  flame — and 

3d.  The  area  of  so-called  complete  combustion, 
where  carbon,  with  any  remaining  hydrogen,  is  also 
oxidized. 

Active  chemical  union  between  the  burning 
gases  and  the  supporting  oxygen  of  the  air,  takes 
place  mainly  on  the  surface  of  the  resulting  flame, 
the  interior  being  hollow;  such  physical  condition 
is  due  to  the  fact  that  the  oxygen  of  the  air  is  ex- 
hausted at  the  immediate  surface,  and  is  tlierefore 
unable  to  penetrate  the  interior  of  the  flame ;  but 
if  the  air  (oxygen)  be  admitted  to,  and  mixed  with, 
the  combustible  gases,  before  ignition,  as  in  the 
Bunsen  burner,  the  extra  oxygen,  thus  supplied, 
supports  the  simultaneous  combustion  throughout 
the  flame,  of  both  the  carbon  and  hydrogen.     Such 


Carbon.  91 

a  flame  is  lacking  in  brilliancy,  but  possesses  great 
lieating  power. 

The  same  principles  apply  to  the  mouth  blow- 
pipe flame.  Air  (oxygen),  is  blown  by  the  cheeks, 
into  the  interior  of  the  flame,  wdiich  resolves  the 
latter  into  two  chief  parts  :  a  bluish  inner  cone  and 
an  outer  cone.  The  outer  cone  is  named  the  oxi- 
dizing area,  because  certain  metals,  when  heated  in 
it,  become  oxidized.  The  apex  of  the  inner  cone 
is  possessed  of  great  heating  power,  and  is  called 
the  reducing  portion  of  the  flame,  because  certain 
metallic  oxides,  when  heated  at  that  point,  are  re- 
duced to  free  metal  and  free  oxygen.  A  little 
practice  with  the  blow-pipe,  under  proper  instruc- 
tions, will  enable  the  dental  student  to  easily  solder 
pieces  of  brass  or  copper,  these  metals  being  good 
substitutes  for  silver  and  gold  in  experimental 
practice. 

The  heat  of  combustion,  ordinary  or  special, 
is  measured  in  heat  units  ;  one  unit  being  the  quan- 
tity of  heat  needed  to  raise  one  gram  of  water 
from  0°  to  1°.  Hydrogen  burning  in  oxygen, 
furnishes  34,462  heat  units,  and  carbon  oxidizing, 
8,080  units;  that  is  to  say,  1  grain  of  hydrogen,  or 
of  carbon  respectively,  in  burning  in  oxygen,  would 
raise  the  temperature  of  34,462,  or  8,080  grams  of 
water  from  0°  to  1°. 


92  Inorganic  Chemistry. 


CHAPTER  XVI., 

CARBON— Continued. 
Cakbon  DioxiDE.-Carbon  and  oxygen  form  two 
compounds,  the  monoxide  (CO),  and  the  dioxide 
(CO  )      The  latter  compound  is  also  known  as  car- 
bonic acid  gas.     It  is  a  substance  of  frequent  oc- 
currence and  wide  distribution,  being  a  product  ot 
ordinary  combustion,  and  fermentation,  and  putn- 
cation  of  vegetable  and  animal  tissues.     From  the 
bodies  of  living  animals  it  is  exhaled  by  means  ot 
the  lungs,  in  respiration.     It  is  usually  set  free, 
when  carbonates   are   decomposed,  and  is  the  im- 
portant constituent  of  the  atmosphere,  which  sup- 
plies carbon  to  the  vegetable  kingdom. 

Carbon    dioxide    is    prepared    for   experimental 
purposes,   or  for   producing,   under   pressure,  the 
effervescence  in  soda  roatcr,  by  reaction  between  a 
carbonate  and  a  dilute  acid,  usually  hydrochloric 
or  sulphuric,  as  the  following  equation  will  show  : 
n    po      +    H  SO,    =    CaSO^   +  H^O  +  CO, 

CaCO,      +      ^iXavtc  calcium*  Water.  Carbm, 

SSte.  iclS""™  Su.p.ate.  B.ox    . 

Carbon  dioxide  is  a  colorless,  odorless  gas,  and 
possesses  a  slightly  acid  taste.  It  is  one-and-a- 
half  times  as  heavy  as  air,  and  twenty-two  times 


Carbon.  93 

as  heavy  as  hydrogen.  It  dissolves  somewhat  in 
water  at  the  ordinary  pressure  and  temperature  of 
the  air,  but  as  the  volume  of  a  gas  is  inversely 
as  the  pressure,  great  quantities  of  COg  can  he 
confined  in  w^ater  under  pressure,  as  is  seen  iu 
soda  water,  certain  mineral  waters,  sparkling 
wnnes,  and  beer,  which,  on  exposure  to  the  air, 
rapidly  lose  their  excess  of  CO2,  and  thereby  soon 
become  flat  and  insipid. 

Carbon  dioxide  interferes  with  combustion  by 
superseding  the  supporting  oxygen,  as  is  noticed 
in  the  action  of  the  ''  Babcock  Extinguisher." 

Animal  respiration  is  also  affected  by  the  pres- 
ence of  an  abnormal  quantity  of  carbon  dioxide, 
although  it  is  not  of  itself  a  poison;  it  simply 
acts  like  w^ater,  or  nitrogen,  by  preventing  the  due 
aeration  of  the  blood;  it  often  accumulates  at 
the  bottom  of  old  wells,  brewery  vats,  etc.,  and  in 
such  places  its  presence  may  be  detected  by  lower- 
ing a  lighted  candle,  which,  if  extinguished,  will 
indicate  an  atmosphere  dangerous  to  animal  life. 
It  is  the  choke-damp  of  the  miners. 

Carbonic  acid  is  formed  by  the  union  of  water 
and  carbon  dioxide  under  pressure. 

H2O     -f-     CO2     =     II2CO3 

Carbonic  Acid. 

This  acid  does  not  exist  as  a  commercial  sub- 
stance, like   nitric,  or  other  acids,  because  on  re- 


94  Inorganic  Chemistry. 

moval  of  pressure,  it  decomposes  into  water  and 
carbon  dioxide. 

H2CO3     =    H,0     +     CO, 

Carbonic  Acid. 

The  salts  of  this  acid,  known  as  carbonates,  are 
easily  disrupted  by  heat,  as  well  as  by  even,  weak 
acids.  Calcium  carbonate,  in  the  form  of  lime- 
stone, marble,  chalk,  oyster  shells,  etc.,  when 
heated,  yield  lime  and  carbon  dioxide. 

CaCOg     +     Heat     =     CaO     +     CO2 

Calcium  Lime 

Carbonate. 

Carbon  monoxide  (CO),  known  also  as  carbonyl, 
and  too  frequently  as  carbonic  oxide,  is  a  combus- 
tible gas,  odorless,  colorless,  and  tasteless,  and 
actively  poisonous ;  one  per  cent  in  the  atmosphere 
is  considered  dangerous.  It  may  be  prepared  by 
various  methods,  but  it  is  probably  never  produced 
synthetically.  Some  of  the  carbon  dioxide  formed 
during  combustion,  when  arriving  at  the  surface  of 
the  heated  coal,  suffers  reduction  (CO2  +  C  =  2C0), 
at  which  point  the  resulting  CO,  meeting  with  at- 
mospheric oxygen,  unites  with  the  latter,  burning 
with  ablue flame, andproducingC02.  CO-j-O^COg. 

Where  the  combustion  is  confined,  as  in  certain 
anthracite  stoves  and  furnaces,  a  portion  of  the 
CO  may  escape  oxidation,  and  pass  through  the 
heated  cast-iron  to  the  surrounding  air,  causing 
serious  annoyance  to  the  occupants  of  the  room. 


Carbon.  95 

Cigarette  smokers  are  probably  injured  more  by 
inhaling  carbon  monoxide  (CO)  than  by  any  other 
cause  connected  with  the  habit.  This  gas  is 
formed  at  the  heated  end  of  the  burning  cigarette, 
and  which,  when  inhaled,  enters  the  circulation 
and  induces  destructive  chemical  changes  in  the 
blood. 

Carbon  disulphide  (CS2)  is  formed  synthetically 
by  passing  a  stream  of  sulphur  vapor  over  red-hot 
charcoal.  The  commercial  carbon  disulphide  has 
an  exceedingly  nauseous  odor,  but,  if  pure,  the 
odor  is  rather  pleasant,  suggestive  of  ether.  It  is 
a  clear  liquid,  of  specific  gravity,  1.29.  Its  vapor 
Hiixed  with  air  is  explosive,  and  the  compound 
itself  is  very  combustible,  yielding  carbon  dioxide 
and  sulphur  dioxide,  CS2  +  60  =  CO2  +  2SO2. 

Carbon  disulphide  owes  its  importance  to  its 
solvent  properties.  It  easily  dissolves  such  sub- 
stances as  caoutchouc,  phosphorus,  sulphur,  oils,  and 
fats,  and  is  used  largely  for  extracting  oils  from 
seeds  and  fats  from  animal  refuse,  and  in  the  vul- 
canization of  rubber. 

With  N,  carbon  forms  one  compound  named  cy- 
anogen (CX),  to  be  described  under  "Organic 
Chemistry." 


96  Inorganic  Chemistry, 


CHAPTER  XVII. 

BORON. 

Symbol,  B.     Sp.  gr.    2.68. 

Boron  is  a  constituent  of  many  minerals.  It 
may  be  obtained  in  two  modifications.  The  first 
is  a  soft,  dark  brown  powder,  analogous  to 
amorphous  carbon,  slightly  soluble  in  water,  and 
fusible  in  the  oxy-hydrogen  flame.  The  second 
variety  is  obtained  in  quadratic  octahedral  crystals, 
varying  in  color  from  yellow  to  garnet  red;  in- 
fusible, and  nearly  as  hard  and  as  highly  refractive 
as  the  diamond. 

Boric  oxide,  B2O3,  is  formed  whenever  boron 
is  burned  in  the  air  or  oxygen.  United  with 
3  molecules  of  water,  it  forms  boric  (ortho-boric) 
acid, 

B2O3        +        3H2O       =:       2H3BO3. 

Boric  Acid. 

Boric  Acid. — Boric  acid  is  usually  obtained  from 
solution  of  borax,  in  boiling  water,  by  sulphuric 
acid.  Occurs  in  white  crystalline  scales,  soluble  in 
water  and  alcohol,  and  possesses  antiseptic  prop- 
erties. 

Boron  unites  with   H   to  form  a  o^aseous  com- 


Silicon.  97 

pound,  BII3,  resembling  NH3  and  PH3.  With  F 
it  forms  a  colorless  gas,  and  with  CI  a  volatile 
liquid  ;  but  by  far  the  most  important  compound 
of  boron  is  borax  (Xa2  0  (6203)2,  which  will  be 
considered  in  connection  with  sodium. 

SILICON. 

Symbol,  At.  Wt.  Sp.  Gr. 

Si.  28.  2.49. 

Inasmuch  as  we  began  the  study  of  the  non- 
metallic  elements  with  oxygen,  it  is  meet  that  we 
conclude  the  subject  with  the  next  most  abundant 
ingredient  of  the  earth's  surface,  namely,  silicon, 
sometimes  called  silicium.  It  is  obtained  by  heat- 
ing together  metallic  potassium  and  potassium  sili- 
cofluoride,  4K  +  l^^^'^"^^  =  6KF  +  Si. 

Like  carbon,  silicon  may  be  obtained  in  three 
different  modifications.  One  is  an  amorphous 
dark  brown  powder.  The  second  consists  of  hex- 
agonal plates  resembling  graphite,  and  the  third 
variety  crystallizes  in  octohedrons  of  exceeding 
hardness.  It  fuses  only  at  very  high  temperatures, 
and  is  insoluble  in  all  acids,  except  hydrofluoric. 
The  isolated  element  has  no  practical  importance. 

Silicon   combined  with   oxygen,   and   also   with 

potassium,    aluminum,    and    other   metals,    enters 

largely  into  the  structure  of  the  solid  crust  of  the 

earth. 
9 


98  Inorganic  Chemistry. 

The  oxide  of  silicon  (SO 2),  known  as  silica,  and 
when  in  powder,  as  silex,  is  the  principal  earthy 
material  of  our  planet,  occurring  more  or  less  pure 
in  sandstone,  quartz,  or  rock  crystal,  amythyst, 
agate,  cornelian,  chalcedony,  and  the  beautiful  opal. 
In  combination  with  certain  metallic  oxides,  it 
forms  a  class  of  salts  called  silicates,  of  which  by 
far  the  largest  variety  of  minerals  consist.  Sili- 
con oxide  is  found  in  animal  tissues ;  it  stiffens  the 
stems  of  the  various  grasses  and  growing  grains, 
and  is  also  found  dissolved  in  the  waters  of  many 
thermal  springs.  It  has  a  specific  gravity  of  2.6. 
The  natural  crystal  is  sufficiently  hard  to  scratch 
glass ;  it  is  but  slightly  soluble  in  water,  and  is  un- 
affected by  acids,  except  hydrofluoric. 

Si02  is  an  acid  oxide.  When  sand  is  fused  with 
sodium  or  potassium  carbonate,  a  reaction  ensues 
by  which  a  silicate  of  these  metals  is  formed. 

Si02  +  Na2C03  =  Na2Si02  +  CO2. 

Sodium  Silicate. 

The  silicates  of  sodium  and  potassium  are  known 
as  ID ater  glass.  They  are  soluble  in  water,  but  the 
silicates  of  the  other  metals  are  in  general,  insolu- 
ble. Porcelain  and  glass  are  artificial  mixtures  of 
silicates.  Porcelain  (artificial)  teeth,  consist  of 
aluminum  silicate  and  the  double  silicate  of  alum- 
inum and  potassium.  Window  glass  is  a  silicate 
of  calcium  and  sodium.     Bohemian  glass. is  a  sili- 


Silicon.  99 

cate  of  calcium  and  potassium.  Crystal  or  flint 
glass,  is  a  silicate  of  potassium  and  lead. 

Silicon  unites  with  hydrogen  to  form  a  colorless 
gas,  SiH^,  analogous  to  CH^.  It  unites  with 
chlorine,  bromine,  and  iodine,  SiCl^,  SiBr4,  81X4, 
corresponding  to  carbon  chloride,  bromide,  and  io- 
dide It  also  forms  a  chloroform,  SiHClg,  similar 
in  some  respects  to  ordinary  chloroform,  CHCI3. 
Indeed,  although  silicon  and  carbon  are  appar- 
ently widely  separated  in  nature,  being  the  char- 
acteristic elements  of  the  mineral  and  organic 
kingdoms  respectively,  they  are  very  near  akin 
in  their  chemical  naturCi. 

If  a  strong  solution  of  sodium  or  potassium  sili- 
cate be  acted  on  by  hydrochloric  acid,  a  jelly-like 
substance  will  separate  out.  This  substance  is 
known  as  or^Ao-silicic  acid,  H^SiO^.  By  losing  a 
molecule  of  water  it  becomes  meta-sWicic  acid, 
1128103.  If  the  mixture  of  hydrochloric  acid  and 
water  glass  be  sufficiently  dilute,  no  separation  of 
the  silicic  acid  will  take  place.  A  separation,  how- 
ever, can  be  beautifully  and  instructively  accom- 
plished by  dialysis.  The  dializcr,  consisting  of  a 
taut  membrane  of  bladder  or  skin  parchment, 
placed  in  the  solution,  whereby  the  sodium  or  po- 
tassium chloride  will  diffuse  through  the  membrane, 
leaving  a  clear,  tasteless  solution   of  silicic  acid. 


100  Inorganic  Chemistry. 

which  in  time  solidifies  to  a  jellj.  Crystallizable 
bodies  like  salt,  sugar,  etc.,  diffuse  readily  through 
the  dializer,  while  non-crystallizable  bodies,  like 
jellies,  glue,  albumen,  etc.,  do  not  pass  at  all. 
These  two  classes  are  termed  respectively  crystal- 
loids and  colloids. 


PAR.T    SECOND. 


INORGANIC  CHEMISTRY. 


CHAPTER  I. 

CHEMICAL  PHILOSOPHY— i^e'SMw^d. 

Now  that  we  are  acquainted  with  some  of  the 
chemical  and  physical  properties  belonging  to  a 
few  of  the  elementary  forms  of  matter,  we  will  be 
better  enabled  to  understand  more  clearly  the  fol- 
lowing additional  facts  in  chemical  philosophy. 

The  atomic  theory  of  Dalton,  which  assumes 
that  matter  is  made  up  of  ultimate  particles,  called 
atoms,  clearly  explains  the  known  laws  of  chemical 
reactions.  As  atoms  are  individually  indivisible, 
whole  atoms,  or  multiples  of  them,  must  be  in- 
volved in  chemical  union.  A  chemical  compound 
is  definite  in  its  nature,  i.  e.,  each  of  its  molecules, 
of  which  the  mass  is  composed,  must  contain  the 
same  kind  and  number  of  atoms,  similarly  ar- 
ranged. 

We  do  not  know  the  real  weight  of  atoms,  but 
as  hydrogen  is  the  lightest  body,  and  therefore 
taken  as  unity,  the  comparative  weights  of  the 
atoms  of  the  several  elements  can  be  ascertained. 

(101) 


102  Inorganic  Chemistry. 

The  real  weights  of  the  atoms  of  the  several  ele- 
ments are  fixed  and  unchangeable  for  each;  it  fol- 
lows that  molecules,  each  containing  the  same 
kind  and  number  of  atoms,  producing  a  given 
compound,  must  be  alike  in  weight.  Equal 
weights  of  water,  under  equal  conditions,  will  con- 
tain  the  same   number  of  molecules;    hence    the 

116 

molecular  formula,  H2O,  not  only  truly  represents 
the  relative  quantities  of  H  and  0,  but  also  the 
comparative  weight  of  a  given  quantity  of  water. 
The  molecular  weight  is  the  sum  of  the  atomic 
weights.     The  molecular  weight  of  water  is  there- 

32  16 

fore  18;  that  of  SO3  is  80;  these  two  substances 
combine  with  each  other  in  the  above  proportions 
to  form  a  molecule  of  H2SO4,  whose  weight  is  the 
sum  of  18  +  80  r=  98. 

Aside  from  the  known  relative  weights,  or  mul- 
tiples of  them,  in  which  the  elements  unite  with 
or  displace  each  other,  there  are  other  relations 
between  the  accepted  atomic  weights,  and  certain 
physical  phenomena,  which  prove  the  correctness 
of  the  former. 

The  remarkable  relation  between  the  atomic 
weights  of  the  elements,  and  their  capacity  for 
heat,  called  specific  heat,  or  atomic  heat,  is  ex- 
pressed by  the  statement  that  the  products  of  the 
specific  heats  of  the  elements  into  their  atomic  weights, 


Chemical  Philosophy.  103 

give  a  nearly  constant  quantity,  the  mean  value  being 
6.4.  The  slight  variations  noticed  are  no  doubt 
due  to  unavoidable  errors  in  experiment.  In  other 
words,  all  atoms  have  equal  capacities  for  heat;  the 
same  amount  of  heat  that  will  raise  1  part  by 
weight  of  hydrogen  one  degree,  will  raise  7  parts 
by  weight  of  lithium,  16  of  oxygen,  23  of  sodium, 
56  of  iron,  108  of  silver,  197  of  gold,  etc.,  one 
deo^ree. 

In  many  cases,  the  molecules  of  compounds 
which  crystallize  in  like  form,  called  isomorphous, 
are  supposed  to  contain  an  equal  number  of  atoms  ; 
thus,  certain  sulphates  are  isomorphous  with  cor- 
responding selenates ;  sesquioxide  of  iron,  Fe203, 
is  isomorphous  with  sesquioxide  of  aluminum, 
AI2O3  ;  and  in  case  of  doubt  as  to  the  correct 
atomic  weight  of  an  element,  as  for  instance  of 
aluminum,  this  relation  is  appealed  to. 

All  molecules,  according  to  the  law  of  Ampere, 
have  the  same  size;  that  is,  all  molecules,  when  in 
the  gaseous  state,  under  equal  conditions  of  heat 
and  pressure,  occupy  the  same  volume,  or  same 
amount  of  space.  The  composition  of  gaseous 
elementary  molecules  can  therefore  be  expressed 
in  volumes,  as  well  as  in  atoms.  The  molecule  of 
hydrogen  is  assumed  to  contain  2  volumes,  or  2 
atoms,  of  hydrogen,  IIII ;  the  molecular  weight  of 


104  Inorganic  Cheynistry. 

hydrogen  is  therefore  2,  twice  that  of  a  single  atom 
of  hydrogen  ;  and  as  this  element  is  taken  as 
unity,  its  density  is  one-half  its  molecular  weio-ht 
or  its  molecular  volume  is  equal  to  2  atoynic  vol- 
umes. Those  elementary  gases  or  vapors  whose 
molecules  are  supposed  to  contain  2  volumes,  or  2 
atoms,  have  a  density,  referred  to  hydroo-en  as 
unity,  equal  to  one-half  their  molecular  weights, 
or  identical  with  their  atomic  weights. 

DENSITY.  DENSITY. 

Hydrogen 1        Sulphur 32 

Oxygen  16        Bromine  80 

Chlorine 35.5     Iodine 127 

Since  the  molecular  weight  represents  the 
weight  of  two  volumes,  as  II— H,  0=iO,  and 
density  represents  the  weight  of  one  volume,  the 
density  of  any  homogeneous  vapor,  either  element- 
ary or  compound,  is  one-half  its  molecular  weight. 

Ordinary  oxygen,  whose  molecular  formula  is 
0=0,  has  a  molecular  weight  of  16  -f  16  =r  32 ; 

its  density  is  one-half  of  32,  or  16.     Ozone     /^\ 

'  O 0 

has  a  molecular  weight  of  48;  its  density  is  24. 

Carbon  dioxide,  whose  formula  is  CO2,  has  a 
molecular  weight  of  12  -f  32,  or  41;  its  density  is 
44  -f-  2,  or  22.  Conversely  by  knowing  the  dens- 
ity, the  molecular  weight  can  be  obtained  by  mul- 
tiplying by  2. 


Chemical  Philosophy.  105 

It  is  also  noticed  that  the  gaseous  product  of  the 
union  of  two  elementary  gases,  when  combining  in 
equal  volumes,  retains  tlie  original  volume  of  its 
constituents;  as  1  vol  of  H  and  1  vol.  of  CI  form 
2  vols,  of  HCl.  When  3  or  more  vols,  of  combin- 
ing gases,  elementary  or  compound,  enter  into 
combination,  condensation  takes  place  to  2  vol- 
umes, as 

2  vols,  of  H  and  1  vol.  of  0  form  2  vols.  H2O ; 

1  vol.  of  ethyl  CH5  and  1  vol.  of  CI  form  2  vols. 
CH5CI; 

2  vols,  of  ethyl  (CH5)2  and  1  vol.  of  0  form  2 
vols.  (CIl5)20. 

Hence  the  law  of  Avogadro:  The  molecules  of  all 
gases,  simple  or  compound,  occupy  equal  volumes ;  or 
equal  volumes  of  all  gases  contain  equal  numbers  of 
molecules.  The  molecular  formula  of  compound 
gases  (or  vapors),  and  the  atomic  weights  of  the 
elements  contained  in  them,  can,  by  noting  the 
vapor  density,  be  determined  by  this  law. 

Equivalency. — Certain  elements  unite  with  each 
other  in  only  one  proportion  ;  they  form,  with  each 
other,  but  one  compound.  Their  atoms  have  only 
one  point  of  attraction  ;  their  atomicity  or  valency 
IS  one.  These  elements  are  called  monogenic  or 
monads,  signifying  one.  The  other  elements  are 
called  polygenic.     The   atoms   of  the   monad   ele- 


106  Inorganic  Chemistry. 

merits  are  equivalent  to  each  other;  the  atoms  of 
the  polygenic  elements  are  equal  in  combining,  or 
substituting  power,  to  two  or  more  atoms  of  the 
monads.  One  atom  or  volume  of  H,  and  one  atom 
or  volume  of  CI  unite;  they  form  but  one  com- 
pound, HCl ;  they  are  both  monads.  One  atom  of 
Na  will  displace  H  and  take  up  with  the  CI : 
HCl    +   Na  =r  NaCl   +  H. 

The  valency  of  ^N'a  is,  therefore,  the  same  as  H 
and  CI ;  it  is  monogenic.  The  atom  of  0,  how- 
ever, is  equal  in  combining  power  to  two  atoms  of 
H,  Na,  or  any  other  monad;  oxygen,  therefore,  is 
a  dyad  element.  One  atom  of  0  and  two  atoms  of 
H  unite  (H2O).  One  atom  of  Na  will  drive  out 
one  atom  of  the  hydrogen  and  take  its  place;  the 
one  atom  of  oxygen  being  able  to  attract  and  hold 
together  the  two  unlike  atoms  in  a  homogeneous 
molecule : 

H2O  +  Na  =:  H^aO   4-  H. 

One  atom  of  Zn  (65  parts  by  weight)  requires 
two  molecules  (73  parts  by  weight)  of  HCl  to  sat- 
isfy its  combining  power: 

Zn  -f  2HC1  =  ZnCl2   +  2H. 

Zinc,  accordingly,  is  a  dyad.    When  zinc  is  oxid- 
ized, the    molecule    produced    contains   one  atom 
each  of  dyad  zinc  and  dyad  oxygen: 
Zn  +  0  =  ZnO. 


I 


Chemical  Philosophy.  107 

This  difference  in  the  number  of  points  of  at- 
traction or  saturating  power  belonging  to  each 
atom  of  the  various  elements  is  often  denoted  by 
placing  Roman  numerals,  or  dashes  above  or  to  the 
right  of  the  symbols,  as — 

Univalent  elements,  or  monads,  as H' 

Bivalent  elements,  or  dyads,  as..  ,0" 

Trivalent  elements,  or  triads,  as Au'" 

Quadrivalent  elements,  or  tetrads,  as...C'^ 
Quinquivalent  elements,  or  pentads,  as..P^ 

Sexvalent  elements,  or  hexads,  as Cv"^ 

Elements  of  even  equivalency,  namely,  the  dyads, 
tetrads,  and  hexads,  are  classed  under  the  general 
term  artiads^  signifying  even;  and  those  of  uneven 
equivalency,  the  monads,  triads,  and  pentads,  are 
called  perissadsy  which  means  uneven. 


108  Inorganic  Chemist?^, 


CHAPTER  11. 

GRAPHIC    FORMULA. 
Formulae  are  sometimes  written  graphically,  that 
is,  a  number  of  lines  or  bonds,  connecting  the  sym- 
bols, indicating  the  equivalency  of  each;  thus: 

Hydrochloric  acid,  HCl H CI 

Water,  H2O H— 0— H 

Carbon  dioxide,  CO2 0— C— 0 

CI 

Am.  Chloride,  NH.Cl "^^iIt-^"^ 

'  H^    \H 

0 

Nitric  Acid,  HNO3 N 0— H 

II 
0 

0  0 

Zinc  Nitrate,  Zn(N03)2 N— 0— Zn— 0— N 

A  II 

0  0 

These  graphic  formulae  are  often  abridged  by  the 
use  of  dots  only,  tlius  : 

H.Cl     H.O.H     0..C..0 

By  observing  the  above  diagrams,  it  will  be  no- 
ticed that  the  units  of  attraction  belonging  to  each 
atom  are  satisfied  by  union  with  those  of  other 


Chemical  Philosophy.  109 

atoms.  And,  accordingly,  it  is  found  that  in  all 
saturated  molecules,  the  sum  of  the  perissad  atoms  is 
always  even.  A  molecule  may  contain  2,  4,  or  6, 
etc.,  monad  atoms,  as  in  PICl,  H2O,  CH^,  C2Hg, 
etc.;  or  1  triad  atom,  as  Au'",  and  3  monads,  as  in 
AuClg ;  or  1  pentad  and  5  monads,  as  in  l^H^Cl; 
but  never  an  uneven  number  of  perissad  atoms. 
This  is  the  law  of  even  numbers. 

For  the  same  reason  the  molecules  of  the  peris- 
sad elements  consist  of  an  even  number  of  atoms. 
The  molecule  of  hydrogen  contains  two  atoms 
H — 11.  So  also  the  molecule 'of  chlorine  CI — CI; 
the  molecule  of  phosphorus  contains  four  atoms, 

P^P  As=As 

II      II       So  also  the  molecule  of  arsenic,       11        11 
r=P.  As=As 

The  molecules  of  dyad  elements,  however,  may 
contain  either  an  even  or  an  uneven  number  of 
atoms,  as  will  be  observed  on  again  submitting  the 
following  : 

.A, 

Ordinary  oxygen.  Ozone. 

The  true  equivalency  of  an  element  may  be  ex- 
pressed as  that  which  represents  the  maxim,um  number 
of  monads  atoms,  with  which  one  atom  of  it  can  com- 
bine. The  molecule,  ammonium  chloride,  NH4CI, 
shows   one   atom  of  IST   saturated   by  five   monad 


110  Inorganic  Chemistry. 

atoms;  no  other  atom  or  atoms  can  unite  with  the 
above  group.  Accordingly  nitrogen  is  a  pentad, 
i,  e.,  its  atom  is  equal  to  five  monad  atoms.  One 
atom  of  dyad  oxygen  can  take  up  with  no  more 
than  two  atoms  of  monad  hydrogen  H2O''. 

When  variation  in  the  valency  of  any  element 
occurs,  it  always  takes  place  by  2  units.  So  that 
an  element  may  appear  as  a  monad  in  one  com- 
pound, a  triad  in  another,  and  a  pentad  in  still  an- 
other; or  an  element  may  act  as  a  dyad  in  one  case, 
or  a  tetrad  in  another,  and  a  hexad  in  another.  For 
instance,  nitrogen  appears  to  be  a  monad  in  nitrous 
oxide  ^2^?  ^  triad  in  ammonia  NH3,  and  a  pentad 
in  ammonium  chloride  NH^Cl;  sulphur  is  a  dyad 
in  dihydrogen  sulphide  HgS,  a  tetrad  in  sulphurous 
oxide  SO2,  and  a  hexad  in   sulphuric  oxide   SO3. 

In  compounds  where  the  full  valency  of  the  ele- 
ment is  not  exhibited,  as  in  NH3,  ammonia,  the 
two  units  belonging  to  I^  uncombined,  probably 
unite  with  each  other,  for  the  time  being;  but  the 
molecule  of  ammonia  is  willing  to  unite  directly 
with  HCl,  forming  NH4CI,  wherein  the  full  va- 
lency of  K"  is  satisfied.  Tetrad  sulphur  in  SOg  can 
be  oxidized  into  SO3,  becoming  thereby  a  hexad. 

A  perissad  element  is  alwa3^s  a  perissad;  an 
artiad  element,  always  an  artiad,  inasmuch  as  vari- 


Chemical  Philosophy,  111 

ation  in  valency  of  either  class,  when  it  does  occur, 
is  always  by  2  units. 

The  statement  that  the  true  valency  of  an  ele- 
ment is  determined  by  the  composition  of  its  hy- 
drides, chlorides,  etc.,  rather  than  by  its  oxides, 
etc.,  will  be  appreciated  if  we  consider  the  part 
dyad  atoms  play  in  combination.  For  example, 
dyad  0"  can  enter  the  saturated  molecule  of  water 

II — 0 II  without  disturbing  the  existing  atomic 

value  of  hydrogen,  thus  H — 0 — 0 — H,  because  any 
dyad  atom  (or  radical),  introduces  one  unit  of 
equivalency  into  the  compound  which  it  enters, 
and  neutralizes  another,  leaving  the  valencies  the 
same  as  before.  Potassium  is  a  monad,  because 
one  atom  of  it  unites  with  only  one  atom  of  chlo- 
rine, K — CI,  and  in  no  other  proportion ;  but  in  ad- 
dition to  its  corresponding  oxide,  K — 0 — K,  there 
is  a  tetroxide  of  potassium  K — 0 — 0 — 0 — 0 — K, 
wherein  the  valency  of  the  K'  is  seen  to  be  the 
same  as  in  its  normal  oxide.  Any  other  dyad  atom 
(or  radical)  can  act  in  the  same  way. 

When  two  or  more  atoms  of  a  polygenic  element 
are  present  in  the  same  molecule,  the  element  in 
question  may  seem  to  possess  less  than  its  normal 
valency.  Carbon  is  a  tetrad  inasmuch  as  four 
atoms  of  hydrogen  or  other  monad, are  as  many  as 
one  atom  of  carbon  can  saturate,  (CH^);  there  are, 


112  Inorganic  Chemistry. 

however,  a  great  many  other  compounds  of  C  and 
H  alone,  whose  molecules  contain  more  than  one 
atom  of  carbon,  and  where  the  C  appears  to  pos- 
sess an  atomicity  of  less  than  four.  This  is  owing 
to  the  units  of  valency,  belonging  to  the  carbon 
atoms,  not  saturated  by  the  hydrogen  (or  in  other 
cases  by  atoms  of  other  elements),  uniting  with, 
and  so  satisfying  each  other.  One  or  two  examples 
will  suffice : 

In  methane,  CH^,  carbon  is  a  tetrad  ;  in  ethane, 
CgHg,  carbon  appears  to  be  triad;  in  ethene, 
C2H4,  it  appears  to  be  a  dyad,  and  in  ethine, 
C2H2,  a  monad.  The  following  diagrams  will 
readily  explain  the  apparent  discrepancy: 
H  H 

I  I 

H— C— H        H— C— H         H— C— H         C— H 

I  I  II  III 

H  H— C— H        H— C— H         C— H 


k 


Methane,  Ethane,  Ethene,  Ethine. 

The  same  faculty,  ot  mutual  combination  of 
otherwise  free  units,  is  possessed  by  the  atoms  of 
other  polygenic  elements,  but  not  in  as  high  a  de- 
gree as  with  those  of  carbon. 

Radicals. — Radicals  may  be  defined  as  residues, 
obtained  by  removal  of  one  atom  or  more  from  a 
saturated   molecule.      There   are   elementary   and 


Chemical  Philosophy.  ■  113 

also  compound  radicals.  A  perissad  atom,  as  an 
atom  of  hydrogen,  H,  is  an  elementary  radical,  and 
probably  never  exists  free ;  such  atoms,  when  set 
free  from  combination,  unite  either  with  each  other 
or  with  atoms  of  another  kind  to  form  again  satu- 
rated molecules.  A  mass  of  hydrogen,  for  instance, 
does  not  consist  of  an  aggregation  of  uncombined 
atoms,  H,  H,  H,  H,  H,  but  of  a  great  number  of 
molecules,  each  containing  two  atoms,  chemically 
united,  H — H.  Suppose  a  molecule  of  hydrogen, 
H — H,  be  acted  on  by  a  molecule  of  chlorine, 
CI — CI,  the  reaction  would  be  as  follows  : 
H— H  +  CI— CI  =  2HC1 

The  two  atoms  (radicals)  of  the  hydrogen  mole- 
cule, and  the  two  atoms  (radicals)  of  the  chlorine 
molecule,  would  become  separated  by  the  influence 
of  the  superior  chemical  attraction  between  the 
unlike  atoms  (radicals),  and  recombination  take 
place,  resulting  in  the  production  of  two  mole- 
cules of  hydrogen  chloride,  as  seen  in  the  equation. 

Again  suppose,  these  latter  two  molecules,  2HC1, 
be  brought  under  the  influence  of  a  molecule  of 
sodium  (l!^a — Na),  another  change  would  occur, 
2IIC1  -f  Na— Na  =  2XaCl  -f  H— II.  The  2C1  rad- 
icals would  leave  the  hydrogen  and  take  up  with 
the  2  Na  atoms  (radicals),  forming  2  molecules  of 

sodium    chloride,  letting    the  211  atoms  go  free, 
10 


11-4  Organic  Chemistry. 

which,  in  the  absence  of  more  attractive  radicals 
of  some  other  kind  of  matter,  would  be  satisfied 
to  unite  with  each  other,  and  give  birth  again  to 
a  molecule  of  hydrogen. 

Compound  radicals  are  unsatisfied  groups  of  two 
or  more  unlike  atoms,  and  have  a  valency  corre- 
sponding to  the  number  of  equivalent  units  removed 
from  a  saturated  molecule.  H — 0 — H  (water), 
is  a  saturated  molecule;  if  one  of  the  hydrogen 
atoms  be  removed,  the  resulting  group,  — 0 — H 
(hydroxyl),  will  evidently  have  the  same  combin- 
ing power  as  the  divorced  atom  of  hydrogen  (H — ). 
Hydroxyl  is,  therefore,  a  univalent  (monad)  com- 
pound radical,  having  one  free  bond.  It  exists  in 
all  the  hydrates  and  in  many  other  compounds. 

Sodium  thrown  on  water  removes  an  equivalent 
quantity  of  hydrogen,  and  takes  its  place,  in  union 
with  the  resulting  hydroxyl : 
[N-a— N"a  +  2H-0— H  =  H— H  +  2]^a— 0— H 

Sodium  Hydrate. 

The  names  of  compound  radicals  of  uneven 
valency  (monads,  triads,  etc.)  end  in  yl;  they  do 
not  exist  free,  but  the  instant  of  their  development, 
if  unaffected  by  radicals  of  another  kind,  they 
tend,  like  perissad  atoms,  to  combine  among  them- 
selves. Free  hydroxyl  is  not  known,  but  a  com- 
pound whose  molecules  are  made  up  of  2  hydroxyl 
groups,  H — 0 — 0 — H,  is  a  well  known  substance. 


Chemical  Philosophy.  115 

Compouuds  in  general  are  often  formulated  so  as 
to  show  their  molecular  constitution  by  radicals. 
Thus,  nitric  acid,  HNO3,  may  be  considered  as  con- 

O 

II 
sisting  of  the  2  radicals,  H— 0—  and  IST  =  HO.NO2. 

II 
O 

Water  is  analogous  in  formula  to  sodium   hydrate, 

H.OH  Xa.OII.    The  graphic  formula  of  phosphoric 

Water.      Sodium  hydrate. 

0— H 

acid  is  0  =  P— 0— H 

^0-H,  etc. 

An  understanding  of  the  part  played  by  radicals 
in  the  carbon  compounds  included  in  organic 
chemistry,  is  most  important,  and  their  relations 
may  be  somewhat  studied  in  this  connection  to 
advantage. 

The  atom  of  carbon  has  four  points  of  attraction ; 
it  can  not,  therefore,  take  up  more  than  four  atoms 
of  hydrogen,  or  other  monad  radical.  Methane, 
C'^'H^,  is  the  typical  saturated  hydro-carbon.  If 
one  of  the  four  atoms  of  hydrogen  be  removed, 
the  residue  will,  of  course,  be  O^'H'g,  named  methyl^ 
which  has  the  same  valency  as  the  atom  of  hydro- 
gen, or  one  unit,  capable  of  uniting  with  one  atom 
of  chlorine,  for  instance,  to  form  methyl  chloride, 
CH'3C1.     Two  atoms  of  hydrogen  removed  from 


116  Inorganic  Chemistry. 

methane,  CH^,  leaves  the  dyad  radical  methene, 
CW ^^  able  to  take  up  two  atoms  of  chlorine  to 
form  methene  chloride,  CH''2^^2-  I'h^ee  atoms  of 
hydrogen  removed  from  methane,  results  in  the 
trivalent  radical  methenyl,  CH'^',  which  in  union 
with  three  atoms  of  chlorine,  produces  methenyl 
chloride,  CHCI3  (chloroform),  and  if  all  four  of  the 
hydrogen  atoms  in  methane  be  driven  out,  the  tet- 
rad carbon  atom  remains  to  be  saturated  by  four 
atoms  of  chlorine,  CCI4,  or  other  monad  element, 
or  by  two  dyad  radicals,  or  by  one  triad  and  one 

monad  radical,  — C — . 

I 

Allusion  has  been  made  to  the  non-interference 

of  dyad   atoms,  or   radicals,  with   the   equivalent 

values  of  the  atoms  or  radicals,  in  those  saturated 

molecules  which  they  may  enter. 

H 

I 
The  dyad  compound  radical,  methene,  — C — 


J, 


like  an  atom  of  oxygen  — O — ,  can  evidently  join 
itself  to  an  already  satisfied  molecule,  because  it 
is  able  to  neutralize  one  unit  of  valency  in  the 
compound  it  enters,  and  introduce  another,  as  may 
be  understood  by  the  following  diagram  : 


Chemical  Philosophy.  ^        117 

H 

H  H-C— H 

CH4  or  H-C— H  -f  H— C— H=  H— C— H  or  Q^B.^ 

I  I  I 

H  H 

Methane.  Methene.  Ethane. 

Ethane,  CgHg,  is  methane  CH4,  plus  the  dyad 
radical  CHg.  If  we  presume  to  abstract  one  atom 
of  hydrogen  from  ethane,  we  will  have  the  univa- 
lent radical  ethyl  Q^W ^,  capable  of  joining  itself 
to  an  atom  of  chlorine,  as  in  ethyl  chloride 
C2H'5^C1,  or  to  hydroxyl,  as  in  alcohol,  C2H'5'OH, 
or  two  such  groups,  to  — 0 — ,  as  in  common  ether 
(CH,),0. 

Hydrogen  is  not  the  only  element  involved  in 
removal  from  saturated  molecules,  to  form  radicals. 
Indeed  it  is  only  necessary  to  assume  a  number  of 
units  of  valency  abstracted  from  any  saturated 
molecule,  in  order  to  obtain  a  radical  of  corre- 
sponding combining  power;  and  it  is  evident,  from 
their  mode  of  derivation,  that  the  number  of  com- 
pound radicals  which  are  capable  of  existence  is 
without  limit.  A  great  many  of  them  are  known 
to  individually  enter  into  the  formation  of  special 
classes  of  compounds,  like  the  salts  of  the  same 
metal,  enabling  us  to  comprehend  clearly  the  rela- 
tions that  exist  between  vast  numbers  of  organic 
compounds,  which  otherwise  would  be  impossible. 


118  Inorganic  Chemistry. 


CHAPTER  III. 

MATERIA  MEDICA. 

Materia  Medica  is  that  part  of  therapeutics  which 
includes  the  study  of  the  origin,  physical  and  chemi- 
cal nature,  therapeutic  and  toxic  effects,  local  and 
general,  of  materials  employed  for  the  cure,  allevia- 
tion, or  prevention  of  disease. 

Although  it  is  not  often  incumbent  on  the  den- 
tist  to  prescribe  medicines  for  internal  administra- 
tion, it  is  proper  that  he  should  know  the  general 
effects,  dosage,  incompatihles  and  antidotes,  when 
so  exhibited,  of  those  drugs  he  uses  in  his  practice 
as  local  agents,  inasmuch  as  a  large  majority  of 
them  are  active  poisons. 

By  knowing  these  facts  he  can  make  judicious 
selection  and  combination  of  materials  for  any  pre- 
scription that,  in  his  judgment,  will  best  suit  the 
case  in  hand.  He  would  not,  for  instance,  order 
a  combination  of  any  soluble  chloride  with  silver 
nitrate,  or  any  vegetable  astringent,  with  persalts 
of  iron;  or  use,  even  topically,  excessive  quantities 
of  arsenic,  or  tincture  of  aconite  root,  etc. 

The  art  of  writing  decent  prescriptions  is  a  seri- 
ous labor  to  the  average  student.    If  we  could  pre- 


Materia  31edica.  119 

vail  upon  him  to  discard  in  toto  the  signs  and 
symbols  of  the  old  system  of  weights  and  measures 
and  adopt  the  metric  system  exclusively,  he  would 
find  the  task  much  easier;  and  if,  as  occasionally 
happens,  he  be  deficient  in  a  knowledge  of  the 
Latin  language,  he  should  take  courage,  and  realize 
tliat  very  few  Latin  phrases,  or  abbreviations,  are 
needed  in  prescribing,  as  the  following  sufficient 
presentment  of  them  will  prove : 

A;  aa.  Ana;  of  each. 

Ad.  add.,  Addendus  ;  to  be  added. 

Ad  lib..  Ad  libitum  ;  at  pleasure. 

Alb.,  Albus ;  white. 

Aq.,  Aqua;  water. 

Aq.  dest..  Aqua  destillata;  distilled  water. 

Chart.,  Charta;  paper. 

Dil.,  Dilutus;  diluted. 

F.,  Ft.,  Fiat;  let  a  —  be  made. 

Fl.,  Fluidus;  liquid. 

Fol.,  Folium;  a  leaf.  Folia;  leaves. 

Gr.,  Granum;  a  grain.  Grana;  grains. 

Gtt.,  Gutta;  a  drop :  Guttse ;  drops. 

Ilyd.,  Hydro ;  water. 

Ilydr.,  Hydrargyrum;  mercury. 

Inf.,  Infnsum  ;   infusion. 

M.,  Misce ;  mix. 

Mist.,  Mistura;  a  mixture. 


120  Inorganic  Chemistry. 

No.,  Numero  ;  in  number. 

01.,  Oleum ;  oil. 

P.,  Pulvis;  powder. 

Ph.,  Pharmacopoeia. 

Pil.,  Pilula;  a  pill ;    pilulse,  pills.' 

Q.  S.,  Quantum  Sufficiat ;  as  much  as  is  sufficient. 

15^.,  Recipe;  take. 

Rad.,  Radix ;  root. 

Rect.,  Rectificatus ;  rectified. 

S.,  or  Sig.,  Signa ;  write. 

Ss.,  Semis;  half. 

Solv.,  Solve ;  dissolved. 

Spr.,  Spiritus;  spirit. 

Tr.,  or  Tinct.,  Tinctura;  tincture. 

U.  S.  P.,  United  States  Pharmacopoeia. 

In  writing  a  prescription  containing  a  number 
of  substances,  it  is  proper  to  place  the  most  impor- 
tant article  in  the  combination,  first,  as  the  basis; 
the  adjuvans  or  assistant  to  the  base,  next;  the  cor- 
rective^ if  the  two  first  have  certain  objectionable 
properties,  as  taste  or  smell,  comes  next;  and 
finally  the  vehicle,  to  give  form  and  elegance  to  the 
whole.    The  following  will  serve  as  an  example : 

R.     Acidi  salicylici.  Basi^. 

Sodii  bi boras,  aa  1.00  Gm.  (gr.  xv),  Assistant. 

Spts.  rect.,  4.00  CC.  (f^i),  Corrective. 

Aq.  rosse  q.  s.  ad  125.00  CC  (f^iv),  Vehicle, 

M.  S.     Use  as  a  general  mouth  wash. 


Materia  Medica.  121 


Apothecaries'  weights  and  measures. 

Pound.  Ounces.  Drachms.  Grains. 

Lb.  1         =        12        =        96  5760 

§i        =  8     =       480 

3i     =         60 

Fluid  measure. 


Pint 
(Octarius). 

F,  Ounces. 

F,  Drachms. 

Minims, 

01 

=        16 

= 

128 

= 

7680 

ill 

= 

8 

= 

480 

f3l 

:;:z: 

n  60 

Metric  System. 

The  meter  is  the  basis  of  the  metric  system,  and 
is  the  standard  unit  of  linear  measurement  of  that 
system. 

The  meter  is  the  10  millionth  part  of  the  distance 
from  the  equator  to  the  pole  (the  earth's  quadrant) ; 
it  is  about  10  per  cent  longer  than  the  yard. 

The  unit  of  fluid  measure  is  the  liter — the  cube 
of  y^^  meter  (one  decimeter),  or  1,000  cubic  centi- 
meters; it  is  equal  to  about  32  fluid  ounces. 

The  cubic  centimeter  (C.C.)  is  equal  to  about  15 
minims.* 

*  Exactly  16.231  minims.  Approximative  comparison  is  suf- 
ficient for  our  purpose. 

11 


122  Inorganic  Chemistry. 

The  Gram  is  the  metric  unit  of  weighty  and  repre- 
sents the  weight  of  1  cubic  centimeter  of  water  at 
its  maximum  density  (4°  C— 39°  F).  The  gram  is 
equal  to  about  15  grains.  Fractions  over  15  grains 
and  15  minims,  with  reference  to  the  gram,  and  to 
the  cubic  centimeter,  may  be  ignored. 

We  accordingly  have : 

1  Gram  equal  to  15  grains. 

4  Grams  equal  to  1  drachm. 

1  Drachm  equal  to  4  Grams. 

1  Cubic  centimeter  equal  to  15  minims. 

4  Cubic  centimeters  equal  to  1  fluidrachm. 

1  Fluidrachm  equal  to  4  cubic  centimeters.* 

The  term  flaigram  has  been  suggested  as  more 
euphonious  than  cubic  centimeter,  but  has  not  been 
generally  accepted.  Inasmuch,  however,  as  the 
gram  expresses  the  weight  of  1  cubic  centimeter 
of  water,  the  term  fluigram  is  not  inappropriate, 
and  will  be  used  by  us  hereafter  instead  of  cubic 
centimeter  :  fluigram  abbreviated  f.  Gm,  and  Cubic 
centimeter  CC,  mean,  therefore,  the  same  measure 
of  any  liquid. 

Gram  should  be  written  with  a  capital  "  G,"  ab- 
breviated Gm ;  and  in  order  to  avoid  mistaking 
this  sign  for  gr,  which  latter  is  always  written 
with  a  small  "  g,"  it  is  proper  to  place  the  Arabic 

*  Slightly  changed  from  Oldberg. 


Materia  Medica.  123 

numerals  before  the  sign  ;  thus,  10.00  Gm  (ten 
Grams).  Apothecaries'  weights  and  measures  (old 
system)  have  their  signs  followed  by  Roman  nu- 
merals, thus,  gr  X  (ten  grains). 

in  writing  prescriptions  according  to  the  metric 
system,  the  only  signs  needed  are  the  Gm  and 
fGm;  and  fractions  of  them  are  stated  decimally, 
in  the  same  way  we  write  our  divisions  of  federal 
money,  thus: 

10.00  Gm  (ten  grams),  analogous  to  $10.00 
(ten  dollars) ;  0.05  Gm  (five  centigrams),  analogous 
to  $0.05  (five  cents). 

If  we  regard  the  Gm  or  fGm,  as  corresponding 
in  this  respect  to  our  dollar,  wq  can  appreciate  the 
relation  most  easily  by  the  following  comparison : 

Gm  $ 

1 .00— One  Gram .  1 .00— One  dollar. 

.50 — Fifty  centigrams.  .50— Fifty  cents. 

.02— Two  "  .02— Two       " 

.001— One  milligram.  .001— One  mill. 

In  speaking  of  the  divisions  of  the  gram,  the 
same  terms  may  be  employed  that  are  used  in 
speaking  of  money  matters.  For  instance,  0.10  Gm 
=  one  dime;  or  0.10  fGm  =  one  fiuidime.  The 
fluidime  may  be  considered  the  minimum  quantity 
for  liquids,  equal  to  IJ  minims,  and   the  mill,  the 


124  Inorganic  Chemistry. 

smallest  representative  of  weight,  equal  to  g^^  of  a 
grain.  -^ 

The  prefixes  used  in  the  metric  system  are 
sometimes  convenient  in  speaking  of  weights  and 
measures,  but  in  prescribing  the}^  need  not  be 
written,  the  Arabic  numerals  being  sufficiently  ex- 
plicit. As,  for  instance,  with  reference  to  any  unit 
in  the  metric  system. 

