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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. 



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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 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 ; ISTa to CI ; H to ; 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 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 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 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 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 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 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 + + 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 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 (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 

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 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 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 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 + = 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— 

CI 

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

' H^ \H 



Nitric Acid, HNO3 N 0— H 

II 




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

A II 



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 — II without disturbing the existing atomic 

value of hydrogen, thus H — — — 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 — — K, there 
is a tetroxide of potassium K — — — — — 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 — — H (water), 
is a saturated molecule; if one of the hydrogen 
atoms be removed, the resulting group, — — 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 — — — 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 = 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 — — , 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 





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 

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 

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. 











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. 



H 

M 



o 

H 

O 

-^ 
H 

o 

(—1 
Q 
O 






1— 1 

> 




o 

03 




"2 
1 O 

00 

IS 


o 

1-1 

pi 




o 

T-i 

cC 

CO 
Ol 

1-1 

u 


1 1 
1 1 

1 
1 


> 






5 

a 




r-l f-t 
CO 




1 
1 


> 


ffio 

P^05 


O 


CO 

a 


OO 

V 
CO 

o 

1^ 


1-1 


1 ^ 

' 00 


05 

CO 

P 


> 


in 


1-1 


r-( 

CO 

> 


CO 

< 


S!5 


r-( 
1-1 

w 

00 

1-( 

83 

H 


00 
§ 


> 


WO 

05 03 


i-t 

o 




c^ o 
i> o> 

ON 


00 O 
»— 1 ^ 

i-t rl 

q 0) 

CBO 




o 
c^ 

Ph 
CO 
CO 

c^ 

H 


1— I 


CO 

lO 


pq 


< 


GO 


00 
CO 
tH 

S3 
B 


CO 

I-H 


i 


-■ 


o 

03 


1 '^ 

1 n 


o 
o 


SB 

u 

CO 


CO 

w 

»-< 




be 

w 


1— J 


JO 

03 






CO 

to 

OO 


1—1 
be 

CO 

eo 
I— 1 

09 










00 

CO 


1-1 04 


w* 


io«o 


t^OO 


o> o 


I— 1 1-1 



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 — — 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 — — 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 + = 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 + = 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 

-^ 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^ — — 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, == 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 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— 



,4 



H2=C C— 

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 
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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