WILLIAM L.CLEMENTS
LIBRARY OF
AMERICAN HISTORY
UNIVERSITY OF MICHIGAN

ank E M. Jene
With the regards
the author
of




ELEMENTS
ор
CHEMISTRY;
CONTAINING THE
PRINCIPLES OF THE SCIENCE,
BOTH
EXPERIMENTAL AND THEORETICAL.
INTENDED AS A TEXT-300K FOR ACADEMIES, HIGH SCHOOLS,
AND COLLEGIS.
ILLUSTRATED WITHI NUMEROUS ENGRAVINGS.
By ALONZO GRAY, A. M.
Tearbor of Chemistry and Nat. Hist, in the Teachers' Sem., Andover, Mass.
FOURTH EDITION, REVISED AND ENLARGED
NEW YORK:
PUBLISHED BY DAYTON & NEWMAN.
SCHOOL BOOK PUBLISHERS,
CORNER OF FULTON AND NASSAU STREETS.
BOSTON: SAXTON AND PEIRCE.
1842.

Entered according to Act of Congress, in the year 1940,
By ALONZO GRAY,
In the Clerk's Office of the District Court of Massachusetts.
ALLEN, MORRELL, AND WARDWELL,
PRINTERS,

PREFACE.
In compiling the first edition of this work, the author
attempted to prepare a text-book which should be well
fitted for elementary instruction. Most of the works on
chemistry appeared to him to be either too profound, on the
one hand, for those who were just commencing the study, or
too superficial, on the other, for those who wished to obtain
a scientific knowledge of the subject.
The design was to avoid these two extremes, and com-
bine the scientific with the popular and useful parts of the
subject. The rapid sale of the first edition, and its intro-
duction into several colleges, has led to the inference that
the attempt has not been wholly unsuccessful. The author
has therefore been induced to revise and enlarge the work,
and put it into a permanent form. A large amount of
matter, and numerous engravings, have been added, for the
purpose of rendering the work better adapted to academies
and other schools.
It is believed that greater success would attend the efforts
of teachers in this branch of science, if more attention were
given to the principles of chemistry, and less to its details.
The fundamental principles being thoroughly understood by
the student, he is prepared to attend to the details with
greater pleasure and success, as he will be able to connect
the effects with their appropriate causes.
Under the influence of this belief, the author has given a
greater prominence to the imponderable agents and the thir-

4
PREFACE.
teen non-metallic substances, than to other parts of the work.
Most of the illustrations and experiments are introduced in
this part, so as to present and illustrate the philosophy of
chemical combinations, and the general nature of the com-
pounds thus formed ; in other words, the causes of chemical
changes and the mode of studying them.
By the introduction of numerous experiments and illus-
trations, the object has been to give to the work a prac-
tical character, so that the teacher, with a very simple
apparatus, and with limited means, may be able to give
numerous experimental illustrations to his classes. The im-
portance of studying chemistry experimentally, is admitted
by all; and to aid teachers in constructing the more simple
forms of apparatus, many notes and drawings have been
added, and experiments described, which may easily be
performed by those who are not privileged with more costly
and extensive means of illustration.
In the arrangement of the imponderable agents, the phe-
nomena of common and voltaic electricity, electro-magnet-
ism, and magneto-electricity, are classed as effects of one
agent — electricity.
In the arrangement of the simple substances, the logical
order has been adopted; that is, each simple substance is
described, and then its combinations with those only which
have been previously described; so that only one substance
with which the pupil is unacquainted is presented at a time.
This classification appears to be the most convenient for
presenting the different compounds, and less liable than any
other to confuse the mind of the learner. This order, how-
ever, has been adopted only with the simple substances and
their binary compounds.
The salts occupy a separate chapter, in the arrangement
of which Turner's Chemistry has been made the basis.
Several new salts, and cne entire family, — the silicates, -
have been added.

PREFACE.
5
Organic chemistry has become so extensive, and so far a
distinct branch of the subject, that a short chapter only is
inserted. For a complete description of these compounds,
the student is referred to Thompson's Chemistry, "Organic
Bodies," which is the most extensive and valuable work on
the subject which has hitherto appeared.
The chapter on Analytical Chemistry has been consider-
ably enlarged; but the methods of analysis have become so
accurate, the details so minute, and the processes so com-
plicated, that those who would obtain a full mastery of the
subject, must consult works which treat particularly of
chemical analysis. Sufficient only has been inserted to
give the pupil some idea of the nature of the processes, and
to enable him to test, if not actually to analyze, the sub-
stances which are mentioned.
The Glossary of chemical terms has been selected from
that prepared by Daniell, of London, and adapted to this
work. The table of contents has been much enlarged, and
a complete analysis of the work presented, in the form of
topics, which are intended to be used instead of questions ;
the topics being so arranged that, when the teacher sug-
gests one, the pupil may give a complete description of it.
This plan, it is believed, will prevent the evils incident to
direct questions, while it will secure all their advantages.
Chemical formula have been extensively adopted. This
appears highly important, especially for those who intend
to become thorough students in the science. The notation,
(the use of symbolical language,) to express, in a condensed
form, complicated chemical changes, seems to be as useful
in chemistry as in algebra, and, although these symbols may
be unintelligible to the common reader, he who will thorough-
ly study them will find them the most efficient aid to a clear,
definite, and easy comprehension of the whole science.
In the description of the ponderable bodies, brevity has
1 *

6
PREFACE.
been consulted, as far as was consistent with perspicuity
The illustrations and descriptions are much more extended
in the first two hundred pages than in other parts of the
work. The method of description which is employed in
natural history has been adopted, where the subject did
not require a more popular style. By this means, and by
using different kinds of type, a large amount of matter has
been condensed into a small compass, while, at the same
time, that which is more important to be studied is rendered
conspicuous. Many subjects of minor importance are only
alluded to, and reference frequently made to more extensive
works.
The source from which most of the materials have been
drawn, is Turner's Chemistry. The works of Henry, Silli-
man, Webster, and Griffin's Chemical Recreations, have
been frequently consulted, and also many original papers in
the scientific journals of the day; and it is confidently be-
lieved that the work contains the most valuable recent
discoveries up to the present time, so far, at least, as they
have been made known to the scientific public.
The acknowledgments of the author are here due to
Professor Charles B. Adams, of Middlebury College, for
important aid, especially in the department of Organic
Chemistry.
A. G.
TEACHERS' SEMINARY,
Andover, September, 1841.

CONTENTS.
INTRODUCTION.
Page
Science defined - Physical and Natural science..
21
Definition of matter how many properties does it embrace ?..... 21
DIVISION OF NATURAL SCIENCE.
I. NATURAL PHILOSOPHY — method and object of.
21
II. CHEMISTRY method and object of..
22
III. NATURAL HISTORY — method and object of.
22
PLAN OF THE WORK.
PART I. IMPONDERABLE AGENTS — why so called.
១១
II. CHEMICAL AFFINITY - definition of..
23
III. PONDERABLE BODIES chemical and natural substances. 24
Division of substances; simple and compound bodies.... 24
Analysis and synthesis ; arrangement of chem. substances 24
PART FIRST.
IMPONDERABLE AGENTS.
CHAPTER 1.- CALORIC.
The term heat how used — meaning of caloric
1. Sensible caloric defined. --2. Insensible caloric do..
25
25
SECT. 1. SENSIBLE CALORIC — COMMUNICATION OF.
The most important property of sensible caloric.....
26
I. Conduction - meaning and illustration of..
26
Conducting power; how does it differ in bodies ?.
26
Different degrees of this power illustrated..
27
1. Conducting power of solids; illustrated by conductometer 27
Best and poorest conductors, metals, stones..
27
Uses of conductors, benevolence of God illustrated.
28
Ratio of the conducting power of solids...
28
2. Conducting power of liquids; how are liquids heated ? Ills. 28
Heat applied at the top of liquids in a glass jar..
29
3. Conducting power of gases; how are they heated ?.
29
II. Radiation - defined; radiant caloric, how projected 30
1. Law of the intensity of heat at different distances..
30
2. Degree of radiation, dependent upon what?..
30
Difference between bright, and dark or rough surfaces, Ills..... 30
Greater radiating power of rough surfaces, depends on what?.. 30

8
CONTENTS.
3. Rapidity of radiation dependent upon what?.....
31
III. Disposition of Radiant Caloric — reflect., absorb., transmit. 31
1. Reflection of caloric; law of reflection, angles of incidence and
reflection. Concave mirrors described.
31
2. Absorption of caloric; depends upon what?.
32
Best absorbers, reflectors, and radiators..
32
Color of surface; its effect upon the power of absorp., Ills.. 32
3. Transmission of caloric; through air and gases, glass, etc..... 32
Opinions of Leslie, Brewster, De la Roche, and other chemists. 33
Radiant caloric modified by its connection with solar light..... 33
IV. Theories of Radiation - how many are worthy of notice ?.. 33
1. Theory of Pictet, described......
...... 33
2. Theory of Prevost, do. grounds of preference..
33
V. Application of the Theory of Prevost to the Expl. of vari's Phen.
1. The phen. of the mirrors explained ; apparent radiation of cold.. 34
2. Formation of dew, process described and explained......... 34
Quantity of dew; dep. upon what? grass, and polished surface.. 34
Why is there no dew in a cloudy night?
35
VI. Cooling of Bodies - different modes by which it is effected. 35
Velocity of cooling, defined; law of cooling, according to Newton. 35
VII. Prac. Application of the Laws of Conduct. and Radiant Caloric.
Best materials for windows; double walls, doors, windows...... 35
Object of clothing; kind best for different seasons of the year..... 36
Effects of Free Caloric.
I. General Law - Caloric expands all Bodies; Liquids, Solids, Gases,
1. Caloric expands solids ; illustrated by what?..
36
2. Equal degrees of caloric expand some solids more than others... 36
Illustrated by pyrometer; description of pyrometer...
36
3. Effect of equal add’ns of caloric on the same solid at dif. temp's. 37
Expansion of brass and iron rods in the higher or lower temp's.. 37
4. Uniformity in the expansion of certain solids...
37
II. Caloric expands Liquids more than Solids.
1. Illustrated by heating water in a glass tube, common thermom'r 38
2. Effect upon different liquids of equal degrees of caloric......... 38
3. Effect upon the same liquids of equal degrees at different temp's 38
Apparent exceptions to the general law that heat expands...... 38
III. Caloric expands Gases more than Solids or Liquids.
1. The expansion of air; in glass ball, bladder..
38
2 Law of the expansion of gases at all temperatures.
39
Difference between gases, and solids or liquids..
39
Theory of expansion; caloric and cohesion, how related ?.. 39
IV. Apparent Exceptions to the General Laro.
Water near the point of congelation; Illustration....
40
V. Force of Expansion when Water freezes.
Florentine Academicians; experiments of Major Williams........ 40
Theory, or the cause of expansion when water freezes.
40
VI. Advantages of this Excep. — wisdom and benevolen. of God 40
Process of freezing water; effect if the contractions continued.... 41
Cast iron and antimony, how affected in cooling ?....
41
VII. Practical Uses of the General Law of Expansion and Contract.
Banding of wheels, steam-engine boilers, gallery at Paris... 41
Winds; depend upon what? land and sea breezes..
42
Thermometers; by whom invented ?..
42
1. Air thermometers; plan of Sanctorius, illustrated.
42

CONTENTS.
9
43
Objections to air for the common purposes of a thermometer.... 43
2. Differential thermometer of Leslie ; mode of construction
Best substance for thermometers; solids, liquids, or gases ?.
43
3. Mercurial thermometer; construction and graduation.
44
Different scales; Fahrenheit's, Reaumur's, De Lisle's, Celsius's 45
4. Register thermometer; construction, object, and principle of... 45
Pyrometers; derivation and meaning of the term...
46
1. Pyrometer of Wedgwood; founded upon what property.
46
2.
do.
of Daniell; construction of..
46
3. Metallic thermometer of Brequet; construction, Illustrated..... 46
Amount of knowledge obtained by therm's and other instruments 47
SECT. 2. INSENSIBLE CALORIC.
Specific caloric; meaning of, illustrated..
Methods of determining specific heat of solids and liquids.
Laws of Specific Heat, 1, 2, 3, 4,5.....
Practical inference from the doctrine of specific heat.
47
48
48
49
...
Effects of Insensible Caloric.
1. Liquefaction states in which bodies exist.
49
1. Point of liquefaction; fusion, congelation..
49
2. Caloric of fluidity ; Illustr., quantity in different substances. 49
3. Freezing mixtures; how produced ? salt and snow..c..
50
4. Limit to the degree of cold; greatest cold by these processes. 51
5. Absolute amount of heat; estimated by what means ?.
52
II. Vaporization - defined, difference between gas and vapor. 52
Definition of volatile and fixed bodies ; liquids how vaporized.. 52
Ebullition ; 1. Boiling point defined ; is it fixed ?
52
2. Circumstances which modify the boiling point of liquids. 53
Pressure of the atmosphere; variations of..
53
Barometer, construction and illustration of.
53
1. Law of the boiling point as the pressure diminishes.
53
Mercury frozen under the exhausted receiver of an air-pump.. 53
2. Law of the boiling point as the pressure increases.
54
Marcet's digester; construction of.
55
Absorption of free caloric in ebullition, Illustration.
55
Table of the latent heat of different vapors.
56
Steam ; its formation and laws of expansive force.
Sensible and insensible caloric of steam at all temperatures. 57
Application of Steam to practical Purposes.
1. Warming rooms; water baths, dyeing vats, etc..
57
2. Steam engine; invention of, principle illustrated.
58
3. Steam generator of Mr. Perkins; steam artillery
58
Distillation; process illustrated and described..
59
Evaporation - difference between it and ebullition.
59
1. Evaporation of different liquids; depends upon what?.
59
2. Effect of increased and diminished pressure upon evaporation... 59
3. Extent of surface; how does it affect the rapidity of evaporation 60
4. State of the atmosphere;
60
5. Absorption of free Caloric by Evaporation ; cryophorus described 60
6. Cause of evaporation; how have some accounted for it?. 61
7. Uses of evaporation; cooling rooms, warm climates.
61
Effect of perspiration explained; fire kings, oven girls.
61
Injurious effects of evaporation, miasma, fever and ague. 62
56
66
66
CG

10
CONTENTS.
Hygrometers; reduced to three principles...
1. Saussure's hygrometer; depends upon what property ?
62
2. Leslie's hygrometer; depends upon what property?
62
3. Hygrometer depending upon the quantity of dew, etc..
62
Application of the Laws of Insensible Caloric to the Expl. Nat. Phen.
1. Processes of thawing and freezing; effect upon climate. 62
2. Effect of vaporization; to modify the heat of summer.
63
3. Effect of condensing vapors; rain, source of the cold.
63
4. Effect of freezing water; to modify the approach of winter. 63
Why are the shores of a country warmer in winter, etc...... 63
SECT. 3. SOURCES OF CALORIC AND OF COLD.
1. Sun; concentration of its rays, degree of heat....
64
2. Chemical action; combustion defined.....
3. Condensation; machinery, friction, percussion,
4. Vital action; how is caloric produced in animals ?. ............. 65
Sources of cold, what?..
65
SECT. 4. NATURE OF CALORIC.
Theory of Sir W. Herschel and Prof. Airy; undulatory theory.... 65
Theory of Newton; what supposition did he make?...
65
.... 64
.... 64
.......
CHAPTER II.-LIGHT.
.....
1. Physical Properties of Light — belong to what science ?..... 66
Velocity of light; disposition of it...
66
II. Reflection - the circumstances which govern it...
66
III. Refraction - defined, refrangibility, Illustration..
66
IV. Decomposition of Light -- how many kinds of rays ?.
67
1. Colorific rays; mode of separating them by prism, Illustration.. 67
Opinion of Wollaston, of Brewster, illuminating power.... 68
2. Calorific rays; their position, and degree of refrangibility.. 68
3. Chemical rays; their position in the spectrum..
68
1. Photographic drawing, Ills. 2. Daguerreotype described... 68
Magnetic rays; do they exist ?.
69
V. Absorption - defined..
69
1. Effect of different surfaces to absorb different colors..
69
Why are objects colored? what produces the variety ?.. 69
2. Effect of chemical constitution upon the power of absorption... 69
3. Effect of absorbing all the rays.
69
VI. Ignition and Incandescence - artificial light, of oil, lime. 70
VII. Phosphorescence - defined..
70
1. Solar phosphori; substances affected by the solar rays.
70
2. Phosphorescence from moderate heat; lime...
70
3. Animal and vegetable phosphori...
71
VIII. Photometers - object and description of.
71
Photometer of Leslie, of Count Rumford.
71
Sources of light; similar to those of caloric...
71
IX. Nature of Light - Newton's theory, undulatory theory.
71
CHAPTER III. – ELECTRICITY.
Electricity; mode of producing it..
Meaning of electrically excited, electrified, cause of it.
72
72