Myria  means 10.000 

Kilo  ''     1.000 

Hecto       "     100 

Deka        "     10 

Deci         "     0.1 

Centi        "     0.01 

Milli         "     0.001 

The  following  approximate  equivalents  are 
mainly  taken  from  Oldberg,  and  are  sufficiently 
accurate  to  answer  all  purposes  of  mere  com- 
parison : 

Troy  Grains  (or  Minims),  Grams  (or  Fluigrams). 

^5 0.001  (1  mill) 

i 0.03    (3  cents) 

1 0.06    (6  cents) 

U 0.10    (10  cents) 

10 0.65    (65  cents) 

15 1.00    (1  Gram),  (or  fGm) 

30 2.00    (2  Grams),  (or  fGm) 

60(1  Drachm)  (Fl  drachm)) .  .4.00  (4  Grams),   (or  fGm) 


Materia  Medica.  125 

Troy  Ounces  (or  Fluid  Ounces).  Grams  (or  Fluigrams). 

1 30.00  (30  Gm  or  fGm) 

4 120.00  (120  Gm  or  fGm) 

With  the  foregoing  preliminaries  in  materia 
medica,  more  or  less  mastered,  our  hope  is  now  to 
study  carefully  the  medicinal  properties,  in  con- 
nection with  the  chemical  history  of  the  various 
metallic  salts,  and  organic  compounds,  that  may  be 
deemed  worthy  of  notice. 

We  shall  endeavor  to  systematize  the  study,  by 
tirst  presenting  their  physiological  and  therapeutic 
effects,  if  any,  when  applied  locally ;  then,  when 
taken  internally,  their  influence  on  the  brain  and 
nervous  system  generally;  on  the  circulation, 
respiration,  temperature,  and  on  the  secretions ; 
naming  the  principal  diseased  conditions  in  which 
they  are  indicated;  and,  finally,  their  antidotes 
and  dosage,  with  an  occasional  prescription. 


126  Inorganic  Chemistry. 


CHAPTER  IV. 

METALLIC  ELEMENTS. 

All  those  elements,  studied  in  Part  First,  with 
the  exception  of  hydrogen,  are  classed  as  non- 
metallic;  those  elements  yet  to  be  considered,  with 
the  exception  of  arsenic,  are  classed  as  metallic. 
Arsenic  seems  to  be  the  connecting  link  between 
the  two  classes. 

A  few  of  the  metals,  as  gold  and  platinum,  are 
found  in  nature,  in  the  metallic  state ;  the  large 
majority,  however,  are  found  united  with  non- 
metallic  elements,  forming  oxides,  chlorides,  car- 
bonates, etc.,  wherein  the  metallic  i)roperties  are 
masked,  and  which  constitute  the  ores  from  which 
the  metals  involved,  are  obtained. 

Some  of  these  elements,  as  gold,  iron,  copper, 
etc.,  are  most  useful  when  in  the  metallic  state  ; 
and  others,  as  potassium,  calcium,  barium,  etc., 
are  most  important  when  in  combination  with  non- 
metallic  elements. 

When  metals  unite  with  non-metals,  true  chem- 
ical compounds  are  formed.  When  metals  unite 
among  themselves  (except  with  arsenic,  and  those 
closely    allied   to   it),   the   combination    does    not 


Metallic  Elements.  127 

produce  a  true  chemical  compound,  but  an  alloy^ 
wherein  the  metallic  nature  is  preserved.  Many 
alloys  are  extremely  useful,  and  exhibit  desirable 
properties  not  possessed  by  their  individual  con- 
stituents ;  gold  is  too  soft  for  ordinary  use,  but  if 
alloyed  with  copper,  or  silver,  or  platinum,  etc., 
becomes  qualified  for  certain  practical  purposes. 
Copper  is  too  soft  and  tough  to  work  in  a  lathe, 
but  if  fused  with  one-half  its  weight  of  zinc,  it 
forms  the  hard,  tenacious  alloy,  known  as  brass. 
Copper  and  tin  in  different  relative  proportions 
give  us  the  useful  alloys,  bronze,  bell  metal,  specu- 
ulum  metal,  etc.  German  silver  consists  of  100 
parts  copper,  40  of  nickel,  and  16  of  zinc.  Type 
metal  is  an  alloy  of  antimony  and  lead.  Alloys 
of  mercury  with  other  metals  are  named  am.algams. 

The  melting  point  of  an  alloy  is  generally  lower 
than  the  mean  melting  [)oint  of  its  constituents. 
For  instance,  tin  melts  at  235°  (455  F.) ;  bismuth, 
melts  at  2(34°  (507  F.) ;  lead  melts  at  320°  (608  F.). 

An  alloy  of  1  part  of*  tin,  2  of  lead,  and  2  of  bis- 
muth will  melt  as  low  as  93°  C  (200  F.).  Such  an 
alloy  is  useful  in  attaching  teeth,  by  dovetail,  to 
old  celluloid  and  rubber  plates,  and  maybe  packed 
in  with  a  warm  burnisher. 

The  metals  differ  greatly  in  specific  gravity,  rang- 
ing from  potassium,  sodium  and  lithium,  which  are 


128  Inorganic  Chemistry. 

lighter  than  water,  to  platinum,  iridium  and  os- 
mium, which  are  more  than  21  times  heavier  than 
water. 

They  differ  also  in  tenacity^  or  the  power  of  re- 
sisting tension.  The  order  of  tenacity  among  those 
metals  susce[)tible  of  being  easily  drawn  into  wire 
is  determined  by  observing  the  weights  required  to 
break  wires  of  the  same  size,  and  is  as  follows : 
Iron,  copper,  platinum,  silver,  gold,  zinc,  tin,  and 
lead. 

Malleability,  or  power  of  extension  under  the 
hammer,  or  between  the  rollers  of  a  flatting  mill, 
is  possessed  in  a  high  degree  by  gold,  silver,  cop- 
per, tin,  platinum,  lead,  and  iron. 

The  fusing  points  of  metals  vary  greatly,  ranging 
from  mercury,  which  melts  at  —  39°,  to  platinum, 
which  requires  the  heat  of  the  oxy-hydrogen  flame. 
A  certain  uniformity  of  color  is  presented  by  the 
metals,  except  copper,  which  is  red,  and  gold,  which 
is  yellow ;  all  the  other  metals  (leaving  out  the 
faintly  pinkish  tint  of  bismuth,  and  the  yellowish 
tinge  of  calcium  and  strontium),  are  included  be- 
tween the  white  of  silver  and  the  blui,sh  gray  of 
lead. 

The  several  metals  are  classified  into  groups,  ac- 
cording to  certain  chemical  and  physical  proper- 
ties possessed  by  them ;  those  of  the  same  group 


Metallic  Elements.  129 

generally,  also,  possess  the  same  valency.  Brief 
allusion  to  some  of  the  characteristics  of  two  or 
three  groups  will  suffice.     For  example: 

The  metals  of  the  alkalies.,  viz.,  K,  IS'a,  Hb,  Cs, 
and  Li,  are  soft,  easily  melted,  volatile  at  a  higher 
temperature,  will  decompose  hot  or  cold  water 
through  their  love  for  oxygen.  Their  oxides  are 
strongly  basic,  and  are  very  soluble  in  water,  form- 
ing exceedingly  caustic  and  alkaline  hydroxides 
Their  carbonates  are  soluble  in  water,  and  being 
monads^  they  each  form  only  one  chloride  (K  CI). 

The  metals  of  the  alkaline  earths^  Ca,  Ba,  and  Sr, 
form  oxides  less  soluble  in  water  than  those  of  the 
preceding  group,  but  exhibiting,  though  in  less  de- 
gree, similar  basic,  caustic  and  alkaline  propor- 
ties.  Their  carbonates  are  insoluble  in  water;  they 
each  form  but  one  chloride,  which,  as  they  are 
dyads,  is  a  dichloride  (CaClg). 

The  metals  of  the  earths,  erbium,  yttrium,  didy- 
mium,  etc.,  form  oxides  that  are  not  soluble  in  water. 
The  metals  of  this  group  occur  only  in  a  few  rare 
minerals. 

All  metals  form  binary  compounds  with  chlo- 
rine. The  monochlorides  and  dichlorides  of  the 
metals,  excei)ting  silver  chloride  (AgCl),  and  mer- 
curous  chloride  (Hg2Cl2),  are  soluble  in  water. 
Metallic  chlorides  unite  with  certain  oxides,  form- 


130  Inorganic  Chemistry. 

ing  oxyehloridfs,  and  with  organic  bases,  also,  such 
as  aniline  and  the  ptomaines. 

]!^early  all  metals  unite  with  Br  and  I.  Most 
metallic  bromides  and  iodides  are  soluble  in  water; 
they  closely  resemble,  in  many  instances,  the  cor- 
responding chlorides. 

Oxygen  unites  with  all  the  metals,  with  many  of 
them  in  several  proportions.  Some  metallic  oxides, 
as  K2O  and  CaO,  do  not  decompose  by  heat  alone; 
others,  as  AU2O3,  Ag2  0,  Pt02  and  HgO,  lose  their 
oxygen  by  a  low  red  heat.  Most  of  them  suffer  re- 
duction by  hydrogen,  aided  by  a  more  or  less  high 
temperature,  while  carbon,  at  a  red  or  white  heat, 
completely  reduces  all  to  the  metallic  state. 


Potassium.  131 


CHAPTER  Y. 

POTASSIUM. 

Symbol,  At.  Wt.  Sp.  Gr.         Yal.ency, 

K.  (Approx.)        0.87.50.  I. 

39. 

L^TASSIUM  occurs  abundantly  in  nature,  always 
however  in  combination.  It  is  an  essential  constit- 
uent of  animal  and  laud  vegetable  bodies,  and  is 
found  largely  in  many  minerals.  The  ashes  of 
land  plants,  are  especially  rich  in  potassium,  hence 
its  name. 

Potassium  was  discovered  by  Davy  in  1807  by 
electrolysis ;  it  is  now  obtained  by  heating  the  car- 
bonate with  charcoal,  e,  g. 

KCO3   -f-  2C  =  3C0  +  2K 

The  metal,  being  volatile,  distills  over,  is  passed 
through  naphtha,  and  condensed  to  proper  form. 
It  melts  at  62.5°  (14'4.5F) ;  it  is  soft  at  common  tem- 
peratures, and  can  be  easily  cut  with  a  knife,  pre- 
senting  a  brilliant  white  surface,  which  soon 
tarnishes,  owing  to  the  strong  liking  it  has  for 
oxygen.  For  this  reason,  it  soon  loses  its  identity 
when  exposed  to  the  air,  and  must  be  preserved  in 
some  liquid,  destitute  of  oxygen,  such  as  naphtha. 


132  Inorganic  Chemistry. 

Thrown  on  water,  it  floats;  at  the  same  time  caus- 
ing equivalent  decomposition  of  that  liquid. 
H-O-II  -f  K  =  K-0— H  +  H 

So  great  is  the  chemical  energy  of  this  reaction, 
that  the  hydrogen  as  it  escapes  from  the  water,  is 
set  on  fire. 

Potassium  forms  several  oxides  ;  the  normal  oxide, 
K2O,  being  obtained  by  direct  oxidation,  or  by  ac- 
tion of  potassium  on  the  hydrate. 

Potassium  Hydrate  (hydroxide)  KOH,  commonly 
called  caustic  potash,  is  generally  prepared  by  ac- 
tion of  calcium  hydrate  fmilk  of  lime)  on  potassium 
carbonate. 

Ca(H0)2   +  K2CO3  =  CaCOg   +  2K0H 

Calcium  Potassium  Calcium  Potassium 

Hydrate.  Carbonate.  Carbonate.  Hydrate. 

Potassium  hydrate  is  a  white,  soluble,  deliques- 
cent solid  ;  strongly  alkaline,  caustic  and  poison- 
ous. 

Potassium  carbonate,  K2CO3,  is  the  familiar  sub- 
stance, potash.  It  is  prepared  from  wood  ashes, 
and  by  various  other  chemical  processes ;  when  re- 
fined it  is  known  as  pearlash  ;  it  has  a  strong  alka- 
line reaction,  is  soluble  in  water,  but  insoluble  in 
alcohol ;  is  used  in  preparing  other  potassium  com- 
pounds, and  for  the  making  of  glass  and  soft  soap. 
By  treatment  with  carbonic  acid  it  produces  the 
"  bicarbonate." 


Potassium..  133 

K.COs   +   H2CO3  =  2KHCO3 

Carbonic  Potassium 

Acid.  Bicarbonate. 

The  bicarbonate  is  also  called  the  hydrogen  car- 
bonate, and  acid  carbonate,  although  it  is  mildly 
alkaline. 

Potassium  chloride,  KCl,  obtained  principally  from 
sea  water,  is  a  colorless  solid,  soluble  in  water,  and 

is  found  in  the  juices  of  animal  bodies. 

Potassium  Iodide,  KI,  is  prepared  by  the  action 
of  iodine  on  potassium  hydrate.  It  occurs  in  color- 
less cubical  crystals,  of  sp.  gr.  3,  soluble  in  water 
and  alcohol. 

Potassium  Bromide,  KBr,  is  similar  in  appearance 
to  the  iodide,  and  is  obtained  by  an  analogous 
process. 

Potassium  Chlorate,  KCIO3,  is  prepared  by  passing 
chlorine  through  a  solution  of  the  carbonate;    or 
through  a  solution  of  the  chloride,  containing  milk 
of  lime. 
KCl-H3Ca(OH)2+6Cl=3CaCl2H-3H20+KC103 

It  is  a  colorless  crystalline  anhydrous  solid,  solu- 
ble in  20  pju'ts  of  cold  water.  When  heated  it 
gives  up  all  of  its  oxygen,  and  when  mixed  with 
combustible  matter,  like  sulphur,  tannin,  etc.,  it 
becomes  explosive.  With  phosphorus  it  is  largely 
employed  in  the  making  of  instantanoous-Jight 
matches. 


134  Inorganic  Chemistry. 

Potassium  nitrate^  KlJ^Og,  commonly  known  as 
saltpeter  and  niter,  occurs  naturally  in  the  soil, 
from  oxidation  of  ammonia  in  the  presence  of  po- 
tassium compounds. 

Potassium  nitrate  crystallizes  in  anhydrous  six- 
sided  prisms,  soluble  in  7  parts  of  water. 

It  is  prepared  in  large  quantity  by  reaction  be- 
tween Chili  saltpeter  and  crude  potassium  chloride. 

Na:^03  +  KCl  =  NaCl  +  KNO3 
When  heated  in  the  presence  of  combustibles,  it 
gives  up  its  oxygen  ;  hence  it  is  used  in  the  manu- 
facture of  gunpowder  and  in  nearly  all  pyrotech- 
nic compositions,  which  accordingly  burn  inde- 
pendently of  atmospheric  oxygen.  Average  gun- 
powder is  a  mechanical  mixture  of  niter,  charcoal 
and  sulphur,  in  the  following  proportions: 


KN03 

75 

0 

15 

s 

10 

100 

The  force  of  the  explosion  of  gunpowuer  is  due 
to  sudden  formation  of  gases  and  their  immediate 
expansion  by  the  heat.  All  of  the  powder  is  at 
once  vaporized,  and  although  the  chemical  reaction 
is  really  complicated,  it  may  be  ap [proximately 
represented  by  the  following  equation  : 

2KKO3   +  3C  +  S  =  K^S  +  3002-  +  21S" 


Potassium.  135 

Potassium  Permanganate,  K2Mn20g,  is  prepared 
from  mixed  aqueous  solutions  of  potassium  chlo- 
rate and  manganese  dioxide,  by  evaporating  to 
dryness,  and  gently  heating.  It  occurs  in  dark 
purple  crystals,  of  a  pleasant,  astringent  taste ;  dis- 
solves easily  in  water,  conferring  a  deep  lilac  color, 
which  may  be  decolorized  by  Fowler's  solution. 

It  is  a  powerful  oxidizing  agent,  used  in  chem- 
ical analysis,  and  for  destroying  putrid  matter. 

Potassium  forms  a  great  many  other  compounds, 
such  as  the  perchlorate,  bromate,  iodate,  sulphide 
and  sulphate,  phosphates,  borates,  silicates,  etc., 
their  consideration,  however,  in  this  connection  is 
unnecessary. 

Materia  Medica. — Some  of  the  potassium  salts 
produce  active  local  eifects.  The  hydroxide  is 
one  of  the  most  penetrating  caustics,  owing  to  its 
removal  of  water  from  the  tissues,  and  saponify- 
ing the  fats. 

The  disadvantage  of  its  penetrating  qualities,  is 
somewhat  overcome  by  combination  with  lime ;  its 
use  as  a  free  caustic  has  been  practically  aban- 
doned. 

The  permanganate,  on  account  of  its  giving  up 
active  oxygen  to  organic  matter,  is  an  excellent 
disinfectant  in  fetid  odors  and  as  a  gargle  in  gan- 


136  Inorganic  Chemistry. 

grenous  conditions  of  the  mouth  and  throat. 
Dose,  0.06  Gm.  (gr.j). 

The  nitrate  and  chlorate  are  employed  in  solution, 
or  powder,  on  inflammatory  mucous  membrane  of 
the  mouth  and  throat.  The  latter  drug  especially 
is  effective  in  mercurial  stomatitis. 

When  taken  internally  the  potassium  salts,  as  a 
rule,  weaken  the  normal  functions  of  the  brain, 
including  the  co-ordination  of  motion,  reduce  the 
reflex  sensibility  of  the  spinal  cord  and  nervous 
system  generally.  They  also  cause  a  lowering 
of  the  heart's  action,  of  respiratory  movement 
and  of  temperature.  The  secretion  of  saliva  is 
lessened, and  of  the  gastric  juice  increased.  It  may 
be  well  to  mention  here  that  alkalies,  in  moderate 
doses,  decrease  the  secreting  power  of  those  glands 
which  normally  secrete  an  alkaline  fluid,  like  the 
parotid  glands,  and  increase  the  power  of  glands 
which  secrete  an  acid,  like  those  of  the  stomach. 
Acids  have  precisely  the  opposite  eflect. 

Most  of  the  salts  of  potassium  are  diuretic  and 
slightly  purgative. 

The  chlorate,  in  doses  of  0.50  Gm.  (gr.viii)  is  indi- 
cated in  mercurial  salivation,  aphtha,  and  ordinary 
tonsillar  inflammation,  suggesting  at  the  same  time 
a  local  exhibition  of  a  strong  solution  as  a  wa&h  or 
gargle,  or  in  the  form  of  trochisci. 


Potassium.  137 

The  Bromide  is  reputable  as  an  antispasmodic 
and  nervine  sedative,  and  is  given  in  epilepsy,  de- 
lirium tremens,  convulsive  seizures  of  children  due 
to  dentition,  laryngismus  stridulus,  acute  mania 
and  loss  of  sleep. 

The  Iodide,  unlike  the  chlorate,  increases  the  se- 
cretion of  saliva,  sometimes  to  the  point  known  as 
iodism. 

Doses:     Pot.  chlorate,  0.65  Gm.  (gr.x). 

Pot.  nitrate,  0.65  Gra. 

Pot.  bromide,  ]  a  r.?-     onn  r>        r  \ 

Pot.  iodide.      I  0-6O-200  Gm.  (gr.x-xxx). 

R.     Potassii  chloratis,  8  Gm.  (^ii). 
Aqua,  250.00  fGm.  (f^viij). 

M.  S.     A  gargle  in  stomatitis. 


12 


138  Inorganic  Chemistry, 


CHAPTER  VI. 

SODIUM. 

Symbol,         At.  Wt.  Sp.  Gr.         Valency, 

:N'a.  23.  0.97.  I. 

Sodium  was  discovered  by  Davy  in  1807  by  elec- 
trolytic decomposition  of  soda.  It  is  a  very  abun- 
dant element,  existing  in  enormous  quantities  as  a 
chloride;  in  sea  water,  as  rock  salt,  in  salt  lakes 
and  mineral  springs,  in  marine  plants,  and  as  a 
necessary  constituent  of  animal  juices. 

Large  deposits  of  the  nitrate.  Chili  saltpeter,  car- 
bonate, and  borate,  occur  in  nature,  also  sodium 
and  aluminum  fluoride,  and  sodium  silicates. 

Sodium  is  a  white  soft  metal;  it  melts  at  95.5° 
(204  F).  It  decomposes  water,  but  not  with  as 
much  energy  as  does  potassium;  if  the  water,  how- 
ever, be  warmed,  or  thickened  with  starch,  the  es- 
caping hydrogen  will  ignite.  The  reaction  corre- 
sponds to  that  of  potassium. 

Sodium  chloride,  I^aCl,  common  salt,  is  obtained 
by  mining  rock  salt,  and  by  evaporating  salt  water. 
It  is  a  transparent,  colorless,  crystalline,  anhydrous 


Sodium.  139 

solid  of  sp.  gr.  2.15,  of  an  agreeable  taste,  slightly 
deliquescent,  and  dissolves  in  3  parts  of  water. 

There  are  two  oxides  of  sodium,  !N'a2  0,  and 
Na^O.^,  of  no  practical  importance. 

Sodium  hydrate,  or  hydroxide,  NaOH,  caustic 
soda,  is  formed  and  held  in  solution  when  sodium  is 
thrown  into  water;  it  is,  however,  practically  pre- 
pared from  the  carbonate,  in  the  same  way  that 
caustic  potash  is  obtained.  It  is  strongly-  alkaline, 
but  not  so  active  a  caustic  as  the  potassium  salt. 
Its  use  in  commerce  is  for  refining  fats  and  oils, 
and  in  making  hard  soaps. 

Sodium  Carbonate,  ^2^,^00^,  is  manufactured 
by  several  processes,  but  is  mainly  obtained  from 
the  chloride,  by  the  "  Leblanc  process,"  the  de- 
scription of  which  is  unnecessary.  It  crystallizes 
with  10  molecules  of  water,  Na2CO3,10H2O,  and  is 
the  "sal  soda"  of  the  laundries.  When  devoid 
of  water,  or  dry  carbonate,  it  is  used  in  very  larg^e 
quantities  in  the  making  of  glass  and  soap. 

Sodium  carbonate  is  strongly  alkaline,  owing  to 
the  strong  base  and  the  weak  acid,  in  its  compo- 
sition. If  it  be  subjected  to  the  direct  action  of 
carbonic  acid,  the  '''  bicarbonate,'^  N'a  HCO3,  a  mild 
alkali  will  be  produced.  This  is  the  cooking  soda 
of    the   kitchen,  is   an  ingredient   of    all   baking 


140  Inorganic  Chemistry. 

powders,  and  of  many  effervescent  drinks,  and  is 
also  used  in  medicine. 

Sodium  Borate  Na20,2B203,  IOH2O  borax,  occurs 
native,  in  colorless  crystals,  slightly  effervescent, 
and  mildly  alkaline ;  soluble  in  water  and  glycer- 
ine, bat  not  in  alcohol.  It  is  used  in  the  arts  as  a 
flux  in  melting,  soldering,  and  welding  certain 
metals.  When  heated,  it  swells  up,  losing  its 
water  of  crystallization,  and  then  subsides  as  a 
vitreous  mass  (borax  glass),  which  is  removed  from 
the  surface  of  the  soldered  metal,  by  dilute  sul- 
phuric acid.  A  solution  of  borax  (or  solutions  of 
sodium  carbonate,  or  of  alum)  will  render  dried 
plaster  casts  comparatively  hard. 

Other  compounds  of  sodium  are  numerous,  and 
some  of  them  important;  they  resemble  for  the 
most  part,  the  corresponding  compounds  of  potas- 
sium. 

Materia  Medica.  Sodium  Chloride  is  a  flesh 
preserver,  and  may  be  considered  a  good  prototype 
of  antiseptics  in  general. . 

Laharraques  Solution,  liquor  sodse  chloratse,  solu- 
tion of  chlorinated  soda,  [N'aCl,  NaClO,  analogous 
to  common  bleaching  powder.  Locally,  it  acts  as 
a  disinfectant,  destroying  maladorous  and  infectious 
matter,  by  reason  of  the  free  chlorine  and  free  oxy- 
gen it  evolves,  in  the  presence  of  acids  (carbonic 


Sodium.  141 

acid  of  the  air) ;  for  the  same  chemical  reason  it  is 
a  good  bleacliing  agent,  if  combined  with  powdered 
ahim. 

The  bicarbonate  is  used  locally  as  an  antacid,  and 
when  mixed  with  water,  as  an  application  to  burns 
and  scalds. 

Borax  is  a  mild  antacid,  antiseptic,  refrigerent, 
and  detergent.  It  is  a  useful  ingredient  of  mouth 
washes,  or  gargles,  in  inflammation  of  mouth  or 
throat,  combined  with  sweetening  correctives,  as 
honey,  glycerine,  etc. 

When  internally  administered  the  sodium  salts 
have  not  the  depressing  influence  on  the  system 
possessed  by  those  of  potassium. 

Dose.     Sodii  Bicarbonas,  )  i  aa  /^       /-  n 

bodn  rJiboras,         j  \fe         ^ 

B.     Sodii  Boras,  4.00  Gm.  (^i). 
Mellis. 
Aqua  aa,  30.00  fGm.  (f^i). 

M.  S.     Use  as  a  detergent. 

The  other  metals  of  the  alkalies,  viz.,  lithium, 
rubidium,  and  caesium,  are  also  monads,  and  are 
comparatively  rare.  They  are  highly  oxidizable  ; 
ciesium  being  the  most  highly  electro-positive  of 
all  elements;  they  decompose  water,  setting  hy- 
drogen free,  and  form  alkaline  caustic   hydroxides. 

Ammonium,  ^H^,  is   a   hypothetical,  univalent, 


142  Inorgnnic  Chemistry, 

electro-positive,  compound  radical.  Although  it 
has  not  been  isolated,  it  acts  like  metals  in  the 
formation  of  various  salts,  being  developed  in  re- 
actions between  ammonia,  NHg,  and  other  bodies 
containing  hydrogen.  Thus,  ammonia  and  nitric 
acid,  HNO3,  unite  with  each  other,  without  setting 
any  hydrogen  free ;  the  hydrogen  of  the  acid, 
probably  joins  itself  most  intimately  to  thelTHg,  to 
form  the  radical  KH4,  which  then,  like  an  atom  of 
potassium,  unites  with  the  electro-negative  radical, 

NO3.  ■ 

NH3     +     HNO3     =    FH^.NOj 

Ammonia.  Nitric  Acid.  Ammonium 

Nitrate. 

Ammonium  salts  are  numerous,  and  resemble  in 
many  respects  the  corresponding  salts  of  the  alkali 
metals.  The  hydroxide,  NH^  OH,  is  an  alkaline 
caustic,  which,  when  dilute,  gives  up  free  ammonia, 
and  is  employed  by  inhalation  as  a  stimulant  in 
ordinary  syncope,  and  in  excessive  anaesthetic 
narcosis. 

The  Chloride,  J^H^Cl,  the  ''sal  ammoniac"  of 
commerce,  is  used  as  a  flux  in  refining  gold ;  and 
as  a  local  stimulant  to  indolent  ulcers.  The  car- 
bonate, which  has  a  rather  complicated  formula,  is 
known  as  "  sal  volatile,"  and  is  the  principal  sub- 
stance in  "  smelling  salts." 


Inorganic  Chemistry.  143 


CHAPTER  VII. 

CALCIUM,  ETC. 

Symbol,         At.  Wt.  Sp.  Gr.         Valency, 

Ca.  40.  1.50.  II. 

Calcium  is  not  found  free  in  nature,  but  exists 
abundantly  in  combination.  As  carbonate  it  occurs 
in  limestone,  marble,  chalk,  coral,  marl,  oyster 
shells,  Iceland  spar,  the  stalactites  and  stalagmites 
of  certain  caves,  and  in  bones  and  teeth;  as  a 
fluoride,  sulphate,  phosphate,  and  in  many  silicates. 

The  metal  itself  is  brilliant,  slightly  yellow,  some- 
what hard,  very  malleable  and  ductile,  oxidizes 
slowly  in  the  air,  decomposes  water,  and  when 
heated  burns  with  an  extremely  bright  light.  It 
may  be  obtained  by  heating  the  iodide  with  sodium, 
but  singly  it  is  of  no  practical  use. 

Calcium  forms  but  one  chloride,  CaCl2,  which 
occurs  as  a  waste  product  in  many  processes. 

Calcium  oxide,  CaO,  lime,  is  always  prepared 
on  a  large  scale  by  heating  the  carbonate,  as  lime- 
stone, in  a  lime  kiln.  The  carbonate  being  com- 
posed of  calcium  oxide  and  carbon  dioxide,  the 
latter  is  driven  off  by  the  heat,  as  will  be  easily  un- 
derstood by  the  equation. 


144  Inorganic  Chemistry. 

CaO,  CO2  +  Heat  =  CaO  +  CO2 

Calcium  Calcium 

Carbonate  Oxide 

(Lime) 

Lime  is  a  hard,  infusible,  white  solid.  When 
slaked  with  water,  which  union  develops  great  heat. 
Calcium  hydroxide,  Ca(H0)2,  is  formed  a  white, 
bulky  powder,  which,  in  an  excess  of  water  dis- 
solves, resulting  in  a  clear  alkaline  liquid,  known 
as  lime  water.  Lime  water  readily  absorbs  CO^ 
from  the  air,  as  does  also  milk  of  lime  (whitewash), 
and  the  lime  of  mortars  and  cements.  It  is  to  this 
fact  that  the  hardening  of  cements,  made  largely 
from  lime  is  due;  the  absorption  of  the  CO^, 
forming  a  quasi  limestone,  a  true  carbonate. 
When  sand  is  present,  calcium  silicate  is  also 
formed. 

Calcium  Carbonate  exists  in  so  many  forms  in 
nature,  as  already  noticed,  that  its  description 
seems  superfluous.  It  is  soluble  in  water  contain- 
ing carbonic  acid,  as  nearly  all  natural  waters  do, 
therefore  such  waters,  in  limestone  regions,  are 
hard.  They  may  be  rendered  soft  by  boiling, 
which  drives  off  the  carbonic  acid;  or  by  an  al- 
kali, like  ammonia,  which  takes  up  the  acid, 
whereby  the  lime  salts  are  precipitated. 

It  is  probably  owing  to  similar  reactions  that 
occasion  the  deposition  of  tartar  on  the  teeth. 

The   fluids   of   the    parotid,   and    submaxillary 


Calcium,  etc.  145 

glands,  holding  lime  salts  in  solution,  by  aid  of 
the  carbonic  acid  present,  upon  their  egress  into 
the  moutli,  meet  with  free  alkalies,  the  results  of 
putrefaction  change,  which  take  up  the  carbonic 
acid;  the  removal  of  the  acid,  thus,  deprives  the 
saliva  (water)  of  its  ability  to  hold  the  lime  salts  in 
solution,  and  they  are  precipitated. 

Calcium  sulphate  occnrs  in  nature  as  alabaster  and 
selenite  and  en  masse  as  gypsum,  CaS04,  2H2O. 
When  heated  sufficiently,  gypsum  loses  its  water 
of  crystallization,  and  becomes  plaster  of  Paris; 
this  plaster  readily  takes  up  water  again,  and 
''sets"  to  a  hard  solid.  It  is  used  in  taking  im- 
pressions, and  in  forming  models  of  the  parts  to 
be  supplied  with  artificial  dentures;  and  also  for 
making  molds  and  casts  of  various  kinds. 

Calcium  Phosphate,  Cag  (P04)2,  bone  phosphate,  is 
found  in  natural  deposits  in  certain  portions  of 
South  Carolina,  Florida,  and  the  islands  of  the 
Carribean  sea,  sup{)Osed  to  be  the  remains  of  vast 
numbers  of  marine  animals  that  were  gradually 
imprisoned  in  the  now  extinct  salt  water  lagoons, 
by  land  appearing  between  them  and  the  ocean.  It 
is  the  principal  constituent  of  bones  and  teeth;  it 
is  found  also  in  the  other  tissues,  and  in  calculi. 
Prepared  as  precipitated  calcium  phosphate,  it  is  a 
white,  tasteless  and  odorless  powder,  insoluble  in 
13 


146  Inorganic  Chemistry. 

water  and  alcohol,  but  freely  soluble  in  even  weak 
acids. 

Calcium  Fluoride^  CaF2,  iluor  spar,  constitutes 
about  two  per  cent,  of  human  bone  and  enamel. 

Chlorinated  Lime,  CaCl2  0,  bleaching  powder, 
sometimes  improperly  called,  chloride  of  lime,  is 
formed  by  action  of  chlorine  on  slaked  lime;  oc- 
curs as  a  gray  white  powder,  or  in  lumps  slightly 
moist,  emitting  a  faint  chlorine  odor,  soluble  in 
water,  and  decomposed  by  the  carbonic  acid  of  the 
air  (likewise  by  other  dilute  acids)  into  free  chlo- 
rine, and  other  bodies.  By  the  influence  of  the 
nascent  chlorine  on  the  hydrogen  present  in  the 
moisture,  active  oxygen  results.  The  preparation, 
therefore,  is  an  excellent  disinfectant  and  bleaching 
agent. 

Oxygen  is  set  free  en  masse,  by  acting  on  a  so- 
lution of  the  powder  with  a  solution  of  nitrate  of 
cobalt. 

For  bleaching  teeth,  the  dry  powder  may  be  in- 
corporated with  tartaric  acid,  introduced  into  the 
cavity  slightly  moistened,  and  covered  with  gutta 
percha. 

Materia  Medica.  Some  of  the  lime  prepara- 
tions used  locally  are  sedative  and  soothing,  as 
linimentum  calcis  (lime  water  and  linseed  oil),  ap- 
plied to  burns. 


Caiciumy  Etc.  l47 

Prepared  chalk  is  probably  the  basis  of  all  tooth 
powders;  it  acts  as  an  antacid  and  astringent. 
When  taken  internally,  lime  and  chalk  act  in  the 
same  way. 

The  phosphate  has  been  recommended,  although 
its  efficacy  is  doubtful,  as  a  food  supply,  whenever 
the  structural  pabulum  in  growing  bones  of  infancy 
and  chilehood  is  deficient. 

Doses.     Liquor  Calcis,  8.00  f  Gm.  (fsij). 

Creta  Prseparata,  1.00  Gm.  (gr.xv). 

Calcii  Phosphas.  Prsecipitata,  1.50  Gm.  (gr.  xx). 

B.     Calcii  phos.  prsecipit,  4.00  Gm.  (51). 
Mistura  Cretse,  125.00  fGm.  (fgiv). 

M.  S.    Give  a  teaspoonful  to  child  at  meals. 

The  two  other  elements  of  the  calcium  group, 
strontium  and  barium,  are  comparatively  rare  and 
unimportant,  strontium  nitrate  Sr(N03)^  is  used 
in  making  "red  fire,"  barium  nitrate  Ba(N03)2 
in  making  "green  fire."  Barium  salts  are  used  as 
a  test  for  suli)huric  acid,  and  vice  versa.  Barium 
sulphate  is  known  as  "  heavy  spar,"  and  when 
ground  is  used  as  a  pigment. 

There  are  two  oxides  of  barium,  and  these  are 
easily  changed,  the  one  into  the  other.  BaO  heated 
in  air,  is  converted  into  Ba02.  This  dioxide  readily 
gives  up  0,  as  in  the  manufacture  of  hydrogen  di- 
oxide, already  alluded  to. 


148  Inorganic  Chemistry. 


CHAPTER  YIII. 

METALS  OF  THE  EARTHS,  AND  SILVER. 

The  metals  of  the  earths — yttrium,  erbium, 
samarium  cerium,  etc. — are  quite  numerous,  but 
are  found  only  in  a  few  rare  minerals,  principally 
as  silicates.  They,  and  nearly  all  their  com- 
pounds, are  mere  chemical  curiosities,  except 
cerium  oxalate,  Ce^  (^2^4)3'  which  is  used  in 
medicine. 

SILVER. 

Symbol,         At.  Wt.         Sp.  Gr.         Valency, 
Ag.  108.  10.5.  i-in. 

Silver  has  been  known  from  the  earliest  times. 
It  is  found  in  various  countries,  in  the  metallic 
state,  but  principally  in  combination,  as  chloride, 
iodide-,  bromide,  sulphide  and  telluride.  The  vari- 
ous elaborate  methods  employed  for  extracting  sil- 
ver from  its  ores  are  interesting  from  a  commercial 
chemical  point  of  view,  but  need  not  be  considered 
here. 

It  is  a  brilliant  white  metal,  malleable,  and  duc- 
tile, and  is  the  best  conductor  of  heat  and  electric- 


Metals  of  the  Earths ,  and  Silver.  149 

ity.  It  melts  at  about  1000°  (1850  F),  does  not  tar- 
nish in  pure  iiir,  although  traces  of  11.^ S  affect  it, 
as  it  sulphidizes  easily;  it  is  also  readily  acted  on 
by  CI  and  P;  hydrochloric  and  sulphuric  acids  at- 
tack it  with  difficulty,  but  nitric  acid,  even  quite 
dilute,  rapidly  dissolves  it. 

Ag.     +    HXO3    =    Ag^O,     +    H. 

Silver  Nitrate  AgNOg,  lunar  caustic,  is  obtained 
according  to  the  above  equation;  by  evaporating 
the  solution,  it  appears  in  the  form  of  colorless, 
transparent,  anhydrous  crystals,  soluble  in  water 
and  alcohol.  When  melted  and  cast  into  proper 
shape,  it  is  known  as  lunar  caustic. 

Silver  nitrate  is  employed  in  photography,  in  the 
making  of  hair  dyes,  inglelible  ink,  etc.,  on  account 
of  its  turning  dark  by  the  influence  of  light,  when 
in  contact  with  organic  matter,  probably  due  to  the 
deposition  of  argentous  oxide. 

Silver  Chloride,  AgCl,  is  precipitated  whenever 
a  soluble  chloride  (common  salt,  etc.),  is  added  to  a 
solution  of  silver  nitrate.  It  is  a  white  curdy  sub- 
stance, insoluble  in  water  and  nitric  acid,  but  dis- 
solves easily  in  a([ue()us  solutions  of  ammonia  and 
potassium  cyanide.  When  heated,  it  fuses,  and  on 
cooling,  assumes  a  horny  consistency,  hence  the 
name  of  the  mineral  horn  silver. 


150  Inorganic  Chemistry. 

Silver  chloride  decomposes  in  the  light,  rapidly, 
when  in  contact  with  organic  matter;  also  when 
heated  with  sodium  carbonate,  or  placed  in  dilute 
sulphuric  acid  with  zinc  or  iron.  In  the  latter  pro- 
cess, the  nascent  hydrogen  removes  the  chlorine, 
leaving  the  silver  in  the  form  of  a  spongy  mass. 

There  is  another  chloride  of  silver  of  uncertain 
constitution;  and  three  oxides.  The  normal  oxide, 
Ag^O,  a  strong  base,  which  yields  salts  isomor- 
phous  with  those  of  the  metals  of  the  alkalies. 

Materia  Medica.  The  nitrate  is  the  only  silver 
compound  that  need  be  noticed  in  this  connection. 
It  is  employed  almost  exclusively  as  a  local  agent, 
and  possesses  decided  caustic  properties,  by  reason 
of  its  coagulating  action  on  albumen ;  by  this 
means,  a  protecting  pellicle  is  soon  formed,  which 
prevents  the  caustic  action  from  extending  deeply. 
It  is  used  to  induce  healthy  granulations  in  ulcers 
and  wounds,  and  when  properly  diluted,  is  one  of 
the  most  efficacious  applications  to  every  variety  of 
inflammation  of  the  mucous  membrane. 

Applied  in  substance  to  sensitive  abraided,  or 
denuded,  or  even  decayed  surfaces  of  teeth,  it  re- 
lieves the  tenderness  and  arrests  the  process  of  de- 
cay. On  account  of  the  permanent  darkening  of 
the  tooth  substance  to  which  it  is  applied,  especial 
discretion  should  be  observed  in  its  use. 


Silver.  151 

Dose.     Silver  Nitrate,  0.01  Gra.  (gr.  -J). 
Antidote,  common  salt. 

B.     Argenti  Nitras,  0.10  Gm.  (gr.  jss). 
Aqua  Dest.,  30.00  fGm.  (f^i). 

M.  S.     Injection  in  diseased  antrum. 


152  Inorganic  Cheynistry. 


CHAPTER   IX. 

COPPER,  MERCURY. 

Symbol,         At.  "Wt.         Sp.  Gr.         Valency, 
Cu.  63.  8.95.  11. 

Copper  is  one  of  the  ancient  metals  and  is  still 
of  great  value  in  the  arts.  It  is  found  in  nature 
both  native  and  in  combination,  as  oxide,  carbon- 
ate, and  sulphide,  and  with  iron  sulphide  as  "  cop- 
per pyrites." 

Copper  has  a  familiar  yellowish-red  color ;  is 
malleable  and  ductile  and  tenacious;  is  one  of  the 
best  conductors  of  electricity  and  heat ;  melts  at 
about  1090  (1994-F),  is  not  acted  on  by  dry  air, 
but  in  moist  air  it  tarnishes  with  a  green  crust, 
consisting  principally  of  the  carbonate.  When 
heated,  scales  of  black  cupric  oxide  form  on  its 
surface.  Chlorine,  sulphur,  and  nitric  acid  attack 
it  readily;  in  the  lalter  case,  setting  free  fumes  ot 
1^^2  02.  It  also  forms  salts  wnth  dilute  acetic  acid 
and  hot  sulphuric  acid,  and  slowly,  with  dilute 
hydrochloric  and  sulphuric  and  carbonic  acids,  al- 
kalies and  saline  solutions.  All  sol  able  salts  of 
copper  are  poisons. 


Copper,  153 

Certain  alloys  of  copper  have  been  mentioned. 
Its  compounds  are  numerous,  but  few  of  them 
need  be  considered  here. 

Copper  forms  two  series  of  salts,  the  eupric  and 
cuprous. 

Cupric  chloride^  CuClj,  obtained  by  dissolving 
eupric  oxide  in  hydrochloric  acid,  and  by  direct  ac- 
tion of  chlorine.  It  makes,  with  water,  a  green  so- 
lution which,  on  evaporation,  deposits  green  crys- 
tals containing  water,  CuClj,  2H2O3.  When 
heated  it  loses  all  its  water  of  crystallization,  and 
half  its  chlorine,  and  is  converted  into  cuprous 
chloride,  CU2CI2,  a  white  fusible  substance,  slightly 
soluble  and  prone  to  oxidation.  Both  chlorides 
form  double  salts,  with  the  chlorides  of  the  alkali 
metals. 

Cupric  oxide,  CuO,  or  black  oxide  of  copper,  may 
be  prepared  by  heating  copper  in  air,  or  by  calcin- 
ing the  nitrate,  carbonate,  or  hydrate.  It  unites 
with  most  acids,  forming  cupric  salts.  With 
[ihosphoric  acid  it  forms  a  hard,  tenacious,  insol- 
uble, black  mass,  which  combination  has  been 
introduced  by  Dr.  W.  B.  Ames,  as  a  tilling  imate- 
rial  in  posterior  teeth,  for  setting  crowns,  etc.  The 
mineral  libethenite  is  IlCu^POr. 

Cuprous  oxide  CU2O,  red  oxide  of  copper,  is  like 


154  Inorganic  Chemistry. 

the  other  cuprous  compounds,  important  only  as 
conferring  a  beautiful  ruby  red  color  to  glass. 

Cupric sulphate,  CuSo4,5H2  0,  blue  vitriol,  prepared 
by  dissolving  cupric  oxide  in  sulphuric  acid,  oc- 
curs in  large  blue  crystals,  and  is  extensively  em- 
ployed in  electro-metallurgy,  telegraph  batteries, 
calico  printing,  the  making  of  Paris  green,  etc. 

Materia  Medica. —  Copper  sulphate  in  substance 
is  an  excellent  application  to  fungous  conditions 
of  the  gums,  as  it  acts  as  an  astringent  and  lessens 
the  local  blood  supply,  and  is  a  mild  caustic. 

Internally  in  large  doses  it  acts  as  an  emetic,  in 
small  doses  as  a  tonic. 

Dose.     (Emetic),  0.20  Gm.  (gr.iij). 
(Tonic),  0.02  Gm.  (gr.  J). 

MERCURY. 

Symbol,         At.  Wt.         Sp.  Gr.         Valency, 
Hg.  200.  13.59.  11. 

Mercury,  quicksilver,  the  argentum  vivum,  of  the 
ancients,  is  found  native,  but  principally  as  a  sul- 
phide, cinnabar,  extensively  mined  in  California, 
Mexico,  and  Peru,  and  portions  of  the  old  world. 
The  sulphide  is  reduced  by  roasting  with  lime,  the 
metal  volatilizes  and  is  condensed  in  suitable 
chambers. 

Mercury   is  a  brilliant  silver- white  liquid.     At 


Mercury.  155 

40°C  (and  F)  it  solidifies  to  a  tin-like  malleable  mass 
of  specific  gravity  14.19.  It  is  slightly  volatile  at 
15°  (60-F)  and  boils  at  357  (666-F)  ;  yields  a  vapor 
of  density  of  100;  the  molecule  of  mercury,  there- 
fore, consists  of  one  atom.  Mercury  is  unaltered 
hy  the  atmosphere,  but  near  its  boiling  point  it 
slowly  absorbs  oxygen,  passing  into  the  red  oxide, 
IlgO.  Chlorine  and  sulphur  unite  directly  with 
mercury.  Boiling  strong  sulphuric,  and  even  di- 
lute nitric  acid  attack  it  easily,  but  it  is  unaffected 
by  hydrochloric  and  cold  dilute  sulphuric  acids. 

Mercury  is  used  in  the  making  of  many  physical 
instruments,  as  thermometers,  barometers,  etc., 
and  in  extracting  gold  and  silver  from  their  ores. 
Its  alloys  are  called  amalgams.  Of  these,  only 
those  used  for  filling  careous  teeth  are  of  special 
interest  to  us.  Copper  amalgam  is  produced  by 
various  processes,  among  the  best,  perhaps,  being 
by  electrolysis  of  copper  sulphate  in  the  presence 
of  mercury.  It  is  a  hard  amalgam  when  properly 
made;  does  not  change  in  bulk  or  shape  in  set- 
ting, and  acts  as  a  germicide  and  antiseptic.  It, 
however,  dissolves  in  weak  acids,  and  the  decidedly 
black  copper  oxide  and  sulphide  which,  together, 
form  on  the  surface,  are  probably  converted  into 
copper  sulphate,  which  we  know  to  be  freely  solu- 
ble.    Both  of  these  facts  combined,  or  either  one 


156  Inorganic  Chemistry. 

singly,  can   explain  satisfactorily  the   wasting  that 
80  often  takes  place  in  copper  amalgam  fillings. 

Mercury  forms  with  many  other  metals,  amal- 
gams of  either  continued  pasty,  or  hard  consist- 
ency, according  to  the  metal  used.  An  amalgam 
of  an  alloy  of  about  50  parts  silver  and  40  parts  tin, 
containing  also  small  additions  of  copper,  gold,  zinc, 
platinum,  palladium,  antimony,  and  cadmium,  sin- 
gly or  otherwise,  seems  to  produce  the  best  results  in 
dental  practice.  The  blackening  of  amalgam  fillings 
is  due  to  the  formation  of  metallic  sulphides,  and 
is  considered  a  not  unmixed  evil ;  the  more  em- 
phatically blacky  the  better  the  preserving  qualities. 

Mercuric  chloride,  HgCl2,  bichloride  of  mercury, 
corrosive  chloride,  corrosive  sublimate,  etc.,  is  usu- 
ally prepared  by  subliming  a  mixture  of  sodium 
chloride  and  mercuric  sulphate. 

2XaCl  +    HgSO^  =  Na^SO^   +   HgCl2 

Sodium  Mercuric  Sodium  Mercuric 

Chloride.  Sulphate.  Sulphate.  Chloride. 

Mercuric  chloride  is  a  semi-transparent  crystal- 
line heavy  solid,  of  an  acid  metallic  taste,  and  acid 
reaction.  It  is  soluble  in  16  parts  of  cold,  and  2 
parts  of  hot  water,  3  of  ether,  and  2  of  alcohol, 
and  is  a  strong  corrosive  poison. 

Mercurous  chloride,  Hg2-Cl2,  proto-chloride  of 
mercury,  mild  chloride  of  mercury,  submuriate, 
calomel,  etc.     Calomel  occurs  native,  in  tetragonal 


Mercury.  157 

crystals,  but    is  commercially  prepared  by  sublim- 
ing a  mixture  of  sodium  chloride,   mercuric  sul- 
phate and  mercury. 
2NaCl    +    HgSO^  +  Hg  ==  Na,S04   +  Hg2Cl, 

Mercurous 
Chloride. 

A  heavy  white,  iine  powder  condenses,  insoluble 
in  water,  and  alcohol,  tasteless,  and  decomposes 
slowly  in  sunlight  into  freeHg  andHgCl^. 

31ercuric  oxide,  HgO,  occurs  in  red  scales,  when 
mercury  is  heated  in  air,  commonly  as  red  precipi- 
tate.    It  forms  with  acids,  mercuric  salts. 

JflercuroiLS  oxide,  Hg^O,  a  black  powder,  produced 
by  action  of  alkali-hydrates  on  calomel.  With 
acids  it  forms  mercurous  salts.  There  are  two 
iodides  of  mercury  analagous  to  the  chlorides. 

Mercuric  sulphide,  HgS,  has  already  been  alluded 
to  as  the  mineral  cinnabar.  When  made  synthet- 
ically it  is  known  as  tlie  brilliant  red  pigment, 
vermilion. 

Mercurous  sulphide  Hg.^S,  is  a  black  powder, 
known  as  ethiopes  mineral. 

f  CI 
Mercuric  chloramide,  ITg      -|  ^^      is  known  as 

white  precipitate. 

Materia  Medica. — Mercurial  preparations  are 
favorite  local  remedies  in  certain  skin  diseases  and 
syphilitic  ulcerations,  in  virtue  of  their  germicidal 
and  antiseptic  properties.     The  practice  of  steril- 


158  Inorganic  Chemistry. 

izing  instruments  in  hot  solutions  of  mercuric  chlo- 
ride is    effective,  although   the  efficacy  of   a  cold 
solution  might  be  questioned.     A  cold  aqueous  so- 
lution of  this  drug  has  been  a  favorite  germicide 
in  sterilizing  root  canals  of  teeth,  preparatory  to 
fining.     It  forms,  with  albuminous  matter,  a  coag 
ulum  of  only  temporary  existence,  consequently, 
the  duration  of  asepsis,  secured  by   it,  is  limited  • 
and  unless  the  disease  germs,  held  in  the  coagulum, 
are  immediately  killed  by  it— a  wished-for  consum- 
mation, the  occurrence  of  which,  many  deny — its 
virtues  as   a  germicide  and   antiseptic    woultT   be 
active  only  during  the  period  of  coagulation ;  and 
if  more  or  less  organized  matter  remain  in  the  ca- 
nals, at  the  time  of  filling,  a  condition  that  unfor- 
tunately sometimes  obtains,  its  coagulation  by  cor- 
sosive  sublimate,   would  therefore  be  of  doubtful 
permanent  efficiency.     The  salts  of  mercury,  nev- 
ertheless, appear  to    possess    especial    destructive 
power  over  the   germs  of  syphilis  at  least,  and  a 
wash  of  corrosive  sublimate  solution,  used  before 
operating  in    the    mouth   of   a  syphilitic   patient, 
would  sterilize  the  part  for  the  time  being. 

Taken  internally,  the  salts  of  mercury  if  pushed 
to  the  limit,  occasion  nervous  debility,  and  cause 
anaemia  by  destroying  the  red  corpuscles.  They 
increase  the  secretion  of  saliva,  mercurial  salivation 


31ercury.  159 

sometimes  following  their  use.  Antidote  to  mer- 
curic chloride — emesis,  albumen,  white  of  ^gg, 
milk,  flour. 

Dose.     Mercuric  Chloride,  0.004  Gm.  (gv.  yL). 
Mercurous  Chloride,  0.30  Gm.  (gr.  v). 

R.     Hydrarg  Chlor.  Corrosiv.  0.10  Gm.  (gr.jss). 
Acidi  Hydrochlorici  Dih,  q.  s.  ad.  solve. 
Mellis  Depurati,  15.00  fGm.  (f^ss). 
Aqua  Dest.,  q.  s.  150  fGm.  (f  3  v). 

M.  S.    To  be  used  as  a  wash,  or  gargle,  in  syphiUtic 
ulceration  of  mouth  and  throat. 


160  Inorganic  Chemistry. 


CHAPTER  X. 

ZINC,  ETC. 

Symbol,         At.  Wt.         Sp.  Gr.         Valency, 
Zn.  65.  7.  11. 

The  chief  ores  of  zinc  are  the  sulphide,  carbon- 

* 

ate.  oxide,  and  silicate.  These  are  calcined  in  air, 
producing  zinc  oxide;  the  latter  is  then  distilled 
with  charcoal  (C),  which  takes  up  the  oxygen,  the 
zinc  vapor  condensing  in  suitable  vessels. 

2ZnO  +  C  :=  CO2  +  2Zn 
Zinc  is  a  bluish  white  metal.  At  ordinary  temper- 
atures it  is  hard  and  brittle ;  at  about  150°  (300°F), 
it  becomes  quite  malleable ;  at  200°  (392°  F),  it  again 
becomes  brittle,  and  may  be  broken  up  in  a  mor- 
tar; at  412°  (773°F),  it  melts,  and  at  about  1000° 
(1832°F),  if  air  be  present,  it  volatilizes  and  burns 
with  a  splendid  greenish  light,  forming  its  only 
oxide,  ZnO.  Zinc  is  slowly  oxidized  in  moist  air, 
and  is  acted  on  easily  by  dilute  acids,  by  alkali- 
hydrates,  and  by  the  halogens.  It  is  used  largely  as 
a  protecting  coat  for  sheet  iron;  it  forms  the  posi- 
tive element  of  galvanic  batteries,  in  making  dies 
for  swaging  dental  plates,  as  a  constituent  for  some 


Zinc.  161 

amalgams,  and  of  other  highly  valuable  alloys,  as 
brass,  etc. 

Zinc  chloride,  ZnCl2,  is  made  by  direct  action  of 
chlorine  upon  zinc,  or  by  dissolving  granulated  zinc, 
or  zinc  carbonate  in  hydrochloric  acid,  purifying 
by  solution  of  chlorine  and  zinc  carbonate,  and 
evaporating  the  solution  to  dryness.  It  occurs  as 
11  grayish-white  translucent,  cr^^stalline  mass,  deli- 
quescent, and  very  soluble  in  water,  and  in  alcohol, 
and  ether.  Liquor  zinci  chloridi,  is  the  official  prepa- 
ration, and  contains  14.00  Gm. (5  ijjss)  of  zinc  chloride 
to  30.00  f  Gm.  (fSi)  of  water.  The  solution  for  oxy- 
chloride  cement  should  have  a  sp.  gr.  of  about  1.50. 

Aside  from  its  use  in  surgery,  zinc  chloride  is  em- 
ployed as  a  chemical  dehydrating  agent;  that  is,  it 
will  not  only  take  away  water,  but  the  elements  of 
water  from  organic  compounds  (and  from  albumin- 
ous organized  structure,  which  probably  explains 
its  action  as  a  caustic).  It  is  also  used  as  a  solder- 
ing fluid. 

Zinc  oxide,  ZnO,  is  the  product  of  the  combus- 
tion of  zinc  in  air;  it  is  used  extensively  as  a  pig- 
ment. The  pharmaceutical  preparation  is  obtained 
by  subjecting  pure  precipitated  zinc  carbonate  to  a 
red  heat,  until  all  the  water  and  CO.^  are  driven  ofl'. 
It  should  appear  as  a  white,  smooth,  impalpable 
powder.  It  is  tasteless,  and  insoluble  in  water,  but 
14 


162  Inorganic  Chemistry. 

is  acted  upon  by  the  common  dilute  acids.  It  is 
the  basis  of  the  various  zinc  cement  preparations, 
mixed  with  variable  quantities  of  silica,  borax,  pul- 
verized glass,  etc 

The  liquid  for  the  oxychloride  has  already  been 
described;  that  for  the  oxyphosphate  consists  of 
tri-basic  phosphoric  acid,  II3PO4,  prepared  by  dis- 
solving pure  glacial  phosphoric  acid,  HPO3,  in 
warm  water  and  evaporating  to  a  syrupy  consis- 
tency. 

In  preparing  the  filling,  the  powder  should  be 
added  to  the  liquid  slowly,  and  mixed  thoroughly, 
until  the  magma  has  a  stiff,  tenacious  feel,  then  in- 
serted in  place,  and  kept  dry  for  20  or  30  minutes. 
The  result  will  be  a  hard  coherent  filling,  of  rea- 
sonably lasting  qualities,  depending  more  than  less, 
on  its  position  in  the  tooth.  Chemical  union  be- 
tween "the  acid,  and  the  zinc  oxide  of  the  powder, 
undoubtedly  takes  place;  the  other  ingredients 
of  the  powder  being  held  mechanically;  but  this 
union  can  be  overcome  by  either  acids  or  alkalies. 
It  is  known  that  these  fillings  give  way  rapidly  at 
the  cervical  wall,  if  under,  or  near  the  gum  mar- 
gin ;  such  positions  are  most  favorable  to  develop- 
ment of  alkalies,  by  putrefaction  (ammonia,  and  its 
derivatives,  the  amines,  a^iiides,  ptomaines,  etc.), 
and  also  somewhat  to  acid  fermentation.    The  alkali 


Zinc.  163 

will  appropriate  its  equivalent  of  the  phosphoric 
acid,  the  cement  losing  its  integrity  to  that  extent; 
while  the  acid  stage  of  fermentation,  if  such  should 
occur,  would  tend  to  destroy  the  cement,  by  at- 
tracting the  oxide  of  zinc.  In  such  a  situation 
the  oxyphosphate  fillings  are,  evidently,  ^'between 
the  devil  and  the  blue  sea." 

Zinc  sulphatCy  ZnS047Il20,  white  vitriol,  obtained 
by  the  action  of  sulphuric  acid  on  granulated  zinc, 
occurs  in  small,  colorless,  efflorescent  crystals,  solu- 
ble in  water,  insoluble  in  alcohol,  and  of  a  metallic 
styptic  taste. 

Materia  Medica.  Zinc  chloride  is  a  powerful 
caustic,  owing  to  its  dehydrating  qualities.  It  is 
employed  in  substance,  or  strong  solution,  for  treat- 
tnent  of  cancerous  and  other  forms  of  ulceration. 
As  an  obtunding  agent  to  sensitive  dentine,  it  is 
affective,  although  superficial ;  but  on  account  of 
the  pain  immediately  following,  and  the  danger  to 
the  vitality  of  the  pulp  involved,  the  practice  of 
applying  it  as  a  dentinal  obtundant,  has  been  nearly 
abandoned.  In  solution,  it  is  successfully  employed 
as  an  injection  in  chronic  alveolar  abscess,  in  an- 
trum disease,  and  in  the  gum  pockets  of  alveolar 
pyorrhoea. 

The  sulphate  acts  locally  as  an  astringent  and 
stimulant. 


164  Inorganic  Chemistry. 

Internally,  the  sulphate  is  tonic,  antisposmodic 
and  astringent.  In  large  doses  it  is  the  favorite 
direct  emetic. 

Dose.     Zinc  Chloride  0.03  Gm.  (gr.ss.) 

ZiDc  Sulphate  0.06-0.30  Gm.  (gr.  j-v.) 

As  au  emetic — Zinc  Sulphate  0.65  Gm.  (gr.  x.) 

Antidote,  Sodium  bicarbonate. 

B.     Zinci  Chloridi  0.06  Gm.  (gr.j). 
Aqua  Rosse  30.00  fGm.  (fgi.) 

M.  S.    A  good  injection,  Antrum,  etc. 
MAGNESIUM. 

Symbol.     At.  Wt.     Sp.  Gr.     Valency. 
Mg.  24.  1.75.  II. 

Magnesium  is  an  abundant  element,  but  is  always 
found  in  nature  in  combination.  The  double  car- 
bonate of  magnesium  and  calcium  MgCa2C03  is 
known  as  dolomite  or  mountain  limestone,  of  which 
whole  mountain  ranges  are  formed.  The  metal 
also  occurs  in  the  single  corbonate,  the  sulphate, 
h^^drate,  fluo-phosphate,  chloride  and  several  sili- 
cates, of  which  latter  class,  meerschaum  is  one 
(2MgO  SiO^). 

Salts  of  Magnesium  are  found  in  sea  water  and 
many  mineral  springs,  also  in  animal  and  vegetable 
bodies. 

The  element  itself  is  generally  obtained  by  heat- 
ing the  chloride  with  metallic  sodium. 


Magnesium.  165 

MgCl2  +  2Na  =  mixQl  +  Mg 

Mafj:iicsium  Chloride. 

It  is  a  bluish  white  brittle  metal,  somewhat  mal- 
leable and  ductile;  melts  at  a  red  heat;  is  not  af- 
ected  by  dry  air,  but  oxidizes  in  moist  air.  Heated 
to  redness,  it  takes  fire,  and  burns  with  an  ex- 
tremely brilliant  white  light,  very  rich  in  the  ac- 
tinic chemically  active  ways;  for  this  reason  it  is 
used  as  a  source  of  illumination,  in  photographing 
the  interior  of  caves,  etc. 

Magnesium  Oxide,  MgO,  is  a  white,  infusible,  in- 
soluble, bulky,  antacid  powder,  known  as  magnesia. 

Magnesium  Sulphate,  MgSo^  7H2O,  is  found  in 
nature,  as  Epsom  salts,  and  may  be  prepared  by 
dissolving  the  oxide,  hydrate,  or  carbonate,  in  sul- 
phuric acid.  It  consists  of  colorless,  odorless, 
soluble  crystals,  of  a  bitter  taste;  used  in  medicine 
as  a  purgative. 

An  interesting  feature  in  connection  with  the 
water  of  crystallization  in  MgS04  TH^O,  is  worthy 
of  notice.  At  a  temperature  of  120°  (248F.)  only 
six  of  the  seven  molecules  of  water  are  driven  off; 
the  remaining  molecule  persistently  resisting  ex- 
pulsion until  the  temperature  reaches  nearly  200° 
(892F).  This  last  is  known  as  water  o^  constitution, 
and  may  be  replaced  by  certain  sulphates,  as  for 
instance  K2SO4,  yielding  a  doable  sulphate. 


166  Inorganic  Chemistry, 


SO.K 


MgSO,,  H^O  6H2O  +  K^SO,  =  Mg{  ^^^^ }  6S0, 

I    pi    rj  Potassio-Magnesium 

^^^2^  Sulphate. 

This  compound  serves  as  a  type  of  double  salts, 
and  is  isomorphous  with  those  produced  by  the 
union  of  the  alkali-sulphates,  with  the  sulphates  of 
zinc,  copper,  nickel,  iron  and  cobolt 

Potassio-Ferrous  Sulphate, 

Showing  also  that  there  is  some  chemical  relation- 
ship between  magnesium  and  the  metals  just 
named. 

Cadmium  (Cd),  is  comparatively  rare,  occurs 
chiefly  as  an  impurity  in  zinc,  and  as  a  sulphide; 
the  precipitated  sulphide,  CdS,  is  a  yellow  pigment 
of  great  beauty,  highly  prized  by  artists.  Cad- 
mium is  obtained  by  converting  the  sulphide  into 
oxide,  and  reducing  the  latter,  by  heating  with 
charcoal.  It  is  a  lustrous  bluish-white,  tinlike 
metal,  of  sp.  qr.  8.6,  at.  wt.  112,  vapor  density 
one-half  the  atomic  weight,  hence  its  molecule  is 
composed  like  that  of  mercury,  of  only  one  atom. 
It  melts  at  260°  (500F.)  •  tarnishes  gradually  in  the 
air,  and  is  acted  on  slowly  by  acids,  and  by  chlo- . 
rine,  sulphur,  and  oxygen.  Its  salts  resemble  those 
of  zinc;  the  metal  itself  is  malleable  and  ductile, 


Cadmium- GrlucinuM.  167 

but  of  no  importance,  except  as  a  constituent  of 
some  fusible,  and  amalgam  alloys. 

Beryllium  or  Glucinum,  (G1),  is  a  rare  metal, 
occurring  in  certain  silicic  minerals,  and  as  an  ahi- 
minate.  It  is  a  white  metal  of  sp.  gr.  2.1  mallea- 
ble, and  sets  hydrogen  free  from  acids.  Its  salts 
have  a  sweetish  tasts,  whence  its  former  name, 
gluciniun. 


168  Inorganic  Chemistry. 


CHAPTER  XI. 

LEAD,  ETC. 

Symbol,      At.  Wt.      Sp.  Gr.      Valency, 
Pb.  206.5.  11.40.  II-IV. 

Lead  was  well  known  to  the  ancients,  and  is  still 
an  abundant  and  useful  metal.  It  is  found  princi- 
pally as  a  sulphide  in  galena,  but  also  occurs  as  a 
carbonate,  sulphate,  phosphate  and  arsenate. 

Lead  is  a  bluish-white  metal,  soft  enough  to  be 
easily  cut  with  a  knife.  The  brilliant  freshly  cut 
surface  quickly  tarnishes  in  moist  air.  It  is  malle- 
able and  ductile,  but  possessed  of  very  feeble  te- 
nacity ;  melts  at  320  (608F) ;  is  acted  upon  by 
nitric,  sulphuric,  hydrochloric,  carbonic,  and  acetic 
acids,  and  by  oxygen,  sulphur,  chlorine,  bromine 
and  iodine. 

All  the  salts  of  lead  are  poisonous.  Waters  con- 
taining nitrates  from  decomposed  animal  matter, 
and  clorides,  are  not  safe  when  passed  through  lead 
pipes.  Hard  waters,  how^ever,  containing  carbon- 
ates, and  sulphates,  are  relatively  safe,  as  the  lead 
carbonate  forms  an  insoluble  protecting  crust  on 
the  interior  lining  of  the  pipe,  unless  a  considera- 
ble amount  of  free  carbonic  acid  is  present.     As  a 


Leady  etc.  169 

precaution  it  is  best  to  allow  water  that  has  been 
long  standing  in  lead  pipes,  to  flow  until  the  fresh 
portion  from  the  mains  appears.  Lead  salts  in 
water  can  be  detected  by  adding  a  few  drops  of  hy- 
drochloric acid  and  then  a  strong  solution  of  sul- 
phuretted hydrogen.  If  lead  is  present,  a  dark 
brownish  color  will  result. 

Cylinders  of  metallic  lead  have  been  successfully 
employed  for  filling  root  canals  of  teeth,  the  lead 
sulphide  and  carbonate,  formed  therein,  probably 
acting  as  antiseptics,  but  as  these  salts,  especially 
the  sulphide,  injure  the  normal  color  of  the  tooth, 
the  practice  of  using  lead  for  such  purposes,  is  not 
much  in  vogue.  In  dentistry  lead  is  more  espe- 
cially used  for  making  counter-dies.  In  the  arts  it 
is  used  alone,  and  alloyed  with  other  metals,  for 
various  purposes. 

Its  compounds  are  important.  Lead  oxides  are 
used  as  coloring  for  porcelain  teeth.  The  hydrated 
carbonate,  2PbC03,  (H0)2,is  the  basis  of  the  well- 
known  paint,  ivhite  lead.  The  monoxide,  PbO,  is 
known  as  litharge,  and  this,  if  heated  in  a  current 
of  air,  is  converted  into  red  lead,  PbgO^. 

Materia  Medica. — All  the  salts  of  lead  are 
used,  as  a  rule,  only  as  external  applications. 
They  are   soothing  and    astringent.     The    acetate, 

15  :     :  •'■'• ':'.'   /-.  '•':'•  •' 


170  Inorganic  Chemistry. 

Pb(C2 11302)27  sugar  of  lead,  is  sometimes  given 
internally  as  an  astringent,  in  diarrhoea  and 
haemoptyses. 

Lead  poisoning  (painters'  colic),  indicated  by  a 
blue  appearance  along  the  gum  margins,  muscular 
weakness  (drop  wrist),  constipation,  etc.,  is  a  fre- 
quent affection  of  workers  in  lead  pigments. 

Antidotes. — Soluble  sulphates,  as  magnesium 
sulphate,  which  cause  formation  of  insoluble,  and 
therefore,  innocuous  lead  sulphate,  followed  by  pot- 
assium iodide  and  sulphur  baths. 

Dose  of  lead  acetate  (sugar  of  lead),  0.10  Gm.  (grjss) 

The  metal  ThalliUxM  (Tl),  discovered  by  Crookes 
in  1861,  by  aid  of  the  spectroscope,  is  a  very  rare 
element,  although  widely  diffused ;  occurring  in 
very  small  proportions  in  iron  and  copper  pyrites 
and  in  native  sulphur.  It  is  obtained  from  the 
flue-dust  of  sulphuric  acid  works.  Although  it  is 
a  triad,  it  resembles  lead  in  nearly  all  its  proper- 
ties. Its  atomic  weight  is  203.  The  salts  of  Tl 
color  the  flame  a  brilliant  green. 

TIN. 

Symbol,       At.  Wt.       Sp.  Gr.       Valency, 
Sn.  1.18.  7.29.  II-IV. 

Tin  is  one  of  the  metals  of  earliest  antiquity. 
The  principal  ore  of  tin  is  the  mineral  cassiterite 


c      c       «■ 


Tin,  171 

stannic  oxide,  SnO^,  found  from  time  immemorial 
in  England  (Cornwall).  Tin  is  now  produced  also 
in  Borneo,  Malacca,  Banca,  and  to  some  extent  in 
the  United  States,  South  America,  and  Australia, 
the  purest  coming  from  the  island  of  Banca. 

The  metal  is  obtained  by  heating  the  crushed  ore, 
with  coal  or  charcoal,  Sn02  +  C  =  CO^  +  Sn.  It 
is  soft,  white,  crystalline,  malleable,  slightly  duc- 
tile, and  feebly  tenacious.  Melts  at  235°  (455F), 
has  a  peculiar  odor,  and  "  cries  "  when  a  bar  of  it 
is  bent ;  retains  its  luster  in  air  at  common  tempera- 
tures, but  if  heated,  oxidizes  readily  ;  is  acted  upon 
by  dilute  acids,  and  by  the  alkalies. 

Tin  is  used  largely  in  the  arts;  common  tin  plate 
is  sheet  iron,  coated  with  tin,  by  immersion.  Tin 
enters  into  the  formation  of  many  important  alloys, 
and  is  used  by  dentists  in  the  form  of  foil,  as  a  fill- 
ing material,  alone,  and  in  mechanical  combination 
with  gold.  The  high  preserving  qualities  of  tin  in 
this  connection,  are  doubtless  due  to  the  formation 
between  the  filling,  and  the  walls  of  the  cavity,  of 
the  insoluble  stannic  oxide,  and  when  with  gold,  in 
addition  to  this,  an  electrolytic  mutual  induction 
continues  between  the  two  metals,  like  that  w^hich 
exists  in,  and  preserves,  galvanized  iron,  (iron  and 
zinc). 

There  are  tiro  sets  pf.tin  compounds.     The  two 


172  Inorganic  Chemistry. 

chlorides,  viz. :  SnClg  and  SnCl4,  plus  water  of  crys- 
tallization, are  used  as  mordants  in  calico  print- 
ing. These  two  chlorides,  obtained  by  dissolving 
tin  in  hydrochloric  and  nitrohydrochloric  acids  re- 
spectively, yield  with  auric  chloride,  the  beautiful 
"  purple  of  Cassius,"  which  is  used  in  coloring  por- 
celain. 

Stannous  oxide,  SnO,  is  basic,  and  with  acids 
forms  a  number  of  salts. 

Stannic  oxide,  SnO 2,  is  peculiar,  when  compared 
with  those  metallic  oxides  we  have  thus  far  con- 
sidered, in  being  neither  decidedly  basic,  nor  acid; 
it  is  weakly  basic  with  strong  acids,  and  weakly 
acid  with  strong  alkalies.  This  oxide  is  known  as 
futty  powder. 

There  are  two  acids  of  tin,  whose  formulas  will 

serve  to  explain  the  meaning  of  the  prefixes,  ortho 

and  meta,  which   are    sometimes  attached   to  the 

names  af  certain  acids  and  salts.     Or^Aostannic  acid, 

H4Sn04,  has  four  hydroxyl  groups  in  its  molecule ; 

all  its  oxygen  has  a  linking  function,  as  the  graphic 

formula  will  show : 

0— H 


H— O— Sn— 0— H 
)— H 

— Sii — being  a..tetrad,«;Beqjiiri5s  four  groups  of 


A. 


<       • 
<    •    < 


Tin.  173 

hydroxyl  (0H)4,  to  satisfy  its  equivalency  oi  four. 
In  all  ortho-acids,  there  should  be  as  many  hydro- 
gen atoms  as  oxygen  atoms;  that  is,  the  number 
of  hydroxyl  (OH)  groups  should  be  the  same  as 
the  valency  of  the  receiving  radical,  which,  in  the 
case  of  Sn,  is  four.  Phosphorus  is  a  pentad,  P^ 
Ortho-phosphoric  acid  should  therefore  have  jive 
hydroxyl  groups  P(0II)5. 

yifefa-acids  are  derived  from  ortho-acids  by  ab- 
stracting a  molecule,  or  molecules  of  water,  from 
the  latter.  In  meta-acids  the  atoms  of  oxygen  serve 
a  saturating  as  well  as  a  linking  purpose  Thus, 
Meta-stannic  acid,  H2Sn03,  is  ortho-stannic  acid, 
minus  one  molecule  of  water: 

0-H  0 

I  II 

H-O-Sn— 0-H  H— 0-Sn 

0-H  0-H 

Ortho-Stannic  Acid.  Meta-Stannic  Acid. 

Where  tino  molecules  of  water  can  be  removed 
from  an  ortho-acid,  a  r/me^a-acid  results;  Mree mole- 
cules of  water  removed,  a  trimeta-acid,  etc. 

0-H  0 

I  II 

H-O^P  -0-H  H-0^^ 

H-0^    ^0-H  11-0--" ^^0-H 

Ortho  phosphoric  Acid.  Metn-phos.  Acid. 

o 


H-^0  ^:r--^.0=i=HPOv,  etc. 

'    ,   M)tn^i;»a-«pbc«.»i'.c\d.  . 
•'•       ••»     > 


"i^V:-...  .., 


174  Inorganic  Chemistry. 

The  salts  of  ortho  and  meta-acids  are  named  with 
corresponding  prefixes. 

Stannic  sulphide,  SnS2,  is  a  golden  yellow  pow- 
der, called  "  Mosaic  gold,"  used  for  bronzing. 

Materia  Medica.  The  medicinal  value  of  tin 
compounds  is  nil. 

Titanium,  Zirconium  and  Thorium,  belong  to  the 
tin  group  of  elements.  They  are  extremely  rare; 
are  tetrads,  like  carbon,  silicon,  and  tin,  to  whom 
they  are  closely  related  in  the  gradation  of  their 
physical  properties,  and  in  the  similarity  of  their 
chemical  compounds.  The  gradation  being  in  the 
following  order : 

Carbon,    Silicon,  Titanium,   Zirconium,  Thorium, 

Tin. 


•   ••••    •    •••  •*;  I 

\:  '.:  r-  -.:>- 


1  •  •  • 

•  •  • 

•  •  • 


Aluminum,  176 


CHAPTER  XIl. 

ALUMINUM,  ETC. 

Symbol,         At.  Wt.         Sp.  Gr.         Valency, 
Al.  27.  2.6.  IV. 

Aluminum  next  to  oxygen,  and  silicon,  is  the 
most  abundant  of  the  elements,  the  crust  of  the 
earth  being  made  up  mainly  of  those  three.  The 
minerals,  corundum,  emer}-,  ruby  and  sapphire, 
are  aluminum  oxide,  and  the  various  kinds  of  clay, 
as  well  as  feldspar,  mica,  slate,  granite,  basalt,  etc., 
are  essentially  aluminum  silicates.  Hydraulic 
cement  contains  al-silicate. 

The  process  of  Deville,  discovered  in  1854,  of 
heating  together  in  a  reverberatory  furnace  a  defi- 
nite mixture  of  fluor  spar,  sodio-aluminum  chlo- 
ride and  metallic  sodium,  furnishes  a  clue  to  the 
mothod^  ad()})ted,  for  obtaining  the  metal. 
AL.dg  +  Nag  =  6NaCl  +  2A1 

This  process  has  been  superseded  of  late  years 
by  various  modifications,  by  which  aluminum  is 
produced  almost  pure,  (98  per  cent),  and  compara- 
tively inexpensive. 

Aluminum  is  a  brilliant  bluish-white  metal,  sus- 
ceptible of  receiv^ng^d'iiigh 'j>o(i'4J!i,;'i8  very  malle- 


>  >  »    >  I 

>  »  »        I  , 


'  "•    '.'•.';.,; 


176  Inorganic  Chemistry. 

able,  ductile,  and  possessed  of  considerable  tenacity. 
It  is  acted  on  by  aqueous  solutions  of  strong  alka- 
lies and  hydrochloric  acid,  but  is  unaffected  by 
other  cold  acids,  inorganic  or  organic;  is  not  af- 
fected by  sulphur,  and  therefore  may  be  conjoined 
with  rubber  in  vulcanizing  the  latter  substance  ;  it 
does  not  oxidize  in  bulk,  but  if  thin  leaves  be 
heated  in  oxygen,  it  burns  readily.  It  melts  at 
700°  (1292F). 

On  account  of  its  lightness,  permanent  purity, 
and  the  tensile  strength  of  the  metal  and  its  alloys, 
it  is  being  largely  introduced  of  late  into  the  arts 
for  many  purposes.  It  can  be  cast  alone  or  alloyed 
with  silver  or  copper,  into  forms  of  singular 
beauty.  10  parts  silver  and  90  of  aluminum  ex- 
hibits a  splendid  white  non-corrosive  alloy;  90 
parts  of  copper  and  10  of  aluminum,  constitutes 
aluminum  bronze,  resembling  gold  in  color,  and  ca- 
pable of  receiving  and  retaining  a  high  polish. 
In  thin  leaves  it  has  been  used,  with  some  euccess, 
as  a  lining  for  rubber  plates.  An  alloy  of  100 
parts  of  aluminum  and  10  of  tin,  is  employed  in 
the  making  of  philosophical  instruments.  The 
apex  of  the  Washington  monument  is  of  alu- 
minum. 

Aluminum  plates,  either  cast  or  swaged  for  arti- 
ficial dentures,  ka>ve  \tak$ii*:£5n  important  rank  in 


•••    •    »     •«•••    ....    ••   •  •••• 


«•   •   •••  ••• 

•  •«•  «   •** 

•  •  •  • 


,    •  •    •  •:  •    •  •, 


Aluminum.  177 

dental  prosthesis.  They  possess  special  properties 
often  requisite  for  certain  mouths. 

Alum,  from  which  the  metal  takes  its  name,  is 
the  most  important  compound  of  aluminum.  Com- 
mon potash  alum  is  a  double  sulphate  of  aluminum 
and  potassium,  Al2(S04)3,K2S04,24H20,  or  AI2 
K2 (80^)4,241120.  Ammonium  alum  is  Al2(]SrH4)2 
(804)4,241120.  There  are  alums  also  of  Xa,Cs, 
Rb,  Ag,  and  Tl,  wherein  these  elements  respect- 
ively occupy  the  place  of  K  or  NH4  ;  and  there 
are  alums  in  which  the  aluminum  itself  is  replaced 
by  Fe,  Cr,  and  Mn,  respectively.  Each  molecule 
of  alum  contains  24  molecules  of  water  of  crystal- 
lization. 

Ordinary  alum  is  manufactured  on  a  large  scale 
by  action  of  sulphuric  acid  on  some  of  the  various 
aluminum  silicates,  whereby  aluminum  sulphate, 
AI2 (804)3,  is  formed.  This  is  then  added  in  solu- 
tion, to  a  solution  of  potassium  sulphate  K2SO4, 
Or  ammonium  sulphate  NH48O4,  as  the  case  may 
be.  The  alum  crystallizes  on  evaporation  of  the 
liquid  mixture. 

Alum  has  an  astringent  sweetish  taste,  and  acid 
reaction;  is  soluble  in  water,  the  hot  solution  be- 
ing a  good  pickle  for  removing  borax  glass  from 
gold,  etc.,  after  soldering.  By  heating  for  a  con- 
siderable time,  at  a  temperature  of  80°  (176F),  all 


178  Inorganic  Chemistry. 

the  water  of  crystallization  is  driven  out,  the  alum 
then  becoming  caustic  alum. 

Aluminum  Oxide,  AI2O3,  alumina,  is  found  crys- 
tallized in  nature,  in  many  varieties,  as  corundum, 
emery,  ruby,  etc.;  colored  by  impurities,  as  sapphire, 
which  is  simply  blue  corundum;  "oriental  amy- 
thist"  is  purple,  "oriental  topas"  is  yellow,  and 
"oriental  emerald"  is  green.  These  gems  can  be 
produced  artificially. 

The  oxide  is  prepared  by  igniting  the  hydrate  (the 
latter  obtained  by  mij{:ing  a  solution  of  alum  with 
excess  of  ammonia),  presents  a  white,  tasteless,  co- 
herent mass,  very  slightly  afiected  by  acids,  and 
fusible  only  in  the  oxyhydrogen  flame. 

The  hydrate  Al2(H0)g  ortho-aluminum  hydrox- 
ide, prepared  as  above,  forms  with  strong  acids, 
characteristic  salts,  like  al-sulphate,  already  men- 
tioned. With  basic  radicals,  it  acts  as  an  acid, 
forming  aluminates,  as  ortho-sodium  aluminate, 
^agAlgOg.  There  are  also  the  mono-meta  hydrox- 
ide, Al2  0(HO)4,  and  the  dimeta-hydroxide,  AI2O2 
(HO) 2,  forming  with  bases,  mono-meta  and  dimeta- 
aluminates,  respectively,  as  dimeta-potassium  alu- 
minate, K2AI2O4,  etc.  Aluminum"  hydrates  are 
largely  used  in  calico  printing,  as  mordants,  inas- 
much as  they  are  able  to  unite  with  organic  dye- 
stuffs,  to  form  "lakes,"  which  are  insoluble;  the 


Aluminum.  179 

(litfereut  colors  being  thus  "fixed"  in  the  fiber  of 
the  cloth. 

There  are  normal,  and  basic  {i.  e.,  containing  hy- 
drogen), aluminum  phosphates  found  in  nature,  of 
which,  the  turquoise,  Al4(r04)2,(HO)g,2H20,  is  an 
example.  The  topaz  is  fiuo-aluminum  silicate,  the 
beautiful  blue  "  lapis  lazuli"  is  sodio-aluminum  sili- 
cate, containing  sulphur.  Its  powder  was  formerly 
used  by  artists,  under  the  name  of  "  ultra  marine." 
This  substance  is  now  produced  very  cheaply ;  vio- 
let, red,  and  green  ultra-marines  are  also  prepared 
artificially. 

Clay  is  the  result  of  the  disintegration  of  the  ua- 
stratified,  primitive  rocks,  as  granite,  porphyry,  etc., 
and  further  of  felspar,  etc.,  these  rocks  consisting, 
in  great  part,  of  this  mineral. 

The  art  of  pottery  making  has  been  known  from 
the  earliest  times.  Porcelain  manufacture,  in  Eu- 
rope, is  of  comparatively  recent  date,  being  derived, 
probably,  from  China,  whence  the  name  "  China- 
ware."  Porcelain  differs  from  pottery,  in  being 
translucent,  and  differs  from  glass  in  being  non- 
transparent,  and  much  more  infusible. 

Porcelain  clay,  or  kaolin,  is  a  hydrous  aluminum 
silicate  — ,  II2 Al2Si20g,H20,  derived  by  atmos- 
pheric influence  on  felspar,  which  is  K2Al2SigOig. 
When  prepared  for  the  furnace,  and  baked,  it  loses 


180  Inorganic  Chemistry. 

its  water,  yielding  a  porous  "  biscuit."  This  is 
dipped  in  a  thin  mixture  of  pure  felspar  and  water, 
and  "fired"  again;  the  felspar  being  fusible, 
"glazes"  the  surface  into  a  smooth  finished  pro- 
duct. The  ornamental  part,  of  gilding,  and  paint- 
ing in  enamel,  is  next  accomplished,  and  the  piece 
(pieces)  heated  again  to  flux  the  colors.  The  colors 
consist  ofpigments  of  metallic  oxides ;  cobalt  oxide 
for  blue,  chromic  oxide  for  green,  etc. 

Crucibles  and  fire-brick  contain  extra  proportions 
of  silica. 

Porcelain  teeth  are  manufactured  by  processes  sim- 
ilar to  those  employed  in  making  porcelain  ware. 
The  6o6/i/ consists  chiefly  of  felspar,  kaolin  and  silica 
(Si02) ;  the  enamel,  mainly  of  felspar.  The  differ- 
ent shades  of  enamel  are  produced  by  fine  division 
of  various  metals,  or  of  metallic  oxides  (purple  of 
cassius,  for  instance).  A  representation  of  a  gold 
filling  may  be  obtained  by  applying  a  mixture  of 
precipitated  gold,  or  auric  chloride  and  chamomile 
oil  to  the  limited  part  desired  on  the  surface  of  the 
tooth,  and  heating.     (See  Gold.) 

Materia  Medica.  Alum,  alumen,  possesses  styp- 
tic and  astringent  properties,  condensing  the  tis- 
sues by  coagulating  their  albumen ;  dried  alum, 
alumen  exsiccatum,  is  mildly  caustic.    In  large  doses, 


Aluminum.  181 

taken  internally,  alum  acts  also  as  an  emetic  and 
purgative. 

Alum  is  employed  locally  to  arrest  alveolar 
hemorrhage,  and  in  solutions  of  varying  strength, 
in  treatment  of  spongy  gums,  of  congested  mucous 
membrane  of  mouth  and  throat,  and  for  relieving 
the  inflammation  and  soreness,  induced  by  wearing 
artificial  dentures,  and  as  an  injection  in  many 
flowing  diseases;  and  as  a  collyrium.  Powdered 
alum,  added  to  Laharragues  solution,  makes  an  ef- 
fective bleacher  for  discolored  teeth. 

Aluminum  chloride.,  sulphate,  and  acetate,  are  dis- 
ir>fectants  and  antiseptics.  Very  weak  solutions  of 
either  of  these,  will  effectually  neutralize  offensive 
breath,  arising  from  catarrhal  affections. 

The  chloride  is  sometimes  used  for  bleaching 
teeth. 

Dose.     Alum  0.65  —  1.00  Gm.  (gr.x  —  xv). 

Alum  (dried),  0.25  —  0.65  Gm  (gr.iv  —  x). 

R.     Aluminis,  4.00  Gm.  (^i). 

Tinctura  myrrhse,  15.00  fGm.  (f^ss). 
Aq.  Dest.  q.  s.  ad.  60.00  fGm.  (f^ij) 

M.  S.     Apply  to  spongy  gums. 

Gallium,  Indium,  etc., 

Ga.  In. 

These  metals  are  chemically  related  to  aluminum. 
They  are  extremely  rare,  only  traces  of  tliem  being 


182  Inorganic  Chemistry. 

found  in  zinc  blende.  The  atomic  weight  of  Al  is 
27,  of  Ga  70,  and  of  In  114,  a  regular  gradation  ; 
the  specific  gravity  of  Al  is  2.6,  of  Ga  5.9,  and  of 
In  7.4,  a  regular  gradation.  Both  gallium  and  in- 
dium were  discovered  by  spectrum  analysis.  Their 
sulphates  form  ammonia  alums. 

Gallium,  and  the  rare  metal  scandium.,  are  of  es- 
pecial theoretical  interest,  on  account  of  their  ex- 
istence and  properties,  having  been  predicted  in 
advance  of  their  discovery. 


Iron.  183 


CHAPTER  XIII. 

IRON. 

Symbol,         At.  Wt.         Sp.  Gr.         Valency, 
Fe.  56,  7.8.  II,  IV,  VI. 

Ever  since  the  ante-historic  times  of  Tubal  Cain, 
who  was  a  worker  in  iron,  this  metal  has  held  its 
own  as  one  of  the  most  important  substances  in 
nature. 

It  is  abundantly  distributed,  although  but  a  very 
small  quantity  of  native  iron  has  been  found ;  a 
large  proportion  of  meteors  consist  of  metallic 
iron.  Iron  is  a  constituent  of  innumerable  min- 
erals, is  present  in  all  kinds  of  rocks,  and  soils,  in 
the  waters  of  nearly  all  mineral  springs,  and  in  the 
bodies  of  plants  and  animals. 

The  ores  from  which  iron  is  obtained,  however, 
are  practically  very  limited  in  number.  These  are, 
chiefly,  magnetic  oxide  (magnetite),  Fe304  ;  ferric 
hydrate  (limonite),  2Fe203  3H20;  ferric  oxide  (he- 
matite), Fe^Og  ;  and  ferrous  corbonate  (siderite), 
FeCOg.  Those  ores  that  are  not  native  oxides, 
are  converted  into  artificial  oxides  by  roasting,  so 
that  practically,  the  chemical  process  of  producing 


184  Inorganic  Chemist?^. 

iron  on  a  large  scale  consists  essentially  in  reduc- 
ing the  oxide  with  carbon.  Alternate  layers  of  the 
ore,  fuel,  and  limestone  are  placed  in  the  "  high 
furnace,"  and  hot  air  forced  upward  through  the 
mass,  producing  such  a  high  temperature  that  the 
oxygen  leaves  the  ore,  and  takes  up  with  carbon, 
leaving  iron  in  the  metallic  state: 

Fe203    +    3C    =    SCO    +    2Fe. 

The  limestone  serves  as  a  flux  in  removing  silica 
and  other  impurities,  which  fuse  into  a  "slag,"  and 
remain  on  top  of  the  molten  iron.  The  process  is 
continuous,  until  the  furnace  wears  out;  the  mate- 
rials being  added  at  the  top  and  the  melted  slag 
and  iron  drawn  off  at  the  bottom  at  regular  inter- 
vals. The  metal  is  drawn  off  into  molds,  and  is 
known  as  cast  or  pig  iron,  and  contains  a  good  deal 
of  carbon^;  this  is  burned  off  in  a  reverberating 
furnace,  together  with  sulphur,  silicon,  phosphorus, 
and  other  impurities  in  the  form  of  oxides.  This 
operation  is  known  as  ''  puddling,"  the  result  being 
wrought  iron. 

The  different  varieties  of  commercial  iron  con- 
tain more  or  less  carbon.  Cast  iron  contains  the 
most  carbon,  2  to  6  per  cent.  Steel  considerably 
less,  0.5  to  2  per  cent,  and  wrought  or  malleable 
iron,  less  than  0.5  per  cent. 

Wrought  iron  is  fibrous  in  structure,  and  tough; 


Iron.  185 

at  a  high  temperature  it  becomes  pasty,  in  which 
condition  it  is  susceptible  of  welding. 

The  melting  point  of  iron  is  very  high,  probably 
above  2000°  (3632F).  It  is  malleable  when  hot, 
and  ductile,  and  possessed  of  superior  tenacity ; 
and  when  pure  is  white. 

Iron  is  acted  upon  by  hydrochloric,  and  sulphuric 
and  dilute  nitric  acids,  and  by  the  haloids;  and 
when  heated,  by  phosphorus,  sulphur,  and  oxygen. 

It  would  be  doing  more  than  our  requisite  duty 
to  attempt  to  name  the  uses  to  which  iron  is  ap- 
plied in  the  arts;  and  w^ould  be  a  work  of  superero- 
gation also,  to  consider  its  numerous  compounds  in 
their  chemical  relation  to  commerce,  the  arts,  and 
medicine. 

Ferrous  Salts,  which  may  be  regarded  as  derived 
from  ferrous  oxide,  FeO,  are  mostly  pale  green  in 
color. 

Ferrous  Sulphate,  FeSo4,7Il2  0,  commonly  called 
green  vitriol,  or  copperas. 

Ferrous  Chloride,  FeClg,  and /errors  iodide,  Yel^, 
are  pale  green,  and  soluble.  Ferrous  sulphide,  FeS, 
made  by  fusing  iron  and  sulphur  together,  dissolves 
in  dilute  acids,  with  evolution  of  II2S. 

Ferrous   Carbonate,  FeCOg,  a.  white  precipitate, 
produced  when  solution  of  a  ferrous  salt,  as  FeSO^, 
is  added  to  a  solution  of  an  alkaline  carbonate,  as 
16 


186  Inorganic  Chemistry. 

ITagCOg,  on  exposure  to  the  air,  this  ferrous  car- 
bonate decomposes  into  free  CO 2,  and  Fe2  03 ;  the 
latter  substance  is  known  as  "jeweler's  rouge" 
(polishing  powder),  and  as  the  pigment,  "Yenitian 
red."  All  ferrous  compounds  are  prone  thus,  to 
take  up  oxygen  from  the  air,  and  become  changed 
into  ferric  compounds,  which  are  chiefly,  either 
red  or  yellow. 

Ferric  oxide,  FcgOg,  sesqui  oxide  of  iron,  may  be 
considered  the  basis  of  the  ferric  salts.  The  oxide 
itself  has  been  sufficiently  described. 

Ferric  Chloride,  Fe2Cl6,  perchloride  of  iron,  can 
be  prepared  by  dissolving  ferric  oxide  in  hydro- 
chloric acid,  or  by  direct  action  of  CI  on  iron,  or 
by  heating  the  hydrate  in  the  presence  of  CI.  It 
consists  of  orange  red,  deliquescent  crystals,  of 
strong  styptic  taste,  and  acid  reaction,  and  very 
soluble  in  water  and  alcohol. 

Ferric  hydrate,  Fe2(H0)gf  hydrated  peroxide  of 
iron,  is  obtained  as  a  reddish  precipitate,  when 
either  ferric  chloride  or  ferric  sulphate,  in  solution, 
is  added  to  solution  of  ammonia  (or  caustic  alkalies). 
It  is  the  favorite  antidote  to  arsenic  ;  should  be 
made  fresh,  washed  in  water,  and  given  ad  libitum.. 
Iron  rust, is  ferric  hydrate. 

Ferric  sulphate,   FeS2,   iron  pyrites,  sometimes 
iirt 


Iron.  187 

called  ''  fools  gold/'  is  used  in  the  manufacture  of 
copperas  and  of  sulphuric  acid. 

Ferric  sulphate,  re2 (804)3,  persulphate  of  iron, 
prepared  by  boiling  a  solution  of  ferrous  sulphate 
and  sulphuric  acid,  and  adding  nitric  acid.  On 
evaporation  it  appears  as  a  buff-colored  mass, 
slowly  soluble  in  water.  Practically,  however,  the 
above  solution  is  not  evaporated;  it  is  a  clear 
brownish-red  liquid,  of  slight  odor,  very  styptic, 
and  of  somewhat  sour  acrid  taste. 

MonseVs  solution,  subsulphate  of  iron  solution,  an 
oxy-sulphate,  probably  2Fe2 03,(804) 3.  The  solu- 
tion is  prepared  as  above,  except  that  only  one- 
half  the  amount  of  sulphuric  acid  is  employed.  It 
is  of  a  deep  ruby  red  color,  no  odor,  and  of  a  very 
astringent  but  not  acrid  taste.  MonseVs  powder  of 
the  subsulphate,  possesses  the  same  properties  as 
the  solution. 

Magnetic  iron  oxide,  FeO,  Fe203,  ferroso-ferric 
oxide,  is  incidentally  produced  in  the  shops  in  the 
form  of  "  iron-scales." 

Dyalized  iron  is  essentially  an  aqueous  solution 
of  the  hydrate  obtained  from  a  mixture  of  ferric 
chloride  and  ammonia ;  the  ammonium  chloride 
formed,  passes  through  the  dyalizer,  leaving  the  iron 
in  a  colloid  state.  It  is  inodorous ;  of  a  non-styptic 
taste,  and  considered  by  some  a  good  chalybeate. 


188  Inorganic  Chemistry. 

Iron  by  hydrogen,  reduced  iron,  metallic  iron  in 
fine  powder,  gray-black  in  color,  produced  by  pass- 
ing a  stream  of  hydrogen  over  heated  ferric  oxide. 

Materia  Medica. — Salts  of  iron,  combined  with 
vegetable  astringents,  form  ink.  They  are,  there- 
fore, incompatible  with  tannin. 

The  per-(ferric)  salts  of  iron  have  a  decided  local 
influence  in  arresting  passive  hemorrhage,  their 
astringency  causing  contraction  of  the  small  ves- 
sels;  and  by  coagulating  their  albumen,  a  corru- 
gating and  hardening  of  the  tissues. 

Whenever  it  becomes  advisable  to  use  a  hse- 
mostatic  after  the  extraction  of  teeth,  either  the 
perchloride  in  semi- crystallized  form,  or  in  solution  ; 
or  the  liquor  ferri  chloride  (ferric  chloride  crystals, 
37.8  per  cent,  in  water),  or  Monsels  powder  or  solu- 
tion may  be  selected  for  the  purpose,  and  applied 
with  a  prospect  of  more  than  average  success.  We 
would  not  recommend  these  salts  of  iron,  how- 
ever, in  gargles  or  washes  for  mouth  or  throat,  \u- 
asmuch  as  they  undoubtedly  corrode  the  teeth. 

The  principal  indication  for  the  internal  exhibi- 
tion of  iron,  is  as  a  tonic  in  ancemia.  Iron  being 
an  essential  constituent  of  the  red  corpuscles  of  the 
blood,  it  not  only  augments  the  quantity  of  haemo- 
globin, but  increases  the  number  of  the  red  corpus- 
cles as  well ;  furnishing  thus,  by  an  extra  supply 


Iron.  180 

of  healthy  blood,  fresh  stimulus  to  the  muscular 
fibers  of  the  heart.  It  tones  up  the  mucous  mem- 
brane of  the  stomach,  inducing  improved  appetite 
and  digestive  power.  It  increases  the  temperature 
by  reason  of  its  function  of  carrying  oxygen  to  the 
tissues. 


190  Inorganic  Chemistry, 


CHAPTER  XIV. 

IKON —  Continued. 

The  actual  state  in  which  iron  exists  in  the  red 
corpuscles,  and  the  exact  relation  it  bears  to  the 
operations  in  tissue  waste,  are  not  definitely  known. 
We  may  assume,  however,  with  some  degree  of 
safety,  that  when  it  takes  up,  in  the  lungs,  the 
oxygen,  received  from  the  air,  by  inhalation,  the 
chemical  state,  in  which  it  passes  through  the  arte- 
rial circulation  to  the  capillaries,  is  as  ferric  oxide 
(FegOg).  In  the  process  of  tissue  waste,  some,  per- 
haps many,  of  the  molecules  of  this  compound  are 
reduced  to  ferrous  oxide  (FeO),  thereby  setting  free 
nascent  oxygen,  which  at  once  plays  its  part  by 
uniting  with  the  carbon  (and  other  elements  also), 
of  the  tissues,  which  union  produces  CO2.  Now, 
CO2  does  not  long  remain  free ;  it  finds  the 
reduced  iron  oxide,  and  they  unite,  producing  fer- 
rous carbonate,  according  to  the  simple  equation, 
FeO  +  Co,=:FeC03. 

The  ferrous  carbonate,  thus  formed,  is  carried 
through  the  venous  circulation  to  the  capillaries  of 
the  lungs,  where  it  suffers  decomposition  by  the  in- 


Iron,  191 

fluence  of  the  inspired  oxygen  of  the  air;  the  CO2 
es(;aping  in  the  respiratory  exhalation,  while  the 
FeO  takes  up  with  the  oxygen  present,  2FeO-|- 
0=Fe,03. 

Sach,  in  brief,  are  probably  the  principal  reac- 
tions, involving  iron,  that  occur  throughout  the 
circulation.  They  afford  us  a  fair  idea  of  at  least 
two  important  functions  performed  by  iron,  namely, 
the  carrying  of  atmospheric  oxj'gen  from  the  lungs 
to  the  capillaries,  via  the  arterial  circulation ;  and 
of  the  carbon  dioxide,  by  way  of  the  veins,  from 
the  capillaries  to  the  lungs. 

A  question  of  some  import  occurs  in  this  con- 
nection. Does  the  CO2,  formed  continuously  in 
every  portion  of  the  living  animal  body,  have  any 
influence  at  the  time  of  its  development,  in  pre- 
venting the  oxygen  of  reserve  from  a  too  active  par- 
ticipation in  the  oxidation  of  the  tissues?  And 
does  its  presoncie,  while  yet  free,  previous  to  its 
union  with  FeO,  tend  to  keep  the  normal  process 
of  oxidation  of  tissues  from  being  painfully  mani- 
ifest  to  our  consciousness,  by  governing,  with  just 
the  exact  amount  of  pressure  required,  the  con- 
ductivity of  the  peripheral  extremities  of  the  sen- 
sory nerves,  or  by  primary  influence,  through  the 
same  direct  means,  on  the  receptive  centers  of  the 
brain  itself? 


192  fnorganic  Chemistry. 

If  CO.,  is  possessed  of  the  attributes  indicated, 
then  any  increase  for  the  time  being,  in  the  amount 
produced,  or  any  means  that  will  prevent,  even 
temporarily,  the  regularity  of  its  removal  from  the 
body,  will  induce  a  corresponding  reduction  in  our 
perception  of  pain.  Rapid  breathing,  "  holding  the 
breath,"  experimentally,  or  as  we  do  instinctively, 
while  awaiting  a  shock,  violent  exercise,  and  men- 
tal excitement,  are  all  productive  of  either  an  in- 
crease in  the  quantity  of  CO 2,  or  of  its  temporary 
retention  throughout  the  tissues  ;  and  w^e  all  recog- 
nize, as  a  fact,  that  the  above  means  are  effective 
for  the  time  being,  in  lessening  our  susceptibility 
to  pain.  Cause  and  effect  seem,  in  these  instances, 
to  agree. 

Physical  causes  —  molecular  physics  —  although 
they  may  not  be  appreciable  to  our  senses,  are  in- 
volved in  all  forms,  plus  or  minus^  of  nervous  or 
mental  phenomena,  including  the  so-called  hyp- 
notic influence  ;  but  in  explaining  the  physiological 
action  of  certain  drugs,  we  are  frequently  com- 
pelled to  dismiss  the  subject  by  saying,  "  they  have 
a  direct  effect  on  the  nervous  system,"  or  some  par- 
ticular set  of  nerves.  . 