CONTENTS.
11
Secr. 1. COMMON ELECTRICITY.
1. Mode of exciting it; friction upon resinous bodies..
73
2. Friction upon vitreous substances; effects of..
73
3. Bodies electrified with each kind; how affected?.
73
Theorics -1. Theory of Franklin; positive and negative states.. 73
2. Theory of Du Fay; vitreous and resinous, correspond to what' 73
Inference from the last theory; law of each fluid..
74
Existence of the two fluids shown; gold leaf electrometer. 74
Non-conductors; defined, conductors, do., insulators .
74
Electrical machine described; Ills., direction of currents. 75
Induction - defined and illustrated, several conductors..
75
Theory of Induction - attraction and repulsion accounted for...... 76
Application of the Theory.
1. To the spark. 2. Stroke of lightning. 3. Leyden jar
76
4. Electrophorus; described, illustrated, its use.
77
Electrometers or Electroscopes - object of.
77
Balance electrometer; described, uses of.
78
Laws of the Accumulation of the Electric Fluid.
1. Quantity of electricity on a conductor; depends on what?. 78
2. Mode of distribution; on a sphere, ellipsoid, effect of points.... 78
3. Tendency to escape from points due to what property ? . 78
4. Law of attraction and repulsion between two electrified bodies.. 78
Sect. 2. VOLTAIC ELECTRICITY, OR GALVANISM.
History - discovery of Galvani, his theory..
78
Discovery of Volta; identity of galvanism, magnetism, etc. 79
1. Simple Voltaic Circles — đescription of..
79
Direction of the positive current; closed and broken circuit. 79
Different modes of forming voltaic circles..
80
Chemical action necessary to excite currents; form of battery 80
Calorimotor; why so called ?...
80
II. Compound Voltaic Circles — 1. Voltaic pile, described. 80
2. Best form of the galvanic battery described..
81
Size and number of plates; Hare's deflagrator...
82
Direction of the currents, relation of electricity to chem. affinity 82
Theories of Galvanism.
1. Theory of Volta. 2. Of Wollaston. 3. Of Davy.
82
Laws of the Action of Voltaic Circles.
Difference between quantity and intensity...
83
1. Relation between the exciting liquid and the zinc.
83
2. Tension and quantity of electricity in simple circles.
83
3. Mode of measuring the energy of voltaic currents.
83
Decomposing power; power of deflecting magnetic needle.... 84
4. Velocity of electricity through perfect conductors..
84
Effects of Voltaic Electricity or Galvanism.
I. Comparison of Common and Voltaic Electricity.
1. Action of voltaic electricity upon the gold leaf electrometer.... 84
2. Leyden jar charged by the battery; conditions of ......
84
3. Velocity of common and voltaic electricity ; effects of.. 85
4. Tension of voltaic electricity; striking distance. ...
85
5. Effect of voltaic electricity upon the animal system..
85
6. Deflection of magnetic needle and chemical decomposition 85
-

12
CONTENTS.
II. Power of Voltaic Currents to ignite the Metals - Illustration 85
Theory; heating power of calorimotor, and compound battery.. 85
III. Chemical Effects of Galvanism — history..
86
1. First substance decomposed; Illustration..
86
Difference between substances as ascertained by galyanism. 87
2. Transfer of chemical substances; Illustration..
87
Theory of Faraday, of Davy; electrodes, anode and cathode.. 88
Electrolyzed, electrolyte, ions, anions, and cations.
89
Results of Faraday's Investigations.
1. Decomposition by primary and secondary action.
89
2. Compounds which are electrolytes.
89
3. Simple substances form ions..
89
4. Single ions indifferent to voltaic currents.
89
5. Conditions for the decomposition of water
89
6. Substances which form electrodes..
89
7. Conditions necessary to electro-chemical decomposition. 89
8. Conduction of electric currents in cells of battery
90
9. Electro-chemical equivalents; defined...
90
Faraday's theory of electro-chemical decomposition.
90
Magnetic Effects of Electricity or Electro-Magnetism.
History; discovery of Oersted..
91
I. Influence of Voltaic Currents upon the Magnetic Needle.
1, 2, 3, 4, 5. Position of the needle in reference to voltaic currents. 91
6. Plane in which a needle moves as related to voltaic currents... 92
7. Electro-dynamic action results from what?.
92
Galvanometers or Multipliers; Illustration.
92
Revolving Rectangle ; described.......
94
II. Influence of Voltaic Currents upon soft Iron and Steel.
1. Helix and stand; description of...
94
2. Kind of pole; dependent upon what? Illustration.
95
3. Electro magnet; what weight will it sustain?.....
95
4. Magic circle; description and illustration of....
96
5. Vibrating magic circle ; description and illustration of.. 96
III. Volta-Electric Induction - Separable Helices, described... 97
IV. Magneto-Electric Induction - defined ; Illustration ...
99
Magneto-Electric Machine described......
99
ỹ Theory of Electro-Magnetism and Magneto-Electricity. 100
Application of the theory; magnetism of the earth
101
VI. Thermo-Electricity — defined; Illustration.
102
VII. Nature of Electricity.
VIII. Use of Electricity - 1. Medicinal Effects....
102
2. Application to the propelling of Machinery...
103
3. Electro-Magnetic Telegraph; principle and description. 103
4. Electrography; Electrotype, description of, theory.
104
PART SECOND.
CHEMICAL AFFINITY.
Cause of chemical changes; affinity defined....
105
Varieties of Chemical Affinity.
Simple affinity, defined, elective affinity, double elective affinity... 106

CONTENTS.
13
Circumstances which modify Affinity.
I. Cohesion — opposes chemical action, how destroyed ?. ... 107
1. By pulverization; Illustration....
107
2. By solution; solvents; saturated solution..
108
Insolubility ; its effect on affinity; Illustration.
108
3. Fusion, defined, effect......
109
II. Elasticity — its effect on affinity.
109
1. Influence on decomposition...
109
2. Effect of a high temperature upon gaseous mixtures
109
III. Quantity of Matter — its effect upon affinity
109
IV. Gravity - specific gravity, effect..
110
V. Imponderable Agents - effect of, upon affinity
110
Measure of affinity; how is the force determined ? Illustration.... 111
Effects of Affinity.
I. Change of Chemical Properties — Illustration, ...
112
II. Change of Color — Illustration; dropping tube..
112
III. Change of Form Illustration of .
113
IV. Change of Temperature — Illustration
V. Change of Specific Gravity — Illustration
113
Laws of Chemical Affinity.
I. Indefinite Proportions — defined; how many cases ?
114
II. Definite Proportions by Weight — described..
114
1st law; mode of expressing the ratio of combination...
115
Standard of comparison ; equivalent, meaning of.
115
Apparent variations of law; Illustration.
115
2nd law; constitution of each substance fixed
116
Discovery of these laws, by whom, their use.
116
III. Definite Proportions by Volume.
Compared with those by weight....
117
Atomic Theory; existence of atoms.
118
Theory of definite proportions by weight; Illustrated.
118
Atomic weight; absolute weight, magnitude and form of atoms... 118
Isomerism, defined, reconciled with definite proportions....
........ 119
Cause of chemical affinity ; electricity, second causes...
119
113
.....
PART THIRD.
PONDERABLE BODIES.
Specific gravity ; defined; standard of comparison..
121
1. Method of obtaining specific gravity of solids..
121
2. do of liquids ; aërometer, Illustration. 3. Of gases.
121
Nomenclature- description of, history of, uses.
122
1. Method of naming simple substances; table of..
122
2. Acid compounds receive what terminations, prefixes? etc. 123
3. Primary compounds not acid; prefixes and suffixes.
"...
124
Metals and alloys; hydrates...
125
4. Secondary compounds or salts; terminations, etc.
125
Notation, defined, symbols described, their use
126
Table of the symbols and equivalents of the thirteen non-metallic
elements, and the symbols of their compounds with each other 127
2

14
CONTENTS
CHAPTER I.- CHEMICAL SUBSTANCES.
CLASS I. NON-METALLIC ELEMENTS AND THEIR PRIMARY
COMPOUNDS.
SECT. 1. OXYGEN.
History of discovery; natural history, process
128
Pneumatic cistern, description of, gasometers.
129
Theory of process by manganese; by chlorate of potassa
130
Physical and chemical properties; Illustrated..
131
Effects of combustion; theory..
132
Oxigenation and oxidation; relation of oxygen to animals.
133
SECT. 2. CHLORINE.
Symb. Equiv. Sp. gr.; history of discovery.
133
Natural history ; 1. Process, theory. 2. Process, theory
134
Physical and chemical properties; Illustrated..
135
Relations to water, to hydrogen; bleaching effects.
136
Relations to animals; uses; 1. Bleaching process, theory
137
2. Disinfecting agency; dissecting rooms; diseases of skin... 138
Hypochlorous acid; Symb. Equiv. Sp. gr. process, properties.. 138
Chlorous, chloric, and perchloric acids; process, properties..... 139
SECT. 3. IODINE.
Symb. Equiv. Sp. gr.; history of discovery; natural history 140
Process; Physical and chemical properties, tests, uses.
142
Iodic acid; process, properties; periodic, and chloriodic acids. 143
SECT. 4. BROMINE.
Symb. Equiv. Sp. gr.; history of discovery
Natural history ; process, physical and chem. properties illustrated 144
Bromic acid; properties, chloride of bromine; bromide of iodine... 145
SECT. 5. FLUORINE.
Symb. Equiv.; natural history, properties as far as known ...... 145
SECT. 6. HYDROGEN.
Symb. Equiv. Sp. gr.; history; nat. history, processes.
146
1. By heated iron; Illustration...
146
2. By zinc and acidulated water; theory, impurities..
147
Physical properties; soap bubbles, method of filling gas bags.. 148
Aërostation ; description of balloons..
149
Chemical properties; illustrated, theory, relations to animals.. 149
Protoxide of hydrogen, water ; Symb. Equiv. Sp. gr., process..
150
Physical and chem. properties illustrated, solvent properties..
151
Composition, eudiometer described; compound blowpipe
Heat produced by blow pipe; binoxide of hydrogen, properties
153
Hydrochloric acid ; history, natural history, process, theory
Woulfe's Appa., physical and chemical properties, illustrated 155
Constitution; uses and impurities....
156
Hydriodic acid; Symb. Eq. Sp. gr.; process, properties, tests.
156
Hydrobromic acid; Symb. Equiv. Sp. gr.; properties..
157
Hydrofluoric acid ; history, process, theory, uses illustrated.
143
152
154
157

CONTENTS.
15
...
SECT. 7. NITROGEN.
Symb. Equiv. Sp. gr.; history of discovery..
158
Natural history; process, 1. By phosphorus..
159
2. By sulphur and iron. 3. By muscle and nitric acid.
159
Theory of process; physical and chemical properties.
159
Effect on combustion ; respiration, its nature..
159
Common air; physical properties, elasticity illustrated.
160
Pressure of the air; how discovered ?.
160
Extent and composition of the atmosphere.
161
Theory of the diffusion of gases of different sp. gr.; Illustrated. 162
Impurities of the air; eudiometry, uses of the air.
163
Protoxide of nitrogen; history, process, theory of, properties. 163
Respiration of; effect upon animals.
164
Binoxide of nitrogen ; history of discovery, process.
164
Theory of process, properties, illustrated, affinity for water. 165
Hyponitrous acid; properties, nitrous acid, history
165
Processes, properties, respiration of. Nitric acid, history.
166
Process, illustrated, impurities, properties..
167
Chemical properties, illustrated, uses...
168
Nitrohydrochloric acid, aqua regia; nitrohydrofluoric acid. 168
Quadrochloride of nitrogen; process, properties.
169
Teriodide of nitrogen; Symb. Equiv. properties.
169
Ammonia ; history, process, theory of, properties, tests, uses. 170
SECT. 8. CARBON.
Symb. Equiv. Sp. gr.; nat. hist.; the diamond, where found, uses 172
Plumbago, anthracite, bituminous coal, peat, and lamp-black. 173
Charcoal; 1. Process by slow combination of wood.
173
2. By distillation of wood. 3. By hot sand.
173
'Properties, hardness, theory of its absorbing properties.
174
Clarifying agency, combustion of, durability of, infusibility, uses 175
Carbonic oxide; carbonic acid, history of discovery..
176
Nat. hist. process, theory of, relation to flame, to water.
177
Fermenting liquors, best test of carbonic acid, solidification of. 178
Relations to animals, choke-damp......
179
Sources of carbonic acid, respiration explained.
180
Chloride, perchloride of carbon, Chloro-carbonic acid, chloral. 181
Periodide and protiodide of, bromide of carbon, properties... 181
Dicarburet of hydrogen; history, process, properties, Illustration.. 182
Olefiant gas, or 2 carburet of hydrogen, Symb. Equiv. Sp.gr.. 182
History, process, theory of, properties, Ills.; action of chlorine. 183
4 Carburet of H. etherine, & carburet, parriffine, 'eupione, naphtha. . 183
Naphthaline, paranapthaline, idrialine, camphene, and citrene 184
Gas lights; history, process, portable gas, fire-damp..
.... 184
Efforts of Davy; discovery of Wollaston.
186
Effect of gauze wire upon flame; safety lamp, construction, etc... 187
Bicarburet of nitrogen or cyanogen, history, process, properties... 188
Cyanic, fulminic, and cyanuric acids
188
Paracyanuric acid, chloride, bichloride, and bromide of cyanogen... 189
Hydrocyanic acid. Process, properties
189
SECT. 9. SULPHUR.
Symb. Equiv. Sp. gr.; nat. hist., process; Illus., sublimation.. 190
Properties, effect of heat, structure, impurities, uses.....
191
Hyposulphurous and sulphurous acids, process, theory, crucibles. 192

16
CONTENTS.
197
Hyposulphuric acid, process, properties; sulphuric acid, process 194
Hydrous sulphuric acid, manufacture of, theory...
195
Properties, affinity for water; Illus, decomposition, tests.
196
Uses; dichloride, iodide, and bromide of sulphur.
Hydrosulphuric acid, process, theory of..
197
Properties, liquid form, tests, uses; Illustration.
198
Production of sulphur; Illustration; hydrosulphurous acid..
199
Bisulphuret of carbon, or alcohol of sulphur, carbosulphuric acid.. 199
Sulphuret and bisulphuret of cyanogen...
200
Hydrosulphocyanic and cyanohydrosulphuric acids.
200
SECT. 10. PHOSPHORUS.
Symb. Equiv. Sp. gr. ; history, source
200
Process, properties, inflammability; Illustrated.
201
Theory of the heat and light, relation to animals.
202
Oxide of phosphorus; hypophosphorous acid..
202
Phosphorous acid, process ; phosphoric acids.
203
Phosphoric acid, process, properties; pyro and meta phosp. acids.. 204
Sesquichloride of phosphorus, Symb. Equiv., process, properties.. 204
Perchloride, protiodide, sesquiodide, and periodide of phosphorus.. 205
Protobromide, perbromide, phosphuret of hydrogen, properties..... 205
Perphosphuret of hydrogen, process, properties, inflammability of, 206
Jack o' the lantern ; sulphuret of phosphorus....
SECT. 11. BORON.
Discovery ; process, property....
207
Boracic acid; source, process, evaporating dishes..
208
Terchloride of boron ; fluoboric acid, suphuret of boron.
209
SECT. 12. SELENIUM.
Discovery, oxide of, selenious acid, properties.....
210
Selenic acid ; chloride and bromide of, hydroselenic acid.
211
SECT. 13. SILICON.
Symb. Eq;, discovery, properties, silicic acid, nat. history, process, 212
Chloride, bromide, and sulphuret of silicon, fluosilicic acid
213
207
........
CHAPTER II.
Class II. METALS, WITH THEIR PRIMARY COMPOUNDS.
General properties of metals, metallic lustre.
214
Sp. gr. of; malleability defined
214
1. Ductility, tenacity. 2. Hardness. 3. Structure. 4. Fusibility 215
5. Volatility. 6. Affinity for other simple bodies.
215
Combustibility; number and date of discovery.
217
Classification of the metals....
217, 218
.....
ORDER I. Metals which, by Oxidation, yield Alkalies Earths.
Sect. 1. METALLIC BASES OF THE ALKALIES.
Potassium; history of discovery...
218
Process, properties, combustibility ; Illustration.
219
Protoxide of potassium; properties, hydrate of; Ills., tests. 220
Potassa; teroxide, iodide, bromide, fluoride, and chloride of.. 221
Hyduret, nituret, sulphurets, phosphurets and seleniuret of..
១១១

CONTENTS.
17
Cyanuret, properties; sulphocyanuret of.
223
Sodium ; Symb. Equiv. Sp. gr...
223
Process, properties, affinity for oxygen,.
223
Protoxide of soda, process; sesquioxide, chloride of, origin, uses. 224
Iodide, bromide, fluoride, sulphuret, and cyanuret of.
225
Chloride of soda, alloys of sodium and potassium..
225
Lithium; protoxide of, or lithia, process, properties, fluoride of... 226
SECT. 2. METALLIC BASES OF THE ALKALINE EARTHS.
Barium; protoxide of, or baryta, how distinguished...
227
Binoxide, chloride, iodide, bromide, fluoride, sulphuret.
228
Cyanuret, sulphocyanuret, phosphuret of....
229
Strontium ; protoxide, strontia, peroxide and chloride of
229
Iodide of, fluoride, protosulphuret
230
Calcium ; protoxide of, or lime, peroxide, chloride, uses; iodide.. 230
Bromide, fluoride, bisulphuret, phosphuret of, chloride of lime.. 231
Magnesium ; discovery, process, properties.
232
Protoxide of, or magnesia, properties, uses.
233
Chloride of, iodide, bromide, fluoride...
233
SECT. 3. METALLIC BASES OF THE EARTHS.
Aluminium ; discovery, process, properties, sesquioxide ofe.
234
Sesquichloride, sesquisulphuret, sesquiphosphuret.
Glucinium ; Symb. Equiv. Sp. gr.; discovery, properties.
236
Sesquioxide of, glucina, discovery, process, properties.
236
Yttrium ; Symb. Equiv.; process, properties...
236
Thorium ; Symb. Equiv. ; process, properties, protoxide, do. 237
Zirconium; Symb. Equiv. ; discovery, process, properties..
237
235
ORDER II. Metals the Oxides of which are neither Alkalies nor
Earths.
SECT. 1. METALS WHICH DECOMPOSE WATER AT A RED HEAT.
Manganese; history, process, properțies, protoxide of, properties.. 238
Sesquioxide, peroxide, red oxide, varvicite, manganic acid. 239
Perchloride, perfluoride, protosulphuret, and cyanuret, alloys..... 240
Iron ; Symb. Eq. Sp. gr.; history, nat. history, process, properties 241
Protoxide of; process, properties, uses,
242
Peroxide of; process, properties, etc.; black oxide, source, tests.. 243
Protochloride; perchloride, protiodide, properties...
243
Periodide, protobromide, perfluoride, protosulphuret.
244
Sesquisulphuret, magnetic iron pvrites, tetrasulphuret. .
244
Diphosphuret, perphosphuret, carburets, graphite, cast iron, steel. 245
Protocyanuret, protosulphocyanuret, sesquisulphocyanuret..... 245
Zinc; Symb. Eq. Sp. gr.; history, nat. history, process, properties. 246
Protoxide, hydrated oxide, chloride, iodide, bromide, fluoride, etc 247
Cadmium ; oxide, chloride, iodide, sulphuret, and phosphuret of.. 247
Tin; process, properties, stream tin, tin foil, protoxide of tin...... 249
Sesqui and binoxide, proto and bichloride, proto and biniodide of.. 250
Protosulphuret, sesquisulphuret, bisulphuret, and tersulphuret of. 251
Cobalt; protoxide, zaffre-oxide, and peroxide of, sympathetic ink. 252
Protosulphuret, sesquisulphuret, bisulphuret, and subphosphuret of 253
Nickel ; properties, protoxide, sesquioxide, and chloride of... 253
Protosulphuret, disulphuret, subphosphuret, and cyanuret of.. 254
2 *

18
CONTENTS
...
SECT. 2. METALS WHICH DO NOT DECOMPOSE WATER AT ANY TEM-
PERATURE, AND THE OXIDES OF WHICH ARE NOT REDUCED TO THE
METALLIC STATE BY THE SOLE ACTION OF HEAT.
Arsenic; discovery, nat. history, fly powder, detonations, uses....
254
Arsenious acid; properties, tests, poisonous properties.
256
Arsenic acid ; properties, protochloride, and sesquichloride of.... 257
Periodide, protohyduret, and sesquibromide of..
258
Arseniureted hydrogen'; proto, sesqui, and persulphuret of.. 258
Chromium, properties, sesquioxide of; chromic acid, properties... 258
Sesqui, ter, and oxychlorides of, sesqui, and terfluorides of.. 260
Sesquisulphuret, protosulphuret...
260
Vanadium, proto, and binoxide of; vanadic acid, properties. 260
Molybdenum, binoxide, bi, and terchloride of; molybdic acid 261
Tungsten, binoxide of; tungstic acid, bichloride of....
262
Columbium, binoxide of; columbic acid, process, properties.. 263
Antimony, sesquioxide of; antimonous and antimonic acids. 263
Sesqui, and oxysulphurets of; kermes mineral, alloys, pewter.... 265
Uranium ; protoxide, sesquioxide, proto, and sesquichlorides of. 265
Cerium; proto, and sesquioxide of, proto and sesqui chlorides of.. 266
Bismuth ; protoxide, pearl white, sesquioxide, and chloride of.... 266
Titanium, oxide of; titanic acid, anatase and rutile.....
267
Tellurium, oxide of; tellurous acid, chloride, sulphurets.
268
Copper; nat. history, process, properties, uses, red or dioxide of.. 269
Black, or protoxide of, copper black, properties, binoxide of..... 270
Dichloride, chloride, diniodide, sulphuret, copper pyrites, tests.... 270
Alloys; brass, Dutch gold, pinchbeck, bell-metal, bronze
270
Lead; protoxide, red oxide, peroxide, chloride, and iodide of..... 271
Alloys of lead; common pewter, fine solder, pot metal.... 271
Sect. 3. METALS THE OXIDES OF
METALLIC STATE BY A RED HEAT.
Mercury; cinnabar, properties, protoxide of, properties.... 273
Binoxide, process, properties; protochloride, process, properties.. 274
Bichloride of mercury, or corrosive sublimate, process, properties. 274
Protosulphuret, bisulphuret, properties, cinnabar, ethiops mineral. 275
Bicyanuret of; amalgams, described, protiodide, etc...
275
Silver ; process, properties, cupellation, uses
276
Oxide, fulminating silver, torpedoes, chloride of.
277
Iodide, sulphuret, cyanuret, and alloys of....
277
Gold ; nat, history, process, quartation, properties
278
Protoxide, binoxide, and teroxide of; fulminating gold..
279
Proto, and terchlorides of; alloys, water-gilding, gold-powder.. 280
Platinum; properties, spongy platinum, proto, and binoxide of.. 281
Sequioxide, protochloride, bichloride of..
281
Protiodide, biniodide, protosulphuret, and bisulphuret of,
282
Fulminating platinum, palladium, rhodium.
282
Osmium, osmic acid, iridium, latanium
282
WHICH ARE
REDUCED
TO THE
CHAPTER III.
CLASS III. Salts, OR SECONDARY COMPOUNDS.
Sect. 1. CRYSTALLIZATION.
Crystal and crystalography defined .....
283
Planes, faces, edges, angles, primary and secondary forms of ..... 284

CONTENTS.
19
284
292
I. Prisms have six-sided or four-sided bases..
284
(1.) Right Prisms - 1. Hexahedron, or cube..
284
2, 3. Right square and right rectangular prisms.
4,5. Right rhombic and right rhomboidal prisms.
284
6. Regular hexagonal prism...
285
(2.) Oblique Prisms — 7. Rhombohedron. 8. Obl. rhombic prism 285
9. Oblique rectangular prism. 10. Oblique rhomboidal prism.... 285
II. Octohedrons - 11. Regular octohedron. 12. Square octoh. 285
13. Rectangular octohedrons. 14. Rhombic octohedrons.. 286
III. Dodecahedrons — 15. Rhombic dodecahedron
286
Secondary forms; cleavage defined, faces and direction of.. 286
Isomorphism, crystallogenic attraction, water of crystallization.... 287
SECT. 2. OXY-SALTS.
General formula for the composition of the salts..
288
1. Sulphates - of potassa, soda, Glauber's salts..
289
Of lithia, ammonia, baryta, strontia, lime, gypsum
289
Of magnesia, alumina, manganese, protoxide of iron.
291
Of protoxide of zinc, (white vitriol) nickel, cobalt, chromium..
Of copper, (blue vitriol,) mercury (turpeth mineral,) silver... 293
Nitro-sulphuric acid, sulphate of soda, lime, potassa, and magnesia 294
Ammonia, soda, iron, chrome, and mangan. alums. 2. Sulphites 294
3. Nitrates — of potassa, (nitre beds,) of soda, ammonia..
295
Of baryta; pyrotechny, green-fire..
296
Of strontia, (red-fire,) lime, magnesia, protoxide of copper..
297
Nitrate and dinitrate of protoxide of lead, of mercury, of silver. 297
Properties, illustration, lunar caustic, indelible ink.
298
4. Nitrites. 5. Chlorates — of potassa, properties...
299
Lucifer matches, chlorate of baryta, process, properties..
300
6. Perchlorates. 7. Chlorites. 8. Hypochlorites. 9. Iodates 301
Iodate of potassa. 10. Bromates. 11. Phosphates .
302
I. Phosphates -- triphosph., diphosph., and phosph. of potassa 302
Of soda and ammonia, ammonia, lime, magnesia, amm. and mag. 303
Triphosphate of silver. — II. Pyrophosphates.
304
III. Metaphosphates — of soda, baryta, silver, etc.
305
12. Arseniates; of soda, table of compounds.
305
13. Arsenites; general properties, tests.
306
14. Chromates; of potassa, lead. 15. Borates; of soda, borax. 307
16. Carbonates; of potassa, soda, ammonia.
308
Of baryta, strontia, lime, magnesia.
310
Of iron, copper, lead, white lead, mercury.
311
17. Double Carbonates ..
312
18. Silicates; simple, bi, tri, and quadri silicates.
312
SECT. 3. ORDER II. HYDRO-SALTS; acids of.
314
SECT. 4. ORDER III. SULPHUR-SALTs; constitution of.
316
SECT. 5. ORDER IV. HALOID-SALTS; constitution and descrip. of 319
321
CHAPTER IV.- NATURAL SUBSTANCES.
ORGANIC CHEMISTRY.
Nature of organic compared with inorganic compounds..
Decomposition of, formation of, relation to inorganic bodies..
VEGETABLE CHEMISTRY.
Proximate principles, proximate analysis, ultimate analysis...
Results of Wöhler, Liebig, Pelouse, and Dumas.
322
322
323

20
CONTENTS.
323
1. Amides, or Amidets; theory, meaning of oxamide and amide... 323
2. Benzoyl; theory. 3. Ethers; theory, radical of the ethers
4. Pyracids; theory. 5. Theory of substitutions ; dehydrogenizing 323
Sect. 1. VEGETABLE Acids; general properties, description of... 323
Sect. 2. VEGETABLE ALKALIES; constitution and description of 332
Sect. 3. NEUTRAL SUBSTANCES; constitution and description of 334
SECT. 4. Oils ; fixed and volatile oils described...
337
Sect. 5. SPIRITUOUS AND ETHEREAL SUBSTANCES; description of 341
Sect. 6. COLORING MATTERS; lakes, dyes, etc.
343
Secr. 7. FERMENTATION; saccharine, vinous, putrefactive
345
Sect. 8. GERMINATION; growth and food of plants....
347
CHAPTER V.- ANIMAL CHEMISTRY.
SECT. 1. PROXIM. PRINCIPLES NEITHER ACID NOR OLEAGINOUS.... 349
SECT. 2. ANIMAL Acids; general principles and description of.... 349
SECT. 3. ANIMAL OILS AND Fars; description of.
350
SECT. 4. COMPLEX ANIMAL SUBSTANCES; blood, chyle, etc. 351
CHAPTER VI.- ANALYTICAL CHEMISTRY.
SECT. 1. ANALYSIS OF MIXED GASES.
1. Gaseous mixtures containing oxygen.
356
2. Gaseous mixtures containing nitrogen
357
3. Gaseous mixtures containing carbonic acid..
357
4. Gaseous mixtures containing hydrogen and other infl'le bodies 357
SECT. 2. ANALYSIS OF MINERALS AND METALLIC ORES.
I. Analysis of minerals soluble in acids, with effervescence.... 357
II. Analysis of minerals insoluble in acids..
358
III. Analysis of minerals containing carbonate of lime.
358
Silica, oxide of iron and magnesia.
358
IV. Tests of the metallic ores.
359
1. Ores of antimony. 2. Of lead. 3. Of mercury.
359
4. Ores of zinc. 5. Of tin. 6. Of iron. 7. Of copper. 8. Of silver 359
9. Ores of gold and platinum; earthy sulphates ..
359
Sect. 3. ANALYSIS OF MINERAL WATERS.
1. Rain water. 2. Well and spring water. 3. Acidulous springs. 350
4. Alkaline springs. 5. Chalybeate and saline springs.
360
6. Sulphureted springs; detection of hydrosulphuric acid
361
Test tubes; filtration; filtering process; supports
361
APPENDIX; Wollaston's synoptic scale of chemical equivalents... 364
Cementing; various cements
369
GLOSSARY...
373
GENERAL INDEX.
385
INDEX OF PLATES.
396
....
NOTE.
F. and Fahr. for Fahrenheit's thermometer. - T. refers to Turner's Chemistry. -
W. to Webster's Chemistry, 3rd Ed. - L. to Liebig. - B. to Berzelius. - Eq. and
Equiv. for Equivalent. - Symb. for Symbol or formula.