In  all  experiments  with  nitrous  oxide,  it  has 
been  found  to  be  active  only  as  a  carrier  of  oxy- 
gen.    Combustibles  burn  in  it  with  more  energ^^ 


Iron.  193 

than  in  the  air,  the  heat  setting  the  oxygen  free, 
oxide  compounds  only  resulting.  It  has  also  been 
ascertained,  that  when  inhaled,  ^2^  dissolves  in 
the  arterial  blood,  unchanged.  In  this  way  it 
supersedes  the  legitimate  carrier  of  oxygen,  Fe^Og, 
and  the  latter  compound,  not  being  allowed  to  de- 
compose, in  the  capillaries,  into  ferrous  oxide,  FeO, 
the  CO2  that  is  formed,  in  much  greater  abun- 
dance than  usual,  by  the  oxygen  of  the  N2O,  can 
not  escape  in  the  usual  way,  as  ferrous  carbonate; 
much  ot  it,  comparatively,  remains  free,  for  the 
time  being,  causing  at  first,  the  pleasurable  excite- 
ment, exaltation  of  the  faculties,  hallucination, 
anoesthesia,  and  finally  a  state  of  carbon  dioxide  as- 
phyxiation, which  are  observed  to  take  place  when 
^2^  ^^  inhaled. 

Nitrous  oxide  is,  therefore,  not  an  asphyxiating 
agent  per  se.  It  so  acts  indirectly,  only  when 
pushed  to  the  extent  of  developing  and  accumu- 
lating CO2,  in  quantity  necessary  for  the  purpose, 
the  danger  line  moving  to  and  fro,  according  to 
the  individual.  The  relative  immunity  from  danger, 
with  N2O  as  an  anaesthetic,  may  be  accounted  for 
by  the  exaggerated  oxidation  of  carbon  (a  natural 
process),  which  immediately  ensues  ;  and  the  rapid 
escape  of  the  active    compound,  CO2,  as  soon    as 

air  is  admitted,  which  at  once  restores  to  iron  the 
17 


194  Inorganic  Chemistry, 

opportunity  of  performing  its  accustomed  duties 
in  the  circulation. 

MANGANESE. 

Symbol,         At.  Wt.         Sp.  Gr.         Valency, 
Mn.  54.  8.  II,IV,VL 

Manganese  is  closely  related  to  iron.  It  occurs 
somewhat  abundantly,  mainly  as  an  oxide,  Mn02, 
which  ore,  when  ground,  is  known  as  the  black 
oxide  of  manganese. 

The  metal  is  chiefly  obtained  from  the  black  ox- 
ide, by  reduction  with  carbon.  It  is  gray-white, 
lusterless,  resembling  cast  iron,  brittle  and  very 
hard,  very  difficult  to  melt,  and  decomposes  water^ 
setting  hydrogen  free.  With  copper  it  forms  a 
beautiful  alloy. 

Four  well  defined  oxides,  MnO,  Mn02,  Mn203, 
and  Mn3  04,  are  known.  The  first  is  strongly  ba- 
sic, the  third  is  weakly  basic,  forming,  with  acids, 
typical  salts,  and  with  basic  oxides  it  acts  as  acid, 
forming  salts  called  manganites.  The  second  and 
fourth  oxides  are  neutral. 

Hydrogen  permanganate,  H2Mn208,  permanganic 
acid,  produced  by  distilling  potassium  perman- 
ganate with  sulphuric  acid,  is  a  most  powerful 
oxidizer,  setting  fire  to  alcohol,  paper,  etc.  Its 
most  characteristic  salt  is  potassium  permanganate, 


Cobalt,  Nickel.  195 

K2Mn208,  prepared  by  mixing  manganese  dioxide, 
potassium  chlorate  and  potassium  hydrate  in  a 
Httle  water,  evaporating  and  heating  to  red  heat. 
It  presents,  as  dark  violet  crystals,  soluble  in  water, 
the  dilute  solution,  exhibiting  a  superb  purple  color. 
It  readily  parts  with  its  oxygen  in  the  presence  of 
organic  matter,  as  alluded  to  under  potassium. 

COBALT,  NICKEL. 

Co.        Ni. 

Both  cobalt  and  nickel  are  closely  related  to 
iron,  but  are  comparatively  rare.  The  atomic 
weight  of  cobalt  is  59,  of  nickel,  58,  and  of  iron, 
56.  The  specific  gravities  of  these  three  metals 
are  also  about  the  same,  and  their  valency  is  the 
same. 

Cobalt  occurs  in  nature  as  a  sulphide,  C03S4  ; 
as  an  arsenide,  CogAsg  ;  as  an  arsenate,  C03 
(As04)28H20;  as  speiss-cobalt,  Col^iFeAsg  ;  and 
as  cobalt-glance,  CoFe  (AsS)2.  Many  of  the  com- 
pounds of  cobalt  are  used  as  pigments  and  for  col- 
oring porcelain  and  glass.  A  solution  of  cobalt- 
ous  chloride,  C0CI2,  in  water,  furnishes  sympa- 
thetic ink  of  a  blue  color,  when  heated,  but  which 
becomes  invisible  on  cooling,  by  absorption  of 
moisture. 

XiCKEL'  is  always  a  constituent  of  meteoric  iron. 


106  Inorganic  Chemistry. 

Its  chief  sources  are,  as  the  arsenide,  kupfernickel, 
a  yellow  ore,  whence  its  name ;  and  as  sulphides 
and  silicates  of  nickel.  The  metal  is  used  some- 
what extensively  for  coating  other  metals  by  elec- 
trolysis, the  electrolyte  employed  being  the  double 
sulphate  of  nickel  and  ammonium  (^"£[4)  2  ^1(804)2, 
6H2O,  dissolved  in  water.  The  lower  salts  of 
nickel  are  generally  green.  An  alloy  of  nickel 
and  copper  is  the  familiar  instance  of  the  "  nickel." 
German  silver  is  nickel,  copper,  and  zinc. 

Like  iron,  both  cobalt  and  nickel  are  magnetic. 
They  are  also  malleable  and  ductile,  and  occupy 
the  first  rank  in  tenacity,  like  iron,  and  are  affected 
by  acids  similarly  to  iron.  The  color  of  cobalt  is 
reddish-white. 


Arsenic.  197 


CHAPTER  XY. 

ARSENIC. 

Symbol,        At.  Wt.       Sp.  G-r.         Valency, 
As.  75.  5.7.  III-V. 

Elementary  arsenic  is  inert,  but  its  soluble  com- 
pounds are  extremely  poisonous.  It  is  found  free, 
and  in  a  great  many  minerals,  in  company  with 
sulphur,  iron,  cobalt,  nickel,  etc.,  as  sulphides,  ar- 
senides, arsenites,  and  arsenates.  It  is  chiefly  ob- 
tained, however,  from  arseno-pyrites,  a  sulphide  of 
iron  and  arsenic,  by  sublimation,  the  arsenic  being 
volatile.  Its  vapor  has  an  odor  of  garlic,  by  which 
its  presence  may  be  indicated,  when  heated  by  the 
blow    pipe.     Like    phosphorus,  its   molecule   con- 

sists   of   four  atoms,    T^^y        inasmuch  as  its  va- 

A.S .A.8, 

por  density  is  150.  Arsenic  is  a  dark-gray,  brittle 
solid,  metallic  in  appearance;  classed  by  some  as  a 
non-metal,  by  others  as  a  metal ;  it  is  about  mid- 
way, in  chemical  properties,  between  these  two 
classes  of  elements.  About  the  only  purpose  for 
which  metallic  arsenic  is  used,  is  for  hardening 
lead  ^' shot."     A  very  impure  variety  is  sold  as  a 


198  Inorganic  Chemistry. 

fly-poison,  under  the  erroneous  name  of  "  cobalt." 
"Marsh's  test"  for  arsenic,  consists  in  the  devel- 
opment of  "  nascent"  hydrogen,  in  the  presence  of 
the  suspected  mixture.  Pure  zinc  and  dilute  hy- 
drochloric acid  will  accomplish  this,  and  if  arsenic 
is  present,  it  will  escape  as  ursine,  AsHg,  an  exceed- 
ingly poisonous  gas,  one  bubble  of  which  proved 
fatal  to  its  discoverer,  Gehlen.  This  gas,  as  it  es- 
capes from  a  jet,  arranged  with  proper  precaution, 
when  kindled,  will  deposit  a  mirror-like  stain  of 
metallic,  As  on  a  cold,  clean  surface  of  porcelain, 
held  in  the  flame.  Antimony  compounds  will  give 
similar  results,  forming  SbHg,  but  the  deposited 
arsenic  is  soluble  in  sodium  hypochlorite  solution, 
whereas  the  antimony  is  not.  It  is  said  that  5-0V0 
of  a  grain  of  arsenic  can  be  detected  in  this  way. 
Two  oxides  of  arsenic,  and  their  corresponding 
acids  are  known. 

AS2O3     +     3H2O     =     2H3ASO3 

Arsenous  Water.  Arsenous 

Oxide.  Acid. 

AS2O5        +       3H2O       =       2H3ASO4 
Arsenic  Arsenic 

Oxide.  Acid. 

Arsenic  compounds  are  not  so  poisonous  as  the 
arsenous,  and  not  so  important. 

Arsenous  oxide,  AS2O,  exhibits  such  momentous 
qualities,  that  it  has  appropriated  the  very  name  of 
arsenic^  and  is   generally  known    as   such.     It  is 


Arsenic,  .  199 

formed  by  roasting  arsenical  ores  in  air,  collecting 
the  vapors  and  resubliming;  it  exists  in  two  varie- 
ties, one  crystalline,  and  the  other  in  lumps,  re- 
sembling porcelain;  the  latter  is  the  usual  com- 
mercial variety,  the  powder  being  white  and  heavy, 
of  a  gritty  feel,  tasteless,  and  odorless,  and  un- 
changed in  air.  It  is  slowly  soluble  in  water,  giv- 
ing rise  to  arsenous  acid,  whose  salts  are  known  as 
arsenites.  The  arsenites  of  the  alkali  metals  are 
soluble  in  water;  the  arsenites  of  iron  and  mag- 
nesium not  so,  hence  the  employment  of  iron  and 
magnesium  hydrates,  as  antidotes.  Sodium  ar- 
senite  NagAs,  as  a  mordant  is  used  in  calico  print- 
ing; and  the  brilliant  pigment,  Paris-green,  a 
double  salt  of  copper  arsenite  and  copper  acetate, 
Cu3Aa2  Cu  (0211302)2  is  extensively  used  for  col- 
oring wall-papers.  Whenever  such  paper  gives  a 
green  color  to  flame,  or  changes  from  green  to  blue, 
by  a  drop  of  aqua  ammonia,  the  presence  of  ar- 
senic may  be  suspected. 

Dissolved^  in  acids,  arsenous  oxide  forms  salts, 
typical  of  the  acid;  as,  for  instance,  from  hydro- 
chloric acid  solution,  arsenous  chloride,  AsOlg,  is 
obtained. 

The  2  sulphides  of  arsenic,  AS2S2,  As^Sg,  are 
known  as  the  minerals,  red  realgar,  and  golden-yel- 
low orpimenl,  respectively. 


200  Inorganic  Chemistry. 

Materea  Medica. — The  official  name  of  arsenous 
oxide,  AS2O3,  is  Acidum  Arsenosum,  but  it  is  com- 
monly spoken  and  written  of  as  arsenic;  also,  as 
arsenous  anhydride,  arsenious  acid,  white  oxide  of 
arsenic,  white  arsenic,  arseniosum  oxidum,  and 
ratsbane;  in  its  medicinal  consideration,  we  shall 
follow  the  custom,  and  call  it  arsenic. 

When  applied  locally,  arsenic  acts  as  a  severe 
caustic  irritant,  inducing  redness  and  excessive  in- 
flammation of  the  part,  followed  by  suppuration 
and  sloughing;  for  this  reason,  it  is  used  some- 
times, as  a  cancer  cure.  In  the  operation  of  devi- 
talizing exposed  dental  pulps,  it  is  the  Samson 
upon  which  nearly  all  dentists  confidently  rely. 
The  amount  of  arsenic  necessary  to  destroy  the 
life  of  the  pulp  need  never  exceed  the  ordinary 
internal  dose.  It  is  usually  mixed  with  some  prep- 
aration of  morphine,  or  cocaine,  of  which  mixture 
a  paste  with  either  creosote,  carbolic  acid,  or  oil  of 
cloves,  etc.,  is  made  and  applied  to  the  pulp,  and 
sealed  with  gutta-percha,  or  cotton  dipped  in  either 
sandorac  varnish,  or  in  a  ssturated  solution  of  aris- 
tol  in  chloroform. 

A  suggestive  method  that  might  decrease  the 
period  of  pain,  would  be  to  apply  a  trace  of  pow- 
dered cocaine  hydrochloride,  say  for  five  minutes, 
before  inserting  a  paste,  made  of  arsenic  and  solid 


Arsenic.  201 

caustic  potash.  Sometimes  tannin  alone,  or  in 
glycerine,  is  employed  as  an  adjuvans  to  arsenic, 
on  account  of  astringent  properties.  In  all  cases 
care  must  be  observed,  lest  a  part  of  the  arsenic 
escape  to  the  surrounding  parts,  inasmuch  as  the 
ar^senic  bum  is  painful  and  slow  to  cure,  and  the  al- 
veolar process  itself  might  be,  to  a  limited  extent, 
completely  destroyed.  Certain  individuals  are 
peculiarly  susceptible  to  the  injurious  effects  of 
arsenic,  and  these  do  not  suffer  in  having  pulps 
devitalized,  as  do  those  who  have  strong  resisting 
power  against  the  action  of  the  drug. 

Taken  internally  in  small  doses,  arsenic  acts  as  a 
tonic,  and  antiperiodic,  increasing  appetite  and 
digestion,  producing  a  rotund  form,  and  fair  skin ; 
increasing  the  secretions  of  the  primce  vice,  exsdtmg 
the  mental  faculties  and  stimulating  the  heart's 
action,  and  respiratory  power.  It  is  recommended 
in  treatment  of  ague,  neuralgia,  asthma,  dyspepsia, 
chronic  skin  affections,  etc.  When  its  use  is  con- 
tinued for  some  time,  it  usually  causes  oedema  of 
the  eyelids,  ptyalism,  disordered  systemic  condition, 
and  eruptions  of  the  skin.  The  arsenic  eaters  of 
Styria  observe  the  precaution  of  not  taking  water 
into  the  stomach  at  the  same  time  they  partake  of 
the  drug,  so  that  its  slow  absorption,  and  probably, 
rapid  elimination  follow.    Toxic  doses  produce  gas- 


202  Inorganic  Chemistry. 

tro-enteritis,  vomiting,  diarrhoea,  etc.  In  chronic 
poisoning,  there  is  in  addition,  a  fatty  degeneration 
of  the  muscles  and  heart,  and  parenchymatous  de- 
generation of  the  liver  and  kidneys. 

Arsenic  is  usually  given  in  the  form  of  Fowler's 
Solution,  Liquor  potassii  arsenitis,  prepared  by  boil- 
ing together  arsenous  oxide  and  potassium  bicar- 
bonate in  water,  to  which  the  compound  tincture 
of  lavender  is  added.  This  preparation  may  be 
taken  in  water,  always  after  meals,  full  doses  at 
first,  gradually  diminishing  as  the  treatment  pro- 
ceeds. 

Antidote. — Emetics  (zinc  sulphate),  followed  by 
freshly  prepared  hydrated  iron  (see  Iron),  and  cas- 
tor oil. 

Dose. — Liquor  Potassii  Arsenitis,  0.10-0.30  fGm.(TTL  ij-v). 
Acidum  Arsenosura,  0.001-0.006  Gm.  (gr.  -^\,  j\). 

R.     Acidi  Arseniosi,  8.00  Gm  (^ij). 

CocaiDi  Hydrochloris,  2.00  Gm.  (^ss). 

M.  S.    For  office  use. 

To  prepare  for  devitalizing  pulp,  make  a  paste 
with  caustic  potash  and  carbolic  acid.  (Robinson's 
Remedy.) 

Antimony. 

Symbol,  At.  Wt.  Sp.  Gr.         Valency, 

Sb.  120  6.7  III— Y. 

Antimony  is  not  an  abundant  metal,  although 


Arsenic.  203 

I'omparatively  inexpensive.  It  exists  in  nature  free, 
and  as  an  oxide,  a  sulphide,  and  with  silver  and  sul- 
phur. The  metal  may  be  obtained  by  heating  its 
sulphide  with  iron,  Sb2S3+Fe3=3FeS  +  2Sb ;  or 
hy  roasting  its  sulphide,  it  is  converted  into  an 
oxide,  which  is  reduced  by  carbon. 

Antimony  is  a  blue-white  solid,  hard  and  very 
brittle ;  does  not  tarnish  in  the  air,  but  takes  tire 
at  a  red  heat ;  is  soluble  in  nitric  acid,  and  forms 
synthetic  binary  compounds,  with  chlorine,  oxy- 
gen, bromine  and  iodine.  Zinc  precipitates  anti- 
mony from  its  solutions,  as  a  black  powder,  which 
is  used  for  giving  plaster  casts  the  appearance  of 
steel.  The  metal  melts  at  450  (840F).  A  curious 
allotropic  variety  is  obtained  by  electrolysis,  w^hich 
is  explosive  when  hammered  or  heated.  The  chief 
use  of  the  metal  is  in  giving  hardness  to  alloys- 
Typemetal  is  an  alloy  of  antimony,  lead,  and  tin  ; 
Britannia  metal,  of  antimony  and  tin  :  and  Babbit's 
anti-friction  metal,  useful  for  dies,  is  composed  of 
antimony,  lead,  tin,  and  copper. 

Antimony  forms  three  oxides  Sb203,  Sb2  04, 
Sb2  05.  The  trioxide  and  pentoxide,  like  those  of 
nitrogen  are  acid  oxides,  but  their  acids  HSb02, 
IlSb03,  unlike  those  of  nitrogen,  are  very  weak. 
There  is  also  an  ortho-antimonic  acid,  H^SbOg, 
and  an    ortho-antimonous  acid,  IlgSbOg. 


204  Inorganic  Chemistry. 

Antimony  and  potassium  tartrate,  is  a  salt  known 
as  "  tartar-emetic." 

Antimonous  chloride,  SbClg,  is  the  "  butter  of 
antimony,"  which  is  changed  by  water,  into  an 
oxychloride,  SbClg  -f  H2O  =  2HC1  +  SbOCl. 

Antimony  oxysulphide,  Sb2  02S2,  imparts  a  yel- 
low tint  to  glass  and  porcelain.  The  nature  of 
HgSb  was  sufficently  indicated  in  the  preceding 
chapter. 


i 


Bismuth.  205 


CHAPTER  XVL 

BISMUTH. 

Symbol,         At.  Wt.         Sp.  Gr.         Valency, 
Bi.  208.  9.80.  III-V. 

Bismuth,  like  antimony,  belongs  to  the  same 
class  with  arsenic.  It  is  principally  found  native, 
and  is  obtained  by  simply  melting  out  the  metal 
from  adherent  rocky  matter  and  collecting  in  suit- 
able molds.  It  is  comparatively  rare,  and  besides 
its  native  condition,  is  found  in  only  a  few  min- 
erals, as  an  oxide,  a  sulphide,  a  sulpho-telluride, 
and  a  carbonate. 

It  is  a  brilliant  reddish- white,  hard  brittle  metal; 
crystallizes  in  rhombohedroiis,  which,  on  account 
of  slight  tarnishing  in  the  air,  present  an  iridescent 
appearance.  It  is  acted  on  readily  by  nitric  and 
nitro-hydrochloric  acids,  and  by  chlorine,  but  not 
by  hydrochloric  or  cold  sulphuric  acids.  It  melts 
at  264°  (507°F),  and  in  solidifying,  expands  3^  of 
its  bulk,  making  a  sharply  defined  cast  when 
poured  into  a  mold. 

Bifemnth  is  important  chiefly  as  a  constituent  of 
fusible  alloys,  one  of  which  was  described  in  a  pre- 


206  Inorganic  Chemistry. 

vious  chapter.  Another  is  composed  of  3  parts 
of  cadmium,  4  of  tin,  8  of  ead,  and  15  of  bismuth, 
which  melts  as  low  as  60°  (140°F);  and  another, 
which  melts  at  82°  (180°F),  is  composed  of  1  of 
cadmium,  6  of  lead,  and  7  of  bismuth.  Other  al- 
loys, of  the  above  kind,  serve  as  safety  plugs  for 
steam  boilers,  vulcanizers,  etc. 

In  most  of  its  compounds  bismuth  acts  as  atriva- 
lent  base,  such  as  the  chloride,  BiClg  ;  the  oxide, 
Bi.^Og  ;  the  sulphate,  312(804)3,  and  the  nitrate, 
Bi(!N'03)3.  When  water  is  added  in  excess  to  a 
solution  of  a  bismuth  salt,  the  bismuth,  salt  decom- 
poses, a  basic  salt  being  precipitated. 

The  formation  of  bismuth  sub-nitrate,  HgBiOg 
NO 3,  by  dissolving  bismuth  in  nitric  acid,  depends 
on  this  principle,  although  the  process  itself  is 
rather  complicated. 

When  water  is  added  to  bismuth  chloride, 
BiCl3,  a  white  precipitate  of  bismuth  oxycloride 
results.  BiClg  +  H2O  =  2HC1  -f  BiOCl.  This 
latter  substance  is  a  white  soft  bulky  powder,  re- 
sembling the  sub-nitrate,  and  is  used  as  a  "face 
powder."  The  following  equation,  BiClg  + 
3K0H  =  3KCI  +  Bi(OH) 3,  shows  the  formation 
of  bismuth  hydrate,  a  precipitate  which,  on  drying, 
loses  water,  and  becomes  an  amorphous  white 
flocculent  powder,  less  unwholesome  to  the  skin 


Bismuth,  Vanadium  and  Tantalum.         207 

than  tlie  oxychloride.  This  hydrated  oxide,  BiO(HO), 
is  basic  to  strong  acids,  as  sulpliuric,  etc.,  and 
acid  to  strong  bases  ,  as  sodium,  etc.;  for  example, 
NaBiO^,  sodium  bismuthate. 

Materia  Medica. — Bismuthi  sub-nitras  is  em- 
ployed locally,  in  powder,  alone,  or  with  charcoal, 
in  eancrum  oris,  and  other  forms  of  ulceration 
of  the  mouth,  in  intertrigo,  and  as  a  snutf  in  inflam- 
mation of  Schneiderian  membrane,  etc.  It  possesses 
astringent,  sedative,  and  antiseptic  properties,  in 
virtue  of  which,  it  probably  acts  internally  in  re- 
lieving gastric  pains,  vomiting,  and  diarrhoea. 

Dose.— 0.50— 1.00  Gm.  (gr.  viij— xv.) 

Vanadium. 

Symbol,        At.  Wt.         Sp.  Gr.  Valency, 

V.  51.  3.6.  V. 

Vanadium  is  an  extremely  rare  substance ;  it  oc- 
curs in  small  quantity  in  some  iron,  lead,  and  cop- 
per ores,  and  is  a  non- volatile  gray- white  powder. 
It  forms  5  oxides  corresponding  to  those  of  nitro- 
gen,  VjO,  V,O„V,0„  V,0„  and  Y,0,.  Vana- 
dium  compounds  have  very  little  practical  import- 
ance. 
Tantalum  and  Niobium. 

Ta.       At.  Wt.  Nb.  Valency, 

182.  94.  V. 

These  so-called  metals  are  very  rare.     Both  are 


208  Inorganic  Chemistry. 

are  black  powders.    They  form  acid  oxides.     W\o- 
bium  is  also  known  by  the  better  name,  Columhium. 

Molybdenum,  Tungsten. 

Symbol,         At.  Wt.       Sp.  Gr.         Valency, 
Mo.  96  8.6  VI. 

Molybdenum  is  another  rare  element,  occurring 
in  small  quantity,  as  a  sulphide,  M0S2,  and  as  lead 
molybdenate.  It  is  a  white,  brittle  metal,  almost  ab- 
solutely infusible.  When  heated  in  air,  it  oxidizes 
to  molyhdic  oxide,  M0O3,  analogous  to  sulphuric 
oxide,  SO3;  molyhdic  aci<i,  H.^MoO^,  is  analogous 
to  sulphhuric  acid,  H2SO4.  Some  of  the  molybde- 
num compounds  are  indispensable  reagents. 

Tungsten. 

Symbol,  At.  Wt.       Sp.  Gr.  Valency, 

W  (Wolfram),       184.  19.26.  VI. 

Tungsten  is  not  abundant,  but  more  so  than 
molybdenum.  It  is  found  as  ferrous  tungstate, 
FeW04,  in  the  mineral  ivolfram,  and  as  calcium 
tungstate,  and  lead  tungstate.  It  is  a  white  metal, 
hard  and  brittle,  and  very  heavy,  hence  its  name, 
signifying  heavy  stone;  it  is  difficult  to  fuse,  and 
when  heated  to  redness  takes  fire,  and  produces 
tungstic  oxide,  WO3.  A  small  addition  of  tungs- 
ten to  steel,  is  said  to  confer  on  the  latter,  extraor- 
dinarv  hardness  and  fineness. 


Uranium.  209 

The  oxide,  WO3,  is  an  acid  oxide,  the  corre- 
sponding acid  having  the  formula,  H2WO4.  The 
tungstate  of  the  alkali  metals  (more  especially  of 
sodium,  NagWO^),  are  sometimes  used  as  mor- 
dants, and  for  rendering  light  cloth  fabrics  unin- 
flammable. 

Uranium. 

Symbol,         At.  Wt.  Sp.  Gr.  Valency, 

U.  2.39.  18.68.  VI. 

Uranium  is  another  rare  metal,  existing  in  only 
a  few  minerals ;  it  is  found  mainly  in  the  form  of  an 
oxide. 

When  fused,  which  is  difficult  to  accomplish,  it 
is  a  white  malleable  metal,  permanent  in  air,  but 
if  pulverized,  and  heated  to  about  200°  (392F),  it 
takes  fire,  and  burns  with  great  splendor,  produc- 
ing a  green  oxide.  It  also  shows  great  energy  in 
uniting  with  chlorine  and  sulphur. 

Uranium  forms  several  oxides,  which  are  basic 
in  the  presence  of  strong  acids,  and  acid  in  the 
presence  of  strong  bases,  like  those  of  tungsten. 
It  is  quadrivalent  in  tlie  uranous  compounds,  as 
UCI4,  UO2,  U(S04)2,  etc.,  and  sexvalent  in  the 
uranic  compounds.  In  the  uranic  salts  the  bivalent 
radical  uranyl,  UO2,  is  supposed  to  be  the  electro- 
positive radical,  as  in  uranic  oxide  (uranyl  oxide), 
(U0,)0;  also  (U0,)C1„  (UO,),2X03),  (UO,)SO,). 
18 


210  Inorganic  Chemistry. 

There  is  no  uranic  chloride  (UClg),  or  bromide,  etc., 
as  with  tungsten. 

Alkaline  bases  form  salts  with  uranic  oxide, 
UO3,  known  as  uranates ;  thus.  Sodium  Uran- 
ate,  Na2  0,  2UO3,  and  Ammonium  Uranate, 
Am20,2U03,  which  are  known  as  "  uranium  yel- 
low," are  used  in  coloring  porcelain  and  glass,  con- 
ferring a  green-yellow  color. 

Chromium. 

Symbol,         At.  Wt.         Sp.  Gr.         Valency, 
Cr.  52.  6.81.  YL 

Chromium  occurs  somewhat  more  abundantly 
than  the  other  metals  of  the  chromium  group.  It 
occurs  as  lead  chromate,  and  also  in  small  propor- 
tion in  several  minerals,  but  is  obtained  usually 
from  ferrous  chromite,  FeCr2  04. 

Chromium,  obtained  by  reducing  its  oxide  by 
carbon,  exhibits  as  a  very  hard,  steel-gray  mass, 
practically  infusible ;  obtained  by  reducing  the 
chloride  by  zinc,  it  occurs  as  a  glistening  gray- 
green  powder,  showing  minute  tetragonal  octahe- 
drons. It  is  unaffected  in  air,  but  burns,  when 
heated  in  oxygen.  It  has  been  found  in  meteoric 
iron.  It  is  readily  acted  upon  by  dilute  hydro- 
chloric acid,  less  so  by  dilute  sulphuric  acid,  and 
not  at  all  by  concentrated  nitric  acid.  The  metal 
itself  is  of  no  practical  use,  but  its  compounds  are 


Chromium.  211 

both  numerous  and  important;  they  are  nearly  all 
brilliant  in  colors,  whence  the  name  of  the  element, 
taken  from  a  Greek  word,  signifying  color, 

Chromous  chloride,  CrCl2,  is  one  of  the  most 
powerful  reducing  agents  known.  It  precipitates 
gold  from  solution  of  auric  chloride. 

Chromic  Chlroide,  Cr2Clg,  occurs  in  crystal- 
line plates  of  a  pale  violet  color.  Its  hydrate, 
Cr2Clg9H20,  is  a  dark  green. 

Chromous  oxide,  CrO,  is  a  strong  base,  forming 
salts  of  a  pale  blue,  but  unstable,  as  they  rapidly 
absorb  oxygen  from  the  air. 

Chromic  oxide,  sesquioxide,  Crg-Og,  is  a  bright 
green  powder.  It  is  used  in  giving  a  green  color 
to  porcelain  and  glass,  and  to  modify  the  yellow  of 
titanium  oxide  in  porcelain  teeth.  The  emerald 
owes  its  color  to  this  compound.  It  is  basic  or  acid, 
according  to  the  presence  of  acid  or  basic  radicals. 

Chromium  trioxide,  CrOg,  may  be  obtained  in 
superb  crimson  needles,  by  adding  strong  sulphuric 
acid  carefully  to  a  saturated  aqueous  solution  of 
potassium  bichromate,  allowing  the  mixture  to 
cool,  and  drying  on  a  porous  tile.  It  is  a  powerful 
oxidizing  substance.  A  drop  of  alcohol  coming 
in  contact  with  the  dry  crystal,  will  ignite  by  the 
heat  of  the  oxidation. 


212  Inorganic  Chemistry. 

Chromic  trioxide  is  the  typical  acid  oxide  of 
chromic  acid  and  the  chromates. 

CrO^    +  H2O  =  H2Cr04 

(Chromic  Acid.) 

With  potassium,  for  example,  it  forms  the  normal 
salt,  K2Cr04,  and  by  addition  to  this,  of  one  more 
molecule  of  CrOg,  we  have  potassium  pyrochro- 
mate  or  dichroraate. 

K^OrOg   +  CrOg  =  K2Cr207. 

This  salt  is  better  known  as  hi-chromate  of  potash. 
It  occurs  iu  splendid  orange-red  crystals,  and  is 
employed  in  the  arts  for  various  purposes;  in  pre- 
paring the  chromium  paints,  in  dying,  in  calico 
printing,  and  in  photography.  Gelatin  containing 
the  salt,  remains  insoluble  wherever  acted  on  by 
light,  but  is  soluble  in  other  portions :  the  photo- 
graph taken  on  such  a  film  of  gelatin  stands  out 
in  bold  relief,  and  can  be  copied  in  electrotype. 
This  salt  is  also  used  in  certain  galvanic  battery 
solutions. 

By  adding  two  molecules  of  2(Cr03)  to  K2Cr04, 
we  have  K2Cr30iQ. 

Plumbum  chromate,  PbCr04,  is  "chrome  yel- 
low," which,  by  boiling  with  caustic  alkali  is  con- 
verted into  PbCr04,PbO,  "chrome  red;"  and 
"  chrome  orange  "  is  a  mixture  of  these,  the  orange 
ray  being  intermediate  between  yellow  and  red. 


Chromium.  2lS 

Materia   Medica. — Chromic   acid   is   one  of  the 
most  energetic  disinfectants,  in  virtue  of  oxidizing 

power.  It  should  not  be  mixed  with  organic  sub- 
stances. As  an  escharotic  it  penetrates  deeply,  and 
wlienever  used  in  the  mouth,  in  treatment  of  phag- 
edsenic  ulcers,  etc.,  it  should  be  in  suitable  dilu- 
tion, and  very  carefully  applied. 


214  Inorganic  Chemistry. 


CHAPTER  XVII. 
GOLD,  ETC. 

Symbol,  At.  Wt.         Sp.  Gr.         Valency, 

Au.  96.5.  19-4.  I-III. 

Gold,  aurum ;  the  alchemistic  "  Rex  Metallo- 
rum,"  has  held  its  supremacy  among  the  metals 
from  the  earliest  historic  times.  It  occurs  native, 
and  though  very  widely  diffused,  is  not  found  in 
"  paying  "  quantities  outside  of  a  few  limited  sec- 
tions, as  in  Australia,  and  the  gold  fields  of  the 
United  States. 

The  association  of  gold  in  nature,  is  generally 
with  quartz,  iron  oxide,  in  the  debris  or  alluvial 
deposits  of  such  rocks,  and  in  the  sands  of  various 
rivers.  The  only  exception  to  its  otherwise  uni- 
versal existence  in  the  metallic  state,  is  as  a  tellu- 
ride,  which  also  contains  silver  and  other  tellurides. 
Alluvial  gold  is  obtained  by  washing,  which  sepa- 
rates the  metal  from  the  earthy  matter.  When  a 
veinstone  is  worked  for  gold,  it  is  crushed  to  pow- 
der, and  if  it  contains  pyrites,  it  is  roasted;  it  is 
then  agitated  with  mercury,  which  takes  up  the 
gold  by  amalgamation.    The  mercury  is  separated 


Gold,  215 

from  the  gold  by  pressure  and  distillation,  and  is 
recovered  for  future  use.  If  traces  of  base  metals 
are  present,  the  gold  is  refined  by  passing  chlorine 
gas  through  the  melted  metal.  By  quartatioriy  it 
is  separated  from  silver;  the  operation  consisting 
of  adding  silver  to  the  bullion,  until  the  latter  is 
made  up  of  three  parts  of  silver  and  one  of  gold. 
The  alloy  is  rolled  into  thin  ribbon,  and  then  the 
silver  in  it  dissolved  out  by  nitric  acid. 

Gold  possesses  considerable  tenacity,  and  ranks 
first*  in  malleability  and  ductility;  it  is  soft,  and 
crystallizes  in  isometric  forms;  its  color  is  brilliant 
orange-yellow,  by  reflected  light;  and  when  beaten 
into  very  thin  leaves,  shows  a  bright  green,  by 
transmitted  light.    It  melts  at  about  1100°  (2012F.) 

Gold  is  always  alloyed  with  other  metals,  to  give 
it  the  required  hardness  for  practical  use  in  the 
arts,  except  in  the  case  of  preparations  of  gold  for 
filling  cavities  in  teeth,  wherein  absolute  purity  is 
desirable. 

Pure  gold  is  24  carats  fine.  The  mint  alloy  of 
the  United  States  is  22  carats ;  that  is,  9  parts  of 
gold  and  1  part  of  copper.  Jewelers'  gold  is  of  a 
less  carat,  ranging  downward  from  18  to  12  carats. 
Copper  confers  a  ruddy  tint  to  the  alloy,  and  silver 
a  paler  color.  Platinum,  or  palladium,  like  Ag., 
glvee  to  gold  a  lighter  shade ;  the  alloy,  with  small 


216  Inorganic  Chemistry. 

proportions  of  platinum,  is  hard  and  elastic;  with 
palladium,  hard  and  brittle.  Traces  of  such  metals 
as  antimony,  tin,  arsenic,  bismuth,  lead,  etc.,  im- 
pair the  malleability  and  ductility  of  gold,  and 
render  it  intractable. 

Dentists'  gold  foil,  presumed  to  approximate  24 
carats,  is  obtained  by  successive  annealings  and 
hammering  of  the  ingot,  until  thin  enough  to  pass 
between  the  rollers  of  a  flatting  mill.  The  thin 
ribbons  of  gold  thus  prepared  are  cut  into  small 
squares,  and  these  are  piled  in  considerable  num- 
ber between  pieces  of  vellum  and  parchment,  and 
beaten;  again  cut  into  squares,  and  beaten;  and 
finally  hammered  between  "  gold  beater's  "  skins, 
until  the  required  foil  number  is  obtained. 

Gold  is  practically  unalFected  by  the  air,  sulphur- 
retted  hydrogen,  the  alkalies,  or  any  single  acid, 
except,  slightly,  by  selenic  acid.  It  yields  readily, 
however,  to  nascent  chlorine,  a  gentle  heat  favor- 
ing the  rapidity  of  the  combination. 

The  chlorine  for  the  purpose,  is  usually  produced 
by  mixing  3  parts  of  hydrochloric  acid  with  1  part 
of  nitric  acid,  the  mixture  being  known  as  aqua 
regia,  alluded  to  in  a  previous  chapter. 

To  obtain  free  gold  from  its  alloy  with  copper, 
and  silver,  or  other  metals,  or  either  one  alone,  dis- 


Gold.  217 

solve  the  alloy  in  aqua  regia,  facilitated  by  a  gentle 
heat.     The  reaction  will  be  as  follows: 

12HC1  +  4IIXO3  =  8H^0  +  4N0C1  +  8C1. 
6C1  -I-  Au  +  Cu  +  Ag  ==  AuClg  +  CuCl^  +  AgCl. 

The  silver  chloride  falls  down  as  a  white  curdy 
precipitate,  and  the  chlorides  of  gold  and  copper 
remain  in  solution;  it  now  remains  to  precipitate 
the  gold,  and  leave  the  copper  in  solution.  This  is 
accomplished  by  various  reagents,  of  which,  two 
only  need  be  mentioned,  namely,  solutions  of  fer- 
rous sulphate  (copperas),  and  oxalic  acid.  The 
ferrous  sulphate  is  changed  into  ferric  compounds, 
and  the  oxalic  acid  into  carbon  dioxide,  and  hydro- 
chloric acid,  thus : 
6FeS04  +  2AUCI3  =  2Fe2(S04),  +  Fe2Cl6  +  2Au. 

or, 

3H2C2O4  +  2AUCI5  =  6CO2  -f  6HC1  +  2Au. 

Oxalic  Acid. 

The  gold  precipitated  by  the  ferrous  sulphate, 
occurs  as  a  dirty-looking  brown  powder;  that  by 
oxalic  acid,  as  spongy  or  crystalline.  The  precipi- 
tate is  washed,  placed  in  a  crucible  lined  with 
borax,  melted,  and  poured  into  proper  ingot. 

Scraps,  filings,  and  sweepings  of  gold  alloys  con- 
taining more  or  less  of  baser  metals,  as  zinc,  tin,  lead, 
antimony,  bismuth,  iron,  etc.,  are  often  refined  by 
the  dry  method  or  roasting  process,  which  consists 
of  adding  to  the  heated  mass,  either  oxidizing, 
19 


218  Inorganic  Chemistry. 

chloridizing,  or  sulphidizing  substances.  lN"iter, 
(KNO3),  is  rich  in  oxygen,  which  it  readily  gives 
up  when  heated.  It  is,  therefore,  the  substance 
usually  employed  as  the  oxidizer,  and  to  whose 
power  all  the  baser  metals  named,  except  tin, 
cheerfully  submit.  The  latter  metal,  however,  is 
easily  chloridized  by  heating  with  mercuric  chlo- 
ride (HgCl^).  When  sulphur  is  needed  in  the  pro 
cess,  it  is  furnished  by  the  crude  antimonium  sul- 
phide (Sb2!S3).  The  disengaged  sulphur  forms  sul- 
phides of  the  base  metals  present;  the  antimony 
alloys  with  the  gold,  and  is  afterward  driven  olf 
from  the  latter,  by  heating  in  an  excess  of  air. 

The  chemical  compounds  of  gold  are  neither  nu- 
merous nor  important. 

Auric  chloride^  AuClg,  resulting  by  dissolving 
gold  in  aqua  regia  and  evaporating  the  solution 
over  the  water  bath,  occurs  as  deliquescent,  dark 
red  crystals,  soluble  in  water,  ether,  and  alcohol ; 
of  a  styptic  taste  and  escharotic  and  disinfectant 
properties,  the  latter  effect  being  due  to  the  ease 
with  which  it  decomposes.  It  forms  yellow  double 
chlorides,  with  the  chlorides  of  sodium,  potassium 
and  ammonium,  asE^aCl,  AuClg,  called  sodio-chlor- 
aurate. 

Aurous  chloride,  AuCl,  is  obtained  as  a  yellow- 
white  substance,  by  heating  evaporated  auric  chlo- 


Gold,  219 

ride.     It  is  insoluble  in  water,  and  tends  to  change 
to  free  gold  and  auric  chloride. 

Auric  oxide,  AU2O3,  is  produced  by  digesting 
magnesia,  MgO,  in  auric  chloride.  The  magne- 
sium aurate  that  is  formed,  is  decomposed  by  nitric 
acid,  and  on  drying  the  residue,  auric  oxide  is  found 
aa  a  dark  brown  powder,  easily  decomposed  by 
light  and  heat.  It  acts  generally  as  an  acid  oxide, 
uniting  with  bases  to  form  aurates  thus 

K2O     +     AU2O3     =:     2KAUO2 

Potassium  Aurate. 

Ammonium  aurate,  obtained  by  digesting  auric 
oxide  in  ammonia,  is  known  as  fulminating  gold, 
a  dangerous  explosive,  ^H^,  AUO2. 

Aurous  oxit/e,  Au  2  0,  is  a  greenish  powder.  Pur- 
ple of  Cassiush  probably  a  compound  of  this  oxide, 
with  the  tw^o  oxides  of  tin,  obtained  by  reaction 
between  auric  chloride  and  the  two  chlorides  of 
tin,  produced  by  dissolving  gold  and  tin  in  aqua 
regia,  and  adding  a  weak  solution  of  tin  in  hydro- 
chloric acid.  Chloridation  and  oxidation  of  both 
metals  take  place  successively.  "  Purple  of  Cas- 
sius  "  (Au20Sn305),  as  before  mentioned,  is  used 
in  coloring  porcelain. 

Materia  Medica. — The  mono-(aurous)  chloride 
is  not  used  in  medicine.  The  tri-(auric)  chloride 
is  sometimes  employed  in  obtunding  sensitive  den- 
tine dissolved  in  ether  or  alcohol.     It  acts  like  the 


220  Inorganic  Chemistry. 

chloride  of  zinc,  by  dehydrating  the  gelatinous  con- 
stituent of  the  dentine. 

For  internal  administration  the  trichloride  is 
usually  combined  with  sodium  chloride.  It  pro- 
duces an  exhilarating  influence  on  the  nervous  sys- 
tem, and  is  useful  in  hypochondriasis,  functional 
impotence,  etc.,  and  in  treating  syphilis,  as  a  sub- 
stitute for  corrosive  sublimate.  Its  antidote  is  the 
same  as  for  the  latter  drug.  The  so-called  bi-ch\o- 
ride  of  gold  cure  mixture  for  alcoholism  and  the 
opium  habit,  is  said  to  contain  no  gold  whatever, 
and  is  not  regarded  as  belonging  to  legitimate 
therapeutics. 

Dose.  Auric  chloride,  0.001-0.003  Gm.  (gr.  q\-2\)- 
Professor  Grant  Molyneux,  of  Cincinnati,  has 
recently  succeeded  in  developing  a  process  of  gild- 
ing porcelain  teeth  with  gold,  to  represent  fillings, 
facings,  etc.  The  process  consists  essentially  of 
compounding  neutral  auric  chloride  (AuClg),  with 
Venice  turpentine,  and  thinning  the  mixture  with 
Artist's  Dresden  "  thick  oil,"  to  the  proper  consist- 
ency. This  is  spread  in  desired  position  on  the 
porcelain,  and  allowed  to  dry  slowly  over  a  water 
bath.  It  is  then  subjected  to  a  red  heat  and,  on 
cooling,  leaves  a  pure  gold  surface,  susceptible  of 
a  fine  polish. 
•  A  similar  process  with  neutral  platinic  chloride, 


Gold,  Platinum.  221 

(PtCl^),  instead  of  gold  solution,  has  been  found 
by  Professor  M.  to  be  effective  in  forming  a  surface 
of  platmum,  as  a  successful  backing  on  porcelain 
teeth,  to  which  gold  can  be  soldered  without  the 
usual  intervention  of  platinum  pins,  making  an 
attachment  thus,  as  strong  as  the  porcelain  itself. 

PLATINUM. 

Symbol,         At.  Wt.         Sp.  Gr.         Valency, 
Pt.  197.  21.5.  II-IY. 

Platinum,  originally  found  in  South  America,  is 
now  principally  supplied  from  the  Ural  Mountains 
and,  to  some  extent,  from  Borneo  and  California. 

It  always  occurs  in  the  metallic  state,  in  little 
grains  or  lumps,  generally  alloyed  with  gold,  cop- 
per, and  iron ;  and  its  natural  congeners  of  the 
platinum  group,  such  as  iridium,  osmium,  etc. 

The  methods  employed  for  separating  pure  plat- 
inum from  its  ores  are  complicated.  It  is  a  blue- 
white  metal,  less  brilliant  than  silver;  not  affected 
by  the  air,  nor  by  any  single  acid.  It  combines 
directly  with  sulphur,  silicon,  arsenic,  phosphorus, 
and  chlorine  ;  is  acted  upon  by  fused  caustic  hy- 
drates, and  dissolves  slowly  in  aqua  regia.  It  is 
malleable  and  ductile  ;  is  possessed  of  considerable 
tenacity ;  is  about  as  hard  as  copper,  expands  uni- 
formly with  glass  or  porcelain,  and  is  relatively  a 


222  Liorganic  Chemistry. 

poor  conductor  of  heat  and  electricity :  it  melts  at 
the  temperature  of  the  oxyhydrogen  flame. 

On  account  of  its  infusibility,  and  insolubility  in 
acids,  platinum  is  used  in  various  forms  in  the 
chemical  laboratory,  such  as  dishes,  crucibles,  stills, 
foils,  wire,  blow-pipe  tips,  etc.;  also  in  the  construc- 
tion of  incandescent  electric  light  lamps,  as  the  neg- 
ative element  in  Grove's  galvanic  battery,  as  sustain- 
ing pins  in  porcelain  teeth,  as  a  basis  for  continuous 
gum  plates,  and  in  combination  with  felspar,  in 
giving  a  required  shade  to  enamel.  In  the  form  of 
platinum-foil,  sponge,  or  better  ^i\\\,j)latinum  black, 
it  possesses,  in  a  high  degree,  the  power  of  con- 
densing gases  on  its  surface,  the  latter  being  able 
to  condense  800  times  its  own  volume  of  oxygen. 

Platinum  compounds  are  numerous  and  some- 
what interesting. 

Platinic  Chloride,  PtCl4,  is  formed  whenever  plat- 
inum is  dissolved  in  aqua  regia;  on  evaporation 
it  shows  as  a  deliquescent  red-brown  substance, 
soluble  it  water,  alcohol  and  ether ;  it  is  used  in 
chemical  analysis  in  detecting  alkaloidal  bases,  as 
'ptomaines,  etc.  It  unites  with  the  alkali  chlorides 
to  form  chloroplatinates,  as  2KC1,  PtCl4. 

Platinous  Chloride,  PtCl2,  is  obtained  when  pla- 
tinic chloride  is  heated  gently,  until  chlorine  ceases 
to  escape;  it  is  a  dark  green  powder,  insoluble  in 


Iridium  and  Osmium.  223 

water.     It  forms  with  alkali  chlorides,  chloroplati- 

nites,  as  2KC1,  PtCl2. 

Platinie  oxide,  PtOg,  and  platinous  oxide,  PtO, 

and  corresponding  sulphides  are  known;  also,  a 

remarkable  series  of  compounds,  formed  by  action 

of  ammonia  upon  platinum  salts,  called  ammoni- 

acal  platinum  compounds,  as 

p    fNH3Cl 
^^t^HgCl 

Iridium  and  Osmium  are  heavier  than  platinum ; 
the  sp.  gr.  of  Ir  being  22,  and  of  Os,  22.5.  Their 
atomic  weights  are  near  that  of  platinum,  being 
192.7  and  198.6  respectively.  Iridium  is  not  acted 
on  by  the  air,  nor  is  it  soluble  in  aqua  regia.  It  re- 
sembles polished  steel,  is  brittle  and  very  hard,  and 
is  often  alloyed  with  platinum,  in  the  form  of  wire 
and  posts,  for  crown  and  bridge  work. 

The  remaining  congeners  of  platinum  are  Palla- 
dium, Rhodium,  and  Ruthenium ;  their  sp.  gr.  are 
respectively  11.4, 12,  and  11.4;  their  atomic  weights 
are  106,  104,  and  103.  They  are  of  little  relative 
importance.  Palladium  has  the  property  of  ab- 
sorbing hydrogen  ;  the  latter  thus,  is  said  to  be 
occluded. 


224  Inorganic  Chemistry. 


CHAPTER  XVIII. 

ELECTROLYSIS. 

Any  compound  liquid,  capable  of  conducting  the 
electric  current,  is  an  electrolyte,  and  will  suffer  de- 
composition by  an  electric  current,  in  direct  pro- 
portion to  its  conducting  power. 

One  of  the  sources  of  electric  development  is  by 
chemical  action,  and  an  arrangement  by  which  the 
force  is  utilized  thus,  is  called  a  galvanic,  or  voltaic 
battery.  Galvanic  batteries  are  constructed  of  vari- 
ous substances,  and  in  various  forms :  one  principle, 
however,  obtains  in  all,  viz.,  unequal  chemical  ac- 
tion on  conductors,  in  the  exciting  liquid.  The 
simplest  conception  of  a  galvanic  battery,  may  con- 
sider its  construction  as  consisting  of  the  metals, 
zinc  and  copper,  immersed  in  dilute  sulphuric 
acid;  the  zinc  and  copper  are  acted  upon  une- 
qually by  the  acid,  zinc  more  than  copper;  zinc 
is,  therefore,  electro-positive  to  copper,  and  the  lat- 
ter becomes  electro-negative.  Electricity  developed 
at  the  zinc  plate,  is  called  positive;  that  at  the  cop- 
per plate,  ne^a<ii;e.  Positive  electricity  passes /rom 
the  zinc  through  the  dilute  sulphuric  acid,  and  is 


Electrolysis.  225 

collected  at  the  negative  plate ;  so  that  if  conduct- 
ing wires  be  attached  to  the  metals,  the  wire  in 
connection  with  the  copper  will  conduct  positive 
electricity,  and  the  one  in  connection  with  the  zinc 
will  be  the  negative  conductor. 

The  extremities  of  these  wires,  or  rheophoies 
{electrodes),  are  denominated  poles ;  or,  positive  pole 
and  negative  pole,  respectively.  When  the  con- 
ducting wires  are  in  contact,  or  another  conductor 
is  interposed  between  them,  the  circuit  is  closed; 
otherwise  the  circuit  is  broken. 