INTRODUCTION.
SCIENCE is classified knowledge. Physical or Natural
Science is the knowledge of the material world. The defi-
nition of matter embraces two properties, without which we
cannot even conceive of its existence. These properties are
extension, which includes length, breadth, and thickness, and
impenetrability, or the impossibility that any two portions of
mátter should occupy the same space.
There are other prop-
erties, which do not necessarily enter into our conception of
matter, but which universally belong to it, such as gravitation,
inertia, mobility, etc.
Natural Science consists of three great branches, which
are characterized chiefly by peculiar methods of investigation.
I. NATURAL PHILOSOPHY employs the method of general
physics; that is, it observes, for example, the gravitation of a
stone let fall to the ground, and, neglecting the other proper-
ties of the stone, observes the same property in other bodies,
and generalizes the phenomena under a law. It is therefore
conversant with general laws, but not with all the general
laws, for its observation is restricted to the phenomena of
perceptible distance. By this we mean that it leaves to the
chemist all those phenomena which arise from the action of
the invisible atoms of matter upon each other, and attends
only to those which belong to bodies of perceptible size.
With a few observations and experiments for data, it depends
for discovery upon calculation, and its character is therefore
eminently mathematical. Its object is a knowledge of the
laws of motions and forces,

22
INTRODUCTION.
II. CHEMISTRY employs, in part, the method of general
physics, and, in part, the method of particular physics. By
the latter, we mean that its object is, in part, to describe
particular bodies or substances, by giving an account of the
various properties of each one, before calling the attention to
another. It invites our attention to the phenomena only of
imperceptible distance. With some aid from calculation and
observation, it depends for discovery chiefly upon experiment,
and has therefore been called Experimental Philosophy. Its
object is a knowledge of the constitution of substances and
of the phenomena attending a change of constitution,
III. NATURAL HISTORY employs the method of particular
physics, observes the phenomena of perceptible distance, and
depends for discovery chiefly upon observation, with some aid
from experiment and calculation. Its object is a knowledge
of natural objects. It embraces Zoology, or the study of
animals; Botany, or the study of plants; Mineralogy, which
treats of minerals; and Geology, which describes and accounts
for the condition of the crust of the earth. The physiology
of plants and animals is sometimes referred to Botany and
Zoölogy respectively, and sometimes regarded as a fourth
distinct branch of Natural Science.
Plan of the Work.
I. The constitution and the changes of the constitution
of substances are intimately connected with the agency of
heat, light, electricity, and galvanism, of which the two last-
mentioned agents are now known to be identical. Whether
these agents are themselves substances, or mere properties
of matter, is not certainly known. They have no appreciable
weight, and are therefore called imponderable agents. They
will form the subject of the First Part.
II. The Second Part will treat of chemical affinity. This
is the great agent to which all the phenomena of chemistry are
referred. It is distinguished from gravitation by exerting its
force between the particles of bodies, and from cohesion by

INTRODUCTION.
23
acting only between particles of different kinds or in different
states of electricity. For example, a block of marble is made
up
of very small particles, each one of which is similar to the
whole; but each of these particles is composed of two others,
carbonic acid and lime, different from each other, and from
marble. When these particles of carbonic acid and lime are
brought into close proximity to each other, they assume dif.
ferent electrical states, and combine by the force of chemical
ajinity, and form particles of marble. Cohesion then attaches
them to each other as fast as formed, and thus the block is
formed. Gravity acts
upon
it in the mass. The carbonic
acid and the lime are called the component particles. When
these combine, they form the integrant particles. Hence
Chemistry is defined to be that science the object of which is,
to examine the relations which affinity establishes between
bodies, ascertain with precision the nature and constitution of
the compounds it produces, and determine the laws by which
its action is regulated.
It is the object of Natural Philosophy to examine the sen-
sible motions and mutual relations of bodies in masses, con-
sequent upon gravity.
Chemistry investigates the constitution and qualities of
bodies as they stand related to chemical affinity.
III. The Third Part will comprise a description of sub-
stances, which will be arranged in two general divisions : The
first will einbrace the elements and those compound sub-
stances which can be formed in the laboratory. These are
chemical substances. The second division will embrace
natural substances, or animal, vegetable, and mineral com-
pounds, which have been formed by natural agencies.
Chemists divide substances into simple and compound. A
simple substance is one which never has been separated into
two kinds of matter, or which has never been decomposed.
There are about fifty-four simple substances. A compound
body is one which is composed of two or more simple bodies,
of which there are many thousands.

24
INTRODUCTION.
The composition of bodies is ascertained by two methods :
1. By separating the body into its simple elements, which
is called analysis ; and,
2. By causing the elements to combine and form the body,
which is called synthesis.
Chemical substances are arranged in three general di-
visions :
I. Non-metallic elements, and their primary compounds
with each other.
II. Metals, and their primary compounds.
III. Salts, or secondary compounds.
In the arrangement of the simple substances and their
primary compounds, the logical order is pursued ; that is,
after describing one substance, the rest are described with the
compounds which they form with those previously described.
The Salts are divided into four orders:
I. Oxy-salts, or those salts the acid or base of which is an
oxidized substance.
II. Hydro-salts. This order includes no salt, the acid or
base of which does not contain hydrogen.
III. Sulphur-salts, or those salts, of which the electro-
positive or electro-negative ingredient is a sulphuret.
IV. Haloid-salts, including none, the electro-positive or
electro-negative ingredient of which is not haloidal, i. e.,
analogous in composition to sea salt.

CHEMISTRY.
PART 1.
IMPONDERABLE AGENTS.
CHAPTER 1.- CALORIC.
sense.
The word heat has two meanings. It is the sensation whici
we experience when we touch a hot body; or it is the cause
of the sensation. In the first sense, it is an effect producer
only upon animals. In the second, it is the cause of a great
variety of effects in the mineral, vegetable, and animal king-
doms. The word caloric (Lat. calor) is used in the latter
Where there can be no ambiguity, the word heat is
often retained in the same sense. Caloric exists in a free
or sensible, and in a latent or insensible state.
1. Sensible Caloric. In this state, caloric is capable of
producing the sensation of heat, and of expanding bodies.
It has sometimes been called the caloric of temperature.
Temperature expresses the power of exciting the sensation,
and is proportioned to the quantity of free caloric. A high
temperature is owing to a great quantity, and a low temper-
ature to a small quantity.
2. Insensible Caloric. In this condition, caloric produces
no sensation, but exists, often in great quantity, in substances,
without affecting their temperature, and appears to be com-
bined with them.
3

26
Conduction of Caloric.
SECT. 1. SENSIBLE CALORIC.
Communication of Sensible Caloric.
The most important property of free caloric is its tendency
to an equilibrium; that is, a tendency to escape from hotter
to colder bodies, so as to produce in all the same degree
of temperature. This communication takes place in two
ways — by conduction, and by radiation.
I. Conduction. By this is meant the passage of caloric
through a body, from particle to particle.
Experiment. Place bits of phosphorus along an iron rod, and apply
heat to one end of it; the progress of the caloric will be indicated by
its igniting the phosphorus.
The property in the body, on which this transmission
depends, is called the conducting power.
If one end of an iron rod be held in the fire, the sensation
of heat will soon be experienced at the other extremity, in
consequence of the conduction of caloric from particle to
particle along the rod. If the rod be of glass, it will be
much longer before any heat is felt. Hence different sub-
stances conduct caloric with different degrees of facility,
If two bodies are in contact, caloric may be conducted
from one to the other. The more perfect the contact, other
things being equal, the more rapid the conduction. This
is the reason why a heated body, when grasped firmly by the
hand, will burn it more severely than when held loosely.
The contact of two solids with each other, or of a solid
with a gas, is not so perfect as that of a solid with a liquid;
and hence the communication is more rapid in the latter
When liquids are mixed with liquids, or gases with
gases, the contact is still more perfect, and the caloric is
more rapidly diffused through the whole.
From the two facts which have been mentioned, it follows
that the rapidity of conduction from a heated to a cold body
depends upon the conducting power of each substance, and
the closeness of contact.
case.

Conducting Power of Solids.
27
Exp. Plunge a heated iron into cold water, and again, equally heated,
into mercury. In the latter case, it will cool more rapidly; for, while
the heat is conducted with equal facility in both cases from the interior
to the surface, it is taken from the surface more rapidly by the mercury
than by the water.
Exp. Plunge into mercury two equal balls, one of iron and the other
of marble, heated to the same temperature. The iron ball will cool the
more rapidly, because the caloric is more freely conducted from its in
terior to its surface.
Exp. Plunge the iron ball into mercury, and the marble into water.
The iron will cool more rapidly, for two reasons; the heat will come
to its surface more freely, and be taken off by the mercury more
rapidly, iron and mercury being each better conductors than marble
or water.
Of the different forms of matter, solids are better conduct-
ors of caloric than liquids, and liquids than gases.
1. Conducting Power of Solids. This power varies greatly
in different solids.
This fact may be shown by
Fig. 1.
the conductometer, (Fig. 1)
which consists of a tin or iron
case, in which there may be
inserted small solid cylinders of
the same dimensions, but of
different materials.
A
Exp. Place upon one end of each, bits of phosphorus, and apply to
the other ends the same degree of heat by placing the case over boiling
water. The caloric will be conducted along from one extremity of
each to the other, and the substance which conducts most rapidly will
first ignite the phosphorus.
According to the experiments of M. Despretz, if the con-
ducting power of
Gold be represented by 1000
Tin 303.9
Silver will be
973 Lead 179.6
Copper
898.2 Marble .. 23.6
Platinum
331 Porcelain 12.2
Iron
374.3 Fine clay . 11.4
Zinc
368
Metals generally are the best conductors of caloric, while
furs and porous substances are the poorest conductors.
The conducting power of stones is next to that of the
metals, and crystalline stones are better conductors than the
uncrystallized.

28
Caloric - Conducting Power of Liquids.
The earths generally are bad conductors. Bricks, glass,
dry wood, charcoal, conduct less; and feathers, silk hair,
and down, least of all.
Among the latter, the finer the fibre, the less its conducting
power. Hence the utility of fine wool and furs in the winter,
to prevent the escape of caloric from the body; while, in the
summer, we select those substances for our clothing which
have a coarser fibre. In this we see the benevolence of God
in furnishing those animals which inhabit the colder regions
of the earth, with finer clothing than those which inhabit
warm climates. The fur of animals is also finer in winter
than in summer.
Snow and ice are poor conductors; and hence, by a wise
constitution, the earth in winter is rarely frozen to any con-
siderable depth. The ice and snow keep it warm by pre-
venting its vital heat from escaping.
The conducting powers of solids are generally in the ratio
of their densities; especially of the same substance. In-
crease of density will increase the conducting power, and
vice versa.
2. Conducting Power of Liquids. In liquids the conduct-
ing power is much less than in solids. So feeble is it, that
some, among whom is Count Rumford, have denied its ex-
istence. But, notwithstanding the slight conducting power
of liquids, heat can be diffused through them much more
rapidly than through solids. This is effected by a motion
among the particles, which brings them successively into
contact with the heated surface.
If, for example, heat is applied to the Fig. 2.
bottom of a vessel of water, (Fig. 2,) those
particles of water which are in contact
with the bottom, are soon heated, and con-
sequently expanded and made lighter, so
that they are forced to rise, in order to give
place to the heavier cold particles, which
fall to the bottom. The latter, in turn, are
heated, and give place to others; and thus
the process continues until two currents
are established, the one of heated particles
rising to the surface, and the other of colder particles falling
to the bottom. In this way all the water is soon heated by

Conducting Power of Gases.
29
direct contact with the bottom.* A little powdered amber or
gum copal, put into the water, will indicate the direction
of the currents.
But if heat be applied to the top of the ves- Fig. 3.
sel, the water at the bottom will remain cold,
while that at the top is boiling.
Exp. Suspend in a tin cup a hot cannon ball on the
top of a jar of water, (Fig. 3,) at the bottom of which is
a piece of ice. The water will boil rapidly at the top,
while the ice remains unmelted. But if the ice is
placed upon the top, and heat applied to the bottom, Fig. 4.
the ice will all be melted before the water can be
made to boil.
Exp. Or, burn ether (Fig. 4) on the top of a glass
funnel filled with water, into which an air thermome-
ter is cemented. The thermometer will not be sensibly
affected. A ring of tin should be placed on the top of
the water, within half an inch of the sides of the fun-
nel; and the ether, poured within this ring, will burn,
without the risk of breaking the glass.
It has, however, been shown that liquids do
conduct heat, independently of any intestine
motion. But the
power
is
very slight.
3. Conducting Power of Gases. Gases and vapors conduct
heat very slightly, if at all. Their particles move with so
much facility when heated, that it is difficult to arrive at any
satisfactory results on this subject. Heat may be diffused
through them in the same manner as through liquids, but
with much greater rapidity.
II. Radiation. If a heated body be suspended in the air,
its caloric will be diffused both by the currents of air, which
circulate to and from its surface, and, in a slight degree, by
the conducting power of the air. But if the hand be placed
beneath the heated body, a sensation of heat will be perceived,
which is not due to either of these causes, but to the direct
passage of the rays through the air.
For if a heated body be suspended in a vacuum, entirely
removed from conducting substances, it will rapidly cool
* A Florence flask, or a glass tube, may be used for this experiment,
and the water heated by a common tin lamp filled with alcohol.
3*

30
Radiation of Caloric
down to the same temperature with surro
rrounding bodies.
Caloric, which is thus thrown off from heated bodies in all
directions, like rays of light from the sun, is called radiant
caloric.
1. If a thermometer be placed at the distance of two
inches from a heated body, it will be affected but one fourth
as much as at the distance of one inch; if it be placed at the
distance of three inches, one ninth as much; if at four inches,
one sixteenth as much; at five inches, one twenty-fifth, etc.
Hence, in consequence of a radiation in all directions, the
intensity of the heat is in the inverse ratio of the square of
the distance. The intensity of light and the force of gravi-
tation follow the same law.
2. The degree of radiation, and consequently the intensity
of radiant heat, are greatly modified by the kind of surface.
Bright, polished surfaces do not radiate so rapidly as those
which are dark and rough.
Fig. 5.
Exp. Take a square
tin cup, a, (Fig. 5,) one
side of which is bright,
another rough, a third
painted black, and the
fourth painted white.
Fill it with hot water,
a
and bring an air ther-
mometer, c, near each
side. The rough and
black surfaces will
radiate more rapidly
than those which are
white and polished.
If the rays of caloric are brought to a focus by the mirror b, the dif-
ferent degrees of caloric from the several surfaces will be much more
evident.*
The greater radiating power of rough surfaces is supposed
to be due to the great number of radiating points; or perhaps
* The late experiments of Melloni do not seem to confirm this view.
By using a cup of marble, whose external surfaces were differently
prepared, the first polished, the second sinooth but tarnished, the third
streaked in one direction, and the fourth in two, crossing each other at
right angles, and filling the vessel with hot water, each of the sides
projected the same quantity of radiant caloric. — Edin. Philos. Jour
XXVI. 299.

Reflection of Caloric.
31
it may be owing to the greater amount of surface exposed
within a given space.
3. The rapidity of radiation also depends upon the differ-
ence between the temperature of the radiating body and that
of the surrounding bodies. Hence, with a given temperature
of the latter, the higher the temperature of the radiating body,
the more rapid the radiation.
III. Disposition of radiant Caloric. Radiant caloric passes
in right lines through a vacuum, through air and gases, with-
out any apparent obstruction ; but when it falls upon solid or
liquid substancês, it is disposed of in three ways: 1. It re-
bounds from the surface, or is reflected. 2. It enters into the
substance, or is absorbed. 3. It passes through the body, or
is transmitted.
1. Reflection of Caloric. When radiant caloric falls upon
bright, polished surfaces, it is mostly reflected in lines, which
form angles with a perpendicular to the reflecting surface,
equal to the angles formed by the same perpendicular, and
the lines in which the rays went to the surface.
Thus, let BAC (Fig. 6) be a smooth sur- Fig. 6.
face, S the incident ray, P the perpendicular o R
to the surface, and R the reflected ray. The
angle RAP is equal to the angle PAS. The
angle PAS is called the angle of incidence, A
-P
and PAR the angle of reflection. Light fol-
lows the same law. If a concave surface be
used, the rays of caloric will be reflected and
BI
S
brought to a focus. This may be shown by
two metallic mirrors, as in Fig. 7. a and
Fig. 7.

32
Absorption of Caloric.
are two reflectors of polished metal, (brass or tin,) 12 inches
in diameter, and segments of a sphere of 9 inches radius.
Place them at any convenient distance apart, from 6 to 12
feet. If a heated ball of iron be placed in the focus of a, and
an air thermometer in that of 6, the caloric will first radiate
to the surface of a, and then be reflected in parallel lines to
the surface of b, whence the rays will be reflected to the focus
in which the bulb of the thermometer is placed, and will
cause the liquid to descend, showing an increase of tempera-
ture. If phosphorus be placed in the focus, it will be ignited,
If snow be substituted for the heated ball, the thermometer
will show, by the rise of the liquid, a diminution of tempera-
ture. As bright, polished surfaces reflect most of the calorific
rays which fall upon them, we can see the reason why they
are not easily heated.
2. Absorption of Caloric. When radiant caloric falls upon
rough, opaque substances, it is mostly absorbed; that is, it
passes directly into the substance, and renders it hot: some
of the rays are also reflected.
The power of absorption, as well as of radiation and re-
flection, depends mostly upon the surface. Those surfaces
which reflect most, radiate and absorb least, and those which
radiate and absorb most, reflect least. The power of absorp-
tion and that of radiation are equal; and as each increases,
the power of reflection diminishes.
The color of the surface also affects the power of absorp-
tion. Dr. Stark has shown that black surfaces, other things
being equal, absorb the most; dark green next to black;
scarlet next; and white the least of all colors.
Exp. This fact may be shown by placing strips of cloth of different
colors upon snow, exposed to the sun's rays; the black will be found
to sink into the snow to the greatest, and the white to the least, depth,
because the black absorbs the rays which melt the snow, and the white
reflects them. Hence the advantage of painting rooms white, or of
whitewashing them: the rays of caloric are thus kept passing from
side to side, without being absorbed and conducted away.
3. Transmission of Caloric. When radiant caloric falls
upon the surface of transparent solid or liquid bodies, it
passes through them in a slight degree.
It
passes easily through air and other gaseous substances,
without sensibly affecting them; but glass and crystalline

Theories of Radiation.
33
substances intercept most of the rays. Prof. Leslie contends
that glass does not permit the rays to pass directly through it,
but absorbs them at one surface, and transmits them to the
other by conduction, from which they are again radiated.
This opinion is supported by Dr. Brewster by an argument
drawn from his optical researches. But the experiments of
De la Roche lead to a different conclusion — that the calorific
rays do pass through glass, although slowly. This opinion is
supported by other chemists.
The radiant caloric which is associated with solar light
passes readily through glass and other transparent bodies.
The caloric, in this case, seems to be modified by its con-
nection with light, and may be collected into a focus with the
light, as in the case of a burning-glass. Caloric, thus asso-
ciated, suffers refraction in passing from one medium to
another, and in general is subject to the same laws with light.
IV. Theories of Radiation. Of the various theories to
account for radiation, only two seem worthy of notice.
1. The theory of Pictet supposes that a hot body will
radiate caloric to surrounding colder bodies, until the equi-
librium is restored, and then cease.
2. The theory of Prevost supposes that all bodies, what-
ever be their temperature, are constantly giving out and
receiving radiant caloric. When a body is giving out more
rays than it is receiving, it is cooling. When it gives and
receives an equal number, its temperature remains stationary,
and is in equilibrium with surrounding bodies. When it
receives more rays than it gives off, its temperature is in-
creasing. On this theory, all bodies — the polar ice, as well
as the burning sands of the tropics -- are constantly radiating
and absorbing caloric.
Although most of the phenomena of radiation may be
explained on both theories, preference is generally given to
that of Prevost. The ground of this preference is found in
the close analogy between the laws of light and heat. It is
well known that luminous bodies continually exchange rays.
A feeble light sends rays to one of greater intensity, and the
quantity of rays emitted by each does not seem to be affected

34
Application of the Theory of Prevost.
by the vicinity of other luminous bodies. In like manner all
bodies are supposed continually to exchange rays of caloric,
V. Application of the Theory of Prevost to the Explana-
tion of various Phenomena.
1. In the experiments with the mirrors, if the ball in the
focus of one mirror is of the same temperature with the
thermometer in that of the other, and with surrounding
objects, the thermometer will remain stationary, because it
receives from the ball the same quantity of rays which it
sends to it; but if the temperature of the ball be raised above
that of the surrounding objects, the thermometer will receive
more rays than it imparts, and will consequently show an
increase of temperature. If ice be substituted for the ball,
the thermometer will show a diminution of temperature, be-
cause it gives out more rays than it receives.
ter
When ice is placed in the focus of a mirror, there is an
apparent radiation of cold. But on this theory it is easily
explained, and is what might be expected previous to experi-
ment. Cold is a negative term, merely expressing the
absence, in a greater or less degree, of caloric.
2. The formation of dew depends upon radiation, and is
satisfactorily accounted for on this theory. The earth, during
the day, becomes heated by absorbing the sun's rays, and the
moisture is driven off into the air. During the night, it radi-
ates more caloric than it receives, and becomes colder than
the surrounding atmosphere. Successive strata of air charged
with moisture, come in contact with the earth, and the
moisture is condensed in the form of dew.
The quantity of dew will therefore depend upon the radi-
ating power of the surface, and the quantity of moisture in
the air; the more rapid the radiation, the more dew will be
formed. There is more dew upon grass and leaves than
upon stones; and the thermometer will sink 15° or 20° lower,
when placed upon grass, than when suspended in the air, or
laid on polished surfaces. In India, ice is formed by ex-
posing water in pans in a clear night, when the temperature
*
See Turner, 6th edition, p. 13, note

Cooling of Bodies.
35
of the air is never down to the freezing point. But why is
there no dew in a cloudy night? Because the clouds reflect
back the radiant caloric to the earth, which therefore cannot
become cooler than the air. In a clear night, there is no
such interchange of rays, and the caloric passes off into the
regions of space.*
VI. Cooling of Bodies. The cooling of a hot body is
effected in two ways, already noticed. When surrounded by
solid bodies in contact with it, the heat is carried off by
conduction, and the velocity of cooling will depend upon the
conducting power. When the heated body is immersed in
liquids, the same is true to some extent, although much de-
pends upon the mobility of the particles. But when sur-
rounded by gases, the cooling takes place by means of con-
duction and radiation, and in a vacuum, by radiation alone.
Velocity of cooling means the number of degrees lost in a
given time. Law of cooling refers to the relation which the
velocities of equal successive periods bear to one another.
The higher the temperature, other things being equal, the
greater the velocity. If a body heated to 1000° lose 100°
during the first second, Newton inferred that it would lose
th of the remainder, or 90°, during the next second, 81° the
next, 72.9º the next, and 65.6º the next. These numbers
form a geometrical series, whose ratio is 1.111; and, though
the law is not universal, it holds true, when the temperature
is but a little elevated above the air.
VII. Practical Application of the Laws of Conducted and
Radiant Caloric. The material for windows should be a bad
conductor of heat, as well as transparent; hence glass is best
adapted to the purpose. Glass also admits solar heat, while
it prevents the escape of artificial heat. Double walls, doors,
and windows, add to the warmth of buildings, because they
confine between them a stratum of air, which, when not in
motion, is a good non-conductor. Snow, furs, woollens, etc.,
are better non-conductors, because they enclose air. Stoves
which are rough radiate more heat than those which are
* The quantity of dew seems to depend also upon the difference be-
tween the temperature of the atmosphere and that of the earth.

36
Effects of Free Caloric.
polished. As the temperature of the human body usually
exceeds that of the atmosphere, the object of clothing in
cold weather is to retain the natural warmth; and hence it
is made of good non-conductors. In hot weather, clothing
should conduct off the heat more freely. Also, under a hot
sun, a black dress is more uncomfortable than one of light
color. Many articles employed in the common uses of life
are selected with reference to their conducting and radiating
properties, as materials for furnaces, culinary apparatus, etc.
Effects of Free Caloric.
The phenomena which may be ascribed to caloric as an
agent, and which may therefore be classified as its effects,
are numerous : some of these effects will now be enumerated.
The most remarkable property of caloric, as we have seen,
is the repulsion, which exists among its particles, by which
it tends to an equilibrium, or to bring all substances to the
same degree of temperature. This property enables it to
penetrate all bodies, and, by its accumulation, to separate the
integrant molecules from each other. It thus acts in oppo-
sition to cohesive attraction; hence it may be stated as a
general law, that
I. Caloric expands all bodies; liquids more than solids,
and
gases more than either.
1. Caloric expands solids. This may be shown by fitting
an iron cylinder to an aperture, so that it will just slide
through; heat it, and it will be too large to pass through.
2. Equal degrees of caloric expand some solids more than
others. This may be shown by an instrument called a
pyrometer, or fire measurer.
Fig. 8 represents this instrument. It is furnished with
several rods, as iron, brass, copper, lead, and glass,
BB, posts standing in A, and secured from spreading apart
by the two bars CC. G, a thumbscrew, passing through the
post B, and entering one end of the rod D, holds it against
a lever at the other end; as the rod is heated, it expands and
presses against the lever, which raises E, at the end of which
is a cord passing up, over the hub of the index, and down

Expansion of Solids.
37
again to the balance rod F; E is raised by the expansion of
the rod D; F falls, drawing the cord, and giving motion to the
hand.
Fig. 8.
300
415
3115
016
122.217)
E
OT
SEL
F
G
D
B
)
B В
60
1
581
<<
66
The following substances, when heated from 32° to 212°
Fahr., are elongated as follows:
Flint glass,
124g of its length.
Iron,
812
Copper,
Brass,
352
Lead,
351
3. Equal increments, or additions of caloric, at different
temperatures, do not expand the same solid equally.
That is, the expansion of a brass or iron rod will be much
greater between 500° and 600°, than between 100° and 200°,
or than between 2009 and 300°. The higher the tempera-
ture, the greater the expansion, with equal additions of
caloric. This results from the fact that the power of cohe-
sion is constantly diminished, the farther the integrant parti-
cles are removed from each other by heat.
4. The expansion of some solids is more uniform than
others, with equal additions of caloric. The expansions of
the more infusible solids are uniform within certain limits
From 32° to 122°, their expansion is equal to that between
4

38
Expansion of Liquids.
as the
122° and 212º. But above 212°, the higher the temperature,
the greater the expansion, for equal additions of caloric.
II. Caloric expands liquids more than solids.
1. This fact may be illustrated by heating a Fig. 9.
column of water in a glass tube, and an iron rod
of the same dimensions, by a spirit lamp; the water
will rise in the tube, while the iron will scarcely be
affected. The reason is, that the cohesive at-
traction in liquids is nearly destroyed.
Exp. Plunge a common thermometer into a jar of hot
water, (Fig. 9.) The bulb of the thermometer will be ex-
pånded, and its capacity increased, but the mercury will
be more expanded, and will rise in the tube.
Fig. 10.
2. Equal increments of caloric ex-
pand some liquids more than others.
This may be illustrated by partially
filling several glass tubes furnished
with bulbs with different liquids, and
placing them in hot water ;
liquids expand, they will rise to dif-
ferent heights in the tubes, as shown
in Fig. 10.
3. Equal additions of caloric, at different temperatures,
do not expand the same liquids equally. The same law holds
here as in the case of solids — the higher the temperature, the
greater the expansion for equal amounts of heat, and those
liquids also which expand the least are more uniform within
certain limits. Apparent exceptions to the general law are
found in the case of some liquids, near the point of con-
gelation. Water expands by a diminution of temperature,
and contracts by an addition of caloric, between the freezing
point and 40° Fahr.
III. Caloric expands gases more than
Fig. 11.
solids or liquids.
1. The expansion of air may be shown by
simply inverting a glass tube terminated by a
bulb, and partly filled with water, (Fig. 11,)
in a vessel of the same liquid: on heating the
bulb, the air will expand, and expel the liquid
from the tube; or by holding a bladder partly

Expansion of Gases.
39
filled with air near the fire, the air will soon expand, fill the
bladder, and even burst it.*
2. All gases, at any temperature, are expanded equally
by equal additions of caloric. In this respect, gases differ
from solids and liquids. If, therefore, we can ascertain the
expansion of one gas for a given number of degrees, we may
know that of all others. The law of the expansion of air
has been determined by Gay Lussac, who found that a given
quantity of dry air dilates to ato of the volume it occupied
at 32°, for the addition of each degree of Fahr.
Theory of Expansion. This has been already noticed. In
the case of solids, the integrant particles are held together
by cohesive attraction, but the caloric, being self-repellent,
has the effect to overcome this force, and to separate the
particles from each other. In case of liquids, cohesive at-
traction is much more feeble; it will therefore require less
power to separate the particles, and hence they are more
expansible than solids. Gases are still less under the influ-
ence of cohesion, and hence are more expansible. In fact,
the form which matter assumes seems to depend upon the
relative force of caloric and cohesion. In solids, cohesion
preponderates; in gases, caloric; but in perfect liquids, these
forces are in equilibrium, (the caloric being in a combined,
and not a sensible state.)
IV. Apparent Exceptions. Allusion was made to water
and some other substances as apparent exceptions to the
general law that heat expands and cold contracts all bodies.
Water continues to contract, until it arrives at 39°, and then
begins to expand until congelation takes place,
* So great is the tendency of air and other gases to expand, that, if
a given portion be confined in a bladder, or in a very thin glass of a
square form, and put under the exhausted receiver of an air pump, the
same effect will be produced as when heat is applied; the particles of
gases seem to be wholly free from the influence of cohesive attraction,
and expand by their own caloric when the pressure is removed.
† On the supposition that caloric is material, the effect is easily ac-
counted for; but though its particles repel each other, they must have
a strong attraction for matter, or they could not be introduced into it
Caloric, therefore, is the antagonist force to cohesive attraction, but
possesses a powerful attraction for matter, peculiar to itself.

40
The Force of Expansion.
Exp. Take a glass tube, with a bulb at one end, fill it with warm
water, and place it in a mixture of salt and snow. The water in the
tube will sink until it arrives at 390, and then begin to rise until it
arrives at 32º. The water, in becoming ice, will increase in bulk ,
and ice, in melting, will diminish in bulk 1v; hence, if the specific
gravity of water is 10, ice will be 9. The maximum density of water
is at 390 Fahr.
V. The force of expansion, when water freezes, is very
great. The Florentine aca emicians burst a hollow brass
globe, whose cavity was only one inch in diameter, by freez-
ing the water contained in it. This must have required a
force equal to 27,720 pounds. Major Williams, in 1784–5,
performed similar experiments at Quebec, by bursting bombs,
which also illustrated the amazing force of water in the act
of congelation.
In consequence of this expansive force, glass and earthen
vessels are broken, by suffering water to freeze within them;
water pipes are burst; pavements are thrown up, and de-
stroyed, and walls, especially in moist grounds, thrown
down.
Theory. The cause of this expansion is supposed to be
due to crystallization. The particles, at 39°, seem to be
endowed with a kind of polarity, and attract the edges of
each other; and, at 32°, they are arranged in ranks and files,
which cross at angles of 60° and 120°, as may be seen when
water is freezing in a saucer. This new arrangement of the
particles is supposed to increase the bulk; but, whether this
hypothesis be correct or not, it seems best to explain the
effect."
VI. Advantage of this Exception. The wisdom and be-
nevolence of God are strikingly exhibited in this arrange-
ment. Otherwise, all our rivers, and lakes, and the ocean
itself, in cold climates, would become solid masses of ice!
When a body of water is freezing, there are two currents
* This hypothesis relieves us from the necessity of supposing a real
exception to the laws of nature. The effect is due to the operation of
another law, (crystallization,) to which the law of expansion gives
place. For, after the crystallization is completed, the usual law pre-
vails, and ice contracts, with the further reduction of temperature. Fis-
sures are thus produced, in extreme cold weather, by the contraction
of ice on ponds.