Other  forms  of  battery,  than  the  one  described, 
are  common.  The  bichromate  of  potash  battery 
consists  of  the  same  materials,  except  it  has  carbon 
instead  of  copper  for  the  negative  element,  and  a 
solution  of  potassium  dichr ornate  mixed  with  the 
dilute  sulphuric  acid.  The  action  of  the  acid  on 
the  zinc,  as  is  well  known,  sets  hydrogen  free, 
which  accumulates  on,  or  polarizes,  the  negative 
plate,  greatly  interfering  with  the  continuance  of 
the  current.  The  solution  of  the  potash  salt,  is 
changed  to  chromic  acid,  which  takes  up  the  hydro- 
gen, thus  preventing  the  polarization  referred  to. 

The  liquid  in  such  a  battery  consists  of  water, 
1000  CC  (fGm),  =  (2.11  pints),  sulphuric  acid, 
350  CC  =  (11.85  f.^),  potassium  dichromate, 
230   Gm.   (7  §).      Dissolve    the    latter  in  boiling 


226  Inorganic  Chemistry. 

water,  675  CC  (1.36  pints),  and  when  cool,  add  to 
the  acid  mixture. 

The  jpoles  of  the  battery,  when  employed  for  the 
purpose  of  mere  analysis,  are  usually  tipped  with 
platinum;  and  when  these  poles  are  immersed  in  a 
compound  liquid^  capable  of  conducting  the  current 
from  pole  to  pole,  decomposition  of  that  liquid  will 
ensue.  The  chemical  affinity,  i.  e.,  the  attraction 
between  the  radicals  of  the  molecules  of  which  the 
liquid  in  question  is  constituted,  will  be  overcome 
by  the  electric  force,  at  the  surface  of  the  poles,  the 
intermediate  portion  of  the  liquid  being  apparently 
unaffected.  The  following  arrangement  of  the 
molecules  of  water,  when  under  the  influence  of, 
the  electric  current,  will  serve  as  a  sufficient  exam- 
ple, for  the  process  of  electrolysis  in  general : 

Ihh} Ihh} Ihh} \Hh} IHh} iKH/HH- 
The  sign  -|-  in  the  above  diagram,  represents  the 
positive  pole  of  the  battery,  and  the  sign  —  the 
negative  pole.  It  will  be  observed  that  free  oxygen 
appears  at  the  positive  pole,  this  element  is  there- 
fore electro-negative  to  hydrogen ;  and  as  hydro- 
gen appears  at  the  negative  electrode,  it  is  positive 
to  oxygen.  In  this  way,  the  electric  status  of  each 
of  the  several  elements  is  relatively  determined. 

Oxygen  is  the  most  electro-negative  of  the  ele- 
ments ;  it  must  therefore  be  placed  first,  in  the  fol- 


Electrolysis.  227 

lowing  comparative  series.  The  other  elements 
are,  severally,  electro-negative  to  those  which  fol- 
low them,  and  electro-positive  to  those  that  precede 
them. 


Electro-negative. 

0 

B 

Sn 

Ba 

s 

C 

Pb 

Li 

:n" 

Sb 

Co 

Ka 

F 

Si 

iN-i 

K 

CI 

H 

Fe 

Eb 

Br 

Au 

Zn 

'Cs 

I 

Pt 

Mn 

Electro-positive, 

Se 

Hg 

Al 

P 

Ag 

Mg 

As 

Cu 

Ca 

Cr 

Bi 

Sr 

It  will  be  further  noticed  that  the  non-metallic 
elements,  as  a  class,  are  electro-negative,  while  the 
metals,  comparatively,  are  decidedly  electro-posi- 
tive. The  rarer  elements  are,  for  the  most  part, 
ignored  in  the  above  classification. 

The  liquid  state  is  essential  to  an  electrolyte;  the 
thinest  film  of  ice  is  sufilcient  to  arrest  the  elec- 
tric decomposition  of  water.  Mere  solution,  or 
fusion  by  heat,  will  accomplish  the  object.  But 
all  Hquids  are  not  electrolytes;  water  itself,  when 
pure,  is  not  a  good  conductor  of  the  current,  and 
therefore  suffers  only  slight  decomposition,  even 
by  a  powerful  battery ;  whereas,  if  it  contains  a 


228  Inorganic  Chemistry. 

very  small  proportion  of  sulphuric  acid,  it  is  ren 
(lered  a  good  conductor,  and  submits  readily  to  the 
process  of  electrolysis.    Alcohol,  ether,  and  numer 
ous  other  compounds  of  organic  chemistry,  and  a 
few  saline  inorganic  compounds,  refuse  to  conduct, 
and  thereby  avoid  decomposition. 

When  oxygen  salts  in  solution  suffer  electro- 
lysis, they  are  at  first  divided  into  free  metal  and  a 
negative  radical.  Sulphuric  acid  (hydrogen  sul- 
phate, H2S04),is  split  up  into  free  hydrogen,  which 
appears  at  the  negative  electrode,  and  sulphione, 
SO4,  which  appears  at  the  positive  electrode.  In 
the  same  manner  cupric  sulphate,  CUSO4,  splits  up 
into  metallic  copper  and  sulphione,  SO4  ;  the  SO4 
loses  an  atom  of  oxygen,  which  escapes,  and  the  res- 
idue, SO3,  unites  with  water  to  become  H2SO4. 
Sometimes  the  base  of  the  salt  is  divided,  so  that  free 
metal  appears  on  the  cathode,  and  metallic  oxide 
on  the  anode.  In  case  the  metal  is  capable  of  de- 
composing water,  as  potassium,  for  instance,  it 
will  form  a  hydroxide,  which  will  unite  with  the 
acid  present,  to  reproduce  the  typical  salt. 

2K0H    +    H,S04    r=   K5SO4    2II2O. 

The  amount  of  decomposition  of  each  electro- 
lyte is  perfectly  definite,  and  is  expressed  for  each 
by  the  value  of  its  chemical  equivalent.  The 
equivalent   value   of  water   is   9 ;  of  hydrochloric 


Electrolysis.  229 

acid,  36.5  ;  of  potassium  iodide,  166.  Now,  the 
same  current  passing  through  these  electrolytes, 
will  cause  simultaneous  decomposition  of  9  parts 
by  weight  of  water,  36.5  of  hydrochloric  acid,  and 
166  of  potassium  iodide,  and  so  on,  for  other  elec- 
trolytes as  well,  according  to  the  same  rule. 

The  process  of  electrolysis  is  subservient  to 
many  useful  applications  in  the  arts,  such  as  elec- 
tro-plating with  gold,  silver,  nickel,  etc.,  and  lately 
with  iridium.  In  the  making  of  electrotype^  by 
which  the  copper  from  cupric  sulphate  is  deposited 
in  the  impression  of  the  type,  set  up  in  the  usual 
way,  forming  a  coherent  matrix  for  a  permanent 
duplicate  cast.  Fac  similes  of  engraving  plates, 
medals,  casts,  etc.,  are  obtained  in  this  manner, 
and  the  wonderful  invention  of  photo-gravure  de- 
pends on  this  process  of  electrolysis. 

For  plating  surfaces  with  silver  .or  gold,  the  cya- 
nide of  the  metal,  obtained  by  reaction  between 
silver  chloride,  AgCl,  or  gold  trichloride,  AuClg, 
and  solution  of  potassium  cyanide,  KC!N",  is  the 
usual  electrolyte. 

A  recent  application  of  this  process  consists  in 
the  deposition  of  silver,  on  plaster  models  of  the 
maxilla,  for  base-plates  for  artificial  teeth.  The 
plaster  is  covered  \yith  graphite,  which  serves  as  a 
conductor,  outlining  the  size  of  the  phite  needed. 


230  Inorganic  Chemistry. 

This  is  attached  to  the  negative  pole  of  the  battery, 
and  metallic  silver  to  the  positive  pole.  The  latter 
is  dissolved,  more  or  less,  by  the  influence  of  the 
electric  current,  thus  keeping  up  the  strength  of 
the  liquid,  while  the  liquid  itself,  AgC^,  in  solu- 
tion, is  decomposed,  the  silver  going  to  the  nega- 
tive pole  until  the  required  thickness  of  the  plate 
is  obtained.  Then,  by  an  analogous  process,  the 
silver  plate  receives  suflacient  deposition  of  gold  to 
render  the  finished  base  all  that  may  be  desired  for 
the  purpose. 

In  all  cases  the  article  to  be  plated  must  be  in 
connection  with  the  negative  pole,  inasmuch  as  the 
electro-positive  radical  (metal),  of  the  electrolyte, 
is  set  free  at  the  negative  electrode.  The  positive 
radical  always  appears  at  the  negative  pole,  and 
the  negative  radical  at  the  positive  pole. 

Storage  batteries  are  plates  which  become  polar- 
ized by  receiving,  on  the  prepared  surfaces,  elec- 
tro-deposition of  certain  substances.  These  sub- 
stances undergo  further  chemical  change  by 
being  placed  in  a  liquid  able  to  act  chemically 
on  them,  by  which  a  secondary  current  is  pro- 
duced. For  example,  if  a  lead  salt  be  decomposed 
by  electrolysis,  metallic  lead  will  be  deposited  on 
the  cathode  (negative  pole),  and  lead  dioxide, 
Pb02,onthe  anode  (positive  pole).     When  plates 


Electrolysis.  231 

thus  prepared  are  placed  in  dilute  sulphuric  acid  aud 
properly  connected  by  outside  conductors,  a  cur- 
rent, reverse  from  the  original,  is  developed  by  the 
resulting  chemical  change ;  the  lead  becomes  oxi- 
dized and  the  lead  dioxide  is  reduced.  In  the  ma- 
jority of  cases  hydrogen  and  oxygen  are  the  polar- 
izing agencies,  and  thereby  prove  once  more  that 
force,  like  the  "  coon,  may  be  caught  a  coming  or 
a  going:" 

The  Faradic  current  is  an  induced,  interrupted 
current,  produced  by  wrapping  around  a  hollow 
cylinder  of  wood,  thick,  insulated  copper  wire,  the 
primary  coil;  the  secondary  coil,  made  of  thinner 
wire,  is  wrapped  around  the  insulated  first  coil. 
The  hollow  cylinder  contains  a  bundle  of  soft  iron 
wire,  which  acts  as  a  magnet,  when  a  current  of 
electricity  is  passed  through  the  inner  coil.  Near 
the  end  of  the  soft  iron  wires  there  plays  a  bar, 
also  of  soft  iron,  regulated  by  a  spring,  the  latter 
being  in  electric  connection  with  the  primary  coil. 
The  current  passing  through  the  primary  coil,  in- 
duces a  secondary  current  in  the  outer  coil,  and  in 
the  opposite  direction ;  the  soft  iron  bundle  is 
magnetized  by  the  current  at  the  same  time,  and 
attracts  the  soft  bar  of  iron,  whose  removal  thus, 
breaks  the  current.     In  consequence  of  the  break, 


232  Inorganic  Chemistry. 

the  bundle  of  iron  is  demagnetized,  permitting 
the  iron  bar  to  assume  its  former  position, 
which  occasions  a  repetition  of  the  phenomena, 
so  long  as  the  current  is  supplied.  The  induced 
current  is  necessarily  a  make  and  break,  or,  to  and 
fro  current,  the  stronger  shock  being  received 
from  the  break. 


Periodic  Law,  233 


CHAPTER  XIX. 

PERIODIC  LAW. 

The  Periodic  Law. — From  the  very  earliest  his- 
toric times,  the  theories  advanced  in  regard  to  the 
ultimate  nature  of  matter,  possessed  a  peculiar 
charm;  The  discovery  of  oxygeu  by  Priestly,  in 
1775,  lent  a  fresh  impetus  to  these  studies. 

Guyton  de  Morveau,  in  1782,  suggested  the  first 
idea  of  systematic  chemical  nomenclature,  followed 
by  Lavoisior,  who  elaborated  the  idea  so  fully,  that 
the  present  system  of  chemical  nomenclature  and 
notation  may  be  considered,  with  a  few  improve- 
ments, to  be  Lavoisian.  The  atomic  theory  of 
Dalton,  later,  accounted  satisfactorily  for  the  mathe- 
matics of  chemical  reactions;  and  the  relations  be- 
tween the  constants  of  the  elements  and  their 
specific  heats,  and  the  electric  behavior  of  the  ele- 
ments themselves,  seem  to  confirm  the  truth  of 
Dalton's  theory.  Prout's  hypothesis,  in  1816, 
that  the  atomic  weights  of  the  several  elements 
might  be  considered  as  exact  multiples  of  the 
atomic  weight  of  hydrogen  (a  theory,  by  the  way, 
which  is  only  slightly  at  variance  with  the  present 
20 


234  Inorganic  Chemistry. 

accepted  atomic  weights,  and  which  may  be  sus- 
tained by  further  corrections),  was  followed  by  the 
suggestion  that  possibly  hydrogen  was  the  "  pri- 
mordial matter  that  forms  the  other  elements,  by 
successive  condensations  of  itself." 

In  1864  and  1870,  Newlands  and  Mendelief,  re- 
spectively, independently  of  each  other,  erected 
tables  of  the  then  known  elements,  beginning  with 
those  of  the  lowest  atomic  weights,  and  advancing 
regularly  to  the  highest.  They  observed  a  natural 
grouping  of  the  elements  that  appeared  to  bear 
some  relation  to  their  several  atomic  weights,  and 
to  their  quantivalence  when  determined  by  their 
oxygen  compounds;  hydrogen  alone,  seeming  to 
be  especially  isolated  from  the  rest.  Therefore, 
leaving  hydrogen  to  itself,  if  we  begin  with  the 
element  of  next  lowest  atomic  weight,  viz.,  monad- 
lithium,  we  find  the  progression  to  be  as  follows: 

1.  H,        —         --        _       —       —      _ 

2.  Li7,      Be9,     Bll,     C12,  m4,  016,  F19  — 

3.  Ka23,  Mg24,  A127,  Si28,  P31,  S32,  C135.5 
If  we  study  the  position  of  the  above  elements,  we 

perceive  that  those  to  the  left  are  metallic^  and  those 
to  the  right  are  non-metallic,  while  the  interme- 
diate elements,  like  silicon,  possess  chemical  prop- 
erties intermediate  between  the  two  extremes.  We 
notice  that  the  line,  commencing  with  Li,  ends  ab- 


Periodic  Law.  235 

ruptly,  with  the  acidulous  fluorine,  inasmuch  as  the 
element  of  next  atomic  weight,  Na,  is  decidedly 
basic,  and  hence  introduces  another  period.  We 
notice,  further,  that  the  corresponding  members  of 
both  periods  have  corresponding  valencies,  so  that 
if  placed  in  vertical  columns,  all  those  in  the  same 
column  possess  the  same  valency.  The  elements 
in  each  group,  in  the  following  table,  arrange  them- 
selves naturally  in  double  columns,  those  on  the 
same  side  resembling  each  other  in  chemical  prop- 
erties. Each  series  is  a  small  period ;  series  1  and  2 
the  first  large  period ;  series  3  and  4  the  second,  etc. 
R  represents  one  atom  of  any  element,  as  RO 
means  one  atom,  united  to  one  of  oxygen,  or  RjO, 
two  atoms,  etc. 


236 


Inorganic  Chemistry. 


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Periodic  Law.  237 

The  blank  spaces  in  the  foregoing  table  indicate 
the  probably  proper  places  of  elements  as  yet  un- 
known. Mendelief  predicted  the  existence  of  two 
elements  —  eka- aluminum  and  eka-horon  —  which 
should  fill  the  places  now  occupied  by  gallium  and 
scandium  respectively,  and  described  the  general 
physical  and  chemical  properties  of  these  elements 
in  advance  of  their  discovery. 

In  consequence  of  the  periodic  law,  the  sugges- 
tion is  now  accepted  as  truth,  that  "the  properties 
of  an  element  are  a  periodic  function  of  its  atomic 
weight."  Those  elements  that  unquestionably  be- 
long to  the  same  group,  often  present  remarkable 
coincidences  with  reference  to  their  atomic  weights. 
Thus,  the  atomic  weight  of  sulphur  is  twice  that 
of  ox^^gen,  and  if  the  atomic  weights  of  sulphur, 
32,  and  of  tellurium,  125,  be  added  together  and 
the  product  divided  by  2,  the  result  will  be  in  the 
immediate  neighborhood  of  78,  the  atomic  weight 
of  selenium.  Again,  the  atomic  weight  of  phos- 
phorus, 31,  and  of  antimony,  120,  added  together, 
give  us  the  number  151,  which  is  almost  exactly 
twice  75,  the  atomic  weight  of  arsenic.  The  sum 
of  the  atomic  weights  of  chlorine,  35,  and  of  iodine, 
127,  is  162,  which,  divided  by  2,  brings  us  suffi- 
ciently near  the  atomic  weight  of  bromine,  80,  as 
to  appear  something  more  than  a  mere  coincidence. 


238  Inorganic  Chemistry. 


CHAPTER  XX. 

SPECTRUM  ANALYSIS. 

In  concluding  the  history  of  the  individual  ele- 
ments, as  well  as  many  of  their  binary  compounds, 
it  will  not  be  inappropriate  to  allude  briefly  to  the 
subject  of  "spectrum  analysis." 

When  sunlight  is  passed  through  a  prism,  it  is 
split  up  into  what  are  arbitrarily  called  the  "  seven 
primary  colors  of  the  solar  spectrum."  The  colors, 
however,  of  solar  light,  strictly  speaking,  are  not 
confined  to  merely  seven  in  number,  but  are  mani- 
fested in  infinite  variety,  each  corresponding  to  a 
special  ''wave  length."  Sunlight  furnishes  a  con- 
tinuous band  of  light,  broken  by  a  great  number 
of  fine  dark  lines ;  but  if  the  light  from  incandes- 
cent individual  terrestrial  elements  be  dispersed  by 
passing  through  a  prism,  it  will  be  found  that  only 
a  few  colors  are  shown  consisting  of  bright  lines, 
which  are  characteristic  only  of  the  elements  pres- 
ent in  a  state  of  luminosity,  by  which  condition 
their  spectra  are  exhibited. 

The  instrument  for  examining  the  light  given 
ofi'  by  special  substances,  is  called  the  "  spectro- 


Spectrum  Analysis.  239 

scope,"  and  the  process  itself  is  called  "  spectrum 
analysis." 

When  cempounds  of  sodium  are  heated  in  a 
common  flame  sufficiently,  the  yellow  light  of  so- 
dium will  confer  on  the  flame  a  yellow  color.  In 
the  same  way  potassium  compounds  will  cause  the 
flame  to  assume  a  decided  violet  tint.  If  there  be 
present  in  the  flame  both  sodium  and  potassium 
compounds,  the  intense  yellow  sodium  light  will  so 
overcome  the  purple  potassium  color  that  the  pres- 
ence of  the  latter  element,  although,  perhaps,  in 
excess,  will  not  be  detected.  If  compounds  of 
either  one  of  these  elements  be  examined  by  the 
spectroscope,  the  light  of  sodium  will  be  indicated 
by  two  bright,  slightly  different  shades  of  yellow, 
lines,  so  close  together  that  ordinary  instruments 
show  them  as  one  bright  yellow  line.  The  light  of 
potassium  will  exhibit  several  bright  lines,  widely 
separated,  varying  in  color  from  strong  violet  to 
red.  Now,  if  compounds  of  both  sodium  and  po- 
tassium be  examined  simultaneously  by  the  spec- 
troscope, the  peculiar  yellow  lines  of  sodium  and 
the  purple  and  red  and  intermediate  lines  of  potas- 
sium will  all  appear  distinctly,  so  that  the  presence 
of  both  elements  in  the  substance  undergoing  ex- 
amination in  this  way  can  be  ascertained  with 
certainty. 


240  Inorganic  Chemistry. 

The  metals  thallium,  caesium,  rubidium,  in- 
dium, gallium,  and  others  were  discovered  by  this 
process. 

Barium  gives  lines  of  light  of  several  different 
colors,  ranging  from  green  to  red  ;  strontium,  bril- 
liant shades  of  red  and  two  of  blue;  thallium,  only 
one — a  splendid  blue  line ;  and  calcium,  quite  a 
number  of  lines,  the  yellow  predominating.  The 
other  metals  also:  gold,  platinum,  silver,  iron,  etc., 
may  each  be  recognized  by  the  peculiar  bright 
lines  belonging  to  their  spectra.  N"itrogen  exhib- 
its a  spectrum,  mostly  purple;  and  hydrogen  one 
bright  red,  one  green,  and  one  blue  line. 

Liquids  and  solids,  when  heated  to  incandes- 
cence, exhibit  continuous  spectra.  It  is  only  lu- 
minous vapors  that  give  discontinuous,  bright  line 
spectrums.  To  obtain  this  luminous  vapor  of 
those  elements  which  require  a  higher  tempera- 
ture for  the  purpose,  than  can  be  conferred  by  a 
Bunsen  flame,  the  electric  spark  is  employed,  which 
in  passing  between  two  points  of  the  metal  in 
question,  volatilizes  a  portion,  or  in  passing  through 
gases,  as  hydrogen,  etc.,  heats  them  so  intensely 
as  to  enable  them  to  give  off  the  peculiar  light 
characteristic  of  each. 

The  spectrum  of  the  sun,  when  examined  by 
means  of  the  spectroscope,  is  found  not  to  consist 


V. 


Spectrum  Analysis.  241 

of  an  absolute  continuous  band  of  light,  ranging 
from  red  to  violet,  but  is  seen  to  be  interpersed 
by  hundreds  of  darJ{  lines,  and  these  lines  are 
observed  to  correspond  in  exact  position  to  the 
bright  lines  in  the  spectra  of  terrestrial  ele- 
ments. 

This  coincidence  in  the  position  of  the  dark  so- 
lar lines  with  the  well-known  bris^ht  terrestrial 
lines,  led  to  the  assumption  that  the  dark  and 
bright  lines  were  produced  by  the  same  incandes- 
cent elements.  Later  experiments  proved  such  as- 
sumption to  be  a  fact.  The  brilliant  lirne  light 
thrown  on  the  field  of  the  spectroscope  shows  a 
continuous  band  of  light  similar  to  that  of  the 
sun.  If,  however,  the  sodium  flame  be  interposed 
between  the  lime  light  and  the  spectroscope,  the 
continuous  spectrum  will  show  a  double  dark  line 
corresponding  to  the  bright  lines  of  sodium  alone. 
The  conclusion  is,  tlierefore,  reached  "  that  the  va- 
por of  an  element  has  the  power  of  absorbing 
light-rays  of  the  same  wave  length  as  those  it 
emits."  In  other  words,  the  luminous  sodium  va- 
por stops  the  light  of  the  same  wave  length  or 
color,  proceeding  from  the  brilliant  lime  light  be- 
hind it.  It  is  opaque  to  the  colors  of  its  own 
kind,  and  allows  the  rest  to  proceed. 

21 


242  .  Inorgayiic  Chemistry. 

The  physical  condition  of  the  sun  is  at  once  in- 
dicated by  these  experiments  of  KirchoiF.  It  con- 
sists of  a  central  incandescent  liquid  or  solid  body 
which  reverses  the  light  of  the  luminous  vapors 
of  the  various  elements  in  its  own  photosphere, 
changing  the  otherwise  bright  lines  into  dark  lines, 
and  these  dark  solar  lines,  corresponding  in  posi- 
tion to  familiar  terrestrial  bright  lines,  prove  the 
existence  of  the  vapor  of  certain  elements  in  the 
atmosphere  of  the  sun,  with  as  great  a  degree 
of  certainty  as  any  other  question  in  physical 
science. 

Oxygen,  hydrogen,  iron,  nickel,  cobalt,  manga- 
nese, calcium,  strontium,  barium,  chromium,  mag- 
nesium, sodium,  copper,  titanium,  aluminum,  lead, 
cerium,  cadmium,  and  uranium,  have  been  identi- 
fied as  solar  elements.  The  planets  give  the  same 
lines  as  those  of  the  sun,  as  they  shine  by  reflect- 
ing his  light. 

Similar  methods  of  observation  prove  the  fixed 
stars  to  be  self-luminous  suns.  Many  well  known 
elements  have  been  recognized  in  the  star  Alde- 
baran,  and  some  also  not  as  yet  detected  in  the 
sun,  as  bismuth,  antimony,  mercury,  and  tel- 
lurium. 

The  true  nebulce  are  ascertained  to  consist  of 
masses    of   glowing   gas,  inasmuch   as    they  give 


Spectrum  Analysis.  243 

bright  lines,  indicating  only,  with  certainty,  the 
presence  of  hydrogen,  a  fact  which  seems  to  prove 
the  nebular  hypothesis^  and  also  the  evolution  of 
the  various  kinds  of  matter  from  one  primordial 
element. 


PAR.T    THIRD. 


ORGANIC  CHEMISTRY. 


CHAPTER  I. 

INTRODUCTORY  REMARKS. 

There  is  but  one  science  of  chemistry.  Its  di- 
vision into  inorganic  and  organic,  is  simply  one  of 
convenience. 

It  was  formerly  supposed  that  the  production  of 
organic  chemical  compounds  was  restricted  to  the 
influence  of  vital  force  in  the  bodies  of  plants  and 
animals.  There  is  now,  however,  no  boundary 
line  between  the  two  divisions,  inasmuch  as  many 
organic  compounds  can  be  produced  synthetically 
from  inorganic  materials,  and  many  others,  such 
as  indigo,  carbolic  acid,  etc.,  may  be  obtained  by 
artificial  means.  But  nevertheless,  the  practical 
source  of  organic  compounds  is  from  substances  of 
animal  or  vegetable  origin,  so  that  those  who 
erected  organic  chemistry  into  a  separate  science 
really  builded  better  than  they  knew,  by  present- 
ing a  division  most  convenient  for  the  separate 
(244) 


Introductory  Remarks.  245 

consideration  of  the  chemical  nature  of  carbon  and  its 
relations  to  the  other  elements. 

Organized  structures,  that  is  to  say,  the  various 
tissues  of  animal  and  vegetable  bodies,  can  not  be 
produced  artificially.  They  are  made  up  of  chem- 
ical combinations  which  obey,  in  unison  with  nat- 
ural affinities,  the  governing  power  of  vitality. 
When  vitality  ceases,  these  tissues  undergo  resolu- 
tion toward  the  formation  of  simple  chemical  com- 
pounds, unless  their  identity  is  preserved  by  im- 
mediate antiseptic  treatment.  When  subjected  to 
a  high  temperature,  with  access  of  air  (oxygen), 
they  are  resolved  at  once,  principally  into  H2O 
and  CO2 ;  and  if  subjected  to  destructive  distillation^ 
volatile  and  liquid  substances  are  given  off,  leaving 
a  residue  consisting  of  the  charcoal  variety  of  car- 
bon ;  and  finally,  if  left  exclusively  to  nature's 
processes,  decay  supervenes  by  the  agency  of  micro- 
organisms; rapidly  or  slowly,  according  to  the  na- 
ture of  the  substance,  and  its  exposure  to  moisture 
and  certain  temperatures. 

Spontaneous  disorganization  of  substances,  rich 
in  nitrogen,  is  called  putrefaction.  They  give  off 
compounds  of  an  unpleasant  odor,  consisting 
largely  of  ammonia  and  its  derivatives ;  whereas 
those  bodies  of  a  non-nitrogenous  composition, 
losing  their  identity  thus,  are  said  to  undergo  fer- 


246  Organic  Chemistry. 

mentation.  In  the  latter  case,  the  compounds  re- 
sulting are  mainly  devoid  of  unpleasant  odors. 

There  is  no  essential  difference  in  the  nature  of 
the  disorganization  in  those  processes  termed  as 
putrefection,  fermentation,  and  eremacausis,  except 
in  so  far  as  the  substances  involved  differ  in  chem- 
ical composition  ;  but  the  part  played  by  micro-or- 
ganisms in  the  phenomena  of  changing  complex 
bodies  into  simplar  forms,  is  as  yet  undetermined, 
and  would  be  out  of  place  in  a  work  of  this  kind, 
even  if  we  had  fixed  theories  on  the  subject.  It 
will,  therefore,  be  sufficient  to  remark  in  this  con- 
nection that  micro-organisms  are  of  various  kinds, 
and  possess  various  functions.  Some  kinds  of  mi- 
cro-organisms, the  saprogenic,  will  affect  changes 
only  in  nitrogenous  material,  and  even  here,  there 
are  many  species  of  the  useful  pests,  which  divide 
the  process  of  putrefaction  into  several  well  marked 
stages.  This  fact  also  obtains  in  fermentation. 
Juices  of  various  fruits,  such  as  apples,  etc.,  freely 
exposed  to  the  air  and  proper  temperatures,  un- 
dergo changes  finally  resulting  in  alcohol  (cider), 

and  this,  if  left  to  itself,  by  the  agency  of  a  special 

* 

micro-organic  germ  or  ferment  (the  microdermi  aceti), 
will  change  into  vinegar,  otherwise  known  as 
acetic  acid.  In  the  same  way,  special  germs,  acting 
on  different  substances,  induce  individual  distinc- 


Introductory  Remarks.  247 

tions  ill  fermentation,  such  as  lactic,  butyric,  etc. 
In  a  given  culture  (decomposable  substance),  arti- 
ficially prepared,  as  solutions  of  the  carbo-hydrates, 
lactic  acid  will  result,  by  the  influence  of  quite  a 
number  of  different  bacteria,  some  of  them  known 
as  pathogenic  (disease-producing),  and  others  as 
non-pathogenic. 

The  tendency  of  fermentation  is  to  produce  acids; 
of  putrefaction,  to  produce  alkalies.  In  the  latter 
case,  as  already  alluded  to,  ammonia  and  its  deriva- 
tives, the  amines  and  amides  are  characteristic, 
together  with  exceedingly  poisonous  and  non-poi- 
sonous diffusive  ptoma-ines,  or  animal  alkaloids, 
resembling  in  their  chemical  nature,  well-known 
vegetable  alkaloids,  such  as  strychnine,  atropine, 
morphine,  etc. 

If  the  substance  undergoing  transformation  by 
bacterial  influence,  be  composed  of  both  fermentive 
and  putrefactive  materials,  then  both  acid  and  alka- 
line products  will  occur.  The  fluid  contents  of  the 
a-verage  human  mouth,  consisting  of  normal  saliva, 
mucus,  and  remains  of  various  kinds  of  food,  af- 
ford an  excellent  example  of  a  heterogeneous  cul- 
ture, and  as  more  than  twenty  different  kinds  of 
bacteria  have  been  detected  in  the  oral  cavity,  it  is 
easy  to  realize  that  in  such  a  state  of  affairs,  chemi- 
cal riots  will  be  the  rule ;  acid  fermentation,  tend- 


248  Organic  Chemistry. 

ing  to  destroy  the  structural  integrity  of  the  teeth, 
and  alkali  fermentation  (putrefaction),  tending  to 
induce  an  inflammatory  condition  of  the  softer  tis- 
sues of  the  mouth,  oftentimes  accompanied  by 
swellings  and  general  septicaemia,  the  latter  symp- 
tom owing  probably  to  the  resorption  of  the  poi- 
sonous ptomaines. 

As  counteracting  influences  opposed  to  the  above 
conditions,  we  have  the  means  of  killing  the  mi- 
crobes direct,  by  the  employment  of  germecides,  and 
by  disinfection,  which  destroys  the  infectious  mat- 
ter, and  at  the  same  time  changes  the  physical,  or 
chemical,  nature  of  the  culture,  so  that  it  can  not 
serve  any  longer  as  suitable  soil  for  microbic  propa- 
gation. Antisejptics  applied  to  the  part,  and  con- 
tinued, after  disinfection,  will  prevent  a  recurrence 
of  the  fermentive  process. 

Germicides  'per  se,  are  of  little  value  as  medicines, 
so  long  as  the  culture  remains  intact,  for,  as  we  may 
readily  believe,  the  presence  of  living  germs  of  the 
common  forms  of  both  phases  of  fermentation  is 
practically  universal.  Disinfection,  therefore,  is  the 
Samson  upon  which  the  dental  surgeon  should  rely, 
followed  by  the  exhibition  of  antiseptics,  to  prevent 
a  return  of  the  disease. 

The  terms  disinfectants  and  antiseptics,  are  often 
improperly  used  indiscriminately;  and  although  it 


Introductory  Remarks.  249 

is  impossible  to  draw  a  sharp  line  of  demarcation 
between  these  two  classes  of  remedies,  inasmuch 
as  some  members  of  each  (like  silver  nitrate,  salicy- 
lic acid,  etc.),  act  more  or  less,  in  both  capacities, 
we  will  presume  to  draw  a  few  distinctions  between 
them,  which,  on  account  of  necessary  brevity,  will 
no  doubt  appear  rather  too  dogmatic. 

It  is  a  question  yet  in  doubt  as  to  whether  full 
grown  micro-organisms,  bacteria,  exist  in  all  infec- 
tious matter;  their  absence  therein  does  not,  there- 
fore, disprove  the  bacterial  genesis  of  disease,  or 
of  their  necessary  presence  in  inducing  chemical 
changes  in  the  organized  tissues  that  have  lost 
wholly,  or  in  part,  the  governing  power  of  vitality. 
Their  spores  can  yet  live  in  the  excrementitious 
matter,  and  when  planted  in  congenial  soil,  will 
sprout  and  grow  into  the  characteristic  bacilli  of 
their  kind.  Poisonous  ptomaines  alone,  when 
forced  into  healthy  living  tissues  play  an  impor- 
tant part,  not  yet  understood,  in  the  production  of 
acute  diseases.  It  follows  accordingly,  that  any 
means  by  which  remaining  bacteria,  spores,  and 
ptomaines  can  be  completely  destroyed,  must  be 
credited  as  belonging  to  the  class  of  thorough  dis- 
infectants. 

Disinfection  can  be  accomplished  in  various  ways. 

First,  by  mechanical  means ;  removing  the  infec- 


250  Organic  Chemistry. 

tious  matter  beyond  the  sphere  of  possible  repro- 
duction ("to  the  bottom  of  the  sea"). 

Second,  by  extremes  in  temperature,  especially  a 
high  temperature,  which  kills  bacteria,  and  spores, 
and  changes  the  chemical  nature  of  the  culture  in 
which  they  thrive,  and  also  the  poisonous  products 
of  decomposition. 

Third,  by  chemical  means ;  chemical  action,  as 
we  know,  causes  complete  loss  of  identity  in  the 
acting  bodies,  and  where  chemical  changes  take 
place  in  infectious  matter,  it  necessarily  loses  its 
power  of  infection.  Oxygen  is  involved  in  this 
form  of  disinfection  more  than  all  other  material 
agencies  combined.  In  the  process  oi  fumigating, 
by  burning  sulphur,  the  freshly  formed  sulphurous 
oxide  (SO2),  deoxidizes  the  injurious  organisms  and 
compounds,  by  taking  away  some  of  their  structu- 
ral oxygen,  which  change,  of  course,  destroys  their 
identity.  On  the  other  hand,  such  incontestible 
disinfectants  as  peroxide  of  hydrogen,  potassium 
permanganate,  chlorinated  lime,  chlorinated  soda, 
etc.,  furnish  active  oxygen,  which  as  stated  under 
their  several  heads,  burns  up  the  infectious  mate- 
rial, in  the  same  way  that  nature's  great  disinfect- 
ant, ozone,  accomplishes  its  peculiar  function. 

The  removal  of  all  infected  matter  in  caries  of 
the  teeth,  by  instruments,  is   disinfection,     Anti- 


Introductory  Remarks.  251 

septic  measures  are  then  adopted,  by  proper  meth- 
ods of  filling  the  cavity,  to  ^prevent  a  return  of  the 
destructive  phenomena  in  that  part  of  the  tooth. 
Or  complete  removal  of  the  contents  in  root  canals 
by  instrumental  manipulation,  is  thorough  disin- 
fection of  the  part,  a  labor  requiring  infinite  care, 
and  which  is  generally  supplemented  by  aid  of 
chemicals  and  a  high  temperature,  followed  by  the 
insertion  of  antiseptics,  as  the  phenols,  iodoform, 
essentials  oils,  etc.,  in  connection  with  the  sealing 
qualities  of  the  filling. 

A  healthy  part  does  not  need  disinfection,  but  it 
does  require  antiseptic  treatment,  to  prevent  the 
development  of  disease.  The  judicious  use  of  the 
tooth-brush,  in  a  healthy  mouth,  is  antiseptic  treat- 
ment by  cleanliness,  tending  to  keep  the  parts 
therein  in  a  healthy  condition ;  much  alike  in  prin- 
ciple and  object  to  the  treatment  of  fresh  meats  by 
the  use  of  the  antiseptic,  common  salt.  Wc  might 
multiply  examples  indefinitely  to  prove  our  thesis, 
but  the  above  brief  remarks,  we  hope,  will  enable 
the  student  to  appreciate  the  distinction  that  really 
exists  between  the  two  classes  of  remedies  known 
as  disinfectants,  and  as  antiseptics. 


252  Organic  Chemistry. 


CHAPTER  II. 

CARBON  COMPOUNDS. 

The  four  points  of  attraction  possessed  by  the 
atom  of  carbon,  furnish  the  basis  by  which  organic 
compounds  are  classified.  These  compounds  are 
made  up,  mainly,  of  carbon,  hydrogen,  and  oxy- 
gen, but  many  of  them  contain  niti'ogen,  phos- 
phorus, and  sulphur;  also  the  haloid  elements  and 
various  metals. 

Methane,  CH4,  serves  as  the  best  prototype  of 
organic  compounds.     As  will   be  observed  by  its 

formula,  one  atom  of  tetrad  carbon  — C —  has  its 

I 

valency  of  four,  completely  satisfied  by  union  with 
the  four  atoms  of  monad  hydrogen  ;  so  that  the 
saturated  compound  is  not  able  to  take  up  any 
more  monad  atoms,  except  by  displacement  of  an 
equivalent  number  of  the  hydrogen  atoms.  In  a 
previous  chapter,  however,  we  alluded  to  the  fact 
that  any  dyad  radical,  elementary  or  compound, 
can  enter  into  direct  combination  with  a  saturated 
compound,  because  the  two  units  of  combining 
power,  belonging  to  the  dyad,  so  act  as  to  neutral- 


Carbon  Compounds.  253 

ize  one  unit  of  the  compound  it  enters,  and  intro- 
duce another,  leaving  the  equivalency  of  the  com- 
pound the  same  as  before. 

Consequently,  methane  may  take  up  the  dyad 
radical  CHg"  to  form  C2H6,  as  may  be  easily  un- 
derstood by  the  graphic  formulas. 

H  H  H    H 

i  I  II 

H— C H(CHJ+— C—  (CH2)  =   H— C— C— H    {C^H.') 

I  I  II' 

H  H  H   H 

Methane  Methene.  Ethane. 

On  the  other  hand,  methane,  CH^,  under  cer- 
tain circumstances,  may  lose  two  of  its  hydrogen 
atoms,  resulting  in  the  development  of  the  above 
dyad  radical  methene;  and  ethane,  C^Hg,  may 
lose  two  of  its  hydrogen  atoms,  and  a  new  series 
of  hydrocarbon  compounds  be  thus  obtained. 

The  following  table  of  some  of  the  hydrocar- 
bons, arranged  and  named  by  Hoffman,  will  enable 
the  student  to  appreciate  the  above  statements : 


254 


Organic  Chemistry. 


CH 


CH. 


Methane. 

Methene. 

■ 

C,He 

C,H, 

(^2^2 

Ethane. 

Ethene. 

Ethine. 

^. 

C^3^8 

^sHg 

C3H4 

C3H, 

^' 

Propane. 

Propene. 

Propine 

Propone. 

s 

C4H10 

C4HS 

C4H, 

C4H4            C4H2 

Quartane. 

Quartene. 

Quartine. 

Quartone.         Quartune. 

C5H12 

C5H10 

^5^8 

^5^6          ClgH^         C5H2 

\ 

Quintane. 

Quintene. 

Quintine. 

Quintone.      Quintune. 

3 

^&^1A 

^6^12 

^6^10 

CgH,    C,H,  CeH„etc. 

^ 

Sextane, 

Sextene. 

Sextine. 

Sextone.     Sextune. 

Greek  prefixes  are  generally  preferred;  thus 
pentane  instead  of  quintane;  hexane  instead  of  sex- 
tane; heptane  instead  of  septane,  etc. 

Now,  by  reference  to  the  table,  it  will  be  noticed 
that  the  compounds  in  each  vertical  column  differ 
successively  from  each  other,  by  CH2 ;  and  those 
in  each  horizontal  line,  differ  from  each  other  suc- 
cessively by  H2.  Those  in  each  vertical  column, 
form  each  a  homologous  series,  and  those  on  horizon- 
tal lines,  an  isologous  series.  The  latter  are  also 
called  the  monocarbon,  dicarbon,  tricarbon,  groups, 
etc. 

The  lowest  member  of  each  homologous  series^ 
leaving  out  a  few  which  are  not  known  to  exist,  is 


Carbon   Compounds.  255 

presented  below  as  far  as  the  eighteenth,  together 
with  the  general  formula  for  each  ; 

Series.  Lowest  Member.  General  Formula. 

1 CH4        CnH2U+2 

2  C2H4      CnH2n 

3 C2H2     CnH2n— 2 

4 C5H6     CnH2n— 4 

5 CgHg     CnH2n— 6 

6 CgHg     CnH2n— 8 

7 CgHg      CnHgn— 10 

8  CjoHg     CnHsn— 12 

9 C12H10 CnHan— 14 

10 C14H12 CnHan— 16 

11 Cj^Hjo CnH2n— 18 

12 Cj^H,^ CnH2n— 20 

13 CjeHjo CDH2n— 22 

14 CjgHjg  CnH2n— 24 

15 C20H14 CDH2n— 26 

16 CnH2n— 28 

17 C22H14.... CnH2n— 30 

18 C26H20 CnH2n-32 

Cn  means  any  number  of  carbon  atoms,  and 
H2n  +  2,  twice  as  many  hydrogen  atoms  and  2 
over;  CnH2n,  twice  as  many  hydrogen  atoms  as 
as  carbon  atoms;  CnH2n — 2,  twice  as  many  hy- 
drogen atoms  as  carbon  atoms,  minus  2,  etc. 

The  hydro-carbons  in  the  first  vertical  column 


256  Organic  Chemistry. 

on  page  254  (series  CnH2n-|-2),  are  all  saturated 
compounds ;  those  in  the  second  column  (series 
CnHgn)  are  dyad  radicals,  capable  of  uniting  with 
2  atoms  of  chlorine  without  displacing  hydrogen, 
as  in  ethene  chloride,  C2H4CI2  ;  those  in  the  third 
column,  are  triads,  etc. 

The  first  members,  as  methane,  CH4  ;  ethane, 
C2Hg;  propane,  CgHg ;  ethene,  C2H4 ;  ethine, 
C2H2,  etc.,  are  gaseous  at  ordinary  temperatures, 
and  increase  in  density  in  regular  ratio,  with  each 
additional  CH2. 

The  higher  members,  of  which  C35H72  is  the 
extreme,  are  solid ;  while  the  intermediate  mem- 
bers, such  astetrane  (quartane  and  butane),  C^H^o ; 
decane,  O^qR^.^,  etc.,  are  liquid.  The  boiling 
points  of  the  liquid  hydrocarbons  increase  regu- 
larly, but  in  diminishing  ratio  with  each  increase 
of  CH2.     Thus: 

Tetrane,    OJ^^^,  boils  at     0°   (32F)  Increase. 

Pentane,  C5H,2,  "      ''    38°  (100)         38  C. 

Hexaiie,  C^R^^,  "       "    69°  (156)         31 

Heptane,  C^Hig,  "      ''    98°  (208)         29 

Octane,    CgHig,  "      ''  124°  (255)         26 


Carbon  Compounds. 


257 


CHAPTER  III. 


CARBON  COMPOUNDS. 

The  hydro-carbons,  containing  an  even  number 
of  hydrogen  atoms,  may  exist  free.  Many  of  them 
are  known. 

Hydro-carbon  radicals,  containing  an  uneven 
number  of  hydrogen  atoms,  do  not  exist  free,  but 
nevertheless  maintain  their  integrity  through  oper- 
ations of  decomposition  and  recomposition,  just 
like  the  elements  themselves,  ranking  as  units,  like 
the  atoms  of  hydrogen,  oxygen,  gold,  etc.  They 
are  derived  from  the  hydro-carbons  of  even  equiv- 
alency, in  the  same  way  that  hydroxyl  (HO),  is 
derived  from  H2O.  A  few  of  the  most  common 
occurrence  are  subjoined: 


CH 


Methane. 


Ethane. 


C3H, 

Propane. 


Butane. 


CH3 

Methyl. 


CJI5 

Ethyl. 

C3II, 

Propyl. 

cjr, 

Jiutyl,  etc. 


CH2'' 

Methene, 


C2H4" 

Ethene. 


CsIIe" 

Propene, 


CH'^' 

Melhenyl. 


C2H3''' 

Ethenyl. 


Fropenyl. 


The  final  syllabic  yl  indicates  a   compound  radi- 
22 


258  Organic  Chemistry. 

cal  of  uneven  valency;  so  also  certain  rajilicals  of 
both  uneven  and  even  valency,  not  derived  from 
saturated  hydrocarbons,  as  nitryl,  NO^,  carbonyl, 
CO,  etc.  The  derivation  of  certain  other  radicals 
suggest  their  names ;  thus  from  ammonia,  ^Hg,  by 
abstraction  of  one  atom  of  hydrogen,  is  derived 
amidogen,  NHg  ;  and  by  taking  away  two  atoms  of 
hydrogen  from  Nllg,  is  derived  the  dyad  radical, 
imidogen,  I^H''.  Cyanogen  (meaning  blue),  C^ 
(quasi  symbol  Cy),  when  free,  is  formulated  as 
C!N"-C^,  analogous  to  the  molecule  of  chlorine, 
Cl-Cl,  and  when  acted  upon  by  a  metal,  as  Kg,  re- 
sults according  to  the  equation, 

K^     +     Cy,     =     2KCy 

Potassium.     Cynogen.  Pot.  Cyanide. 

Just  like  a  molecule  of  chlorine  on  a  molecule  of 
potassium,  Kg  +  Clg,  =  2KC1.  The  radical  cya- 
nogen, CN,  (Cy)  is  one-half  the  molecule  of  free 
cyanogen,  just  as  the  atom  of  chlorine,  CI,  is  the 
radical  of  the  free  molecule  of  chlorine,  Cl-Cl. 

These  latter  compound  radicals,  carbonyl,  nitryl, 
amidogen,  imidogen,  and  cyanogen,  are  not  strictly 
classified  as  organic,  but  are  interesting  in  this 
connection,  inasmuch  as  they  enter  largely  into 
the  formation  of  many  accepted  organic  com- 
pounds. 

The    hydrocarbon    radicals,  however,   such    as 


Carbon  Compounds.  259 

nictliyl,  nietlienyl,  ethyl,  propyl,  etc.,  are  the  ones 
that  should  engage  our  especial  attention  in  study- 
ing organic  chemistry.  They  behave,  as  before 
remarked,  similarly  to  the  atoms  of  the  elements, 
and  like  the  latter,  are  relatively  electro-positive 
or  electro-negative.  With  0,  CI,  etc.,  they  are 
electro-positive,  as  in  ethyl  oxide,  (0115)20,  and 
ethyl  chloride,  CH5CI  ;  and  electro-negative,  in 
metallic  salts,  as  in  lead  ethide,  rb(CH5)2. 

From  them,  all  well  defined  organic  compounds 
maybe  presumed  to  be  formed,  most  of  which  may 
be  assumed  to  be  derived  from  the  following 
members : 

1-  Alcohols. — Formed  by  the  union  of  hydro- 
radicals  with  hydroxyl. 
CHg,OH     C2H5,OH      C2H4(OH),     C3H5(OH)3 

Methyl  Alcohol.    Ethyl  Alcohol.         Ethene  Alcohol.    Propenyl  Alcohol. 

Alcohols  are  really  hydroxides^  analogous  to  the 
hydroxides  of  metals.  Thus  sodium  hydroxide, 
NaOH,  calcium  hydroxide,  Ca(0II)2:  The  first  is 
similar  in  composition  to  methyl  and  ethel  alco- 
hols, and  the  latter  to  ethene  alcohol. 

2.  Oxygen  Ethers. — Are  formed  after  the  water 
type,  11 — 0 — U,  and  consist  of  hydrocarbon  radi- 
cals and  oxygen.  Common  ether  is  ethyl  oxide, 
0211,5^0 — 02115.  A  mixed  ether  contains  more 
than  one  hydrocarbon  radical ;  methyl-ethyl 
ether,  OH 3 — O — Ogllg,  is  a  mixed  ether. 


260  Organic  Chemistry. 

3.  Haloid  Ethers,  are  compounds  containing 
hydrocarbon  radicals,  and  a  haloid  element;  chlo- 
roform, CIICI3  is  a  haloid  ether,  made  up  of  the 
trivalent  hydrocarbon  radical  methenyl,  and  three 
atoms  of  univalent  chlorine. 

Iodoform  CHI3,  and  "Dutch  Liquid"  C2H4CI2, 
are  also  examples  of  haloid  ethers. 

4.  Organic  Acids,  may  be  defined  as  -oxygenated 
hydrocarbon  radicals  and  hydroxyl,  as  acetic  acid 
C2H3O,  OH,  formic  acid  CHO,  OH,  lactic  acid, 
C3H5O2,  OH.  The  molecule  of  an  organic  acid, 
therefore  contains  at  least  two  .atoms  of  oxygen ; 
they  may  also  be  regarded  as  being  produced  by 
union  of  a  hydrocarbon  residue  and  the  univalent 

I 

radical  carhoxyl  COOH,  graphically  0=0 — 0 — H, 
thus  acetic  acid  CH3COOH ;  formic  acid,  H,  COOH ; 
lactic  acid  C2H5O,  COOH.  Where  but  one  group 
of  carboxyl  is  shown,  as  in  the  above,  such  acid  is 
monobasic^  giving  up  only  the  hydrogen  of  carboxyl 

to  a  metal ;  and  when  two  such  groups  are  shown, 

CH,— COOH, 

as  in  succinic  acid,    |  it  is  dibasic. 

CH2— COOH, 

5.  Esters,  are  ethereal  salts,  formed  by  hydro- 
carbon radicals,  and  organic  or  inorganic  acid 
radicals,  for  example  ethyl  acetate,  C2H5,  C2H3O2. 
Ethyl  alcohol  and  nitric  acid,  yield  the  ester,  ethyl 
nitrate,  and  water. 

C2H50H+HN03=C2H5N03+H,0. 


Carbon  Compounds.  261 

6.  Aldehydes,  meaning  less  hydrogen  than  is 
contained  in  the  corresponding  alcohols,  are  com- 
pounds, intermediate  between  alcohols  and  acids. 
That  is, they  contain  less  hydrogen  than  the  alcohol, 
and  less  oxygen  than  the  corresponding  acid,  and 
are  derived  by  the  removal  of  hydrogen  from  the 
alcoliol,  by  oxygen,  all  of  which  may  be  understood 
by  the  empirical  formulas  : 

C^HgO  +  0  =  C2H4O  +  H2O. 

Ethyl  Alcohol.  Aldehyde. 

C2H4O  +  O  =  C2H4O2. 

Aldehyde.  Acetic  Acid. 

An  aldehyde  can  be  converted  into  an  alcohol, 
but  an  acid  can  not. 