Uses of the Law of Expansion.
41
established, as in the case of boiling water. The surface
gives off its caloric to the air, and the particles become heavy,
and sink down. This forces the warm particles below to
rise. But at 39° these currents are arrested, because the
colder particles begin to expand, and remain at the top. As
soon as they are frozen, a covering of ice prevents, in a great
measure, the escape of caloric from beneath, and the process
of freezing is greatly retarded. But, if the contraction ex-
tended to the freezing point, the colder particles would con-
tinue to fall to the bottom, until the whole should be brought
to that point, and then suddenly freeze; or, if they should
freeze upon the surface, the ice would continue to sink down
until the whole should become a solid mass.
Hence, in'cold climates, the rivers and lakes would be
converted into solid ice, and all their inhabitants would be
destroyed! But, by this simple and beautiful arrangement,
the ice is retained upon the surface, and confines sufficient
stores of caloric to preserve the inhabitants of the waters, and
render the coldest climates habitable by man.
Water is not the only liquid which expands under the
reduction of temperature; as the same effect has been ob-
served in a few others, which assume a highly crystalline
structure, on becoming solid. Hence the exactness with
which cast iron fills the mould, and the use of antimony in
casting types. Mercury is a remarkable instance of the re-
verse; for, when it freezes, it suffers a very great contrac-
tion,
VII. Practical Uses of the general Law of Expansion and
Contraction. All kinds of machinery are, of course, affected
by this law. It must be strictly regarded in the construction
of delicate time-pieces. Great use is made of it in the band-
ing of wheels; the iron is heated, and fitted to the dimen-
sions, and then suddenly cooled, so that, by its contraction,
it presses with great force, and becomes immovably fixed.
In riveting together iron plates for steam engine boilers, it is
necessary to produce as close a joint as possible. This is
effected by using the rivets red-hot; the contraction, which
the rivet undergoes in cooling, draws the plates together
with a force which is only limited by the tenacity of the
metal of which the rivet itself is made.
M. Melard, a few years since, at Paris, availed himself of this

42
Thermometers.
principle, to restore to their perpendicular direction two opposite walls
of a gallery, which had been pressed outward by incumbent weight
Through holes in the walls, several strong iron bars were introduced,
so as to cross the apartment, with the ends projecting; upon which
strong iron plates were screwed. The bars were then heated, and,
while hot, the plates were screwed up. On cooling, the bars con-
tracted, and drew the walls together. By repeating this process several
times, they were restored to their original position. Balloons were
first sent up filled with air which had been expanded by heat.
Winds. The phenomena of winds depend upon the expan-
sion of the air by the heat of the sun. In this way the trade
winds are produced. Land and sea breezes depend upon radi-
ation and expansion. During the day, the earth is more
heated than the water, and the air is more expanded, and
rises up. This will produce currents of cold air from the
water to the land, called sea breezes. During the night, the
earth radiates caloric more rapidly than the water, the air be-
comes cooler, and currents pass from the land to the water,
which are called land breezes. Winds are also produced in
those deserts which become greatly heated during the day.
Thermometers. But one of the most ingenious and useful
applications of this law is to be found in the thermome-
ter. Its invention is generally ascribed to Sanctorius, who
flourished in the seventeenth century. Some ascribe it to
Cornelius Drebel, and others to Galileo.
1. Air Thermometers. The substance employed
by Sanctorius was atmospheric air, by the expan- Fig. 12.
sion and contraction of which he was enabled to
measure variations of temperature. His plan was
very simple. The instrument consists of a glass
tube, (Fig. 12,) open at one end, with a ball blown
at the other; enough of some colored liquid is
poured in to fill half the tube, which is then in-
verted in a vessel of the same liquid. The air in
the bulb, by its expansion, causes the water in the
tube to sink, and, by its contraction, the pressure of
the atmosphere causes it to rise. By adapting a
scale to the tube, the instrument is fitted for use.
On one account, air is the best substance for a thermometer,
* This instrument is easily constructed by heating a glass tube in
the fire, and blowing a bulb upon the end; then insert the open end in
some colored liquid.

Differential Thermometer.
43
because its expansions and contractions are equal, with equal
additions of caloric. But there are two objections to the use
of this instrument; - it can be depended upon only when the
barometer stands at a fixed point; variations of atmospheric
pressure materially affect the rise or fall of the liquid. The
expansion of gases, also, with slight degrees of caloric, is so
great, that the length of the tube for measuring high or low
temperatures would render the instrument inconvenient in
practice.
2. Differential Thermometer. Sir J. Leslie, in 1804, con-
structed a thermometer, in which air is used, which is not
affected by atmospheric pressure.
It consists of two glass balls, (Fig. 13,) Fig. 13
joined together by a glass tube, bent twice
at right angles. The balls contain air, but
the tube is nearly filled with sulphuric acid,
colored with carmine. To one leg of this
tube is applied a scale. It is evident that no
effect will be produced upon the liquid, if
both balls are heated alike, because the air
in both will suffer equal expansion; but the
slightest difference between the temperature
of the two balls, will instantly be indicated by
the rise or fall of the liquid in the tube.
Hence its only use is to detect slight variations of tempera-
ture between two substances, or of two contiguous spots in
the same atmosphere, in very delicate experiments, where
caloric is reflected, or refracted to a focus. It is hence called
the Differential Thermometer.
A much more delicate instrument of this kind has been
constructed by Dr. Howard, of Baltimore, in which the vapor
of ether, or alcohol, in vacuo, is used instead of air.
But if air expands too much, and is affected by pressure, so
as to be unfitted for the common purposes of measuring the
degrees of temperature, solid substances, on the other hand,
expand too little.
The substance most convenient is a liquid, and the object
is, to find some liquid whose dilations are nearly equal with
equal additions of caloric, and whose boiling and freezing

44
Mercurial Thermometer.
It is
points are removed at the greatest distance from each other.
Alcohol and ether would answer this purpose very well in
one respect, — they resist congelation to a very low tempera-
ture, but boil much sooner than water. Mercury seems to be
the only substance which will answer the necessary condi.
tions.
3. Mercurial Thermometer. This instrument Fig. 14.
(Fig. 14) is constructed in the following manner :
A tube is selected with a small bore, of uniform
diameter, and a small ball is blown at one end.
The air is then mostly expelled from the bulb, by
holding it in a spirit lamp, and the end of the tube
quickly inverted in a cup of clear, dry mercury.
As the bulb cools, the atmosphere forces the mer-
cury into the bulb, which fills it two thirds full;
the bulb is again heated, and the mercury rises up,
nearly filling the tube, and expelling the air.
again inverted over mercury, when the bulb and
one third of the tube are filled; it is then heated
until it boils, and fills the tube to the top. A fine flame is
then darted from a blowpipe * upon the open extremity of
the tube, so as to fuse the glass, and close the aperture
before the mercury recedes. It is then said to be hermeti-
cally sealed, and the space abandoned at the upper extremity
of the tube, as it cools, is a vacuum.
Graduation. This is effected by ascertaining two fixed points; and,
as water always freezes at the same temperature, and also boils at the
same temperature, when the barometer stands at the same height, we
have only to immerse the bulb and a part of the stem in melting snow,
or water containing ice, and mark the point to which the mercury
sinks. This is the freezing point. To fix the boiling point, distilled
water should be used, and the barometer should stand at 30 inches.
A small quantity of the water, not more than one inch in depth, and
contained in a deep metallic vessel, is made to boil briskly, and the
point to which the mercury rises, is marked; this is the boiling point.
These two points being fixed, the interval is variously divided into
equal parts.
Fig. 15.
Fig. 15 represents the most common forms
of the blowpipe. It consists of a brass or copper
tube, tapering nearly to a point, through the small
end of which the air is forced, either by placing
the large end in the mouth, or by adapting to it a
pair of bellows.

Register Thermometer.
45
Fig. 16.
Fahrenheit.
Reaumur.
De Lisle,
15040
210-
Newton first suggested a scale, in which
the zero was placed at the freezing point,
and the interval divided into 40 parts, or
degrees. In Fahrenheit's thermometer,
which is generally used in this country and
in England, the zero is placed at 32° below
the freezing point, and the interval between
the freezing and the boiling points is divided
into 180 parts, so that the boiling point of
water is 212º. Fahrenheit fixed his zero
by immersing the thermometer in a mixture
of snow and salt. Reaumur's scale places
the freezing point at zero, and the boiling at
80º. De Lisle placed the boiling point at
zero, and the freezing at 150° below; this
1111' $Centigrade.
200
Ho
190
1190
10
20-
(180-
T
-80
3D-
170
60-
140
160-
170
50-
150-
140-
50
-60-
SC
130-
120
70
6040
80
1110-
1240
90
1200-
100-
90-
-30
80-
HO
20-
70-
scale is that of Celsius, in which the freez-
ing point is at zero, and the boiling at 100°,
called the Centigrade thermometer; this is
used in France. The different scales are
seen in Fig. 16.
The scale is either marked on the tube
by a diamond, or on ivory or paper, and at-
tached to the tube. The degrees above the
boiling and below the freezing points occupy
equal spaces with those between these points.
The temperature expressed by one scale can
be reduced to that of another, by knowing
the relation which exists between their de-
grees. The lower part of the scale, in labo-
ratory thermometers, (Fig. 14,) turns up by
a hinge, so that the bulb can be immersed
in corrosive liquids.
20
-
120-
60-
130
10
50
He
140
40
30-
-0
20-
HSE
10
10-
170
noLDERE
LATER ONTMOEDD
4. Register Thermometer.
Fig. 17.
This instrument consists of
two thermometer tubes, (Fig.
17,) bent at right angles, and
retaining a horizontal position.
One tube contains alcohol, and
the other mercury.
A small piece of black enamel is placed
in the tubes on the surface of each liquid. As the alcohol
contracts by exposure to cold, the enamel follows it towards

46
Pyrometers of Wedgwood and Daniell.
the bulb; but when it expands, the enamel remains stationary,
and suffers the liquid to pass by it. When the mercury con-
tracts, the enamel does not follow it; but when the mercury
expands, it is forced along. Consequently, it remains at the
highest temperature. The enamel, in the tube of alcohol
,
will indicate the lowest, and that in the tube of mercury the
highest, temperature during any given time.
For measuring temperatures below 39° F., the freezing
point of mercury, alcohol, or ether, must be employed ; for
temperatures above 662°, no liquid can be used, as they are
all either decomposed, or dissipated in vapors. For very high
temperatures, therefore, some of the more infusible solids
are used. The instruments for this purpose are called
Pyrometers. This term is derived from two Greek words,
signifying measurer of fire.
1. Pyrometer of Wedgwood. This is founded on the
property which clay possesses of contracting when strongly
heated, without expanding when cooled; but the indications
of this instrument cannot be relied on, and it is seldom used,
2. Pyrometer of Daniell. This instrument, the best now
in use, consists of a bar of platinum enclosed in a case 71
inches in depth, made of black lead: one end of the bar is
fixed; the other is made to move an index, as it is heated.
This, however, is not perfectly accurate, owing to the greater
expansion of the platinum, in high temperatures, with equal
degrees of heat. Generally, these instruments depend upon
the elongation of a metallic bar by heat; and one of the best
for illustration is described on page 37.
3. On the same principle is the
Fig. 18.
Metallic Thermometer of Brequet,
(Fig. 18,) for temperatures between
the freezing and boiling points of
water. It consists of a slip of silver
and one of platinum, united face to
face with solder, and coiled into a
spiral, d, one end of which, c, is 15
fixed, while the other is connected
with an index, e, which moves over
a circular, graduated plate, f, f.
This index is found to move over
equal spaces with equal additions of
caloric; and so sensible is it to slight

Insensible Caloric.
variations, that when enclosed in a large receiver, which
was rapidly exhausted by an air pump, it indicated a reduc-
tion of temperature from 66° to 25º = 41°, while a sensible
mercurial thermometer fell only 36º.
It will be readily seen that thermometers do not give us
the absolute, but only the relative quantity of caloric con-
tained in bodies. The true zero, or that point where abso-
lutely no caloric exists, is unknown. Some have conjectured
that it is 1200° or 1400° below the freezing point of water.
But it is mere conjecture; nor is it known, on the other hand,
how high a temperature might result from an accumulation
of heat. Neither limit is known. The thermometers and
other instruments measure only a few degrees, in the middle
of a scale, whose extremities are indefinitely extended.
SECT. 2. INSENSIBLE CALORIC.
Every one sees that a quart of water contains double the
quantity of caloric which is contained in a pint of the same
liquid, when the temperature of both is the same. This is
called insensible caloric, because it does not affect the ther-
mometer.
Specific Caloric. But different quantities of caloric are
required to raise equal weights of different substances to the
same temperature; and, conversely, different quantities are
given out by them in cooling equally. Suppose, for example,
that, on adding a given quantity of heat to a pound of water
at 50°, the temperature will become 60°, — the addition of the
same quantity to a pound of sperm oil at 50°, will raise the
temperature to 70°, while a pound of powdered glass will be
raised from 50° to 100° by the same quantity of caloric.
The temperature is increased 10°, 20°, and 50°, in these dif-
ferent substances; i. e., if the required temperature to which
they shall be raised be given, the oil will require but half as
much heat as the water, and the glass only one fifth as much.
Specific heat is the relative quantity of caloric requisite to
raise the temperature of substances equally; i. e., taking
water for a standard at i, the specific heat of sperm oil will
be Por, and of powdered glass 2*
* The phrase capacity for caloric was formerly used, and was in-

48 Methods of determining Specific Heat.
In these experiments, a portion of caloric disappears
.
This portion has been called latent or combined caloric,
in reference to the theory mentioned in the note below
The phrase insensible heat is preferred, as not involving any
theory.
Methods of determining Specific Heat. Various methods
have been employed to ascertain the specific heat of sub-
stances. The most convenient method is to mix with the
substances, all being at the same temperature, a given quantity
of some liquid, as water, at some other given temperature,
and observe the relative effects. Thus, as in the example
given, a pound of water at 80° may be added to a pound of
the same at 50°, and the resulting temperature will be the
mean, 65°; another pound of water at 80° to a pound of oil
at 50°, and the resulting temperature will be 70°; i. e., the
oil will gain 20° while the water loses but 10°; and again, a
pound of water at 80° to a pound of glass at 50°, and the
temperature of the mixture will be 75°, the glass gaining 25°
by 5° loss of the water. Other and more difficult experi-
ments are necessary to ascertain the specific heat of gases
and of solid bodies.
Laws of Specific Heat. The principal laws of specific
heat are the following: -
1. At the same temperature, and, in the case of gases,
with the same pressure, the specific heat of each body is
constant.
2. The higher the temperature, and, in the case of gases,
the less the pressure, the greater the specific heat of the same
body.
This is supposed to be owing to expansion. In gases,
the
specific heat varies with the density and elasticity; the greater
the density, the less the specific caloric; and the greater the
elasticity, the greater the specific caloric.
3. A change of form is accompanied by a change of spe-
cific caloric. The specific heat of a body, as it passes
from
a solid to a liquid state, is increased. It is also supposed to
tended to convey the idea, that a portion of the heat enters into and is
combined with substances in a latent state ; but this is hypothetical,
and the phrase specific heat is preferred, as involving merely a fact.

Effects of Insensible Caloric.
49
be increased by a change of the body from a liquid state to
that of a gas or vapor.
4. As each substance has a specific heat peculiar to itself,
it follows that a change of constitution is accompanied by a
change of specific heat.
5. A change of specific heat is generally accompanied by
a change of temperature. Thus the expansion of a gas,
which increases its specific heat, diminishes its temperature.
As a practical inference from the doctrine of specific heat,
it may be remarked, that much less fuel will be necessary to
heat some substances than others.
Effects of Insensible Caloric.
These are liquefaction and vaporization.*
I. LIQUEFACTION. All bodies exist in one of three states,
solid, liquid, or gaseous, and their forms seem to depend, as
we have seen, (page 39,) upon the relative forces of cohe-
sion and caloric. Hence, by the increase and diminution
of either of these forces, we can cause the body to assume
either of these states. If a solid be sufficiently heated, it will
become liquid, and then gaseous. So general is this fact,
that it
may
be stated as a law.
1. Point of Liquefaction. The temperature at which
liquefaction takes place, is called the melting point, or point
of fusion, as that at which liquids solidify is termed the point
of congelation. These points are identical; but there is a
very great difference in substances as to the degree of heat
which is required to fuse them. Each substance has a fixed
point of fusion and of congelation.
2. Caloric o Fluidity. If a pound of ice, which is at
32°, be melted in a pound of water at 172°, the temperature
of the whole will not be at the mean of 102°, but at 32°,
showing that 140° have been taken into a latent state, by the
liquefaction of the ice. Generally, liquefaction is accom-
* Classed as effects of insensible caloric, because the free caloric
passes into an insensible state, which is essential to the process.
5

50
Caloric. -- Freezing Mixtures.
66
66
66
panied by the conversion of free into insensible heat. The
heat which thus disappears seems essential to the process of
liquefaction, and is called the caloric of fluidity. Its quantity
varies in different substances, as in the following table:-
Ice. 140° Fahr. Beeswax . 175° Fahr.
Sulphur 143.68°
Zinc 490°
Spermaceti 145°
Tin . 500°
Lead
162°
Bismuth 550°
Irvine.
When the process is reversed, in congelation, this insensi-
ble caloric is thrown out in a free state. Thus the freezing
of water produces heat.
3. Freezing Mixtures. Liquefaction may be produced
without the addition of heat, and hence the caloric of fluidity
will be obtained, in part, from the temperature of the sub-
stances melted, but chiefly from the surrounding bodies; a
great degree of cold is thus often produced. On this princi-
ple various freezing mixtures are contrived. The most com-
mon method of producing cold is, to mix together equal
quantities of fine salt and fresh fallen snow, or pounded ice
,
The salt melts the snow by its affinity for water, and the
water dissolves the salt, so that both are liquefied. The degree
of cold produced is 32° below the freezing point of water
,
or at zero. This led Fahrenheit to commence his scale at
that point. Any other substance, which has a strong affinity
for water, may be substituted for salt. The crystallized
chloride of calcium is the best, because it produces the most
rapid liquefaction. The following table, constructed by Mr.
Walker, contains the proportions of several substances to
produce different degrees of cold.
Parts
MIXTURES.
Thermometer sinks
by Weight.
produced,
Sea-salt
1 l
Snow
2
to — 5°
Sea-salt
2
Muriate of ammonia 1
to -12°
Snow
5
Sea-salt
5
Nitrate of ammonia. 5
to — 25°
Snow
12
Diluted sulphuric acid 2
Snow
55 deg.
3
from +32° to - 23°
Deg. of Cold
.

Freezing Mixtures.
51
Parts
Concentrated muriatic acid 5?from +32° to — 27° 59 deg.
Snow
)
Concentrated nitrous acid 4) from +32° to -30° 62
Snow
7
Chloride of calcium
5
from +32° to -40° 72
Snow
4
Fused potassa
4
from +32° to -51° 83
Snow
3
Freezing may also be effected by the rapid solution of
salts. The following table exhibits the proportions, taken
from Walker's essay in the Phil. Trans. 1795. The salts
must be finely powdered and dry.
MIXTURES.
Thermometer falls
Deg. of Cold
by Weight.
produced.
Muriate of ammonia.
Nitrate of potassa 5 from +50° to +10° 40 deg.
Water:
16
Nitrate of ammonia 1
from +50° to + 4° 46
Water
Nitrate of ammonia 1
Carbonate of soda
1 from + 50° to 7° 57
Water
1
Sulphate of soda
3
Diluted nitrous acid 2
from +50° to - 3° 53
Sulphate of soda
6
Nitrate of ammonia 5 from +50° to - 14° 64
Diluted nitrous acid 4
Phosphate of soda
4} from + 50° to — 12° 62
Diluted nitrous acid
Phosphate of soda
9
Nitrate of ammonia 6 from +50° to - 21° 71
Diluted nitrous acid
4
Sulphate of soda
81
Muriatic acid
0° 50
from +50° to
53
Sulphate of soda
5
Diluted sulphuric acid
In order to the greatest effect, the substances should be
cooled in a freezing mixture before they are united.
4. The degree of cold produced by these artificial pro-
cesses, is limited. The greater the difference between the
temperature of the air and that of the mixture, the more
rapidly will the air communicate caloric to it; and this soon
.
*}from +50° to + 3° 47

52
Vaporization - Ebullition.
puts a limit to the degree of cold. According to Mr. Walker,
the greatest cold did not exceed 100° below the zero of
Fahrenheit. But a more intense cold is produced by evapo-
ration.
5. No process, however, will deprive a body of all its
caloric. Dr. Irvine has attempted to infer the absolute
amount from the specific caloric of bodies; thus ice contains
in less specific caloric than water; and, as this tu is equal to
140°, it is inferred, that water contains ten times the amount
,
or 1400° of caloric; but the estimates made by different
chemists vary from 900° to 8000°, which shows that but little
confidence can be put in their calculations.
II. VAPORIZATION. By vaporization is meant the conver-
sion of liquid and solid substances into vapor. It is generally
supposed that, if sufficient caloric be applied, all substances
are susceptible of this change.
A gas differs from a vapor in the circumstance that it is
not so easily condensed into a liquid; it retains its state at
ordinary temperatures and pressures. “The only difference
between gases and vapors is the relative forces with which
they resist condensation.” — T.
Some substances yield vapor readily, and are called vola-
tile. Others sustain the strongest heat of furnaces, without
volatilizing, and are hence said to be fixed in the fire. This
difference seems to depend on the relative forces of cohesion
and caloric. Liquids are more easily vaporized than solids ;
and solids, with a few exceptions, like camphor, assume the
liquid state before they are converted into vapor.
Liquids may be vaporized in two ways: 1. by ebullition;
2. by evaporation. In the first case, there is a rapid produc-
tion of vapor, causing commotion in the liquid; and in the
second, the process is conducted silently, the vapor impercep-
tibly passing off from the surface of the liquid.
Ebullition.
1. Boiling Point. The temperature at which a liquid is
converted by ebullition into a vapor, is called its boiling
point. This point varies greatly in different liquids under the
same circumstances, and in the same liquid under different

Ebullition.
53
degrees of pressure. But each liquid has a fixed boiling point,
when all the circumstances are the same.
2. The chief circumstance which modifies the boiling
point of the same liquid, is the pressure of the atmosphere.
A column of air, extending to the top of the atmosphere,
presses upon every square inch of surface with a force equal
to 15 lbs. This is sufficient to sustain a column of mercury
39 inches, or a column of water 34 feet. But the pressure
varies at different times on the surface of the earth; and as
we ascend high mountains, the pressure diminishes rapidly.
The instrument by which this variation is measured is called
the
Barometer, the principle of which may be illustrated by
filling a glass tube, open at one end, and about 33 inches long,
with mercury, and inverting the open end in a cup of the
same liquid. (See Fig. 19.) The pressure of the atmos-
phere on the surface will sustain the mercury in the tube to
the height of from 27 to 31 inches.
When the barometer stands at 30 inches, ether boils at
96°, alcohol at 176°, water at 212°, and mercury at 662°, F.
If the barometer stand at 28 inches, all these substances will
boil at a lower temperature, and if it rise to 31 inches, the
boiling points will be raised. Hence the two following laws:
1. As the pressure on the surface of liquids diminishes,
their boiling temperatures diminish. Thus water heated to
72°, and placed under the receiver of an air pump, will boil,
on exhausting the air, if the temperature be preserved.
Ether will boil violently, under an exhausted re- Fig. 19.
ceiver, at the common temperature of the atmos-
phere.
Exp. 1. Fill the barometer tube a with mercury, (Fig. 19,
and invert it in a cup c of the same liquid ; then introduce a
small quantity of ether. As soon as it reaches the vacuum
7, it boils rapidly, and the vapor forces the mercury down the
tube.
Fig. 20.
Exp. 2. The pulse glass (Fig. 20)
acts on the same principle. It is con-
a
structed by blowing a bulb b on the end
of a glass tube, in which a small open-
ing is made, and through this a similar
L
a
6
C
5*

54
Influence of Pressure upon the Boiling Point.
bulb a is blown on the other end. Some spirits of wine are now in.
troduced, and heated in the closed bulb a until the vapor escapes from
the aperture in b, when it is hermetically sealed. The heat of the hand
upon either bulb is sufficient to cause violent ebullition.
Ether boils in vacuo at — 44°, alcohol at 36°, and water
at 72°, and liquids generally boil at temperatures 140° less in
vacuo than at the common pressure.
It is owing to this fact, that intense cold can be produced
by boiling ether in vacuo. Water, and even mercury, under
favorable circumstances, may be frozen. To render the
experiment successful, there should be sulphuric acid in
the receiver to absorb the vapor of ether, which, by its
.
pressure, would otherwise soon prevent the ether from
boiling.
2. As the pressure on the surface of liquids increases, their
boiling temperatures increase. When water is heated to the
temperature of 212°, its force upon each square inch is equal
to 15 lbs. As this is equal to the pressure of the atmosphere,
it will, at this temperature, escape in vapor; hence it cannot
be heated in the open air above this point. But if the prez-
sure be increased sufficiently, it may be heated to any extent,
without exhibiting the phenomena of ebullition.
Fig. 21.
Exp. Boil water in a Florence flask, (Fig. 21,) and cork
it tight; the ebullition will instantly cease, because they
steam formed will press upon its surface; but by pouring on
cold water, and condensing the steam, it will boil violently;
pour on warm water, and it will stop boiling. This is a
convenient mode of illustrating both of the above laws:
as
the pressure is increased by the formation of steam, the
boiling point is raised, while it is lowered by condensing
the vapor and diminishing the pressure. This is called the
culinary paradox.
But,in order to exhibit the influence of pressure upon the
boiling point, we must employ a strong metallic boiler, called
a digester, which consists simply of a strong boiler furnished
with stop-cocks and valves, and an apparatus to ascertain the
temperature and pressure. Water confined in this boiler
may be heated to a very high temperature without boiling;
but the steam which will be formed will endanger the boiler,
before we can ascertain its greatest expansive force or pres-
sure upon the liquid.

Marcet's Digester.
55
*
o
For experiments on the pressure of Fig. 22.
steam, Marcet's digester (Fig. 22) is
well adapted : a is a strong brass globe,
into which a portion of mercury is poured,
and then half filled with water; b a ba-
rometer tube passing through a steam-
tight collar to the bottom of the globe; c
is a thermometer graduated to 400° or
500°; d a stop-cock; e a spirit lamp ;
b
and f a brass stand, upon which the whole
is supported. Upon the stop-cock d a
steam gun may be screwed. When heat
is applied, the pressure is measured by
the height to which the mercury rises in
the tube 6, and the temperature is ascer-
tained at the same time by the thermome-
ter c. On the application of heat, as
soon as the water boils, the thermometer
will stand at 212°, and the pressure, of
course, will be equal to one atmosphere,
or 15 lbs. to the square inch. As the
temperature increases to 217°, the pres-
sure will elevate the mercury 5 inches,
and at 242° about 30 inches, each degree of temperature
raising the mercury about one inch.
Absorption of Free Caloric in Ebullition. When water is
converted into steam, a great quantity of sensible heat is
taken up into a latent state; which, on condensation, again
appears in a free state.
If, for example, steam at 212° sufficient to form one pint
DU
a
e
Fig. 23.
* The spirit lamp is very useful for pro-
ducing heat in the laboratory. It consists
of a small glass lamp a, (Fig. 23,) the wick
of which passes through a metallic collar c;
b is an extinguisher, to prevent the wicka
from absorbing water when not in use. It is
5 Б
filled with alcohol, which burns in the same
manner as oil, but does not yield any smoke.
A common glass or tin lamp will answer a
a
very good. purpose, using alcohol instead
of oil.

56
Steam
Latent Heat.
of water, be condensed in ten pints of water at 117°, the
temperature of the whole will be 212°; the ten pints will be
elevated 95°: this is equivalent to raising the temperature of
one pint 950º. The latent heat of steam is, therefore, 950º;
other substances are subject to the same law. Hence it
may
be stated generally, that, in ebullition, heat is taken into a
latent state, and given out on condensation.
The latent heat of different vapors is various, as may be
seen in the following table :-
Vapor of water at its boiling point
967°
Alcohol
442
Ether
302.379
Petroleum
177.87
Oil of turpentine
177.87
Nitric acid
531.99
Liquid ammonia
. 837.23
Vinegar
.875
Steam is formed, ordinarily, by ebullition. At the moment
when water takes the state of vapor, in the open air, it has an
expansive force equal to one atmosphere, or 15 lbs. on the
sq. inch. If, then, it be disconnected from water, its laws of
expansion and contraction, at all temperatures above 212°,
are the same as all gaseous bodies. Equal increments of
caloric expand it equally, and its expansion is in the ratio of
the heating power; for every degree of Fahrenheit's ther-
mometer, it expands to of what its volume would be at 32°,
if it did not condense. It may be heated, like any gas,
until
it is red hot, if the vessel is sufficiently strong. But steam
is usually formed in the boiler where water is present, and, as
the temperature increases, fresh portions of steam are con-
stantly added to that which is already formed, so that its
expansive force increases in a much more rapid ratio.
According to the experiments of Dulong and Arago, if we
take atmospheric pressure for unity, we shall find the pres-
sure of steam at 233.96º, equal to 11 atmospheres.
250.52 equal to 2 atmospheres, or 30lbs. to the sq. inch.
275.18
3
45
320.36
6
90
66
66
60
60
66

Uses of Steam.
57
66
66
66
60
66
66
374 equal to 12 atmospheres, or 180lbs. to the
sq.
inch.
435.56
24
360
486.59
40
600
510.60 50
750
When steam, at a high temperature, is condensed in cold
water, a loud, crackling noise is heard, which is due to the
collapse of the water, a vacuum being formed by the sudden
condensation of the steam.
Exp. Let a jet of steam rush from the digester through a pipe into
cold water.
When liquids are converted into vapor, under high pres-
sure, the vapor is very dense. If, then, it is allowed to escape
from the orifice of the boiler, the hand may be held at a short
distance without being burned, though the temperature of the
steam, before it escapes, is several hundred degrees.
This is due to its expansion, and the consequent absorption
of its sensible caloric. When water is converted into steam
at 212°, it absorbs 950° of caloric. If now it be condensed
to 32°, it will give out 950° of latent, and 180° of sensible
caloric=1130°. Now, if we take the same weight of steam,
at a higher temperature, 250°, and condense it to 32°, it will
give out 912° of insensible, and 218° of sensible caloric=
1130°; hence the sum of the sensible and insensible caloric
contained in equal weights of steam, is exactly the same at all
temperatures = 1130°.
The absorption of caloric seems to perform a similar office
in vaporization and liquefaction, being essential both to the
formation of vapors and of liquids.
Application of Steam to practical Purposes.
1. It is used for warming rooms. For this purpose it is
conveyed in pipes, and continues to beat the room until its
caloric is nearly exhausted. It is then condensed to water,
and gives out its latent caloric.
Every cubic foot of steam in the boiler will heat 200
feet of space to 70° or 80°; and each square foot of steam
pipe will warm 200 cubic feet of space.
It is used for heating water-baths and dyeing-vats; for

58
Caloric. - Steam Engine.
bleaching cloth; for producing a vacuum by its condensa-
tion; for various culinary purposes; also, for drying various
substances, such as muslins, calicoes, gun-powder, etc.
2. But its most important application is to the propelling
of machinery: the instrument employed for this purpose is the
steam engine; the invention of which is due to Capt. Savery.
The principle of his invention may be illus-
Fig. 24.
trated by a tube, with a ball blown at one end,
(Fig. 24); fill this with water, and invert it in
the same liquid; apply heat to the bulb, and,
as soon as the water is at 212°, steam will be
formed, and force the water out; but, as soon as
the steam comes in contact with the cold water
in the vessel, it is suddenly condensed; a
vacuum is formed, and the atmosphere forces
the water with great violence up the tube, so
as to fill the bulb. If a piston be fitted to
the tube, it will constitute the instrument devised by Dr.
Wollaston, except that the steam in his apparatus is con-
densed by putting the bulb into cold water. The atmos.
phere presses the piston down, while it is raised by causing
the water in the bulb to boil..
The moving power of the steam engine is the same as in
this apparatus, but the steam is condensed in a separate ves-
sel called the condenser : this constitutes the improvement of
Watt, by which means, the temperature of the cylinder is
never below 212° Fahr.
3. The steam generator or Mr. Perkins sustains a pres-
sure of 800, 1000, and even 1500lbs. on the square inch.
The steam is then so hot as to set fire to tow, and even ignite
the generator at its orifice. At this very high temperature,
it is about half as heavy as water. It is a remarkable fact,
that, at such pressures, the steam will not rush through a
small aperture, through which it will rush with great violence,
and a roaring noise, when the temperature and pressure are
diminished. Mr. Perkins thinks that 400 atmospheres, or
6000 lbs. to the square inch, is the maximum of pressure;
i. e., that under this pressure, water will remain liquid at any
temperature, even at a white heat. The boiler of the gener-
ator is small, and not more than a gallon of water is used at
a time.