7.  Ketones  are  derived  from  aldehydes,  by  replac- 
ing one  atom  of  hydrogen  by  an  alcohol  radical. 

Acetone. 

or  they  may  be  considered  graphically  as  two 
univalent  radicals,  held  by  bivalent  carbonyl  CO. 
The  ketones  are  quite  numerous,  of  which  acetone 
is  the  best  prototype.  Acetone  itself,  may  be  re- 
garded as  dimethyl  ketone  CH3 

0=0 

CH3.     There    are    also 
diethyl,  and  ethyl-methyl,  etc.,  ketones. 

8.  Amines,  are  derivatives  of  ammonia  by  sub- 
stitution of  hydrogen,  by  hydrocarbon  radicals. 


262  Organic  Chemistry. 

,H  fC.fi,  fC^Hj  fC^H, 


Ammonia.  Ethylamine.  Diethylamine.  Triethylamme. 

The  amines  are  numerous,  and  are  mostly  basic 
in  character.  Where  all  the  hydrogen  is  removed, 
the  trivalent  radical  IT  is  evidently  capable  of  taking 
up  three  univalent  radicals  as  above,  or  one  triva- 
lent radical,  as  below : 

Methenyl  Nitril.  Ethenyl  Nitril. 

These  trivalent  nitrils  are  not  basic ;  they  are  all 
neutral,  except  the  first,  which  is  acid,  capable  like 
HCl,  of  exchanging  its  hydrogen  for  a  metal,  and 
may  therefore  be  regarded  as  composed  of  hydro- 
gen and  the  univalent  radical  cyanogen, 
I^CH        -=        HCK 

Methenyl  Nitril.  Hydrogen  Cyanide. 

(Hydrocyanic  Acid). 

ITC2H3      =      CH3CK 

Ethenyl  Nitril.        Methyl  Cyanide. 

Analogous  to  the  amines,  are  the  arsines,  stibines, 
and  fhosjMnes. 

9.  Amides  are  analogous  to  the  amines  in  com- 
position, except  they  contain  acid  radicals,  instead 
of  hydrocarbon  radicals.  Those  which  are  made 
up  of  a  bivalent  acid  radical,  and  imidogen,  are 
called  imides. 

C2H30,KH2  C4H4O2NH 

Acetamide.  Succiuimide. 


Carbon  Compounds.  26B 


CHArTER  IV. 
CARBON  COMPOUNDS. 

When  two  or  more  corapoiinds  can  be  represented 
by  the  same  empirical  formuhx,  they  are  said  to  be 
isomeric.  The  difference  in  the  chemical  and  physi- 
cal nature  of  isomeric  bodies,  is  due  to  the  difference 
ill  the  relative  position,  or  arrangement,  of  the 
atoms  in  the  molecule,  and  it  is  upon  this  fact  that 
the  somewhat  startling  innovation  o^ stereo-chemistry 
is  founded. 

True  isomeric  bodies  are  those  which  have  the 

same  kind  and  number  of  atoms,  not  grouped  into 

special  compound  radicals.     These   isomers   react 

similarly,  by  the  influence  of  the  same  reagents. 

There  are   many   examples  of  this    class,  two    of 

which  will  suffice  : 

H 

H  I 

I  H-C-HH 
•    H-C-H  I  I 

H-(^-n  H— C C-II 

H-O-H  I  I 

H-C-H  H-C-HH 

H-C-H  H— 6— H 


i 


H 

Pentane.  Isopentane. 


264  Organic  Chemistry, 

Metameric  isomers,  are  those  bodies  which  have 
the  same  composition,  but  differ  greatly  in  their 
transformations  under  similar  circumstances ;  as  an 
example,  the  formula  C3Hg02  represents  methyl 
acetate,  ethyl  formate,  and  propionic  acid,  two  of 
which  we  subjoin  graphically. 

H3C 


H3O  H^ 


i 


0-rC— 0— CH3  0=C— O— H 

Methyl  Acetate.  Propionic  Acid. 

Polymeric  compounds  are  those  which  have  the 
same  percentage  composition  but  difier  in  molecu- 
lar weight.  Examples  of  this  class  are  found  in 
the  series,  homologous  with  CH2: 

Ethene  (ethylene)  C2H4. 

Propene  (propylene)  C3Hg. 

Tetrene  (bytylene)  C^llg. 

Pentene  (amylene)  C^IIiq. 

Several  essential  oils  are  isomeric  with  oil  of 
turpentine,  C^  qHj  g  ;  and  others  are  polymeric  with 
the  latter,  having  the  formulas,  C20H32  C3QH48, 
etc.  All  polymeric  compounds,  exhibit  regular 
gradation  in  density,  and  boiling  points,  from  the 
lowest  to  the  highest. 

Optical  isomerism,  possessed  by  similar  com- 
pounds, is  due,  according  to  stereo-chemistry,  to 
asymetric  carbon  atoms  in  each  molecule. 


Carbon  Compounds.  265 

The  above  examples  of  isomerism  show  the  im- 
portance of  rational  formulas.  The  empirical 
formula  of  methyl  alcohol,  for  instance,  is  CH4O. 
The  rational  formula  is  CH3OH.  The  formula 
C2H4N2O,  expresses  the  number  and  kind  of  atoms 
in  both  ammoniuyyi  cyanate  and  carbamide^  and 
might  also  be  supposed  to  suggest  the  direct  union 
of  methane  and  nitrous  oxide;  but  if  each  be  for- 
mulated rationally,  we  can  then  have  easy  con- 
ception of  differences  in  their  chemical  and  phys- 
ical properties. 

Ammonium  Cyanate.       Carbamide  (Urea). 

Ammonium  cyanate  can  be  prepared  from  inor- 
ganic sources.  Its  molecular  transformation  into 
urea  by  Wohler  marked  the  lirst  artificial  produc- 
tion of  an  organic  compound. 


23 


266  Organic  Chemistry, 


CHAPTER  V. 

PARAFINS,  SERIES  CnH2ii+2. 

The  formulas  of  the  first  members  of  the  me- 
thane series  of  hydrocarbons,  suggest  asymmetrical 
arrangement  of  the  atoms  of  hydrogen,  in  con- 
nection with  the  atom  of  carbon.  The  four  points 
of  attraction  belonging  to  the  latter,  are  properly 
represented  by  the  four  solid  angles  of  a  tetrahe- 
dron, to  each  of  which  is  attached  an  atom  of  hy- 
drogen in  methane.  In  the  next  member,  ethane, 
containing  two  atoms  of  carbon,  one  point  of  at- 
traction belonging  to  each,  is  united  to  the  other, 
leaving  3  points  free  to  unite  with  hydrogen,  and 
so  on  with  the  next  member,  propane,  where  the 
middle  carbon  atom  can  satisfy  only  2  of  hydro- 
gen. Such  stereo  arrangement  can  not  be  repre- 
sented on  a  plane  surface,  except  feebly  in  per- 
spective, but  the  following  diagrams  will  ade- 
quately express  the  mathematical  values  of  each 
compound : 


Parajins,  etc. 

267 

H 

H 

H 

H     C     H 
H 

Methane. 

H     C     H 

H- 

-0- 

-C- 
-C- 

n 

-H 

H     C     H 
H 

Ethane. 

H- 
H- 

-H 
-H 

Propane. 

Modifications  of  these  molecules  are  probably 
impossible,  and  therefore  there  are  no  isomers  of 
methane,  ethane  or  propane,  but  with  the  next 
member,  butane,  C4H1Q,  it  is  possible  to  write  the 
graphic  formula  in  at  least  tw^o  w^ays ;  and  it  is  a 
fact  that  two  kinds  of  butane  are  recognized  : 

H 


H  H-C— H 

I  I 

11— C C— H 

H  ii_i_H 

Isobutnne. 

As  the  individual  hydrocarbons,  of  this  or  other 
series,  increase  in  the  number  of  carbon  atoms,  it 
is  evident  that  many  modifications  are  possible, 
and  a  corresponding  number  of  isomers  may  be 
produced.  A  mathematical  limit,  however,  in  each 
case,  is  also  evident. 


268  Organic  Chemistry. 

The  methane  series  of  hydrocarbons  are  found  in 
petroleum.  The  first  four  members,  are  gases,  the 
fifth  a  light  liquid,  and  so  on,  increasing  in  specific 
gravity  by  each  increase  in  CH2  ;  the  latter  mem- 
bers, being  solid.  Parafin  itself  is  a  mixture  of 
the  higher  members. 

Methane,  CH^,  as  well  as  each  of  the  other  satu- 
rated hydrocarbons  is  formulated  rationally  as  a 
hydride,  to  indicate  the  presence  of  a  compound 
radical  which  retains  its  identity  in  many  reactions. 
For  example,  methyl  hydride,  CH3,  H  (methane), 
when  acted  on  by  chlorine  forms  methyl  chloride 
CH3,  CI.  Ethyl  hydride  C2H5,H  (ethane)  simi- 
larly also  forms,  by  losing  an  atom  of  hydrogen, 
ethyl  chloride  C2H5CI,  etc. 

By  acting  on  methyl  chloride,  with  excess  of 
chlorine,  the  isologous  radical  methenyl,  CH,  is 
produced;  this  takes  up,  3  atoms  of  chlorine,  and 
methenyl  chloride,  chloroform,  CHCI3,  results. 
Chloroform  however,  is  commercially  prepared,  by 
distilling  together,  either  methyl,  or  ethyl  alcohol, 
and  bleaching  powder. 
2C2H60+5CaCl202=2CaC03-f2CaCl2+Ca(HO)2+4H20+ 

Alcohol. 

2CHCI3. 
Chloroform. 

Chloroform  is  a  haloid  ether,  of  an  agreeable 
odor.  -It  is  a  colorless  liquid,  of  specific  gravity 
1.52,  and   boils   at   62°   (143    F.).     Its    molecular 


Parafins,  etc.  269 

weight  as  seen  by  formula,  is,  in  round  numbers, 
120;  its  vapor  density  compared  with  hydrogen,  is 
one-half  its  molecular  weight,  or  60,  and  as  air  is 
nearly  15  times  as  heavy  as  hydrogen,  the  vapor  of 
chloroform  is  therefore  about  4  times  as  heavy 
as  air. 

The  purest  chloroform  is  now  made  from  chloral 
lu'drate.  It  possesses  strong  solvent  powers  on  the 
diiFerent  oils,  camphor,  caoutchouc,  resins,  the 
amines,  and  bromine  and  iodine.  It  is  not  inflam- 
mable;  is  freely  soluble  in  ether,  and  alcohol,  and 
sparingly  so  in  water. 

Materia  Medica. — Chloroform  has  been  a  favorite 
anaesthetic  from  the  period  of  its  introduction  in 
1847,  but  on  account  of  the  many  fatal  cases  which 
have  occurred  under  its  influence,  it  is  being  dis- 
carded more  and  more,  in  favor  of  ether.  Its  em- 
ployment alone,  or  in  combination  with  other 
ansesthetics,  in  the  simple  though  painful  opera- 
tion of  extracting  teeth,  is  not  regarded  as  legiti- 
mate practice  by  the  highest  authorities  in  our 
profession.  It  kills  by  direct  heart  paralysis,  prob- 
ably due  to  the  physical  change  which  chloroform 
produces  in  the  blood  itself.  The  strong  tendency 
to  immediate  coagulation  of  fresh  blood,  by  outside 
experiments  with  chloroform,  is  at  least  suggestive. 


270  Organic  Chemistry. 

Locally  applied,  chloroform  is  an  irritant,  and 
reduces  painful  impressions  in  the  part ;  it  is  also 
a  good  haemostatic.  Taken  internally  it  is  em- 
ployed as  an  anti-spasmodic  and  anodyne. 

Dose,  0.06-0.30  fGm.  {y(i  i-v). 

For  iuhalation  4. — 8  f  Gm.  (f^i-ij). 

Iodoform,  methenyl  iodide,  CHI3,  is  a  haloid 
ether,  analogous  to  chloroform,  and,  like  the  latter, 
is  a  derivative  of  methane.  It  is  prepared  by 
heating  to  a  temperature  of  40°  (104F),  an  alco- 
holic solution  of  potassium  iodide  with  bleaching 
powder.  It  occurs  in  small  yellow  crystals,  some- 
what volatile,  giving  oii'an  unpleasant  saffron-like 
odor ;  is  insoluble  in  water,  but  is  freely  soluble  in 
oils,  chloroform,  ether  and  alcohol. 

Materia.  Medica. — Iodoform  is  a  typical  anti- 
septic; applied  to  a  disinfected  part,  it  effectively 
prevents  the  development  of  both  alkali  and  acid 
ferments.  As  a  dressing  to  ulcerous  sores,  open 
and  sloughing  wounds,  it  is  anaesthetic,  and  stimu- 
lates healthy  granulations  by  preventing  profuse 
discharge  and  consequent  irritating  sequelse. 

As  an  antiseptic  dressing  in  root  canals  of  teeth, 
it  is  favored  by  many  of  our  most  eminent  prac- 
titioners, notwithstanding  its  rather  enervating 
odor.  This  single  objection  to  iodoform  is  easily 
overcome  by  the  addition  of  either  one  of  several 


ParaJinSj  etc.  271 

essential  oils,  which  act  both  as  adjuvans  and  cor- 
regens  to  its  medicinal  value. 

The  principle  of  the  Blair  apparatus,  by  which 
iodoform  is  vaporized  by  heat  and  forced  into  root 
canals,  is  a  correct  idea  in  therapeutics;  ^.  e.,  the 
thorough  disinfection  by  the  heat  required  to  hold 
the  vapor,  and  the  immediate  deposition  of  the 
sublimed  iodoform,  which  fills  the  open  spaces, 
and  by  its  insolubility  and  iodic  action  on  micro- 
organisms, prevents  a  return  of  the  disease.  A 
thermometer  attached  to  the  apparatus  would  be 
desirable — together  with  other  improvements — as 
the  compound  easily  decomposes  by  heat  into  free 
iodine  and  hydrocarbons,  principally  ethene,  C^H2, 
2CHI3  +  q.  s.  Heat  =  1q  +  C,H2. 

Iodoform  is  neither  a  local  nor  general  irritant. 
Internally  exhibited,  it  is  antiseptic,  anodyne, 
stimulant,  alterative,  and  tonic.  It  is  not  loholly 
decomposed  in  the  body,  as  its  odor  can  be  de- 
tected in  the  blood  and  the  several  tissues. 

Dose,  0.06—0.012  Gm.  (gr.  i-ij) 

Bromoform,  methenyl  bromide^  CIIBrg,  is  another 
haloid  ether,  analogous  to  the  foregoing  com- 
pounds, but  is  not  important.  To  show  these  bodies, 
as  derivatives  of  methane,  the  simplest  possible 
organic  chemical  hat-rack  is  erected  : 


272  Organic  Chemistry. 

H  CI  I  Br 

H-C— H      H— C— CI      H-C-I        H— C-Br 


i 


H  CI  I  Br 

Methane.  Chloroform.  Iodoform.  Bromoform. 


Alcohols,  etc.  273 


CHAPTER  VI. 
ALCOHOLS,  ETC. 

Methyl  Alcohol,  CH3OH,  is  known  as  wood 
spirit,  obtained  by  the  dry  distillation  of  wood,  and 
may  also  be  produced  by  direct  synthesis;  it  is  a 
constituent  of  oil  of  winter-green  from  gaultheria 
procumbens.  It  is  a  colorless  mobile  liquid,  of  spe- 
cific gravity  81,  which  boils  at  66°  (150F),  and  is 
used  as  a  substitute  for  ethyl  alcohol  in  various 
manufacturing  processes. 

The  alcohols  are  not  necessarily  similar  in  phys- 
ical properties  to  common  alcohol.  Some  of  them 
are  solid,  but  all  may  be  regarded  as  consisting  of 
hydrocarbon  radicals  and  hydroxyl. 

They  are  called  monatomic,  when  the  molecule 
contains  only  one  group  of  hydroxyl  (OH) ;  and 
they  are  known  as  primary^  secondary  and  tertiary, 
according  as  the  carbon  atom  in  combination  with 
hydroxyl  is  also  united  to  one,  two  or  three  other 
carbon  atoms. 

H  rcH, 


c< 


H  pjH 

on 

Methyl  Alcohol.  EthyfAlcohol.  Propyl  Alcohol 


H  ^^H 

on  i^on 


274  Organic  Chemistry. 

If  the  hydrocarbon  type  of  the  alcohol  be  pre- 
served, there  can  be  no  modification  of  the  first 
formulas;  in  other  words,  there  can  be  no  isomeric 
alcohols  of  these;  but  the  higher  members  of  the 
series,  as  butyl  (tetryl,  or  quartyl),  alcohol  CJl^^O, 
etc.,  admit  of  three  modifications,  and  form  three 
insomeric  alcohols,  primary,  secondary  and  ter- 
tiary. 

f 


rCH,CH,CH3 


CH,CH3        rcH3 

CH„  r.  I  CH, 

CH3 


c  1  c^— »         c<;_ 

tOH  I^OH  I^OH 

Primary.  Secondary.  Tertiary. 

Primary  alcohols  of  the  methane  series  are  con- 
verted into  aldehydes  by  losing  2  atoms  of  hydro- 
gen, and  then  by  oxidation  into  corresponding 
acids. 

Secondary  alcohols  in  losing  by  oxygen,  2  atoms 
of  hydrogen,  are  converted  into  ketones;  as  second- 
ary propyl  alcohol. 

rcH3 

(,  I  CH3  -  H,  =  CH3  -  CO  -  CH3 

'    H      Minus.  Dimethyl  Ketone. 


[oh 


And 


fCH2CH, 
(.ICH3-1I,  =  CH3-C0-C,H, 

)  H      Minus.  Methyl-ethyl  Ketone. 


Secondary  Butyl  Alcohol.- 


Alcohols^  etc.  275 

Ketones  are  CO,  united  to  two  univalent  hydro- 
carbon radicals. 

Tertiary  alcohols  do  not  yield  either  aldehydes, 
ketones,  or  acids,  containing  the  same  number  of 
carbon  atoms  as  do  the  alcohols  themselves,  but  are 
split  up  into  bodies  which  show  a  less  number  of 
carbon  atoms.     Thus,  with  tertiary  butyl  alcohol  : 

cJ  ?S3  +  o,  =  cn,o,  +  C,H,0,  +  H,0 

OH 


CHo  Formic  Acid.    Propionic  Acid. 


The  following  table  contains  in  empirical  form- 
ulae, the  known  monatomic  alcohols  and  corres- 
ponding acids,  together  with  acids  which  have  no 
known  alcohol  prototypes : 


Z/l) 


Organic  Chemistry. 


o 


+ 

o 
<1  'p^ 


t-       Pw^lnw  '^n       00  I -co  CO  (M      •  Oi  lO  CO  t^  CC  00 

^    j^eiow  zu.    ,— I 'M  Tif  lo  o    •  CO  t^  1^  t- 1^  00 


O 

OOOOOI^CiCiOO 
Or— i-^COt^OlOiCOCO 


"^^  "^O o ooooooooo 


o     CO  CO  Oi  Ol  O  Tf 

;:^  t^  Oi  O  CO  lO  CO 


.  d  

•  n^  O  •     •     •     •     •  Oi  lO 

•  Ph  oi t^  00 

!  +j  !    .    !    .    . 

•  1;  ..... 


^-OOOO 

,_    O  W        O      IM      ■*      «5 
s^         to       00       ,-1       -H       rH       ^ 

l-H  hM  HH  -J-l  ^  HH  HH 
>-Ih      m     CO     -<i<     m     CO     t~- 

OOQOOOO 


O 

I^"    . 

^ 

^ 

t^     . 

CO 

ffi  • 

ffi 

o 

:o 

_l 

,_( 

Q    . 

GO 

CO       PJ 

in    CO 

1:-      O 


c;i 

a; 


a; 


Ethyl  Alcohol^  etc.  277 


CHAPTER  VII. 

ETHYL  ALCOHOL,  ETC. 

Ethyl  Alcohol,  C2H5OH,  is  the  active  prin- 
ciple of  brandy,  rum,  whisky,  beer,  ale,  and  wine. 

It  may  be  produced  by  synthetic  processes, 
and  by  various  reactions,  but  is  practically  ob- 
tained by  fermentation  of  starchy  and  saccharine 
substances,  such  as  the  different  grains,  cane  sugar, 
fruits,  etc. 

The  mashed  grain  in  aqueous  solution,  fer- 
ments by  aid  of  the  yeast  germ,  the  starch  being 
turned  into  glucose;  a  weak  solution  of  alcohol  is 
thus  obtained. 

Glucose.  Alcohol, 

This  alcoholic  solution  is  then  distilled^  and  the 
process  repeated  until  about  a  90  per  cent  alcohol 
is  obtained.  The  water  still  remaining,  is  par- 
tially removed  by  distilling  with  quicklime;  the 
product  is  then  called  absolute  alcohol,  a  colorless 
liquid  of  sp.  gr.  80,  of  a  pungent  burning  taste  and 
spirituous  odor.  Is  boils  at  78.5C  and  freezes  at 
— 130.5C.  Alcohol  mixes  with  water  in  all  propor- 
tions; is  a  solvent  for  various  gums  and  resins,  in 


278  Organic  Chemistry. 

the  making  of  medicinal  tinctures,  and  is  used  in 
many  chemical  and  manufacturing  processes;  it 
is  also  a  valuable  antiseptic  against  putrefaction 
and  burns  in  the  air,  evolving  great  heat. 

Proof  spirit  contains  about  50  per  cent  of  alco- 
hol :  whisky,  rum  and  brandy,  from  40  to  50  per 
cent ;  wines  from  5  to  20  per  cent,  and  beer,  from 
3  to  7  per  cent. 

Alcoholic  or  vinous  fermentation  will  run  into 
acetous  fermentation,  unless  prevented  by  joas- 
teurizing,  by  heat  or  by  bottling,  or  the  use  of 
chemicals. 

C2H6O  +  O  =:  C2H4O  +  H2O 

Alcohol.  Aldehyde. 

C2H4O  +  0  =  C2H4O2 

Aldehyde.  Acetic  Acid. 

AcET- Aldehyde  C2H4O.  This  compound  is  the 
best  known  of  its  class,  called  aldehydes.  They 
contain  the  group  COH,  and  are  intermediate  be- 
tween the  foregoing  alcohols  and  their  correspond- 
ing acids. 

Acet-aldehyde,  also  formulated  as  acetyl  hy- 
dride, C2H3O.H,  is  produced  by  oxidation  of  di- 
lute alcohol,  and  by  several  other  processes.  It  is 
a  clear  liquid  of  sp.  gr.  0.81,  at  1°;  of  an  ethereal 
suffocating  odor,  and  mixes  in  all  proportions  with 
water,  alcohol,  and  ether.  With  chlorine  it  forms 
acetyl  chloride,  CH3O.CI;  with  nascent  hydrogen, 


Ethyl  Alcohol,  etc.  279 

alcohol;  and  with  oxygen,  acetic  acid.  It  reduces 
metallic  silver  from  a  solution  of  the  nitrate,  and 
unites  with  the  alkali  metals,  and  with  ammonia, 
to  form  solid  compounds,  C2H3O.NH4.  Polymers 
of  aldehyde  are  known,  a  doubling  and  trebling  of 
the  molecule,  as  C4Hg02,  and  C^H^<^0^,  It  is 
isomeric  with  ethene  oxide  and  acts  in  many  cases 
as  the  oxide  of  a  dyad,  under  the  name  of  alde- 
hydene. 

Acetic  acid,  C2II3O2.H  (in  the  dilute  state, 
known  as  vinegar),  is  the  most  familiar  of  the  acids 
corresponding  to  the  methane  series  of  alcohols. 
The  first  of  this  series  of  acids  is  formic  acid, 
CHO2H  ;  next,  acetic,  and  so  on.  With  each  ad- 
dition of  CH2  they  vary  in  their  physical  proper- 
ties, ranging  from  the  light  volatile  formic  acid,  on 
to,  and  above,  the  9-carbon  molecule,  where  they 
become  semi-solid,  of  waxy  or  greasy  consist- 
ency; hence  their  general  nsuney  fatty  acids.  The 
best  known  of  these  higher  acids,  are  palmitic,  mar- 
garic,  stearic  and  mellissic. 

Acetic  acid  is  generally  obtained  by  fermenta- 
tion (oxidation)  of  wine,  cider,  etc.,  or  from  the 
alcoholic  mash  from  which  spirit  is  distilled. 
When  pure,  it  is  a  colorless  liquid  which,  at  a  tem- 
perature of  18  (64.5F),  freezes  into  a  solid  ;  hence 
the  name,  glacial  acetic  acid.     It  mixes  in  all  pro- 


280  Organic  Chemistry. 

portions  with  water,  alcohol,  and  ether,  and  is  mon- 
obasic, forming,  with  metallic  bases,  salts  called 
acetates^  and  with  alcohol  radicals,  such  as  methyl, 
ethyl,  etc.,  it  forms  esters  or  compound  ethers  ;  in 
these  cases,  giving  up  one  atom  of  typical  hydro- 
gen to  make  room  for  the  base,  just  like  similar 
reactions  with  the  inorganic  acids.  Acetates  of 
iron  and  aluminum  are  used  as  mordants  in  calico 
printing.  Verdigris  is  copper  acetate ;  and  sugar  of 
lead  is  plumbum  acetate,  Pb  (0311302)2  +  ^  Aq. 
The  latter  compound  is  of  great  value  to  the 
•  chemist,  and  possesses  soothing  astringent  medic- 
inal properties.  Oalcium  carbonate  will  dissolve  in 
acetic  acid  (even  dilute)  forming  calcium  acetate 

Ca(C,H302)2. 

Compound  ethers,  formed  by  the  fatty  acids 
with  the  alcohol  radicals  of  the  methane  series, 
are  becoming  quite  important  as  flavoring  extracts. 
The  peculiar  flavors  of  fruits  are  probably  due  to 
the  presence  of  these  same  esters  in  the  substance 
of  the  fruits.  Amyl  acetate,  05H^^02H302,  has 
the  flavor  of  bananas;  ethyl  butyrate,  O2H5C4 
H7O2,  of  pineapples,  and  amyl  valerate,  OgH^j 
O5H9O2,  is  known  as  ''  apple  oil."  We  may  here 
state,  as  a  matter  of  some  interest,  that  when  or- 
ganic esters  are  treated  with  caustic  alkalies  the 
acid  radical  unites  with  the  alkali  metal,  and  the 


Ethyl  Alcohol,  etc.  281 

typical    alcohol    of    the     hydrocorbon    radical    is 

formed.     For  example  : 

C.HuC^HjO^     +     NaOH     =     NaC2H30,     + 

Amyl  Acetate.  Sodium  Acetate. 

C5H11OH 

Amyl  Alcohol. 

Acetic  acid  acted  upon  in  different  proportions, 
by  chlorine,  yields  three  well-defined  chloracetic 
acids,  by  giving  up  hydrogen.  It  is  not,  however, 
the  hydrogen  of  the  group  COOH  in  the  acid, 
which  is  replaced  by  chlorine,  as  is  the  case  when 
acted  upon  by  metals. 

Acetic  acid,  CgH^Og 

Monochloracetic  acid,     C2H3CIO2 
])ichloracetic  acid,  C2H2CI2O2 

Trichloracetic  acid,         C2HCI3O2 

The  aldehyde  of  trichloracetic  acid  is  the  liquid 
chloral,  C2HCI3O,  a  substance  which,  united  with 
water,  forms  the  familiar  chloral  hydrate. 

Chloral  is  prepared  by  prolonged  action  of  chlor- 
ine gas  on  pure  ethyl  alcohol. 

CgllgO     +     8C1     =     5HC1     +     C2HCI3O 

It  is  a  thin,  colorless,  oily  liquid,  of  little  taste, 
but  pungent  odor;  its  sp.  gr.  is  1.502,  it  boils  at  94^ 
(201F),  and  is  freely  soluble  in  water,  alcohol, 
and  ether.  Solutions  of  caustic  alkalies  decompose 
it  into  formate  and  chloroform. 

C2lI(M30    +    KOII    =    KCIIO2    -H    CIICI3 

Chloral.  Pot.  Formate.  Chloroform. 

24 


282  Organic  Chemistry. 

Chloral  forms  with  water  in  molecular  propor- 
tions, chloral  hydrate^  C2HCl30,H20,  a  solid  crys- 
talline soluble  substance  of  peculiar  odor  and  sharp, 
unpleasant  taste.  It  melts  at  46°  (114F),  and  boils 
at  97°  (206F). 

Materia  Medica.— Locally  applied,  chloral  hy- 
drate possesses  sedative,  anaesthetic  and  antiseptic 
properties,  and  is  assuredly  an  excellent  topical 
remedy  as  an  ingredient  of  liniments  for  the  relief 
of  neuralgia  and  rheumatic  pains.  Powdered 
chloral  (hydrate)  pressed  into  the  alveolar  pockets, 
in  pyorrhose,  will  serve  the  double  capacity  of 
anodyne  and  antiseptic.  Applied  in  substance  to 
slightly  moistened  sensitive  dentine,  it  cuts  off, 
partially,  indirect  communication  with  the  pulp  by 
extracting  moisture  from  the  tubuli ;  and  to  the 
exposed  pulp,  either  alone  or  combined  with  cam- 
phor, or  with  aconite  tincture,  it  causes,  probably 
by  the  same  physical  change,  an  immediate  lessen- 
ing of  pain.  It  is  of  service  also  in  the  cure  of  in- 
dolent ulcers  in  the  mouth  and  other  parts. 

Taken  internally,  chloral  acts  as  a  sedative  to  the 
entire  nervous  system,  and  secondarily  to  the  heart. 
As  a  hypnotic,  it  reduces  the  blood  pressure  on  the 
brain,  and  thus  induces  sleep  by  imitating  the  nat- 
ural anatomical  phenomenon  of  that  process,  and 
by  diminishing  at  the  same  time  the  conductivity 


Ethyl  Alcohol,  etc.  283 

of  the  sensory  nerves.  Awakening  is  not  accom- 
panied by  the  digestive  disturbances,  nausea,  and 
headache,  which  usually  result  from  the  use  of 
opium. 

In  full  doses  chloral  slows  the  heart's  action  and 
respiration,  and  lowers  the  temperature.  It  may 
cause  death  by  either  syncope,  or  coma,  and  those 
addicted  to  the  chloral  hahit  often  suffer  with  scor- 
butic sores  and  ulceration  of  the  gums. 

Dose:  0.30  -  1.25  Gm  (gr.  v  -  xx). 

R.  Chloral  hydratis. 

Pot.  Bromide,  aa  0.65  Gm  (gr.  x). 

Syrupi  aurantii  cort. 

Aq.  menth  pip.  aa  15.00  f  Gm  (f.^ss). 
M.  S,     A  hypnotic  potion  in  acute  alveolar  abscess. 


284  Organic  Chemistry. 


CHAPTER  YIII. 

ETHERS,  ETC. 

Oxygen  Ethers  are  defined  as  alcohols  (typical), 
with  the  hydroxyllic  hydrogen  replaced  by  an  al- 
cohol radical.     Thus : 

Ethyl  Alcohol.  Ethyl  Oxide. 

They  may  nlso  be  regarded  as  bearing  the  same 
relation  to  the  alcohols  that  metallic  oxides  bear  to 
the  metallic  hydrates,  and  all  belong  to  the  water 
type. 

ll\^  1^2\^  Na|() 

Hp  H  p  Nap 

Sodium  Hydrate.        Sodium  Oxide. 
Ethyl  Alcohol.  Ethyl  Oxide. 

Ethyl  Oxide  (0.^115)20,  comynon  ether ^  known 
also  as  sulphuric  ether,  can  be  obtained  from  a 
large  number  oH  ethyl  compounds,  as  for  instance  : 


c,Hj  +  c.nJo   =  Ki    +     %fAo 

Ethyl  Iodide.  Pot.  Ethylate.  Ethyl  Ether. 


Ethers,  etc.  285 

Practically,  ether  is  obtained  from  ethyl  alcohol 
by  the  dihydrating  influence  of  sulphuric  acid,  at 
the  proper  temperature  : 
2C,H,0   -   11,0   =    C.Tli^O    for,  {C^ll,).0,] 

Alcohol.  Ether.  I  J 

Ether  is  a  clear  mobile  liquid  of  a  strong,  though 
not  unpleasant  odor,  and  a  warm  penetrating  taste. 
Its  specific  gravity  is  0.730.  It  is  not  readily  solu- 
ble in  water,  and  is  not  as  good  a  general  solvent  as 
chloroform.  Its  boiling  point  is  dangerously  low, 
35-5°  (96F),  and  at  still  lower  temperatures  it 
evaporates  rapidly ;  the  vapor  is  about  two  and  a 
half  times  as  heavy  as  air,  and  is  highly  inflam- 
mable. If  ether  be  freely  exposed  to  the  air,  it 
tends  to  oxidize  into  acetic  acid. 

Materia  Medica. — Inasmuch  as  the  rapid  ab- 
straction of  heat  from  a  part  reduces  sensibility, 
the  local  employment  of  ether  in  the  form  of  spray, 
on  account  of  its  volatility,  has  been  favored  to 
some  extent  in  the  operation  of  extracting  teeth. 

Ether  internally  administered  in  the  form  of 
Iloft'mann's  anodyne,  which  is  a  compound  of  ether, 
alcohol,  and  ethereal  oil,  is  antispasmodic,  stimulant, 
and  carminative ;  in  the  preparation  known  as 
spirits  of  nitrous  ether,  composed  of  alcohol  and 
ethyl-nitrite  (02115^02),  it  is  an  excellent  diuretic 
and  diaphoretic,  in  fevers. 


286  Organic  Chemistry. 

The  first  practical  use  of  ether  as  a  general 
anjBsthetic  was  made  by  Dr.  Morton,  a  dentist  of 
Boston,  in  1846. 

Althoug?i  much  slower  in  its  immediate  eifects, 
ether  is  considered  a  safer  anaesthetic  than  chloro- 
form ;  the  stimulus  to  the  heart  is  more  pronounced, 
and  continuous  than  with  chloroform,  albeit,  ether 
should  not  be  exhibited  no  more  than  other  anaes- 
thetics wherever  decided  weakness  of  the  heart, 
lungs,  or  brain,  is  seriously  suspected. 

In  ether  narcosis,  the  cerebrum  seems  to  be  the 
first  of  the  nerve  centers  involved ;  then  the  sensory, 
followed  by  the  motor  centers,  of  the  cord  ;  and 
finally  the  sensory  and  motor  functions  of  the  me- 
dulla oblongata;  thus,  in  the  later  stages  inducing  a 
slowing  of  both  the  heart's  action  and  respiration. 
The  time  required  for  complete  etherization,  is  from 
three  to  five  minutes,  and  the  quantity  of  ether, 
about  60.00  Gm  (gij). 

We  may  here  place  on  record  merely  as  a  fact, 
and  not  in  any  degree  as  encouraging  to  dental 
quackery,  the  composition  of  so-called  vitalized  air. 
To  one  gallon  of  nitrous  oxide  gas,  is  added  three 
drops  of  an  equal  mixture  of  alcohol  and  chloro- 
form. 

Ethyl  chloride,  C2H5CI,  on  account  of  its  ten- 
dency to  induce  excessive  cold  by  rapid  evaporation, 


Ethers,  dc.  287 

lias  been  employed  as  a  local  aiuestlietic  for  sensitive 
dentine,  etc. 

Chlorine  forms  with  the  different  series  of 
homologous  hydrocarbons,  a  new  homologous 
series  in  each  case;  each  member  differing  from  the 
next,  by  CH2,  and  containing  equivalent  chlorine 
as  a  substitute  for  liydrogen. 

CTI3CI  CII2CI2 

Methyl  Chloride.  Mithcne  Chloride. 

Ethyl  Chloride.  Etheuo  Chloride. 

C3H7CI  C3HgCl2 

Propyl  Chloride.  Propeae  Chloride. 

The  density  of  these  haloid  ethers,  increase  in 
regular  gradation,  by  each  addition  of  CH2,  just  like 
the  tj^pical  saturated  hydrocarbons.  Indeed,  we 
can  almost  realize  in  every  instance,  the  physical 
properties  of  organic  compounds,  by  observing 
their  molecular  weights,  as  to  whether  they  are 
gaseous,  liquid,  or  solid,  and  in  every  instance  the 
vapor  density  of  the  substance,  compared  with 
hydrogen,  is  ascertained  by  dividing  its  molecular 
weight  by  2. 

Thus  methyl  chloride,  CII3CI,  is  a  gas  25  times  as 
heavy  as  hydrogen,  a  little  more  than  one  and  a  half 
times  as  heavy  as  air.  Ethyl  chloride,  C^lTsCl,  is 
a  light  liquid,  the  vapor  of  which  is  two  and  a  half 
times  as  heavy  as  air;  and  ethyl  bromide,  CgllsBr, 
is  a  liquid  almost  twice  as  heavy  as  water,  although 


288  Organic  Chemistry. 

it  boils  at  a  lower  temperature,  72  (163F.)  Its 
vapor  density  is  nearly  four  times  that  of  the  at- 
mosphere. 

Mixed  oxygen  ethers  contain  two  different  alcohol 
radicals,  united  to  hydroxylic  oxygen.  They  are 
produced  by  various  reactions,  as  for  example  : 

^^4  o  +  C,H  J  =  KI  +  CH,  I  0 

-^  J  Ethyl  Iodide.  P     FT     J 

Pot.  Ethylate.  ^2'^^5 

Methyl-ethy]  Ether. 

Methyl-ethyl  ether,^^      |  O         Boils  at  11°C 
Ethyl-butyl  "     ^2^5    Iq  u      3Q0 

Methyl-amyl        "     ^^|      |o  "      92° 

Ethyl-amyl  "     ^2^5    |q  u    112° 

The  other  alcohols  of  the  methane  series,  aside 
from  those  already  alluded  to  (methyl  and  ethyl 
alcohols),  and  amyl  alcohol,  are  interesting  to  us 
only  as  chemical  curiosities. 

Butyl  and  propyl  alcohols,  and  those  following, 
are  susceptible  of  isomeric  modifications.  Cetyl 
alcohol^  CjgHggOII,  is  characteristic  of  spermaceta ; 
and  rnelyl  alcohol,  CgoHg^^OH,  is  a  necessary  con- 
stituent of  beeswax.     These  alcohols  are  solid. 

Spermaceta  and  beeswax  are  really  compound 
ethers,  or  esters,  formed  by  alcohol  radicals,  united 
respectively  to  palmitic  and  melissic  acids. 


Mhers,  etc.  289 

Amyl  alcohol,  pentyl  alcohol,  Cgll^^OH,  is  the 
chief  constituent  of  fusel  oil,  and  occurs  as  a 
residue,  after  distillation  of  ethyl  alcohol,  espe- 
cially from  the  starch  of  potatoes.  When  pure, 
amyl  alcohol  is  a  colorless  liquid,  of  unpleasant 
burning  odor  and  acrid  taste.  Its  specific  gravity 
at  0°  is  0.825.  It  boils  at  130  (266F),  and  freezes 
at — 20°.     It  changes  by  oxidation  into  valeric  acid. 

CHI 
Amyl  acetate,    p^tt^A    >  0,  as  its  name  suggests, 

is  an  amyl  ester  which,  on  account  of  its  pear-like 
odor,  is  used  in  flavoring  cheap  confectionery. 

Amyl  nitrite,  C5Hi^]S"02,  is  also  a  compound 
ether,  obtained  by  action  of  nitric  acid  on  amyl 
alcohol;  is  a  yellow  colored  oily  liquid,  of  sp. 
gr.  0.877,  volatile,  and  inflammable;  boils  at  83 
(182F),  and  emits  a  persistent  diffusive  odor  of 
ripe  pears.  In  materia  medica  this  ether  is  known 
as  amyl  nitris,  and  is  used  as  a  stimulant  to  the 
heart,  in  case  of  ordinary  syncope  or  exces- 
sive anaesthetic  narcosis.  The  vapor  from  2  or  3 
drops,  inhaled  from  a  napkin,  produces  immediate 
flushing  in  the  face,  dilatation  of  the  arterial 
system  and  rapid  pulsation  and  breathing.  If 
pushed  too  far,  the  symptoms  of  carbon  dioxide 
coma  supervene.  Its  employment  with  ansemiac 
patients  is  safer  than  with  those  of  plethoric  habit. 
25 


^90  Organic  Chemistry. 


CHAPTER  IX. 

OLEFINES,  ETC. 

The  homologous  hydrocarbon  series  CnHgn,  next 
isologous  to  the  paratins,  are  simple  multiples  of 
CH2.  They  are  dyad  radicals,  produced  by  ab- 
straction of  two  atoms  of  hydrogen  from  the  satu- 
rated paraiius.     Thus — 

CH4       —       H2        rzr       CH2 

Methane.  Methene,  or  Methylene. 

C2H6    —      H2       =       C2  H4 

Ethane.  Ethene,  or  Ethylene. 

«         -      H,      =      CgHe 

Propene,  or  Propylene. 

«      -    H,     =     C.Hg 

Tetrene,  or  Butylene. 
Penrene,  or  Amylene,  etc. 

These  dyad  hydrocarbon  radicals  are  known  as 
olefines,  from  the  fact  that  the  most  important  mem- 
ber of  the  series,  ethene  C2H4,  forms  with,  chlorine, 
an  oily  liquid,  CgH^Clg- 

The  first  free  members  of  the  series,  ethylene  and 
propylene,  are  gases;  butylene  is  an  exceedingly 
volatile  liquid,  which  boils  at  3°  (37F),and  amylene 
also,  which  boils  at  35°  (95F) ;  the  higher  members 
of  the  series,  as  melene,  CgoHgQ,  are  solid. 


OlejineSy  etc.  291 

The  olefines  maybe  formed  by  various  reactions, 
only  one  of  which  we  will  mention,  i.  e.,  the  ab- 
straction of  water,  from  corresponding  monatoraic 
alcohols  (methane  series),  by  powerful  dehydrating 
agents,  such  as  sulphuric  acid,  zinc  chloride,  or  phos- 
phoric oxide.     Thus — 

Amyl  Alcohol.  Araylene. 

The  alcohols  of  the  olefine  series  are  diatomic,  as 
ethylene  alcohol,  C2H4  (0H)2.  They  are  called 
glycols  because  the}'  are  intermediate  in  the  series 
belonging  to  ordinary  alcohol,  and  the  series  of  tri- 
atomic  alcohols,  of  which  latter  glycerine,  C3H5 
(OH) 3,  is  the  best  known. 

Diatomic  alcohols,  glycols,  produce  by  oxidation, 
two  series  of  acids,  monobasic  an-d  disbasic,  re- 
spectively. The  first  is  derived  by  replacing  2 
atoms  of  hydrogen,  in  ethylene,  for  instance,  by  1 
atom  of  oxygen,  and  the  second  by  replacement  of 
all  4  atoms  of  hydrogen  by  2  atoms  of  oxygen. 
CII2OH  C2OH  COOH 

CII^OH  COOH  COOU 

Ethylene  Alcohol  Glycollic  Acid.  Oxalic  Acid. 

The  acids  of  the  glycollic  series  having  but  one 
group  of  COOH  are  monobasic  ;  those  of  the  oxalic 
series  are  dibasic.  Accordingly  we  have  the  gly- 
collic, or  lactic  acid  series: 


29^        '  Organic  Chemistry. 

Carbonic  acid,  CHoOg 
Glycollic  acid,  C2H4O3 
Lactic  acid,  CgHgOg 
Butylactic  acid,  C4Hg03 
Valerolactic  acid,  Ogll^QO^ 

And  the  oxalic  series: 

Oxalic  acid,  C2H2O4 

Malonic  acid,  C3H4O4 

Succinic  acid,  04Hg04 

Pyrotartaric  acid,  CgHgO^,  etc. 
Lactic  acid  is  the  characteristic  acid  of  sour  milk. 
It  is  formed  also  by  lactic  fermentation  of  glucose, 
and  starch,  and  many  other  vegetable  products  by 
the  influence  of  several  bacteria,  the  special  microbe 
penicillium  glaucum  being  probably  the  most  charac- 
teristic. The  acid  is  now  extensively  prepared  by 
supplying  a  pure  culture  of  lactic  ferment  to  glu- 
cose obtained  from  corn  starch.  It  can  also  be 
obtained  artificially,  by  direct  oxidation  of  propy- 
leue  glycol,  C3H,  (OH)^  +  O^  =  H,0  +  CgHeO,, 
and  by  various  other  chemical  processes.  It  is 
found  in  the  stomach  and  small  intestines ;  the  flesh 
of  animals  also  contain  an  isomeric  modification, 
called  para-lactic  acid.  All  the  salts  of  lactic  acid 
are  soluble  in  water  and  alcohol,  insoluble  in  ether. 
Lactic  acid  is  a  heavy  liquid  of  specific  gravity 
1.215  ;  it  is  highly  hygroscopic  and  is  soluble  in  water, 
alcohol,  and  ether.     The  formula : 


Olefines,  etc.  293 

f  OH       \      j 
\COOH/^^^) 


CH2— OH 
-^  COOH  /       (^  6H2-COOH, 


will  enable  us  to  understand  the  reactions  that  may 
occur  between  lactic  acid,  and  positive  radicals. 
With  metals  such  as  zinc,  and  calcium,  it  is  only 
the  hydrogen  of  the  group  COOH  that  gives  its 
place  to  the  metal;  the  metals  of  the  alkalies 
however  are  capable  of  removing  likewise,  the 
hydroxylic  hydrogen.  In  this  connection  the  fol- 
lowing formulas  are  suggestive : 

2(CH3-CH  <coo)^^-       ^^3-CH<^(^(^j^^ 

Calcium  Lactate.  Sodium  Lactate. 

Disodium  Lactate. 

Hydrocarbon  radicals  can  displace  either  the  alco- 
holic hydrogen,  or  the  basic  hydrogen,  or  both,  in 
the  lactic  series  of  acids,  and  these  acids  therefore, 
can  form  three  different  ethers.     As, 

Ethyl  Lactic  Acid  Monoethyl  Lactate. 

CH3-CH<g5%H»j^^ 

Diethyl  Lactiite. 

The  principal  exciting  cause  of  caries  of  the  teeth, 
has  been  generally  accepted,  since  the  published 
experiments  of  Prof.  W.  D.  Miller,  as  due  to  lactic 
fermentation  in  the  mouth.  Food  carbohydrates, 
amylaceous,  and  saccharine,  are  especially  disposed 
to  this  form  of  fermentation, 


294  Organic  Chemistry, 

starch.  Glucose,  Levulose,  and  Dextrose 

CeHi,Oe=2C3He03. 

Glucose.  Lactic  Acin. 

Ci2H.,Oi,+H,0-4C3He03. 

Grape  or  Milk  Sugar.  Lactic  Acid. 

Free  lactic  acid  destroys  the  bacteria  that  produce 
the  fermentation  ;  but  the  acid  as  it  developes  in 
the  cavity  of  decay,  is  at  once  neutralized  at  the 
expense  of  the  mineral  portion  of  the  tooth  struc- 
ture, calcium  lactate,  CaCCsH^Og),,  being  formed, 
which  permits  a  continuation  of  the  process. 

Oxalic  Acid,  C2H2O4,  is  the  characteristic  acid 
of  wood  sorrel  and  rhubarb.  When  evaporated  from 
solution,  it  occurs  in  prismatic  crystals,  resembling 
magnesium  sulphate,  but  very  poisonous.  It  may 
be  produced  artificially,  by  oxidizing  starch  or 
sugar,  with  nitric  acid,  and  is  now  largely  manu- 
factured from  sawdust. 

Oxalic  is  the  first  of  a  long  homologous  series  of 
acids  ;  the  immediate  succeeding  members  are  given 
on  page  292.  They  are  all  dibasic,  and  can  there- 
fore form  both  normal  and  hydrogen  salts.  Of 
these,  succinic  acid  is  the  most  interesting  on  ac- 
count of  its  relation  to  malic  and  tartaric  acids. 
CII  -COOH     CHOH-COOIl     CHOH-COOIl 

I  1 

iH,-COOH     CH2-COOH         CHOH-COOIl 

succinic  Aoid.  Malic  Acid.  Tartaric  Acid. 


Olefines,  etc.  295 

Malic  is  the  acid  of  apples,  and  certain  other 
fruits  and  vegetables,  it  occurs  in  white  soluble 
crystals. 

Tartaric  acid  exists  in  the  juice  of  grapes,  tama- 
rind, etc.  During  the  fermentation  of  wine,  potas- 
sium tartrate  is  deposited  on  the  sides  of  the  wine 
casks ;  hence  the  name  tartar,  is  given  to  deposits 
on  the  teeth. 

Tartaric  acid  occurs  as  a  white  crystalline  sub- 
stance, of  very  sour  taste.  It  forms  the  contents 
of  one  of  the  papers,  in  Seidlitz  powder;  the  other 
paper  containing  a  mixture  of  hydrosodium  car- 
bonate and  potassium  sodium  tartrate.  On  solution 
in  water,  effervescence,  by  the  escape  of  CO 2,  takes 
place. 

Cream  of  tartar,  is  hydrogen-potassium  tartrate, 

TT  1 

-j^  >C4H40g;  the  best  varieties  of  baking-powders, 

are  mixtures  of  cream  of  tartar,  and  hydrogen 
sodium  carbonate  (bicarbonate  of  soda). 

The  moisture  of  the  dough,  when  heated  induces 
the  following  reaction  : 

HNaC03+HKC4H406=KNaC4H40e4-H20+C02. 

Rochelle  Salt. 

The  escaping  CO2,  raises  the  dough,  thus  confer- 
ring lightness;  the  Rochelle  salt  remains  with  the 
bread. 


296  Organic  Chemistry. 

Tartar  emetic  is  tartrate  of  potassium  and  anti- 
mony,  qi  ^  VC^H^Og,  used  more  or  less  in  medi- 
cine, as  an  emetic. 

Citric  acid,  CgHgO^,  although  not  related  to  the 
above,  is  also  a  fruit  acid,  being  found  in  the  juice 
of  oranges  and  lemons;  and  in  other  fruits,  as 
gooseberry,  currant,  etc.,  in  company  with  malic 
acid. 

This  acid  is  tribasic,  as  may  be  seen  by  the  sub- 
joined condensed  formulae : 

Hj  Hj 

Citric  Acid.  Monopotassium. 

Citrate. 

Hj  Kj 

Dipotassiura.  Tripotassium. 

Citrate.  Citrate. 


Fatty  AcidSy  etc.  297 


CHAPTER  X. 

FATTY  ACIDS,  ETC. 

By  reference  to  the  table  of  corresponding  alco- 
hols and  acids  on  page  276,  it  will  be  seen  that  the 
solid  acids,  named  pahiiitic,  margaric  and  stearic 
belong  to  the  group  of  monobasic /a^^y  acids.  Pal- 
mitic acid,  Cigll3202,  occurs  as  an  ether  of  pro- 
penyl,  in  many  natural  fats,  and  in  palm  oil;  also 
in  cetin  of  spermaceti,  and  in  melissin  of  beeswax. 
It  is  a  solid,  lighter  than  water ;  it  melts  at  62° 
(144F),  and  when  heated  with  alcohols,  yields 
compound  ethers.  Margaric  acid,  C^rjU^^O^^is  in- 
termediate between  palmitic  and  stearic  acids.  The 
latter  acid,  CigHggO,  occurs  in  the  more  solid  fats 
of  animals  ;  also  in  the  softer  fats,  as  butter  and 
goose  grease,  and  in  some  of  the  fats  of  vegetable 
origin,  as  in  cocoa  butter.  Stearic  acid  is  a  solid, 
a  little  heavier  than  water;  it  melts  at  69°  (162F) 
and  distils  without  alteration. 

Oleic  acid,  C18II34O2,  is  monabasic,  but  belongs 
to  another  series  of  acids,  having  the  general 
formula,  CnH2n — 2^2-  -^^  ^^  ^^^  fluid  constituent 
of  most  natural  fats  and  fixed  oils;  it  solidifies  at 


298  Organic  Chemistry. 

4°  (39F),    and    is,   therefore,   liquid     at    common 

temperatures ;  its  specific  gravity  is  0.898.     These 

fatty  acids  are  found  in  nature   as  ethers  of  the 

radical  propenyl,  C^H^'^'. 

Glycerine,  Glycerol,  is  propenyl  alcohol,  and  as 

propenyl,  is  a  triad  radical,  the  alcohol  in  question 

must  be  triatomic. 

fOH 

{  OH 

(OH 

With  some  monobasic  acids,  therefore,  this  alco- 
hol may  form  three  distinct  ethers,  as  with  acetic 
acid  : 

CC,R,0,  (C2H3O2  fC^HgO^ 

C3HJ0H  C3hJc,H30,      C3HJCHO 

(-0H  (OH  (C,H30, 

The  natural  oils  and  fats  are  generally  found  as 

triple  (normal)  ethers  of  palmitic,  margaric,  stearic 

and  oleic  acids : 


CgH^'^'^OH 


C3hJc,,h,,o,  C3hJo,,h   O 

IC16H31O,  lCi,H330 

Palmitin.  Margarine. 

c3hJc,,h::o:  c3hJc;h  o 

t-CisHjsO^  IC13H35O 


Stearin.  Olein. 

When  these  fatty  ethers  are  saponified  by  alka- 
lies, a  salt  of  the  alkali  metal  (soap)  is  formed,  and 
propenyl  alcohol  thus  set  free. 


Fatty  Acids,  etc.  299 

C3H5  (Ci3H3502)3  +  3K0H  =  3KCi«H3,02  +  C3H,  (0H)3 
Propenyl  Stearate.  Pot.  Stearate.       Prepenyl  Alcohol. 

(Stearin).  (Soap).  (Glycerine). 

Glycerine  is  also  produced  in  small  quantity  in 
sugar  fermentation,  and  is  now  separated  largely 
from  the  fats,  hy  high  pressure  steam. 

When  acted  on  by  dilute  nitric  acid,  glycerine 

exchanges   2  atoms  of   hydrogen  for  0,  forming 

glyceric  acid. 

CH2OH 

CHOH 

I 
COOH 

When  treated  with  strong  nitric  and  sulphuric 
acids,  glycerine  yields  the  explosive  compound 
known  as  nitro- glycerine,  C3H5  (^Ogjg.  This  pro- 
penyl-nitrate  is  a  thick  oily  liquid  ;  it  burns  quietly, 
but  if  struck  fiercely  or  ignited  by  a  fulminate,  it 
explodes  witli  frightful  violence.  It  is  the  basis  of 
different  varieties  of  dynamite,  which  consists  of 
absorbed  nitro-glycerine  in  infusorial  earth  or  saw- 
dust, etc.,  to  a  porous  pasty  solid,  of  less  danger  in 
handling  than  the  liquid. 

Glycerine  itself  is  a  syrupy  liquitl  of  sp.  gr.  127, 
is  nearly  colorless,  and  of  sweetish  taste.  When 
pure,  it  is  said  to  boil  at  the  high  temperature  of 
290°  (554F),  a  fact  which  suggested  its  employment 
in  an  open  dish  for  valcanizing  rubber,  to  avoid  the 
danger  attending  the  ordinary  method. 


800  Organic  Chemistry. 

• 

Commercial  glycerine  contains  too  much  water 
to  permit  a  sufficient  elevation  of  temperature  for 
the  purpose,  and  even  where  the  pure  variety  is 
used,  acrid  vapors  consisting  of  acrolein^  C3H4O, 
are  given  oft*,  the  same  as  from  the  wick  of  an  im- 
perfectly quenched  candle. 

Materia  Medica. — Glycerine  is  soluble  in  water 
and  alcohol ;  insoluble  in  chloroform  and  ether. 
It  is  a  good  solvent  for  various  drugs,  such  as  tan- 
nin, creosote,  carbolic  acid,  iodine,  borax,  quinine, 
etc.  It  is  antiseptic  and  soothing,  and  is  applied 
as  an  emollient  to  sore  or  inflamed  surfaces,  either 
alone  or  as  a  vehicle  adjunct  for  other  remedies,  as 
in  the  following  Glycerita: 

Glycerina,      .     30.00    fGm.   (fgi) 
Acidi  Tannici,      8.00     Gm.    (^ij) 

Glycerina,     .      30.00    fGm.    (fgi) 
Acidi  Carbolici,    8.00    fGm.  (f^ij) 

Glycerina,     .      30.00     fGm.  (f^i) 
Sodii  Biboras,   .    8.00      Gm.   (gij) 

The  univalent  radical  allyl,  CI3H5,  is  isomeric 
with  the  trivalent  radical  of  glycerine,  propenyl. 
They  differ  in  structure,  however,  as  the  following 
formulas  will  show : 


Fatty 

Acids, 

etc. 

H 

1 

H  L 

H-C- 

-OH 
-OH 

H    C     H 
C     H 

H    C     OH 
H 

Allyl  Alcohol. 

H     C 
H 

Glycerol. 

-OH 

301 


The  natural  oil  of  garlic  owes  its  pungency  to 
allyl  sulphide  (C3H5)2S  ;  the  oil  of  mustard,  to  allyl 
sulphocyanate,  C3H5CNS. 


302  Organic  Chemistry. 


CHAPTER  XL 

AMYLENE,  ETC. 

We  have  alluded  to  the  olefines,  dyad  hydrocar- 
bons of  the  general  formula,  CnH2n,  and  stated 
that  one  source  of  their  derivation  is  by  dehydrat- 
ing the  alcohol  of  the  same  number  of  carbon 
atoms.  Thus,  isopentene  (amylene),  CgHj^,  is  ob- 
tained by  action  of  dehydrating  agents,  such  as 
sulphuric  acid,  zinc  chloride,  phosphoric  oxide, 
etc.,  on  pentyl  (amyl)  alcohol, 

C,HiiOH-H,0  =  C,Hi„. 

The  formula,  CgHj^,  is  capable  of  four  modifi- 
cations. Normal  pentene,  sometimes  regarded  as 
ethyl-allyl,  C2H5,C3H5,  is  obtained  by  action  of 
sodium  on  mixed  ethyl  and  allyl  iodides.  The 
third  possible  modification  is  not  well  known, 
while  the  fourth  variation,  is  probably  identical 
with  the  new  anaesthetic  called  pental. 

These  possible  variations  of  C^H^q  are  repre- 
sented below : 


Amylene,  etc.  303 

1st.  CH3  —  CH,  —  CH2  —  CH  =  CH2 

Normal  Pentene. 

2d.   QH^>CH  —  CIL=  CH2 

Isopentene. 

3d.  CH3  —  CH2  —  CH  =  CH  —  CH3. 
4th.  qh'>C  ==  CH  —  CH3 

Pental. 

Pental  is  said  to  be  produced  from  amylene  hy- 
drate (amjlene  alcohol),  by  heating  in  the  presence 
of  acids.  This  hydrate  is  isomeric  with  amyl  alco- 
hol. They  differ,  however,  in  certain  properties, 
and  therefore  must  differ  in  structure. 

C^HjiOH  C5H1JOH 

Amyl  Alcohol.  Amylene  Hydrate, 

If  these  two  alcohols  be  acted  on  by  the  same 
dehydrating  agent,  the  resulting  compounds  would 
differ  in  some  of  their  properties.  They  must, 
however,  have  the  same  vapor  density.  The  boil- 
ing points  of  normal  pentene,  isopentene  (amylene), 
and  pental,  approximate  35°-38°  (95-104F),  and 
probably  vary  in  this  respect,  only  on  account  of 
difference  in  absolute  purity.  Their  specific  grav- 
ities also  approximate  0.663-0.6783.  They  are  in- 
soluble in  water,  but  mix  freely  in  ether,  chloro- 
form, and  alcohol.  They  are  exceedingly  volatile 
and  inflammable,  and  their  vapor,  when  inhaled, 
causes  insensibility  to  pain. 


304  Organic  Chemistry. 

Amylene  was  introduced  as  an  ansesthetic  in  1856, 
but  made  slight  impression.  Pental  was  intro- 
duced to  the  profession  in  this  country  in  1891. 
Its  odor  somewhat  resembles  that  of  mustard  oil, 
suggesting  the  radical  allyl. 

The  claims  made  for  pental  as  an  anaesthetic  in. 
dental  operations,  are : 

To  reach  narcosis,  requires  but  from  1-3  minutes. 

Heart's  action  and  respiration  are  not  materially 
interfered  with. 

There  is  no  spasm  of  the  muscles. 

The  narcosis  is  brief,  and  the  patient  recovers 
without  any  accompanying  headache,  nausea  or 
vomitings  l^evertheless,  pental  has  not  been  re- 
ceived thus  far  with  as  much  favor  as  its  friends 
think  it  deserves. 

The  series  of  hydrocarbons,  CnH2n — 2,  of  which 
Ethine  (acetylene),  C2H2,  is  the  only  important 
member,  belong  to  the  fatty  compounds,  like  the 
paraffins  and  alefines,  as  distinguished  from  the 
aromatic  compounds.  The  first  two  numbers  are 
gases,  the  others  increasing  in  density  through 
liquid  and  solid  states,  by  each  additional  CH2. 

Acetylene,  C2H2,  is  a  constituent  of  coal  gas,  on 
which  it  confers,  largely,  a  disagreeable  odor.  It 
may  be  produced  by  various  decompositions  of 
organic    compounds,   but  it  is   especially   distin- 


Amyhne,  etc,  305 

giiished  ag  the  only  compound,  formed  synthetically 
by  direct  union  of  carbon  and  hydrogen. 

When  a  strong  electric  arc  current  is  passed 
from  carbon  poles  through  an  atmosphere  of  hy- 
drogen, the  carbon,  as  it  volatilizes,  unites  with 
the  hydrogen,  2H  +  2C  =  C2H2. 

From  acetylene,  a  great  number  of  organic  com- 
pounds can  be  obtained.  Thus,  by  aid  of  platinum 
black,  it  will  take  up  2  atoms  of  hydrogen  to  form 
ethylene,  C^H^,     C^H^  -f  H2  =  CJi^. 

Ethylene  combines  with  concentrated  sulphuric 
acid  to  form  basic  ethyl-sulphate,  03114  +  H2SO4 
=  H,  C2H5SO4,  and  this,  when  heated  with  caustic 
potash,  yields  as  follows  :  ^ 

H,  C2H5SO4  +  2K0H  =  C2H6O  +  H2O  +  K2SO4 

Alcohol, 

In  ethane,  C2Hg,  the  2  carbon  atoms  are  united  by 
1  bond,  in  ethene  (ethylene  (C2H4),  the  carbon  atoms 
are  united  by  2  bonds,  and  in  ethine  (acetylene)  the 
carbon  atoms  are  united  by  3  bonds,  thus : 
H 

H— C— H 

H— C— H  H— C-H  C— H 

I  II  III 

H  H— C— li  C— H 

Ethane.  Ethene.  Ethine. 

The  hydrocarbons  of  the  general  formula,   Cn 
26 


306  Organic  Chemistry. 

HgH — 6,  are  represented  by  the  first  member  of  the 
series,  Benzene,  C5gHg,  (not  the  petroleum  product, 
Benzine);  the  second  member  Toluene,  C^Hg,  is 
also  frequently  miscalled  benzol  and  toluol.  The 
other  members  of  the  group,  are  susceptible  of 
isomeric  modifications,  and  they  all  belong  to  the 
Aromatic  series  of  hydrocarbons,  so  named  because 
many  derivatives  of  benzene,  such  as  benzoic  acid, 
oil  of  bitter  almonds,  etc.,  possesses  a  fragrant 
odor. 

Benzene,  C^Mq  is  chiefly  obtained  from  the  coal 
tar  of  the  gas-works.  It  is  a  light  highly  inflam- 
mable liquid,  which  boils  at  80°  (176F.)  and  freezes 
at  3°  (37F.) ;  it  is  soluble  in  alcohol  and  ether, 
scarcely  so  in  water,  has  an  ethereal  odor,  and  is 
produced  largely,  for  the  manufacture  of  aniline 
dyes. 

The  six  carbon  atoms  in  benzene,  form  a  closed 
ring ;  they  are  united  by  1  and  2  bonds,  alternately, 
permitting  one  bond,  belonging  to  each  atom  to 
remain  free,  forming  thus  a  quasi  hat-rack,  which  is 
capable  of  receiving  alternately,  innumerable  ele- 
mentary or  compound  univalent  radicals ;  so  the 
derivatives  of  benzene  may  be  considered  practically 
illimitable,  and  thousands  of  them  are  already 
known. 


Benzene,  etc. 

30 

c  c 

H    C    C    H 

//      \ 
H    C            C    H 

\      / 

H    C            C     CH 

\      / 
H    C-=C    H 

Benzene  Ring. 
(Hat-rack). 

Benzene. 

Methyl  Benzene. 
(Toluene). 

Groups  of  compound  radicals  like  CHg  attached 
to  the  nucleus  ring,  in  the  place  of  II,  form  lateral 
chains,  which  themselves  may  give  up  H,  to  form 
substitution  derivatives. 

The  homologues  of  benzene,  as  toluene,  etc., 
(CgIIg  +  CH2,  etc.),  may  be  derived  by  substitution 
of  methyl,  CHg,  for  one  or  more  of  the  six  hydro- 
gen atoms  ;  and  where  but  one  hydrogen  atom  is 
removed  from  benzene,  the  compound  radical  j)/ien?/^, 
C5II5,  is  presented. 

Benzene  itself,  is  the  hexune  of  Hoffmann  ;  and  its 
homologues  are  isologous  with  many  hydrocarbons 
of  great  interest,  and  practical  use,  such  as  cinna- 
mene,  Cgllg,  naphthalene,  C^QlIg,  and  anthracene, 
Cj4H^Q,  and  the  terpenes,  Cj^Hig. 

PAen?/?rt^co/io^,CgH5  0H,  commonly  called  carbolic 
acid,  is  usually  obtained  from  coal  tar  by  distilla- 
tion, between  the  temperatures  of  150°  and  200° 
(302-392F.)  It  is  also  produced  by  various  other 
methods  of  reaction  on  benzene  derivatives,  and 
by  dry  distillation  of  organized  complex  substances, 
such  as  coal  and  wood. 


308  Organic  Chemistry. 

This  phenol  shows  its  relation  to  benzene,  by  the 
graphic  formula  :    H — C — C — H 

H_C  C— 0— II 

\        / 
H— C=C— H.        Although  not 

an  acid,  it  takes  its  name  as  such,  because  it  forms 
salts  with  the  alkalies,  such  as  potassium  phenate 
OgHgOK,  by  giving  up  its  hydroxylic  hydrogen  to 
the  metal.  This  reaction  however  suggests  an 
alcohol,  and  moreover,  carbolic  acid  forms,  like 
the  alcohols,  compound  ethers,  such  as  methyl 
phenate  O^H^ — 0 — CHg,  {anisol),  and  ethyl  phe- 
nate CeH^r^O— C2H5,  (phenetol),  etc. 

Materia  Medica. —  Phenyl  alcohol,  carbolic  acid, 
phenic  acid,  simply  phenol,  w^hen  pure,  occurs  in 
clear  prismatic  needles  of  specific  gravity  1.066; 
it  melts  at  40°  (104F),  and  boils  at  181°  (357F).  It 
possesses  a  smoky  odor  and  burning  taste.  It 
forms  a  complete  aqueous  solution  with  95  per 
cent  of  water,  and  will  liquefy  by  the  presence  of 
5  per  cent  of  water. 

It  acts  as  a  local  anaesthetic  when  applied  to  soft 
parts,  as  the  dental  pulp,  probably  by  forming, 
with  albuminoids,  a  protecting  coagulum.  It  acts 
as  a  superficial  caustic  when  applied  undiluted, 
and  is  one  of  the  best  antiseptics,  so  long  as  the 
coagulum,  which  it  forms  with  the  substance  of  the 


Benzene,  etc.  309 

tissue  acted  on,  or  with  the  substance  of  bacteria 
themselves,  remains  undissolved. 

When  dissolved  in  chloroform,  ether,  or  alcohol, 
the  caustic  properties  of  carbolic  acid  are  enhanced; 
it  also  dissolves  in  the  essential  oils  and  in  glycerine, 
which  somewhat  diminish  its  causticity.  It  is  an 
active  poison. 

Dose,  0.06  Gra.  (grj)  in  solution,  or  pill. 

Antidotes,  olive  oil  and  saccharated  lime. 

Bobinson's  Remedy,  composed  of  equal  parts  of 
carbolic  acid  and  caustic  potash,  is  useful  in  al- 
veolar pyorrhoea,  and  with  arsenic,  for  destroying 
dental  pulps. 

Phenol  Sodique  is  a  solution  in  water  of  5  parts 
carbolic  acid  and  1  part  of  caustic  soda,  useful  as 
an  ingredient  of  antiseptic  mouth  washes.  Phe- 
nol trichloride  is  antiseptic  and  a  powerful  disin- 
fectant. 

B.     Acida  carbolici,        2.00      Gin.         (3ss) 
Glycerin!,        .  10.00     fGm.      (fsijss) 

Aq.  Rosaq.  s.  ad.,  120.00  fGm.  (f^iv) 
M.  8.  Antiseptic  solution. 
Creasote  is  a  product  of  the  distillation  of 
wood  tar,  and  is  a  mixture  of  several  phenols, 
such  as  carbolic  acid,  creasol,  C8H1QO2,  and  cre- 
sylol,  C^IIgO.  These  latter  may  also  be  attached 
to  the  benzene  hat-rack: 


810  Organic  Chemistry. 

H-d  C— OH  H— C  6— OH 

H— C-=C— OH  H— C=C— H 

Creasol.  Cresylol. 

Creasote  is  an  oily  liquid  of  specific  gravity  1.08. 
It  possesses  a  caustic  burning  taste,  and  a  pene- 
trating empyreumatic  odor.  On  long  exposure  to 
light,  it  turns  to  a  reddish  yellow.  It  mixes  in  all 
proportions  with  ether,  alcohol,  acetic  acid,  and 
naphtha,  but  not  with  glycerine.  With  water  it 
forms  two  solutions,  1  part  creasote  to  80  of  water, 
and  10  parts  creasote  to  1  of  water.  It  may  be 
distinguished  from  carbolic  acid  by  producing  a 
green  instead  of  a  brown  color,  with  alcoholic  so- 
lution of  ferric  chloride. 

Creasote  possesses  many  of  the  virtues  of  car- 
bolic acid.  It  is  antiseptic,  anaesthetic,  escharotic, 
and  styptic.  When  applied  to  exposed  dental 
pulp,  it  effectually  relieves  the  pain;  and  when  di- 
luted, it  is  useful  as  an  application  to  ulcerative 
conditions  of  the  skin  and  mucous  membrane.  It 
is  preferred  to  carbolic  acid  as  an  internal  remedy 
in  phthisis,  nausea,  cholera,  and  passive  hem- 
orrhage. 

Dose,  0.06-012  fGm.  (ntj-ij) 
Antidotes,  same  as  carbolic  acid. 


Benzene  Group.  311 


CHAPTER  XII. 
BENZENE  GROUP. 

The  aromatic  alcohols  of  the  henzene  homologues, 
are  formed  by  substitution  of  OH  for  H  in  the  lat- 
eral chains,  and  contain  the   group  CH^OH.     As, 

H_C— C— H  H— C— C— H 

H_C  C— CH,  H— C  C— CH.OH 

\        /  '  \       / 

H— C=.C— H  H— Cr=C— H 

Toluene.  Benzyl  Alcohol. 

They  are  therefore  primary  alcohols.  They  change 
to  aldehydes,  and  acids,  by  oxidation,  and  yield 
ethers,  analogous  to  those  of  the  monatomic 
alcohols. 

Benzoic  Acid,  CgllgCOOlI,  is  characteristic  of 
the  urine  of  herbivorous  animals.  It  exists  already 
formed  in  certain  balsams  and  gum  resins,  as  in 
gum-benzoin f  which  exudes  from  the  Styrax  Benzoin 
tree  of  Borneo,  and  adjacent  countries.  It  may 
also  be  obtained  by  various  reactions  on  many 
benzene  derivatives.  It  is  an  inodorous  solid,  but 
when  warm,  emits  a  faint  agreeable  odor;  it  melts 
at  120°  (248F.)  and  boils  at  250°  (482F.) ;  is  freely 
soluble  in  alcohol  but  sparingly  so  in  water.     Its 


812  Organic  Chemistry. 

salts  called  henzoates  are  generally  soluble  in  water 
and  have  the  formula,  MC^HgOg. 

Calcium  benzoate  is  changed  by  dry  distillation 
into  calcium  carbonate  and  benzone,  or  the  ketone 
of  benzoic  acid. 

Ca(C,H50,),  =CaC03  +  C.H^-CO-OgHj. 

Benzoic  acid  is  a  good  germicide  and  antiseptic, 
and  is  stimulant  to  mucous  surfaces.  It  is  proba- 
bly the  most  active  ingredient  of  the  antiseptic 
mixture  known  as  Listerine,  and  is  also  one  of  the 
ingredients  of  ^'Harris'  Gum  WasA."  It  is  used 
internally  in  gout,  calculi,  inflammation  of  the 
bladder,  and  incontinence  of  urine. 
Dose,  0.50  Gm.  (gr.  vij.) 

Benzoin  tinctures,  are  effective  in  treatment  of 
ulcerative  inflammation  of  the  oral  mucous  mem- 
brane, and  of  sloughing  wounds. 

Ammonium  benzoate,  ^}l^CrjlIfi2^^^  antacid  and 
stimulant,  and  is  acceptable  to  the  stomach,  in  acid 
dyspepsia. 

The  new  substance,  saccharine,  which  is  said  to 
possess  300  times  the  sweetening  power  of  cane 
sugar,  is  a  derivative  of  benzoic  acid.  It  is  the 
anhydride  of  orthosulphamidobenzoic  acid. 

Benzaldehyde,  is  the  familiar  fragrant  oil  of  bitter 
almonds. 

Salicylic  acid,  QqW^^^^^^^jx  occurs  in  salicin,  of 


Benzene  Group.  313 

the  willow  and  poplar,  and  free,  in  the  flowers  of 
meadow-sweet;  and  as  niythylic  ether,  in  oil  of 
wintergreen  (Gaulheiia  procinnhens)^  from  which 
it  may  be  obtained  by  distillation  with  potash.  It 
is  however  principally  prepared  by  heating  sodium 
phenate  with  carbon  dioxide. 

Salicylic  acid  appears  as  a  white  crystalline 
powder,  freely  soluble  in  glycerine,  alcohol,  and 
ether,  sparingly  soluble  in  water;  is  without  odor, 
or  taste,  but  leaves  a  sweet  astringent  aftertaste; 
it  is  resolved,  by  heating  with  pounded  glass,  into 
carbon  dioxide,  and  phenol.  It  is  an  excellent  anti- 
septic, and  is  somewhat  disinfectant,  and  is  fre- 
quently employed  with  good  results,  in  powder  or 
ethereal  solution,  as  a  dressing  in  suppurating  root 
canal ;  and  in  alcoholic  solution  with  borax,  in 
treatment  of  aphthae,  and  other  inflammatory  con- 
ditions of  the  mouth.  Mild  alkalies,  as  borax  and 
Hodii  phosphas,  increase  its  solubility.  It  is  afi:ec- 
tive  as  a  deodorizing  dentifrice,  when  combined  in 
proper  proportion  with  suitable  vehicles;  when  in 
strong  solution,  its  acid  nature  is  objectionable  to 
the  teeth. 

Dose,  0.50-1.25  Gm.  (gr.  viij-xx.) 

Gallic  Acid,  dioxysalicylic  acid,  trioxybenzoic 

acid,  CyHgOg,  may  be  also  erected  on  the  benzene 

ring. 

27 


Si 4  Organic  Chemistry. 

H-C— C— OH 

H— C  C— OH 

\        / 
HO— C=C— COOH 

Gallic  acid  is  a  constituent  of  nut  galls,  and 
many  other  vegetable  bodies,  but  is  most  conven- 
iently prepared  from  tannin.  It  is  acid  in  reaction^ 
is  only  slightly  soluble  in  cold  water,  but  freely  solu- 
ble in  hot  water,  and  in  alcohol,  ether,  and  glycerine. 
It  possesses  astringent  and  styptic  properties. 

Dose,  0.10-0.30  Gm.  (gr.ij-v.) 

Tannin,  tannic  acid,  gallotannic  acid, 
C,,R,,0,  ==  0 C,11,={0R), 

CO-CeH^^COH)^ 

COOH 
Ordinary  tannic  acid  is  obtained  from  nut  galls, 
which  are  produced  as  an  excrescence  on  the  young 
twigs  of  the  species  of  oak  known  as  the  quercus 
infectoria,  by  the  puncture  of  the  insect  cynips  gallce 
iinctorice.  The  galls  are  irregularly  rounded  and 
tuberculated  nuts,  from  J  to  }  of  an  inch  in  diame- 
ter, of  a  green  gray  color,  and  of  decidedly  astrin- 
gent taste.  The  favorite  galls,  come  chiefly  from 
the  Levant.  They  are  rich  in  tannic,  and  gallic 
acids. 

Medicinal  tannin,  is  obtained  from  powdered  galls 
by  the  action  of  commercial  ether.     It  is  a  feathery 


Benzene  Group,  315 

amorphous  powder,  of  a  light  yellow  color,  soluble 
iu  water,  glycerine,  alcohol,  and  ether.  It  produces 
coagula  with  gelatine  and  albumen,  smd  precipitates 
with  vegetable  alkaloids,  and  with  ferric  com- 
pounds. These  substances  are  therefore  incompat- 
ible with  tannin. 

Materia  Medica.  Locally  applied  tannic  acid 
is  especially  astringent.  It  is  therefore  suggested 
as  a  good  local  application  in  inflammations  of  the 
mucous  membrane,  in  either  one  of  the  extreme 
portions  of  the  prima  via.  In  passive  hemorrhage, 
sometimes  excessive,  after  the  extraction  of  teeth, 
pledgets  of  cotton  wool,  holding  tannin  en  masse, 
inserted  into  the  bleeding  sockets  of  the  alveoli,  will 
nearly  always  eifectually  arrest  the  hemorrhage,  by 
its  astringent  action  on  the  vessels,  and  by  its  coag- 
ulating effect  on  the  albumen  of  the*escaping  blood. 

Internal  1}%  tannin  combinations,  are  frequently 
exhibited  in  diarrhoea,  cholera,  and  hemorrhage. 

Dose  0.06-0.18  Gm.  (gr.j-iij.) 

R.     Acidi  Tannic!  4.00  Gm.  (.^i). 
Glycerins). 
Aqua  Dest.  aa  15.00  fGm  (fgss). 

M.  S.     Apply  in  nursing  sore  mouth. 

The  tannins  are  the  active  astringent  principles 
of  various  vegetable  bodies,  such  as  krameria, 
catechu,  kino,  hsematoxylon,  hamamelis,  or  witch- 


316  Organic  Chemistry. 

hazel,  and  of  quercus  alba,  and  other  species  of 
oak.  They  are  denominated  glucosides  because 
like  amygdalin,  coniferin,  salicin,  etc.,  they  change 
by  the  action  of  ferments,  or  by  dilute  acids,  or 
alkalies,  into  glucose  (dextro)  and  other  bodies, 
which  are  mainly  derivatives  of  benzene. 

Tannin  may  be  regarded  as  gallic  anhydride. 

Tannin.  Gallic  Acid. 

Nitro-benzene,  C6H5NO2,  is  a  volatile  liquid,  used 
in  making  cheap  perfumery  and  flavoring  essences. 

When  nitrobenzene  is  acted  on  by  nascent  hy- 
drogen it  is  changed  to  j)henylamine,  C^H^l^YL^', 
also  known  as  amidobenzene,  or  aniline. 

C6H,K02+6H  =  2H204-CeH5NH2.  ' 

Nitrobenzine.  Aniline. 

Aniline  is  a  liquid,  slightly  heavier  than  water. 
It  possesses  a  smooth  disagreeable  odor ;  is  strongly 
basic  and  unites  with  acids  to  form  salts.  It  istho 
basis  of  aniline  dyes.  And  thus  from  the  benzene 
of  coal  tar,  erstwhile  a  waste  product  in  the  manu- 
facture of  illuminating  gas,  comes  those  splendid 
colors,  which  confer  on  fabrics  of  silk,  etc.,  the 
elegant  shadings  now  so  noticeable. 

Trinitrophenol,CQH^     OH^  ^' ^^  ^^^^  known  as 

picric  acid.     The  picrates  are  highly  explosive  salts. 

Many  derivatives  of  benzene  are  used  in  medi- 


Benzene  Group.  817 

cine,  such  as  salol,  a  compound  of  salicylic  acid  and 
phenol;  phenacetine,  and  the  analogous  com- 
pound, acetanilide,  Cgll^ — NH — C2H3O2  ;  resor- 
cin,   Cg  114(011)2  ;   pyridine,    CgH^^;    naphthaline, 

I       I 

H— C         C         C— H 

I  II  I 

H— C         C       /C-H 

c   c 


k  k 


formulated  by 
over  lapping  of  two  benzine  rings;  quinicine, 
C9H9N2,  to  which  antipyrine,  CiiHi2^2^?  i^  ^^" 
lated,  etc. 

They  are  antiseptic,  antipyretic,  and  analgesic  ; 
and  alone,  or  in  various  combinations  with  each 
other,  or  with  other  drugs,  they  are  effective  in 
performing  the  functions  assigned. 

Their  dosage  ranges  from  0.25  Gm.  to  1.00  Gm. 
(gr.  iv-xvi),  and  their  probable  action  consists  of 
destructive  deoxidation  of  protoplasm. 


318       ,  Organic  Chemistry. 


CHAPTER  XIII. 


CARBO-HYDRATES. 


Carbo-hydrates,  so-called,  because  their  molecules 
represent  H  and  0  in  the  proportion  to  form  water, 
united  to  carbon.  They  include  starchy  woody  fiber ^ 
and  sugars. 

Starch,  CgH^oOg,  is  an  important  constituent 
of  the  vegetable  kingdom,  especially  in  grains, 
such  as  corn,  wheat,  and  rice,  and  in  potatoes.  It  is 
probably  formed  in  the  plant,  somewhat  according 
to  the  following  equation  : 

6CO2   +  5H,0  =  CeHioO^   +  O^, 

Starch  consists  physically  of  minute  granules, 
insoluble  in  water,  but  which,  when  heated  with 
water  to  71°  (160F),  burst  open  and  form  starch 
paste.  When  heated  to  205°  (400F)  starch  is 
changed  to  isomeric  dextrin^  a  soluble  substance 
used  on  the  sticky  surface  of  postage  stamps.  The 
same  isomeric  change  is  produced  on  starch  by  cer- 
tain dilute  acids.  Dilute  sulphuric  acid  turns 
starch  to  dextrin,  then  to  glucose.  Saliva  also  pro- 
duces a  similar  change,  as  does  the  ferment  on  the 


Carbo- Hydrates.  319 

farinaceous  mixture  in  the  first  stages  of  alcoholic 
fermentation. 

The  natural  gums  contain  polymers  of  starch. 
Gum-arabic  is  a  combination  of  potassium  and 
calcium,  with  arabic  acid  -{CqYL^qO^)^.  Agar- 
agar,  or  Ceylon  moss,  used  for  thickening  soups 
and  jellies,  and  in  cultures  for  growing  microbes; 
and  other  vegetables,  as  beets  and  carrots,  as  well 
as  many  fruits,  contain  polymers  of  starch  and 
dextrin.  Animal  starch,  glycogen^  is  found  in  the 
liver  and  placenta. 

Solutions  of  starch  and  iodine,  when  mixed,  turn 
to  blue,  by  which  the  presence  of  starch,  as  dis- 
tinguished from  its  isomers,  may  be  determined. 

Cellulose,  CgHjoOg,  is  the  chief  constituent  of 
vegetable  liber.  Bleached  cotton  is  practically  pure 
cellulose,  as  is  also  linen  that  has  been  frequently 
laundried,  a  process  which  removes  the  inherent 
gums  and  resins  from  the  surface. 

When  cellulose  is  treated  with  nitric  and  sul- 
phuric acids,  NiTRO-CELLULOSE,  or  guncotton,  also 
known  as  pyroxylin,  Cgll^  (1^02)305,  is  produced. 
Guncotton  is  highly  explosive. 

Celluloid  consists  of  pyroxylin  mixed  with  cam- 
l)hor,  zinc  oxide,  and  coloring  matters,  and  sub- 
jected to  pressure  while  in  the  pulpy  state. 


320  Organic  Chemistry. 

Collodion  is  obtained  by  dissolving  guncotton  in 
a  mixture  of  alcohol  and  ether.  When  the  liquid 
collodion  evaporates,  it  leaves  a  coherent  iilm, 
known  in  surgery  as  a  sort  of  artificial  skin.  Can- 
tharidal  collodion,  is  used  with  some  advantage  as 
a  counter-irritant  in  periodontitis. 

The  sugars  are  divided  into  two  groups,  sucroses, 
and  glucoses. 

SucROSES  have  the  formula,  Ci2ll2  2^ii?  ^^^^  ^'^" 
elude  cane  and  beet  sugar  (sucrose),  milk  sugar 
(lactose),  and  a  variety  of  starch  sugar  (mal- 
tose), etc. 

Glucoses,  CgH^2^6?  include  grape  sugar  (dex- 
trose), SLiid  fruit  sugar  (levulose),  etc. 

Cane  sugar  (Sucrose),  is  obtained  from  the  sugar 
cane,  sugar  beet,  sorghum,  and  sugar  maple.  It  is 
a  most  important  article  of  human  diet.  When 
refined,  cane  sagar,  presents  a  white  crystalline 
form,  perfectly  soluble  in  water.  When  heated  it 
loses  part  of  its  aqueous  elem.ents,  and  is  converted 
into  caramel. 

Grape  sugar  (Glucose)  exists  in  many  sweet 
fruits,  and  m  honey ;  it  occurs  also  as  a  concomi- 
tant in  the  disease  known  as  diabetes. 

Glucose  IS  largely  produced  artificially,  by  action 
of  dilute  sulphuric  acid   upon  corn  starch.     It  is 


Carbo- Hydrates.  321 

used  extensively  as  a  substitute  for  cane  sugar,  being 
cheaper,  in  the  making  of  syrups,  and  candies;  and 
on  account  of  its  ability  to  ferment,  in  the  produc- 
tion of  beer  and  ale. 


322  Organic  Chemistry. 


CHAPTER  XIV. 

TERPENES,  ETC. 

The  Terpenes,  C^  oHj  g,  are  homologous  v^iihjpen- 
tone,  CgHg,  having  the  general  formula  CnH2n — 4 ; 
and  areisologous  with  decane,  CjqH22-  They  exist 
in  the  volatile  or  essential  oils  of  certain  trees  and 
plants,  especially  of  the  coniferous  and  aurantia- 
ceous  orders.  They  have  not  as  yet  been  produced 
artificially,  although  some  of  them  are  structurally 
related  to  benzene. 

Their  formula  is  isomeric  with  decone,  C^oH^g, 
and  are  regarded  as  tetrad  radicals  ;  although  ap- 
parently satisfied,  they  are  capable  of  taking  up 
two  molecules  of  HCl.  If  the  molecule,  C^oHjg, 
be  doubled,  the  polymer,  C20H32,  as  in  the  case  of 

2   atoms   of   carbon, — C — C — ,   loses    2    units    of 

I    I 

valency,  and  becomes  a  hexad. 

Cologne  is  an  alcoholic  solution  of  certain  essen- 
tial oils. 

Turpentine  Oil,  Oleum  Terebinthince,  C^oH^g,  is 
the  most  familiar  representative  of  the  terpenes.  It 
is  obtained  by  distilling  the  juices  which  exude 


Terpenes,  etc.  323 

from  cuts  in  the  bodies  of  several  species  of  the 
genus  jpine.  The  commercial  variety  contains  some 
admixture  of  other  hydrocarbons,  and  traces  of 
oxidation  products. 

Rosin  which  remains  in  the  retort,  consists  essen- 
tially of  silvic  acid,  Cj9H2  9COOH. 

Other  resins,  such  as  shellac,  copal,  sandarac,  etc., 
are  rosins,  obtained  similarly  from  various  terpenes 
by  distillation,  or  as  the  exudate  from  various 
kinds  of  trees. 

The  terpenes  are  disposed  to  absorb  oxygen  from 
the  air,  and  thus  pass  into  camphors. 

That  many  volatile  oils  isomeric  with  oil  of  tur- 
pentine, such  as  oil  of  neroli,  bergamot,  cloves, 
pepper,  caraway,  lemon,  etc.,  should  exhibit  such 
diversity  of  physical  properties,  is  a  problem  which 
stereo-chemistry  will  doubtless  be  able  to  explain 
satisfactorily,  in  t4ie  near  future. 

The  antiseptic,  and  disinfectant,  properties  of  the 
terpenes  (essential  oils)  are  in  all  probability  due 
to  their  power  of  taking  up  oxygen  from  the  air, 
by  which  two  atoms  of  hydrogen  are  removed, 
resulting  in  CioHj404,  a  highly  oxidized  hydro- 
carbon, which  with  moisture,  and  summer-heat, 
developes  nascent  oxygen. 

C,„II,,0,+2H,0  =  H,0,+CioH,,0,. 

Oxygenated  Hydrogen  Camphoric 

Terpene.  Dioxide.  Acid. 


324  Organic  Chemistry. 

Materia  Medica. — Although  many  of  the  essen- 
tial oils  (especially  that  of  cloves),  have  been, 
from  time  immemorial,  favorite  domestic  remedies 
afi^ainst  toothache;  and  in  practice,  as  ingredients 
of  pulp  capphigs,  their  introduction  as  disinfectant, 
and  antiseptic  dressings,  in  root  canals,  is  mainly 
due  to  Drs.  Harlan,  Black  and  Barrett. 

Oil  of  Cloves,  oleum  caryophilli,  is  obtained  by 
distilling  the  dried  buds  (cloves)  of  an  evergreen 
tree  of  the  myrtle  order,  Eugenia  caryophillata.  The 
oil  consists  of  caryophillin,  CjoH^g,  and  an  oxygen 
oil,  eugenol,  or  eugenic  acid,  CgH^jCOOH.  When 
fresh  it  is  colorless,  but  by  exposure,  becomes  yel- 
low, and  finally,  reddish-brown.  It  possesses  a 
strong  fragrant  odor,  and  a  hot  aromatic  taste;  is 
nearly  insoluble  in  water,  but  freely  soluble  in  alco- 
hol. When  mixed  in  small  proportion  with  either 
carbolic  acid,  or  creasote,  it  eflectually  masks  their 
peculiar  odors.  If  applied  to  irritable  dental  pulp, 
in  odontalgia,  it  reduces  sensibility  by  its  power 
of  extra  stimulation,  and  as  a  dressing  in  root  ca- 
nals, by  its  diffusion  through  the  tubuli,  and  its 
ultimate  reduction  to  a  camphor,  prevents  a  return 
of  the  process  of  putrefaction  in  the  part  and  the 
consequent  pathological  sequelae. 

It  is  frequently  exhibited  internally  as  an  anti- 


Terpenes,  etc,  325 

spasmodic  stimulant,  in  flatulent  colic,  nausea,  and 
vomiting. 

Dose,  0.12-0.30  fGm.  (nt  ij-v) 

Oil  of  Sassafras  is  obtained  oy  distilling  the 
bark  and  wood  of  the  root  of  the  sassafras  offici- 
nallis,  a  native  tree,  of  the  genus  laurel.  The  oil 
has  a  pleasant  odor,  a  warm  pungent  aromatic  taste ; 
oxidized  by  cold  nitric  acid,  it  is  converted  into  a 
red  resin.  It  is  an  excellent  germicide,  and  is  one 
of  the  ingredients  of  "sarsaparilla"  syrup.  The 
aqueous  infusion  of  sassafras  root  bark  is  a  popular 
"tea"  and  "blood  purifier."  Sassafras  possesses 
mild  astringent,  stimulant  alterative  and  diapho- 
retic properties.  The  powdered  root,  mixed  with 
"  chewing  gum,"  and  used  as  a  masticatory,  is  a 
good  adjunct  in  the  treatment  of  alveolar  py- 
orrhoea. 

Dose  of  the  oil,  0.06-0.25  fGm.  (n^  j-iv) 

Oil  of  Cinnamon,  oleum  cinnimomi,  is  obtained 
from  the  inner  bark  of  the  shoots  of  the  cinnimo- 
mum  zeylanicum  (cassia),  trees  of  the  natural  order 
Lauracese,  growing  In  China,  Ceylon,  and  adjacent 
countries.  The  Ceylon  variety  is  the  most  es- 
teemed. 

The  oil  is  somewhat  heavier  than  water ;  of  an 
agreeable  odor,  and  a  very  hot  penetrating  taste. 
It  is  a  powerful  local  stimulant,  and  when  applied 


326  Organic  Chemistry. 

to  an  aching  dental  pulp,  relieves  the  pain.  It  is 
also  a  diffusive  disinfectant  and  antiseptic,  and  is 
employed  as  such,  preparatory  to  filling  root  ca- 
nals. On  exposure,  the  oil  of  cassia  tends  to  de- 
velop cinnamic  acid  (phenyl-acrylic  acid, 
CfiHg  -  CH  =  CH  -  COOH). 
The  properties  of  cinnamon,  as  a  sialogogue, 
stimulant,  astringent  carminative,  and  uterine  he- 
mostatic, when  taken  internally,  is  due  to  its  con- 
tained oil  and  resin,  and  some  tannic  and  cinna- 
mic acids. 

Dose  of  the  oil,  0.06-0.30  fGm.  (j\  g-v) 


Ter penes y  etc.  327 


CHAPTER  XV. 

TERPENES,  ETC.— (Continued). 

Oil  of  Wintergreen,  oleum  Gaultheria,  from  the 
leaves  of  the  indigenous  evergreen  plant,  Gaultheria 
procumbens,  or  Partridge-berry  ;  it  exists  also  in  the 
sweet  birch,  and  other  plants,  and  is  largely  composed 
of  methyl  salicylate  CHgC^H^Og.  It  is  the  heaviest 
of  the  essential  oils,  and  is  largely  used  for  flavor- 
ing; its  principal  use  in  dentistry  is  to  disguise  the 
disagreeable  tastes  and  odors  of  other  certain  drugs, 
albeit  it  is  itself  an  excellent  antiseptic.  It  is  em- 
ployed internally  in  rheumatic  disorders,  as  a  pleas- 
ant substitute  for  salicylic  acid.  A  cold  "•  tea  "  of 
the  leaves  of  the  plant,  is  a  popular  astringent, 
carminative,  and  emmenagogue. 

Dose  of  the  oil  0.20-0.60  fGm.  (ni  iij-x.) 

Oil  of  Eucalyptus,  oleum  Eucalypti,  from  the 
leaves  of  the  matured  Eucalyptus  Globulus,  or  blue 
gum  tree,  a  native  of  Australia,  but  now  grown  to 
some  extent,  in  Italy,  California,  etc.  The  oil  has 
a  pleasant  aromatic  odor,  a  pungent  somewhat  cam- 


328  Organic  Chemistry. 

phoraceous,  cooling  taste;  it  is  composed  of  terpene, 
C10H16.  cymene, 

CioHi4=(C6H4<ci'-CH,-CH3) 

and  eucalyptol,  CjqH^5(0H).  It  exhibits  a  destruc- 
tive influence  on  microbic  forms  of  animal  and 
vegetable  life. 

Alone  or  combined  with  other  antiseptics,  it  is 
eftective  in  treatment  of  suppurating  pulps,  oral 
ulcerations,  pyorrhoea,  and  chronic  alveolar  abscess. 
It  is  a  solvent  for  gutta  percha. 

Internally  administered,  the  preparations  of  eu- 
calyptus, act  as  a  stimulent  to  the  brain  and  nervous 
system;  they  increase  the  circulation,  and  respira- 
tion, and  a  re  sialogogue,  and  diaphoretic;  and  tonic 
in  gastric  dyspepsia. 

Dose  of  oil  0.30-2.00  fGm.  (nv-xxx.) 

Dose  of  tincture  2.00-8.00  fGm.  (fSss-ij.) 

B.    Olei  eucalypti. 

Acidi  carbolici  aa  6.00  fGm.  (f^jss.) 

Olei  Gaultheria  2.00  fGm.  (f^ss.) 
M.  S.     Apply  by  syringe,  in   pyorrhoea  (Dr.  G.  V.  Black, 
from  (jorgas.) 

Oil  of  Caraway,  oleum  cari,  is  obtained  from  the 
fruit  of  a  European  plant,  the  Carum  Carvi.  Its 
odor  is  aromatic,  and  its  taste  acrid.     It  consists  of 


Ter penes,  Phenols,  etc.  329 

the  terpene,  carvene  O^QH^g,  and  the  ten  carbon 
phenol,  carvol,  C^oHjgOH. 

Dose  of  the  oil  0.06-0.30  fGm.  ("I  j-v.) 

Carvacrol,  CjQH^gOH,  is  isomeric,  and  probably- 
identical  with  carvol.  It  has  a  taste,  persistent 
and  strongly  acrid,  and  a  creasotic  odor.  It  is  a 
solvent  for  gutta  percha.  Is  disinfectant  and  anti- 
septic ;  and  is  analgesic,  and  escharotic  on  sensitive 
dentine. 

Its  principal  source  is  oil  of  caraway. 

Dose,  not  used  internally. 

Thymol,  C ^  qH ^  3(0H),  is  Isomeric  with  carvacrol. 
It  is  a  constituent  of  the  volatile  oil  of  the  garden 
plant,  Thymus  vulgaris,  and  of  several  other 
phmts.  The  isomeric  relation  of  thymol,  to  carva- 
crol, may  be  most  easily  understood  by  the  benzene 
hat-rack, 

I  I 

H-C^         C— OH  H— C^         C-H 


H— C 


n— H  H— a  £—011 

Carvacrol.  Thymol. 

Both  are  methyl-propyl-phenols.     In  carvacrol  the 
28 


330  Organic  Chemistry. 

methyl  group  (CHg)  stands  to  the  hydroxyl  group 
(OH)  in  the  or^Ao-position,  and  in  thymol,  in  the 
977  e^a- position. 

Thymol  crystallizes  in  transparant  plates,  of  a 
mild  pleasant  odor,  and  peppery  taste.  It  is  prac- 
tically insoluble  in  water,  but  is  freely  soluble  in 
alcohol,  chloroform,  and  ether,  and  liquefies  with 
camphor,  and  chloral  alkalies.  It  forms,  with  glyc- 
erine, a  good  antiseptic. 

Aristol,  CioHi3(OI),  is  obtained  from  an  alka- 
line solution  of  thymol,  by  adding  potassium 
iodide  solution  of  iodine,  by  which  is  produced  a 
red-brown  amorphous  precipitate,  consisting  of 
thymol,  minus  its  hydroxjdlic  H,  plus  I,  and  may 
be  chemically  known  as  thymol  lodroxide. 

Aristol  occurs  in  impalpable  powder,  almost 
tasteless  and  odorless.  It  is  insoluble  in  water, 
glycerine,  alcohol,  and  alkalies,  but  freely  soluble 
in  chloroform  and  ether,  and  is  readily  decomposed 
by  light  and  heat. 

Its  insolubility  in  water  enables  it  to  act  as  an 
antiseptic,  by  preventing  egress  to  the  part,  of 
septic  germs ;  and  as  a  germicide,  by  the  free 
iodine,  which  it  slowly  gives  off,  at  the  tempera- 
ture of  the  mouth. 

Cotton    wool,  holding  a  saturated    solution    of 


Terpenes,  Phenols,  etc.  331 

aristol  in  chloroform,  or  ether,  placed  between 
teeth  or  over  dressings  in  their  cavities,  will  re- 
main comparatively  odorless  for  indefinite  periods 
of  time. 

Dose — Not  used  internally. 


332  Organic  Chemistry, 


CHAPTER  XYI. 

TERPENES,  PHENOLS,  ETC.— (Continued.) 

Resorcin,  CgH4(OH)2,  as  may  be  presumed  from 
its  formula,  is  closely  related  to  carbolic  acid.  It 
is  a  diatomic  phenol,  obtained  by  fusing  caustic  al- 
kalies with  certain  gums,  as  galbanum,  or  with  po- 
tassium-benzol-disulphonate.  By  the  latter  pro- 
cess resorcin  and  potassium  sulphite  result. 

Rosorcin  occurs  in  prismatic  shining  crystals,  of 
a  sweetish  pungent  taste,  freely  soluble  in  water, 
less  so  in  alcohol,  ether,  and  glycerine,  and  not  at 
all  in  chloroform.  It  is  not  so  caustic  and  irri- 
tating as  carbolic  acid,  although  in  strong  solution 
it  is  fully  as  good  an  antiseptic.  It  is  preferred  to 
carbolic  acid  as  an  internal  antiseptic  and  antipy- 
retic, being  less  poisonous. 
Dose,  0.30  Gm.  (gr.  v) 

Oil  of  Peppermint,  oleum  menthce  piperitm,  ob- 
tained by  distilling  the  fresh  leaves  of  the  plant. 
It  consists  of  a  terpene  and  a  mon atomic  alcohol, 
the  latter  called  menthol,  CiqHj9(0H);  also  known 
as  peppermint  camphor. 


Terpenes,  Phenols,  etc.  338 

Menthol,  applied  locally,  is  a  non-corrosive  vas- 
cular stimulant,  antiseptic,  and  anaesthetic. 

Pyrethrum,  Pellitory ;  the  root  furnishes  an  oil 
which,  applied  in  ethereal  solution,  relieves  adon- 
talgia.  The  flowers  of  Persian  pellitory  are  used 
as  "  insect  powder." 

Oil  of  Orange  Flowers,  oleum  neroli,  is  of  de- 
lightfully fragrant  odor. 

Caoutchouc,  India-rubber,  is  a  thickened  gum 
of  the  milky  juice  of  several  trees,  as  Euphorbia, 
growing  in  tropical  countries.  Para  gum,  shipped 
from  Para,  on  the  Amazon,  is  the  most  highly 
prized.  Caoutchouc  consists  essentially  of  a  mix- 
ture of  terpenes,  isomeric  or  polymeric,  with  oil  of 
turpentine  (C^oH'^g).  It  softens  by  heat;  is  not 
soluble  in  water  or  alcohol,  but  dissolves  in  chloro- 
form, pure  ether,  turpentine,  benzene,  and  carbon 
disulphide.  Mixed  in  variable  proportions  with 
sulphur,  and  heated,  it  becomes  vulcanized  India 
rubber.  With  one-half  its  weight  of  sulphur,  ebonite 
is  formed.  Coloring  matters  are  also  often  added, 
as  Vermillion  (Hg2S),  to  give  it  a  red  color;  white 
clay  and  zinc  oxide,  to  produce  white  rubber,  etc. 

Gutta-percha  is  the  hardened  juice  of  the  iso- 
nandra  percha  tree,  growing  in  Malacca  and  adjacent 
islands.  It  resembles  caoutchouc  in  many  re- 
spects,   being   insalubla.  lu.  w.atex,.  aud  capable  of 


334  Organic  Chemistry. 

vulcanizing  with  sulphur.  It  is  less  elastic  than 
rubber,  and  is  a  very  poor  conductor  of  electricity, 
hence  it  is  extensively  used  as  an  electric  insulator. 
Gutta-percha,  mixed  with  zinc,  oxide,  is  used  as  a 
"  filling  "  material,  and  retains  its  identity  in  the 
teeth  against  chemical  action,  but  soon  succumbs 
to  active  attrition. 

IS'aphthaline,  CjoHg,  is  a  product  of  the  distil- 
lation of  coal-tar.  It  occurs  in  large  white  crys- 
tals of  tarry  odor  and  somewhat  aromatic  taste ; 
insoluble  in  water  and  in  dilute  acid  and  alkaline 
solutions,  but  soluble  in  chloroform,  ether,  volatile 
and  fixed  oils,  benzene,  and  hot  alcohol.  It  is  a 
valuable  antiseptic;  combined  with  iodoform  it 
forms  an  excellent  dressing  in  root  canals. 

Hydronaphthol,  C^qH^OH,  derived  from  naph- 
thaline, crystallizes  in  shiny  white  scales,  sparingly 
soluble  in  water,  freely  soluble  in  alcohol,  glyc- 
erine, etc.  It  is  non-poisonous,  but  is  an  excel- 
lent germicide  and  antiseptic  in  dental  practice, 
and  is  also  favorably  exhibited  as  such,  in  general 
practice,  especially  in  ailments  of  the  intestinal 
canal. 


HesinSy  Camphors^  etc.  335 


CHAPTER  XVII. 

RESINS,  CAMPHORS,  ETC. 

Myrrh  is  a  fair  representative  of  gum  resins.  It 
is  an  exudate  from  the  stems  of  the  Balsomodendron 
myrrha,  a  small  tree  of  South-western  Asia  and 
I^orthern  Africa.  When  comparatively  pure,  it 
comes  to  us  in  semi-transparent  yellow-reddish 
tears,  held  together  in  considerable  bulk,  of  agree- 
able odor  and  aromatic  bitter  taste.  It  may  be 
pulverized,  and  is  soluble  in  ether  and  alcohol.  It 
is  a  mild  stimulant  astriiigent  to  mucous  surfaces, 
and  is  an  effective  application  in  the  form  of  pow- 
der or  tincture,  to  relaxed  ulcerated  conditions  of 
the  gums  and  throat. 

Dose  of  the  tincture,    2.00-4.00    fGm.  (fess-i) 

K.       Aluminis,     ....  4.00      Gm.  (^i) 

Tincture  Myrrhse,     .     .        8.00    fGm.       (f^ij) 
Infusi  Rosse  comp.     .     .    160.00    fGm.      (f^v) 

M.  S.  Use  as  a  gargle. 

(Modified  from  Farquharson.) 

Camphor,  C^oII^gO,  common  camphor,  (like  other 
camphors,  such  as  caryophillin,  02  0113  2  0^),  may 
be  regarded  as  an  okyK^v''?'t.c>d''^^rp'feii.f,\     Closely  re- 


•  •  •  •   •    • 

'  •  •    •    •  •    • 

'  •  •    •    •  •   t 

I  •  •    •  •  •  •  • 

•  •  •     •  •  <  • 


336 


Organic  Chemistry. 


lated  to  these,  are  many  solid  and  liquid  camphors 
which  react  as  alcohols  or  stearoptenes,  such  as 
Borneol,  or  Borneo  camphor,  C^qH^-^OII,  and  its 
homologue,  patchouli  camphor,  C^  5 II 2  7 OH,  menthol, 
or  mint  camphor,  C  ^  q  II  ^  9  OH,  absinthol,  C  ^^  q  H  ^  5  OH, 
etc.  Camphors  are  also  obtained  from  the  volatile 
oils  of  many  plants,  such  as  the  oils  of  lavender, 
cajeput,  orange,  rosemary,  coriander,  hops,  marjo- 
ram, etc.,  etc.  By  reaction  with  strong  oxidizing 
agencies,  such  as  nitric  acid,  ozone,  etc.,  they  are 
changed  into  acid  com[)Ounds,  of  which  camphoric 
acid,  CgH^ 4(00011)2,  is  a  fair  representative. 

The  chemical  relation  between  camphor,  which 
is  a  ketone,  and  Borneol,  which  is  a  monatomic  al- 
cohol, and  camphoric  acid,  may  be  differentiated  by 
erecting  them  in  graphic  formulae,  thus : 


CH, 


CH 


H— C^         C=C=.0 

\  /          2 
C-H 

H-C^         C— 0-H 

H^^C           C=:H2 

C-H 

C3H, 

Camphor. 

C3H7 

Borneol. 

c  » 

e    «• 
t  c  < 


I 


liesinSj  Camphors y  etc.  337 


3 

PH 
11— C'        ^C— 0 


,4 


H2=C  C— 0 

C-II   OH 

C3H7 

Camphoric  Acid. 

Common  camphor  is  obtained  in  a  crude  way 
by  distilling  with  water  the,  wood  of  the  Laurus 
camphora  tree  of  South-eastern  Asia.  It  is  a  col- 
orless translucent  solid,  of  sp.  gr.  0.935  ;  of  a  pen- 
etrating, aromatic  odor,  and  rather  unpleasant 
taste  ;  sparingly  soluble  in  water,  but  freely  soluble 
in  volatile  oils,  strong  acetic  acid,  ether  and  alco- 
hol. Pieces  of  camphor  thrown  on  water,  show 
the  high  volatility  of  the  substance  by  the  vapor 
pressure  on  the  water,  causing  a  rotatory  motion  of 
the  granules;  if  they  be  covered  with  oil,  which 
prevents  evaporation  of  the  camphor,  rotation  in 
water  will  not  occur. 

Camphor  is  an  important  ingredient  of  many 
liniments  in  common  use.  When  locally  applied, 
it  exhibits  irritant,  rubefacient,  and  finally,  ano- 
dyne properties.  ComVjined  with  chloral,  or  in 
strong  solution  with  chloroform,  it  is  an  effective 
local  anaesthetic,  and  i^  lused  ^s  euch  in  obtunding 


29 


J  J  J    > 


338  Organic  Chemistry. 

sensitive  dentine^  exposed  dental  nerce^  and  in  al- 
laying the  pain  which  often  follows  the  extraction 
of  teeth. 

Internally  administered,  camphor  is  strongly  an- 
tispasmodic, diaphoretic  and  anaphrodisiac.  In 
large  dose  it  is  narcotic  and  depressant,  but  in 
small  doses  it  is  mildly  stimulant  and  diaphoretic. 
Dose,  0.06-0.60  Gm.  (grj-x) 

Chloral  camphor  is  a  liquid  obtained  by  triturat- 
ing together  equal  weights  of  chloral  hydrate  and 
camphor.  The  mixture  exhibits  antiseptic  and  ob- 
tunding  properties,  and  is  a  good  solvent  for  many 
alkaloids. 

Compho-phenic,  as  its  name  implies,  is  a  combi- 
nation of  camphor  and  carbolic  acid.  It  is  non- 
caustic  and  non-irritant,  and  is  antiseptic  and 
somewhat  anaesthetic  when  applied  to  sensitive  in- 
flamed surfaces. 

R.        Camphora — 

Chloral  hydratis,  aa,  16.00    Gra.  (giv) 
Etheris  sulph.  30.00  fGm.   (fgi) 

M.  S.  For  office  use. 

Capsicum,  cayenne  pepper,  is  the  fruit  of  the  plant 
capsicum  fastigiatum.  It  possesses  a  peculiar  odor 
and  very  hot  taste,  and  contains  capsicin,  the  active 
principle  and  a  volatile  alkaloid. 


Resins,  Camphors,  etc.  389 

Capsicum  is  one  of  the  most  familiar  of  local 
irritants.  They  produce  on  the  part,  a  vascular  ex- 
citement which  oftentimes  modifies  the  pain  of 
coming  inflammation.  Hence  capsicum,  as  well  as 
the  fruit  of  the  piper  nigrum  (black  pepper),  etc., 
are  severally,  and  combined,  employed  in  plaster 
form  to  prevent  the  painful  development  of  ex- 
pectant periodontitis,  subsequent  to  the  operation 
of  tilling  root  canals. 

HuMULUS,  Hops,  the  fruit  cones,  (strobiles,)  of  the 
common  hop-vine,  (humulus  lupulus).  The  glandu- 
lar portion  of  the  strobiles  consist  of  irregularly 
rounded  small  grains,  of  a  yellow  color,  known  as 
lupulin,  which  contains  also,  in  most  abundance, 
waxy  resins  and  tannin,  and  a  volatile  oil,  consist- 
ing of  trimethylamine  (valerol,  and  lupulinic  acid. 

Hops  are  mildly  hypnotic,  tonic,  and  somewhat 
astringent.  They  increase  cutaneous  circulation, 
when  externally  applied,  followed  by  a  soothing 
influence  on  sensory  nerves.  A  calming  efl'ect  is 
produced  on  localized  inflammation,  such  as  acute 
alveolar  abscess,  by  a  warm  hop  poultice,  external 
to  the  part. 

Dose  of  Lupulin,  0.30-0.90  Gni.  (gr.  v-xv.) 

Calendula,  the  fresh  flowering  garden  marigold, 
furnishes   a  tincture  which  possesses  a   stmiulant 


S40  Organic  Chemistry. 

resolvent  power,  and  which  when  applied  to  ex- 
posed pulp,  or  in  alveolar  sockets,  after  extraction 
of  teeth,  impresses  itself  favorably,  by  relieving  in 
a  large  measure,  the  consequent  pain. 


>--.yl 


Alkaloids.  341 


CHAPTER  XVIII. 
NATURAL  ALKALOIDS. 

Alkaloids  are  organic  bases  capable  of  uniting 
with  acids  to  form  salts.  Many  of  them  exist  in 
union  with  characteristic  acids,  in  certain  vegetable 
products ;  they  also  occur  in  animal  bodies,  as 
leucomaines ;  and  as  a  result  of  putrefaction,  as 
ptomaines.  They  are  mostly  poisons,  are  closely 
related  to  the  artificial  amines^  and  contain  !N^  as  an 
essential  element. 

Those  that  are  made  up  of  C,  H,  and  I^,  as 
nicotine,  CjqHj4]N'2,  etc.,  are  generally  volatile 
liquids;  while  those  which  also  contain  0,  as 
Caffeine,  CgH  ^^fi^^  Morphine,  C^^H^glN'Oj, 
etc.,  are  non-volatile  solids. 

^h.Q\r  graphic  formulas  are  not  as  yet  determined. 
When  uniting  with  acids  to  form  salts,  they  behave 
like  ammonia;  the  hydrogen  of  the  acid  is  not  set 
free,  thus  differing  in  interaction  with  acids,  from 
the  general  effect  produced  by  metals. 

(NH3),  +  H2SO4  =  (NH,).,SO,. 

Ammonia.  Am.  Sulphate. 

C,,HigN03  +  H2SO4  =  C,,1I^3N03H2S04. 

Morphia.  Morph.  Sulphate. 

Zn  +  H2SO4  =  ZnS04  +  II,. 

Zn  Sulphate. 


342  Organic  Chemistry. 

Their  names  terminate  in  either  ine  or  ia  accord- 
ing to  preference.  As  a  rule,  they  are  less  soluble 
in  water,  than  are  their  salts. 

Quinine,  quinia,  02  0112  4^2  02,3112  0,  is  the  most 
highly  prized  active  principle  of  Cinchona  bark. 

The  genus  cinchona  comprise  many  species. 
They  were  named  in  honor  of  the  Countess  of 
Cinchon  who  was  cured  of  a  relapsing  fever  by 
infusions  of  the  bark,  sent  her  by  the  Jesuit  Mis- 
sionaries in  Peru. 

Cinchona  trees  flourish  mainly  on  the  eastern 
slope  of  the  Andes,  between  the  20th  degree  S. 
latitude,  and  the  10th  degree  N.  latitude.  They  are 
now  profitably  cultivated  in  India,  and  in  southern 
Asiatic  islands. 

Three  varieties  of  cinchona  bark  are  sufficient 
representatives  of  the  entire  genus. 

1.  C.  Calisaya,  C.  Flava,  yellow  bark. 

2.  0.  SucciRUBA,  red  bark. 

3.  C.  Pallida,  pale  bark. 

Different  cinchona  barks  contain  variable  quan- 
tities of  numerous  active  medicinal  alkaloids,  of 
which  quinia  and  cinchona  are  the  most  valuable. 
They  exist  in  the  bark,  in  union  with  kinic  or  quinic^ 
(monobasic  pentatomic)  acid,  CgH7(OH)4COOH. 

Quinine  is  separated  from  the  bark,  and  the  kinic 
acid,  by  dilute  hydrochloric  acid,  which  forms  the 


Alkaloids.  343 

soluble  quinia  hydrochloride.  By  the  addition  of 
lime,  calcium  chloride  is  formed,  taking  thus  from 
the  quinia,  the  hydrochloric  acid,  and  compelling 
the  alkaloid  to  precipitate.  This  precipitate  is 
washed  in  water,  and  taken  up  by  boiling  alcohol, 
which  is  afterward  set  free  by  distillation. 

Quinine  occurs  as  a  white  amorphous  crystalline 
powder,  inodorous,  but  of  an  exceedingly  bitter 
taste;  very  sparingly  soluble  in  water;  freely  sol- 
uble  in  hot  alcohol,  chloroform,  ether,  and  the 
fixed  and  essential  oils ;  is  alkaline  in  reaction  and 
forms  salts  with  acids,  of  which  the  sulphate  is  the 
most  generally  employed,  and  which  has  appropri- 
ated the  name,  quinine. 

Quinia  sulphate,  (0201^24^2^2)2)  HgSO^jSHgO, 
quinine,  is  rarely  used  locally. 

In  small  doses,  internally  administered,  it  acts 
as  a  tonic,  an  antiseptic,  and  antiperiodic.  In  full 
doses  it  causes  anemia  of  the  brain,  accompanied 
by  ringing  in  the  ears  (cinchonism),  partial  deaf- 
ness and  blindness,  and  frontal  headache. 

It  reduces  the  reflex  irritability  of  the  spinal 
chord.  At  first  it  increases,  and  afterward  slows 
the  heart's  action.  It  increases  the  number  of 
white  corpuscles,  but  prevents  their  amoeboid  move- 
ments, and  prevents,  also,  the  due  giving  up  of  0 
to  the  tissues.     For  this  latter   influence,  quinine 


344  Organic  Chemistry. 

might  be  suggested  internally  in  localized  inflam- 
mation, such  as  acute  alveolar  abcess.  It  has  but 
slight  effect  on  the  temperature  of  the  body  in  full 
health  ;  but  in  fevers^  the  temperature  is  dimin- 
ished by  quinine. 

Dose,  0.12-1.25  Gm.  (grij-xx) 

B      Quinia  sulphalis,  1.00  Gin.  (grxv) 

Ft.  capsules,  No.  5. 
S.      Take  one  every  two  (2)  hours. 

(In  either    acute  alveolar  abcess  or  periodic  supra- 
orbital neuralgia.) 

Artificial  substitutes  for  quinine  are  being  rap- 
idly introduced  by  manufacturers.  They  are  gen- 
erally of  coal-tar  origin,  and  belong  to  the  ben- 
zene series,  either  directly,  or  as  substitution  pro- 
ducts. Some  of  them  have  been  alluded  to  on 
page  316.  They  also  possess  active  analgesic,  germ- 
icidal and  antiseptic  properties.  Of  these  com- 
pounds, Pyoktanine,  methyl  violet,  is  the  one  most 
used  in  dentistry,  as  an  antiseptic  dressing  in  root 
canals,  but  is  objectionable  as  such,  on  account  of 
its  coloring  influence  on  dentine.  It  is  a  violet 
blue  powder,  odorless,  non-poisonous,  sparingly 
soluble  in  water  and  alcohol,  insoluble  in  ether, 
and  very  diffusible  in  animal  fluids. 


Alkaloids.  345 


CHAPTER  XIX. 

ALKALOIDS— (Continued). 

Morphine,  Morphia,  Ci^H^gl^Og,  is  the  principal 
individual  of  the  many  active  alkaloids  found  in 
opium. 

Opium  is  the  inspissated  juice  of  the  unripe  cap- 
sules of  the  papaver.  somniferum,  or  white  (or  black) 
poppy,  indigenous  to  Asia  Minor,  and  cultivated 
extensively  in  other  countries.  The  poppy  is  an 
annual  plant,  growing  from  2  to  3  feet  high.  The 
milky  juice  obtained  from  incisions  in  the  capsules 
(poppy  heads),  becomes  concrete  by  exposure  to 
the  air,  and  comes  to  us,  in  irregularly  rounded  or 
flattened  cakes,  of  a  brown  color,  strong  narcotic 
odor,  and  bitter  taste,  exciting  to  salivation.  It 
yields  its  numerous  virtues  to  water,  and  alcohol, 
and  dilute  acids,  but  not  to  ether. 

Morphine  exists  in  opium  in  union  withmeconic 
acid,  CgllgOgCOOH.  The  favorite  salt  of  mor- 
phine, is  the  sulp hate y  (C^  71119^03)2,  H2SO45H2O, 
soluble  in  water  and  alcohol,  but  not  in  chloroform 
or  ether.  Consists  of  w4iite  flocculent  crystals,  of 
bitter  taste;  is  less  astringent  and  diaphoretic  than 
opium,  but  possesses  greater  power  as  a  hypnotic 


346  Organic  Chemistry. 

and  anodyne.    Morphine  is  not  regarded  with  much 
favor  as  a  local  anodyne;  but  if  it  be  injected  in 
solution  hypodermatically,  or  taken  by  way  of  the 
primce  vice,  it  exhibits  the  most  distinguished  nar- 
cotic properties.     At  first,  the  brain  is  gently  ex- 
cited, as  with  opium,  followed  by  a  soothing  seda- 
tive eflect ;   and  sleep  ensues,  induced  by  cerebral 
anemia.     Awakening  is  accompanied  by  headache, 
digestive  disturbance,  and  (with  opiura)constipation. 
Subcutaneous  injection  of. 
Morphia  0.01  Gm.  (gr.f ) 
Aqua  Dest.  1.00  fGm.  (rn,xv)  M., 
will  relieve  the  exceeding  pain  of  periodontitis. 

Coffee  and  Belladonna,  or  their  most  active 
alkaloids,  caffeine  and  atropine,  are  the  principal 
physiological  antidotes  to  morphine. 

Dose  of  Morphine,  0.01-0.02  Gm.  (gr.i-|.) 
Dose  of  Opium,  0.06  Gm.  (gr.  j.) 
Dose  of  Tinctura  opii,  1.00  fGm.  (n^^xv.) 
Dose  of  Tinctura  opii  et  camphorata,  4.00  fGm.  (f^i.) 
Cocaine,  is  obtained  fi?om  the  leaves  of  Erythroxy- 
lon  Coca,  a  small  plant,  indigenous  to  the  mountain- 
ous portions  of  Peru  and  Bolivia,  and  now  exten- 
sively cultivated  elsewhere.     The  leaves  have  been 
used  from  time  immemorial  as  a  masticatory,  by 
the  natives  of  those  countries,  by  aid  of  which, 
they  are  enabled  to  undergo  fatiguing  labor,  with 


Alkaloids.  347 

apparent  impunity,  through  the  obtunding  influence 
on  the  sensory  nerves,  and  loss  of  the  sensations  of 
hunger,  and  thirst,  produced  by  the  drug. 

Cocaine  is  a  univalent  base  of  alkaline  reaction, 
and  has  the  empirical  formula,  C17H21NO4.  It 
forms  with  acids,  neutcal  salts,  of  which  the  Hy- 
drochloride (vide  ''  nomenclature  "  in  Part  first)  is 
the  most  useful. 

The  distinction  which  cocaine  hydrochloride  has 
assumed  as  a  local  anaesthetic  is  well  deserved. 
Applied  to  the  mucous  membrane,  or  ocular  con- 
junctiva, or  injected  hypodermatically  (hypoder- 
mically)  in  other  parts,  it  causes  profound  aneesthesia 
over  a  limited  area,  sufficient  for  minor  surgical 
operations.  ^It  causes  thus,  local  anemia,  by  which 
probably  the  sensory  nerves,  are  rendered  unable 
to  transmit  normal  impressions. 

Cocaine  hydrochloride,  C17H19NO4,  HCI2H2O, 
occurs  as  colorless  small  prismatic  crystals,  soluble 
in  alcohol,  water,  chloroform,  and  vaseline,  but  not 
in  ether.  It  is  odorless,  but  possesses  a  bitter  taste, 
followed  by  loss  of  the  sense  of  taste,  through  its 
paralyzing  influence  on  the  peripheral  extremities 
of  the  gustatory  nerve. 

0.65  f  Gm.  (rrix)  of  the  5  per  cent,  aqueous  solu- 
tion injected  into  the  immediate  neighborhood  of 
the   apex   of  root,    will    develope   sufficient    local 


348  Organic  Chemistry. 

anaesthesia  to  permit  the  painless  extraction  of  the 
tooth.  One  of  the  best  stimulants  in  collapse,  which 
some  times  supervenes  after  the  operation,  is  Hoff- 
man's Anodyne  (Spiritus  ^theris)  in  half  teaspoon- 
ful  doses,  and  also  if  necessary,  subcutaneous  in- 
jection of  Atropine. 

Aqueous  solution  of  cocaine  hydrochloride  should 
be  fresh,  as  it  tends  to  rapidly  deteriorate  by  fer- 
mentation; to  overcome  this  latter  difficulty,  small 
proportions  of  salicylic  acid,  or  carbolic  acid,  are 
added;  and  also  as  physiological  antidotes,  either 
atropine,  or  chloroform. 

Various  combinations  of  cocaine  with  other 
drugs,  have  been  patented  as  local  anaesthetics,  and 
given  suggestive  names,  by  which  coftfiding  mem- 
bers of  the  profession  are  being  extensively  imposed 
upon.  Practitioners,  worthy  of  the  name,  should 
be  possessed  of  more  self  respect  than  is  indicated 
by  the  encouragement  many  of  them  extend  to  the 
mercenary  aspect  of  such  secret  nostrums. 

Cocaine  is  a  cerebral  stimulant ;  it  also  excites 
the  general  nervous  system,  and  increases  cardiac, 
and  respiratory  movement.  In  small  doses  it  is  a 
tonic  and  diuretic.  In  Lethal  doses,  death  occurs 
by  simultaneous  cardiac  and  respiratory  failure. 

Dose— 0.01  -  0.06  Gm.  (gr.  -H). 


Alkaloids,  etc.  349 

R.     Cocnina  Hydrochloric  1.00  Grri.  (gr,  xv). 
Atropia  Sulphas  0.01  Gm.  (gr.  |-). 
Aridi  Carbullci  (cryst.)  0.25  Gm.  (gr.  iv). 
Chloral  Hydratis  0.20  Gm.  (gr.  iij). 
Aqua  Dest.  Ad.  32.00  fGin.  (f^i). 

M.     For  extraction  of  tooth,  inject  1.00  fGm.  (rrt^xv). 

(Modified  from  formula  given  in  "  Transactions  of  Kan- 
sas D.  A.") 

R.     Cocaina  phenatis  0.10  Gm.  (gr.  jss). 
Alcoholis  (ad  solve)  4.00  fGm.  (fsi). 
Aqua  Dest.  6.00  fGm.  (fsjss). 

M.     Six  (6)  Injections. 

U.  Cocaina  Hydrochloris  (cryst).  Insert  in  moist  cav- 
ity, and  let  remain  ten  minutes;  for  sensitive 
dentine. 

R.     Cocaina  Hydrochloris  0.10  Gm.  (gr.  jss). 
Alcoholis, Chloroform!  aa  4.00  fGm.  (f^i). 

M.  Apply  to  Gum  as  a  local  anaesthetic  (Dr.  H.  J.  McKel- 
lop,  from  Gorgas). 


350  Organic  Chemistry. 


CHAPTER  XX. 


ALKALOIDS,  ETC. 


AcoNiTiNE,  Cg3H4  3]SrOi2?is  the  active  alkaloid  of 
the  leaves  and  root  of  the  Anconitum  Napellus,  or 
monkshood,  a  perennial  plant,  indigenous  to  the 
mountainous  portions  of  Europe.  The  leaves  are 
deeply  divided;  the  flowers  of  a  purple  blue  color, 
and  of  bell-shaped  pendant  form.  All  parts  of 
the  plant  possess  medicinal  bitter  properties,  but 
the  root  is  richest  in  active  principles.  Tinctura 
aconiti  radicis  is  the  most  favored  preparation. 

Tincture  of  aconite,  applied  locally,  causes 
a  tingling,  burning  sensation,  followed  by  numb- 
ness, due  probably,  to  the  paralyzing  influence  of 
aconite  on  the  extremities  of  the  sensory  nerves. 
It  produces  sedative  and  anodyne  effects  when 
used  topically  in  neuralgia  and  rheumatism,  and 
relieves  the  pain  of  acute  periodontitis. 

When  taken  internally,  even  in  full  doses,  aco- 
nite does  not  interfere  with  the  normal  intellectual 
faculties  of  the  brain.  The  reflex  irritability  of 
the  spinal  chord  is  greatly  diminished,  cardiac  ac- 
tion, respiratory  movement,  and  temperature  are 


Alkaloids,  etc.  351 

reduced.     It  increases  the  flow  of  saliva  and  the 
secretions  of  the  skin  and  kidneys. 

On  account  of  excessive  slowing  of  the  heart's 
action  by  aconite,  its  eraploymeut  should  be 
avoided  in  cases  of  suspected  cardiac  weakness. 

Antidotes  :  Emetic,   animal  charcoal  pulv.  Tannin,  hot 
alcoholic  stimulapts,  and  digitalis  ;  also,  arayl  nitrite. 
Dose,  tincture  of  the  root,  0.06-0.30  fGm.  (^^ij-v) 
"      Aconitine,     .      .     .         0.001    Gm.  (gr.  -J^) 

Atropine,  Cj7H23]Sr03,  is  the  active  medicinal 
principle  of  the  root  and  leaves  of  atrop a  belladonna, 
or  deadly  nightshade,  sl  perennial  herbaceous  plant, 
natural  to  the  mountainous  regions  of  Southern 
Europe  and  Asia,  but  now  cultivated  in  this  coun- 
try and  elsewhere. 

Atropine  Sulphate  (0^711231^03)2112804, is  much 
more  soluble  in  water  than  is  the  alkaloid.  It  is 
also  freely  soluble  in  alcohol,  but  not  in  ether.  It 
is  neutral  in  reaction,  without  odor,  and  of  a  bitter 
taste,  and  like  aconitine,  very  poisonous. 

Topical  application  of  belladonna  preparations 
is  soothing  and  anodyne  in  neuralgic  pains  and  in 
abcesses,  and  is  efficacious  in  reducing  or  arresting 
suppurative  processes,  localized  perspiration  and 
the  secretion  of  the  mammary  glands.  Taken  in- 
ternally, belladonna  causes  gentle  hallucinations  of 
a  joyful  character,  and  calming  sleep.     The  reflex 


352  Organic  Chemistry. 

irritability  of  the  spinal  chord  is  diminished,  but 
cardiac  and  respiratory  movements  are  increased. 

These  latter  phenomena  are  supposed  to  be  due 
to  paralysis  of  the  pneumogastric  nerve ;  which 
condition  permits  the  sympathetic  nerves  to  come 
into  full  play,  ungoverned  for  the  time  being,  by  the 
pneumogastric,  and  thus  exert  their  peculiar  power. 
Belladonna  therefore  is  a  temporary  cardiac  tonic. 

It  induces  dilatation  of  the  pupil,  by  its  paralyz- 
ing influence  on  the  raotor-oculi  nerve,  which  sup- 
plies the  sphincter  muscular  filaments  of  the  iris, 
allowing  the  sjunpathetic,  which  rules  over  the 
radiating  fibers,  to  become  extra-active  in  the 
performance  of  its  usual  function.  Belladonna, 
checks  the  secretion  of  saliva,  by  selective  influence 
on  the  secretory  branches  of  the  chorda  tympani 
nerve,  supplied  to  the  submaxillary  ganglion. 

Antidote:  Animal  charcoal,  vegetable  astrin- 
gents, opium,  calabar  bean  (physostigma  veneno- 
sum),  and  tartar  emetic. 

Dose,  Astropine  0.001  Gm.  (gr.  -g*^.) 

Dose,  Fluid  Extract  of  root  0.06-0.30  fGm.  ^Mlj-v.) 

R.    Extractum  Bellad.  fluidum  Rad. 

Tinctura  Aconiti  Radicis  aa  8.00  fGm.  (^ij.) 
Acidi  Carbolici  0.30  fGm.  (gttv.) 
Chloroformi  30.00  fGm.  (fgi.) 

M.  S.  Poison.  Use  as  a  liniment  only,  in  painful  restricted 
inflammation. 


Alkaloids,  etc.  353 

Hyoscyamine,  the  principal  alkaloid  from  the 
leaves  of  Hyoscyamus  Niger  (Henbane)  a  biennial 
plant,  and  Daturine  from  the  leaves  and  seed  of 
Datura  Stramoniam,  are  chemically  identical  with 
Atropine,  and  possesses  like  the  latter  anodyne  and 
antisposmodic  properties. 

The  Datura  Stramonium  plant,  also  known  as 
Thornapple  and  Jimson  (Jamestown)  weed,  is  an 
annual  of  common  occurrence. 

A  poultice  oi  jimson  leaves,  is  very  efficacious 
in  reducing  the  pain  and  swelling,  in  acute  alveolar 
abscess. 

Cannabin,  is  the  most  active  principle  of  cannabis 
saliva  or  Hemp,  [Cannabis  Indica  and  C.  Americana), 

Cannabis  sativa  must  not  be  confounded  with 
Ajpocynum  Cannabinura  "  Canadian ,  or  Indian 
Hemp,"  the  common  Milkweed. 

Cannabis  sativa  furnishes  several  preparations  of 
more  or  less  mystical  importance. 

Gunjah  is  the  dried  female  flowers  and  leaves, 
sold  for  smoking  purposes.  Churrus  is  a  resinous 
substance  obtained  by  rubbing  together  the  leaves 
of  the  plant ;  and  Hasheesh,  or  bhang,  consists  of 
the  small  broken  stalks  and  leaves,  mixed  with 
aromatics  and  fruits. 

Preparations  of  Cannibis  Sativa  taken  in  full 
dose,  cause  an  exalted  intoxication,  and  loss  of 
30 


354  Organic  Chemistry. 

conception  of  time,  followed  by  sleep,  and  great 
depression  ;  they  act  in  moderate  doses,  as  antispas- 
modics, and  aphrodisiacs. 

Applications  of  warm  Tindura  Cannabis  Indica. 
(Dose,  2.00-4.00  fGm.  (n|^xxx-lx)  has  been  sug- 
gested as  a  local  anaesthetic,  in  the  operation  of 
extracting  teeth. 

Hamamelis  Vrrginica,  or  Witch  Hazel,  is  a  native 
shrub,  from  the  bark  and  leaves  off  which,  a  fluid 
extract  is  obtained,  possessed  of  tonic,  astringent, 
and  anodyne  properties. 

Dose  of  the  Fluid  Extract  0.06-4.00  fGm.  (ntj-lx.) 

R.  Extractum  Hamaraelidis  Fluidum  4.00  fGm.  (f^j.) 
Aqua  Dest.  q.  s.  Ad.  30.00  fGm.  (fgj.) 

M.  S.  An  excellent  lotion  to  sore  gums,  afte-  removing 
salivary  calculus. 


Numbers  of  new  remedies  belonging  mainly  to 
the  "  Antiseptic  "  class,  have  been  introduced  during 
the  present  year. 

They  are  generally  termed  by  their  manufac- 
turers, "  Synthetic  "  (better,  J.r^i^ciaQ,  preparations, 
to  distinguish  them  from  natural  products.  Their 
names  are  sometimes  quite  fanciful;  two  at  least, 
of  which  are  ridiculously  similar  in  sound  and 
orthography,  i.  e.,  Europhen  and  Euphorin.  The 
first  is  probably  named  in  honor  of  Europe,  and  the 
other  in  recognition  of  the  genus  Euphorbia  tree, 


Alkalies,  etc.  355 

from  one  of  the  species  of  which,  our  Rubber  is 
obtained. 

EuROPHEN  occurs  as  a  jellow  tasteless,  odorous 
powder,  insoluble  in  water,  and  glycerine,  but  solu- 
ble in  ether,  alcohol,  and  chloroform. 

Locally,  it  is  anaesthetic,  and  antiseptic,  and  pre- 
sumes to  act  as  a  substitute  for  Iodoform,  being  less 
poisonous,  and  decidedly  of  less  unpleasant  odor. 
It  is  prepared  by  dehydrating  Isobutyl  alcohol  and 
ortho-cresol,  by  zinc  chloride,  resulting  in  isobutyl- 
orthocresol,  which,  dissolved  in  alkali,  and  acted 
upon  by  solution  of  iodine  in  potassium  iodide,  pre- 
cipitates as  Europhen.  It  consists  of  hydro-carbon 
radicals,  about  72  per  cent,  and  of  iodine  28  per 
cent,  while  iodoform  is  made  up  of  hydro-carbon,  3 
per  cent  and  of  iodine,  97  per  cent. 

Europhen  is,  therefore,  comparatively  very  weak 
in  iodine,  which  fact,  however,  need  not  prevent  the 
manifestation  of  the  virtues  ascribed  to  it,  inasmuch 
as  the  action  of  any  drug,  local  or  general,  does  not 
necessarily  depend  on  its  chemical  decomposition. 

EuPHORiN  is  a  crystalline,  substance  structurally 
related  to  carbolic  acid,  and  acetanilide,  and  is 
therefore  easily  erected  on  the  benzene  ring.  It  is 
insoluble  in  water,  but  dissolves  in  alcohol,  and  is 
recommended  internally,  as  an  effective  anti-pyretic, 
and  analgesic. 


356  Organic  Chemistry. 

AsAPROL  is  a  crystalline  substance,  and  Diaph- 
THERiN,  is  an  amorphous  powder.  Both  are  soluble 
in  water,  and  possess  active  germicidal,  and  anti- 
septic properties. 


Analysis  of  Teeth  (Berzelius) : 

Organic  substance  28.0 

Calcium  phosphate  64.4 

Calcium  carbonate  5.3 

Magnesium  phosphate  1.0 

Sodium  carbonate  and  chloride  1.3 


100.0 


(Fremy). 

Ash.  Calcium  Phos.      Mag.  Phos.         Cal.  Garb. 

Enamel,  96.9  90.5  traces.  2.2 

Dentine,  76.8  70.3  4.3  2.2 

Cement,  67.1  60.7  1.2  2.9 

[  Taken  from  MitcheWs  Chemistry.  ] 


General  Index. 


357 


GENERAL  INDEX. 


PAGE, 

Acids 38 

Acid  Acetic 279 

Arsenic 197 

Arsenous 199 

Benzoic 311 

Boric  96 

Butyric 273 

Butylactic 292 

Carbonic 93 

Carbolic  307 

Chromic 212 

Cinnamic 326 

Camphoric 323-336 

Citric 296 

Eugenic 324 

Formic  275 

Gallic 313 

Glacial  Acetic 279 

Glyceric 298 

Glycollic  291 

Hydrochloric 55 

Lactic 292 

Malic 295 

Maloric 292 

Margaric 297 

Metaphosphoric 83 

Molybdic. 208 

Nitric 67 

Nitro-hydrochloric 69 

Oleic   297 

Oxalic 291-292-294 

Oxids 46 

Palmitic 297 

Phosphoric 82 

Permachoric 194 

Phosphorous 82 

Pyrophosphoric 82 

Pyrotartaric 292 

Salicylic 312 

Selenic 79 


PAGE. 

Acid,  Silicic 100 

Stearic 297 

Succinic 292 

Sulfuric 75 

Sulf  urous.. 74 

Tannic 314 

Tartaric 295 

Tungstic 209 

Valerolactic 292 

Absinthol 336 

Acetic  Acid 279 

Acetates 280 

Acids 38 

Halogen 63 

Acetone 261 

Acetylene 304 

Acetanilid 317 

Aconitin.. 350 

Alcohols 259-273 

Aldehyds 261-274 

Allyl 300 

Alkaloids 341 

Alum 177-180 

Aluminum  175 

Acetate 181 

Chlorid 175-181 

Hydrate 176 

Oxid 178 

Phosphate 179 

Sulfate 177 

Amalgams 155 

Amids. 262 

Ammonia 65 

Ammonium 142 

Aurate 219 

Benzoate  312 

Chlorid 66 

Nitrate  71 

Amids 261 

Amins 262 


358 


General  Index, 


PAGE. 

Amidogen 258 

Amylene  291-302 

Amyl  Acetate 289 

Amyl  Alcohol 289 

Amyl  Nitrate 289 

Analysis 30 

Ansesthetics 71 

Anisol 308 

Anilin 316 

Antimony  202 

Acids    203 

Oxids 203 

Oxysulfid 204 

Antimonous  chlorid 2Q4 

Antipyrin 317 

Antiseptics 248 

Aqua  Regia  217 

Argentum 149 

Aristol 330 

Arsenic 197 

Arsenic  Acids   199 

Oxids 198 

Sulfids    199 

Artiads  109 

Asoprol 356 

Atmosphere 4 

Atoms  28 

Atropin 351 

Attraction. 29 

Auric  chlorid 218 

Oxid 219 

Arum 214 

Aurous  chlorid 218 

Oxid 219 

Babbit's  Metal ...  203 

Bacilli 249 

Bacteria 249 

Baking  Powder 295 

Barium. .147 

Nitrate 147 

Oxids 147 

Sulfate  147 

Barometer 5 

Basalt 175 

Bases  38 

Beeswax 288 

Belladonna 351 


PAG*. 

Benzene    306 

Group  311 

Benzoic  Acid  — 311 

Benzol  Hydrate, 312 

Beryllium 167 

Benzyl  Alcohol 311 

Bismuth 205 

Chlorid 206 

Hydrate 206 

Nitrate 206 

Oxid 206 

Oxychiorid 206 

Subnitrate 206 

Sulfate 206 

Bleaching  — 54 

Blow-pipe  flame 91 

Borax 97-140-141 

Borneol 336 

Boric  Acid 96 

Boron 96 

Britannia  Metal 203 

Bromin 61 

Bromoform 271 

Butane 267 

Butter  Antimony 204 

Butylactic  Acid 292 

Cadmium 166 

Caflfein 341 

Calcium. 143 

Benzoate 312 

Carbonate 144-147 

Chlorid 143 

Fluorid 146 

Hydrate 143 

Lactate 293 

Oxid 143 

Phosfate    145-147 

Sulfate  145 

Calendula 339 

Calisaya     342 

Camphors    323-335 

Campho-Phenic 338 

Camphoric  Acid 323-336 

Cannabis  Indica 353 

Carbolic  Acid 307 

Carbon •    85 

Compounds 252 


General  Index. 


359 


PAGE. 

Carbonic  Acid 93 

Carbon  Oxids 92-94 

Disulfid 95 

Carbo-IIyd  rates 318 

Carbom  id 265 

Carboxyl 260 

Caryophillin 264 

Capsicum 338 

Caoutchouc 333 

Carvacrol 329 

Carvol 329 

Celluloid 319 

Cellulose 319 

Cerium 148 

Oxalate 148 

Charcoal  86 

Chalk 143 

Chemical  Affinity 29 

Equations 33 

Philosophy.. 103 

Chemism 29 

Chili  Saltpeter 134 

Chloral  281 

Camphor.. 338 

Hydrate 281 

Chlorin... 53 

Chlorinated  Lime  46 

Chloroform 268 

Chloroplatinates 223 

Chromium  210 

Compounds 210 

Cinnabar; 144 

Cinnamic  Acid. 326 

Citric  Acid 296 

Cinchona    342 

Clay 375-379 

Cobalt 195 

Compounds 195 

Cohesion 29 

Colloids     101 

Combustion. 87 

Copper  152 

Compounds  153 

Amalgam 155 

Cocain 346 

Collodion 320 

Cologne 322 

Corundum 175 


PAGE. 

Creasote 309 

Creasol 310 

Cresylol  310 

Cream  Tartar 295 

Cyanogen 258 

Cymene 328 

Decay 245 

Black  77 

Brown 60 

Dental 57 

White 69 

Dentists'  Gold  Foil 216 

Destructive  Distillation 245 

Dextrin 318 

Diamond 85 

Disinfectants 248 

Disinfection 249 

Distillation 17 

Dolomite 164 

Dry  Method 217 

Dynamite 299 

Earths 147 

Ebonite 333 

Ebullition 16 

Electrolysis  224 

Elements 25 

Electro-negative 227 

"        positive 227 

Electro-plating 229 

EfFects  of  Medicines  127 

Emory 175 

Esters 260 

Essential  Oils 264-325 

Equivalency 107 

Variations 112 

Ethane 253-267 

Ethene 88-253 

Alcohol 291 

Erbium 148 

Eremacausis  246 

Ether 284 

Ethers 284 

Compound 280 

Haloid 269 

Mixed 250 

Oxygen . .  259-284 


860 


General  Index. 


PAGE. 

Ethine 304 

Erythroxylon 346 

Ethyl 277 

Alcohol 277 

Chlorid 286 

Oxid  284 

Lactates 293 

Ethylene 305 

Eucalyptol 328 

Eugenol 324 

Euphorin 354 

Europhen 350 

Evaporation 15 

Face  Powder 206 

Faradic  Current 231 

Fatty  Acids 279 

Felspar 175-179 

Fermentation 246 

Ferric  Chlorid 186 

Hydrate 186 

Oxid 186 

Sulfate 186 

Ferrous  Carbonate 185 

Chlorid 185 

Chromite 212 

lodid 185 

Oxid 185 

Salts 185 

Sulfate 185 

Sulfid. 185 

Flame 89 

Blow-pipe,    . . ,. 95 

Fluorin.. 62 

Fowler's  Solution 202 

Fulminating  Gold. 219 

Fusible  Alloys  205 

Gallic  Acid.. 313 

Gallium 281 

Galvanism 224 

Gases 28 

Gaseous  Diffusion 5 

Germicides 248 

Glacial  Acetic  Acid 279 

Glass. 99 

Glucinum 157 

Glucose 318-320 


PAGE. 

Glucosids..   316 

Glycerin 298 

Glycerita 300 

Glycolls 291 

Gold ...  214 

Alloys 215 

Facings 220 

Precipitates ^ 217 

Granite . .  175 

Grape  Sugar 320 

Graphic  Formulae  110 

Graphite 86 

Gravitation 29. 

Gums 319 

Gun-cotton 319 

Powder 134 

Gutta-percha 333 

Haemostatic 188 

Halogens :    58 

Hamamelis 354 

Hasheesh 353 

Heat 6 

Atomic 104 

Combustion  of 91 

Conduction    10 

Effects 7 

Expansion 7 

Latent 13 

Nature  of 18 

Radiant 22 

Specific. 12 

Units  50 

Hemetite 183 

Homologous  Series 254 

Hoffmann's  Anodyne 285 

Table 253 

Hops 339 

Horn  Silver 149 

Hydrogen  49 

Chlorid 55 

Permanganate  194 

Peroxid 51 

Hydro-Naphthal  334 

Hydro-Carbons    253 

Hydraulic  Cement    175 

Hyoscymin 353 


General  Index. 


361 


PAGE. 

Illuminating  Cas 87 

Imidogeu 258 

Iiidium.. . . . .   181 

India  Rubber 333 

Ink  188 

lodin 60 

Iodoform 270 

Iridium .-.  223 

Iron 183 

By  Hydrogen 187 

Iron,  Cast 184 

Dyalized 187 

Malleable 184 

Pig 184 

Wrought 184 

Isobu  tane 267 

Isomerism 263 

Optical 264 

Isomorphous 105 

Isopentene  302 

Isologous  Series 254 

Kaolin    179 

Ketones 261-274 

Labaraques  Solution    140 

Lactic  Acid 292 

Latin  Abbreviations 121 

Law,  Avagrado 109 

Even  Numbers ...  Ill 

Periodic 233 

Leucomains 341 

Lead 168 

Lead  Acetates 169-280 

Carbonate 169 

Oxids 169 

Light  18 

Decomposition 20 

lieflection 21 

Refraction 19 

Lime  143 

Water  144 

Linimentum  Calcis  146 

Liquids 28 

Litharge 169 

Lunar  Caustic 149 

Magnatite 183-187 

31 


#  PAGE. 

Magnesium 164 

Compounds  165-166 

Malic  Acid  295 

Malouic  Acid  292 

Manganese  194 

Compounds  194 

Margaric  Acid ,.  297 

Margarin  298 

Marsh's  Test  198 

Marsh  Gas 87 

Masses 28 

Matter,  Constitution  of 25 

Compound 25 

Elementary. 25 

Materia  Medica  120 

Mercury 154 

Compounds    156-157 

Meerschaum 164 

Meta-Compounds 173 

Metallic  Alloys 128 

Classification 130 

Elements 128 

Properties 130 

Methane 87-252-267 

Methene 253 

Methenyl 268 

Methyl 257 

Alcohol 273 

Menthol 332 

Metric  System 123 

Mica 175 

Micro-Organisms 246 

Mixed  Ethers 259-288 

Molecular  Weights 105 

Molecules 28-105 

Compound 30 

Simple 30 

Molybdenum 208 

Compounds  208 

Monatomic  Alcohols 273 

Morphin  ,         345 

Mosaic  Gold 174 

Monsel's  Powder 187 

Solution  187 

Myrrh  335 

Naphthalin 317-334 

Nebulae 242 


362 


General  Index, 


PAGE. 

Nickel 195 

Compounds 196 

Nicotin ...  341 

Niobium 207 

Nitrogeu.-. —    64 

Oxids 67 

Nitric  Acid 67 

Nitrous  Ether 285 

Oxid 71 

Nitro-Benzene 316 

Glycerin 299 

Cellulose  319 

Nitryl  258 

Nomenclature  33 

Notation 31 

Nutgalls 314 

Oil,  Caraway  328 

Cassia  325 

Cinnamon 325 

Cloves 324 

Eucalyptus 327 

Orange  Flowers. 333 

Peppermint 332 

Sassafras 325 

Turpentine 323 

Wintergreen  B27 

Oils,  Essential  264-325 

Olefins 290 

Oleic  Acid 297 

Olein 298 

Opium 345 

Optical  Isomerism 264 

Organic  Acids  260 

Chemistry 244 

Ortho-Compounds 172 

Osmium  223 

Oxalic  Acid 291-294 

Oxidation 44 

Oxids,  Acid 46 

Basic  46 

Neutral 46 

Oxygen. 43 

Ethers 259-284 

Ozone 46 

Test 48 

Palladium 223 


PAGE. 

Palmitic  Acid  ...  297 

Paraflns  266 

Paris  Green 199 

Pental ■■ 302 

Perissads 109 

Periodic  Law  233 

Table 236 

Phenol 308 

Phenols  332 

Phenol  Sodique  309 

Phenacetin 317 

Phenetol 308 

Phenic  Acid 307 

Phenyl 307 

Amin 316 

Alcohol 307 

Phosphorus  81 

Compounds 82 

Phosphin 83 

Platinum..  .. 221 

Backing  220 

Compounds 222 

Plumbum  Acetate 169 

Chromate 212 

Polymerism 264 

Porcelain 99-179 

Teeth 180 

Potassium  131 

Compounds 132-137 

Chromate 212 

Cyanid 258 

Aurate  219 

Prepared  Chalk 147 

Primary  Alcohols  273 

Proof  Spirit 278 

Proponyl 298 

Alcohol 298 

Ptomains  247-341 

Purple  of  Cassias 172-219 

Propane 267 

Putrefaction 245 

Putty  Powder 172 

Pyridin 317 

Pyoktanin 344 

Pyrethrum 333 

Pyroxylin 319 

Quinin...     342 


General  Index. 


363 


PAGE. 

Quinicin  317 

Quick-silver 154 

Radicals  114 

Compound 116 

Red  Lead 169 

Resins 223-335 

Resorcin   332 

Rhodium  223 

Robinson's  Remedy 309 

Rosin  323 

Ruby  175 

Rules,  Prescribing.. 122 

Ruthenium 223 

Salts 38 

Salol 317 

Salicylic  Acid 312 

Saltpeter 131-136 

Samarium 148 

Scandium 182 

Selenium  79 

Silicon 98 

Silicic  Acid 100 

Silicon  Oxid 98 

Siderite 183 

Silver 148 

Compounds 149-150 

Slate 175 

Soap 298 

Secondary  Alcohols    273 

Solar  Spectrum 37 

Solids 28 

Sodaj  Chloratse 140 

Sodium 138 

Arsenite 199 

Compounds 138-141 

Bismuthate 207 

Lactate 293 

Tungstatc 209 

Specific  Gravity   1 

Heat 101 

Spectrum  Analysis 238 

Spermaceta 288 

Spores 249 

Starch 318 

Stearin 298 

Stereo-Chemistry 263 


PAGE. 

Stramonium 353 

Stibin 183 

Strontium 14/, 

Nitrate 147 

Storage  Batteries, 230 

Sugars 320 

Sucrose 320 

Sublimation 17 

Sulfur.. 73 

Compounds 74-78 

Tannic  Acid 314. 

Tantalum 207 

Tartar 144 

Tartaric  Acid 295 

Tartar  Emetic 204 

Teeth,  Analysis 356 

Tertiary  Alcohols 273 

Terpenes 322 

Tellurium 80 

Thallium 170 

Thermometers 8 

Thorium 174 

Thymol 329 

Tin 170 

Compounds 172 

Titanium 174 

Toluene 306 

Trinitophenol  — 320 

Tungsten 208 

Compounds 208 

Type  Metal 203 

Uranates 211 

Uranium 209 

Compounds 209 

Yellow 210 

Uranyl 209 

Valerolactic  Acid. 292 

Vanadium 207 

Oxids 207 

Vapor  Density     106 

Verdigris 280 

Vermilion.. 157 

"  Vitalized  Air  " 286 

Volatile  Oils 323 


364 


General  Index. 


PAGE. 

Water 50 

Glass. 90 

Weights,  Measures 123 

Wet  Method 216 

White  Lead 169 

Witch-Hazel..... 354 

Wolfram 208 

Yttrium 148 


PAGE, 

Zinc 160 

Cblorid 161 

Oxid 161 

Oxychlorid 162 

Oxy-phosphate 162 

Sulfate 163 

Zirconium 174 


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