Evaporation.
59
a
Steam Artillery. Mr. Perkins has succeeded in applying this amaz-
ing force to the propelling of cannon balls. He states that sixty 41b.
balls can be discharged in a minute, with the accuracy of a rifle
musket, and to a proportional distance. A musket may also be made
to throw from one hundred to a thousand balls per minute. It is great-
ly to be hoped that his experiments will prove successful; for, if such
engines of death could be brought into the field of battle, few nations
would be willing to settle their disputes in that way. Few would fight
in the prospect of certain death.
Fig. 25.
Distillation. This process is
d
conducted by converting liquids
into vapor, which passes into a
long, metallic tube, or worm, sur-
rounded by cold water. The va-
por is condensed, and the liquor
runs off at the opposite extremity
of the tube. Fig. 25 represents
this apparatus; a a copper boiler,
10+
bits head, connected with the
worm, which is coiled in the refrigerator d. The vessel d is
filled with cold water to condense the vapor in the worm as
it passes through it.
Evaporation.
The only difference between evaporation and ebullition is,
that the one takes place quietly, and the other with the ap-
pearance of boiling. Evaporation takes place at all temper-
atures, but ebullition at fixed temperatures. The former
takes place, not only in all liquids, but in many solids, as
camphor; the latter is confined to liquids.
1. Evaporation is much more rapid in some liquids than in
others, and it is always found that those liquids whose boiling
points are lowest evaporate with the greatest rapidity.
Thus alcohol, which boils at a lower temperature than
water, evaporates also more freely, and ether, whose point
of ebullition is yet lower than that of alcohol, evaporates
with still greater rapidity. Also, if the temperature of the
liquid be raised or lowered, the evaporation will be more or
less rapid.
2. Increase of pressure checks evaporation, and diminution
of pressure promotes it ; thus water will evaporate much more
rapidly in a vacuum,

60
Caloric. — Uses of Evaporation.
This is precisely what we should expect from the fact
just mentioned, that evaporation is most rapid in liquids
whose boiling point is lowest; for the diminution of pressure
lowers the boiling point. From the three facts which have
been mentioned, it may be inferred that evaporation is more
rapid as the distance between the boiling point and the tem-
perature of the substance diminishes.
The other circumstances that influence the process of
evaporation are,
3. Extent of Surface. As evaporation goes on from the
surface, it is evident that, the greater the extent of surface,
the more rapid the evaporation.
4. State of the Atmosphere. If the atmosphere be already
saturated with moisture, evaporation will be checked; or, if
the air remain still, it will soon become saturated, and the
evaporation is promoted by the motion of the air.
5. Absorption of Free Caloric by Evaporation. If a dish
of water be placed in the exhausted receiver of an air
pump,
and another, of sulphuric acid, to absorb the vapor of the
water, the water will evaporate so rapidly, as to be frozen by
the absorption of its sensible caloric. * Hence the effect of
evaporation is to produce cold; because the sensible caloric
passes
into an insensible state.
Exp. This may be further illustrated by filling a small glass tube
with water, and surrounding it with cotton wool. If the cotton wool
be soaked with ether, and a current of air, from a common bellows, be
directed upon it, the water, in the course of a few moments, will congeal.
Exp. A very satisfactory experiment
is performed with the cryophorus, an in-
Fig. 26.
strument invented by Dr. Wollaston.
It consists of two glass balls, (Fig. 26,)
connected by a glass tube. Both balls
are free from air ; but one of them con-
tains a portion of distilled water. When
the other ball is placed in a freezing mixture, so as to condense the
watery vapor as fast as it formed, the evaporation is so rapid from the
* The most intense cold which has been produced is the effect of
evaporation. If a large quantity of carbonic acid gas be condensed
into a liquid by pressure, and suifered to escape through a small aper-
ture, it will congeal by its own expansion; the solid acid thus formed
will evaporate so rapidly in a vacuum, as to produce the cold of -- 136°
Fahr. At this temperature, the strongest alcohol becomes viscid, and
common alcohol becomes frozen.

Uses of Evaporation.
61
surface of the water in the other ball, as to freeze it in two or three
minutes.
6. Cause of Evaporation. The cause of evaporation is,
doubtless, the same as that of ebullition — caloric ; although
some have attempted to account for it on the supposition of
an affinity between the air and the evaporated liquid; but
evaporation in a vacuum is fatal to this hypothesis.
7. Uses of Evaporation. It is well fitted for cooling
apartments. All that is necessary for this purpose, is to
sprinkle the floor with water.
It moderates the heat of warm climates; hence places near
large bodies of water are cooler in the summer than those
more remote, and the greater the heat from the sun's rays,
the more rapid the evaporation, and of course the greater
quantity of sensible caloric goes into an insensible state.
Evaporation not only takes place from the surface of water,
but from the surface of the earth, and from plants and ani-
mals; hence it tends to defend the animal, as well as the
vegetable system, from external heat. When an animal is
exposed to external heat, perspiration commences over the
whole surface, and the liquid, in passing to a vapor, absorbs
the sensible caloric. On this principle fire-kings subject
themselves to a high temperature, with but littie inconve-
nience. The oven girls of Germany, also, often expose them-
selves to a temperature of from 250° to 280°, and one girl
breathed five minutes in an atmosphere of 325°. In these
cases, water boils rapidly, and beef-steak is cooked in a
few minutes. If, however, the air be moist, or the body be
varnished, so as to prevent perspiration, the heat cannot be
sustained for a moment. The heat produced by violent
exercise is carried off in the same manner.
But the vital principle, doubtless, has much to do in forti-
fying the system against the extremes of heat and cold; for,
although men may be subjected to a range of temperature
of more than 400°, - from 350° above to 75° or 80° below
zero, the temperature of their bodies does not vary five
6

62
Caloric. - Hygrometers.
degrees, but remains stationary at 98° and 100°, during all
the varieties of external temperature,
Evaporation often fills the air with deadly miasma. The
fever and ague is supposed to be produced in this way. Con
siderable effect is also produced upon the bulk of gases, and
it becomes a point of great interest to ascertain the amount
,
especially when delicate experiments are to be performed,
The atmosphere, of course, always contains a portion of
watery vapor. At the freezing point it contains ato of its
volume, and the higher the temperature, the more vapor is
it capable of sustaining. The instruments for measuring the
amount of vapor in the air, and other gases, are called
Hygrometers. These vary in form, but may all be reduced
to three principles.
1. The first is founded on the property of some substances
to elongate when placed in a moist atmosphere, and to con-
tract when dry. The human hair possesses this property in
an eminent degree, and is the substance employed by Saus-
2. The second kind of hygrometer depends on the rapidity
of evaporation, the temperature and pressure being the same ;
the more vapor there is in the air, the slower will the
process
Leslie's hygrometer is constructed on this prin-
ciple.
3. The third kind depends on the fact that, if a cold body
be introduced into moist air, the moisture will condense on
it; as is sometimes seen on the surface of glass and earthen
vessels filled with cold water, and is an indication of rain.
The temperature at which the moisture is condensed is
called the dew point.
sure.
go forward.
Application of the Laws of Insensible Caloric to the Explana-
tion of Natural Phenomena.
1. We have seen that, when solids are converted into li-
quids, they absorb large quantities of caloric. Hence the
process of thawing, contrary to the common belief, is a
freezing process. Ice, in becoming water, absorbs 140° of
sensible caloric; hence countries surrounded by water are

Explanation of Natural Phenomena.
63
cooler in the spring than those where less ice is formed dur-
ing the winter.
2. Liquids, in passing to vapors, absorb sensible caloric.
In the vaporization of water, nearly 1000° of caloric are ab-
sorbed. It is therefore a much more powerful cooling pro-
cess than the liquefaction of ice; hence the heat of warm
countries is greatly reduced by the constant formation of
vapor. This is the reason why the transition from the cold
of winter to the heat of summer is not sudden, but gradual ;
the ice and the water cannot obtain caloric in sufficient
quantities to convert them into vapor.
3. When vapors and gases become liquids, they give out
large quantities of caloric; hence it is usually warmer after
a rain, a large quantity of caloric being evolved by the con-
densation of the vapor in the atmosphere. If, however, the
earth is dry and hot, the heat converts the water into vapor,
and renders the air cooler.
4. Liquids, in becoming solids, give out caloric; hence
the process of freezing is a heating process. To prevent
some substances from freezing, we have only to place them
near those which congeal at a higher temperature; thus
water placed in a cellar will prevent vegetables from freezing,
because they require a lower temperature than water to
freeze them; before they reach the point of congelation, the
freezing of the water renders its insensible caloric sensible,
and prevents them from attaining it.
By the process of converting water into ice, a process
constantly going forward when the thermometer stands at
32° Fahr., - large quantities of caloric are thrown off into the
atmosphere; hence the shores of a country are warmer in
the winter than the interior; hence, too, the approach of the
cold season is gradual, — the greatest degree of cold rarely
occurs till after the winter solstice, twentieth of December.
Were these laws suspended, September and March would
be of equal temperatures. June would be the warmest, and
December the coldest month in the year.

64
Caloric. — Sources of Caloric.
Sect. 3. SOURCES OF CALORIC.
The principal sources of caloric are,
1. The sun.
2. Chemical action, including electricity, galvanism, and
combustion,
3. Condensation by mechanical action, including percus-
sion and friction.
4. Vital action.
1. Sun. The heat produced by the sun varies with the
kind and color of the surface, according to principles already
noticed. The temperature produced by their direct action is
seldom more than 120°; but, when the rays are concentrated
by means of convex lenses, or concave mirrors, a very intense
heat is produced. Lenses have been constructed concen-
trating sufficient heat to melt some of the most refractory
metals; but the most intense heat, at any considerable dis-
tance, is produced by several concave mirrors, which reflect
the rays to one focus. Metals and minerals have thus been
melted at the distance of 40 feet, and wood ignited at the
distance of 120 feet from the mirrors.
2. Chemical Action. Caloric is often produced by chem-
ical and electrical action. A very great heat occurs in the
phenomena of combustion, which may be defined to be the
disengagement of light and heat in substances by chemical
action. But the most intense heat is produced by voltaic or
electrical action.
3. Condensation. It has been already stated that sub-
stances develop caloric by diminution of their bulk, as when
gases pass to liquids and to solids. A fire is often kindled
by rubbing pieces of dry wood against each other; heavy
machinery, if not properly oiled, often ignites wood, and
axletrees of carriages are burned off'; the sides of vessels are
set on fire by the descent of the cable. The friction in these
cases condenses the parts, and the caloric is developed. So,

Nature of Caloric.
65
when iron is struck with a hammer several times, it becomes
hot. Fire is also struck from steel with any hard substance,
like flint. This is denominated percussion.
4. Vital Action. The caloric developed by vital action is
supposed to be owing, in part, to the chemical action of the
air upon the blood; but it is more probable that the vital
principle operates to produce most of it, in a way not well
understood.
Sources of Cold. The sources of cold are, liquefaction,
vaporization, and rarefaction.
SECT. 4. NATURE OF CALORIC.
On this subject there are two theories. Sir H. Davy and
some others considered caloric as a property of matter; and
Sir William Herschel and Prof. Airy have attempted to ex-
plain its nature by supposing that there exists a subtile ether,
which pervades all space and all matter, and that caloric is
the effect of vibrations made in this fluid, somewhat similar
to the vibrations of the air which produce the sensation of
sound. This theory is called the undulatory theory, and is
most favorably received by chemists.
Sir Isaac Newton supposed that caloric was a subtile, ma-
terial fluid. If caloric is material, it is matter under very
peculiar circumstances. So far as we can determine, it pos-
sesses few, if any, of the common properties of matter; its
particles are self-repellent, opposed to cohesive attraction.
If it is material, its particles must be exceedingly small, as
they penetrate all other substances, however dense. They
must also be influenced by gravity; but no quantity of them,
however great, possess the least appreciable weight. It pos-
sesses neither extension nor impenetrability; but if it is mat-
ter, it must have these properties.
6*

66
Physical Properties of Light - Refraction.
CHAPTER II.
LIGHT.
bo
The physical properties of light belong to the science of
Optics, a branch of Natural Philosophy. But light has also
chemical properties, which come within the province of
Chemistrybutos do
I. Physical Properties of Light. Light is emitted from
every visible point of a luminous object, and is equally dis-
tributed on all sides, if not interrupted, diverging like radii
drawn from the centre to the circumference of a sphere. It
travels at the rate of 192,000 miles in a second, requiring
about eight minutes to pass from the sun to our earth. Its
velocity is so great, that the light emitted in the firing of a
cannon, or a sky-rocket, will be seen by different spectators
at the same instant, whatever may be their respective dis-
tances from it; the time required for light to travel one
hundred or one thousand miles being inappreciable by our
When light falls upon any body, it is either reflected,
refracted, or absorbed.ee more
II. Reflection. The reflection of light is influenced by
the same circumstances as that of caloric, and follows the
same laws; the angles of incidence and reflection are equal
.
(Fig. 6, page 31.) It is owing to the reflection of light that
we are able to see the various objects in nature, an image
of the object being formed by the reflected rays upon the
retina of the eye.
III. Refraction. When a ray passes from a rarer to a
denser medium, as from air into water, it is refracted towards
a perpendicular to the refracting surface: this property is
called refrangibility.
Thus (Fig. 27), 1 is the ray before it reaches the refract-
ing surface 3. Instead of passing directly through to a, it
is bent towards the perpendicular, to the surface p, and pro-
senses.

Decomposition of Light.
67
r
ceeds to r. But in passing from a denser Fig. 27.
to a rarer medium, it is refracted from id k
a perpendicular to the refracting sur-
face. Thus, in passing from r, it is re-
3
fracted at the surface towards l, instead
of proceeding to d. Hence a stick
partly in water appears bent. Objects
viewed through some substances, as Ice-
land spar, appear double in consequence of a double re-
fraction.
IV. Decomposition of Light. Solar and stellar light con-
tain three kinds of rays :-
2
1. Colorific, or rays of color.
2. Calorific, or rays of heat.
3. Chemical rays, or those which produce chemical
effects.
1. Colorific Rays. These may be separated into seven
primary colors: red, orange, yellow, green, blue, indigo, and
violet.
Fig. 28.
с
P
Violet, 2-
Indigo,
6
Blue,
5-
Green,
-
Yellow, 3-
Orange, 2-
Red,
1 -
80.-
The instrument by which this separation is effected is a
triangular prism (Fig. 28) of glass, ice, or any transparent
substance. A beam of light r is admitted into a dark room,
and, passing obliquely through two sides of the prism p, is
refracted by both. The different colors are separated, be-
cause some are refracted more than others; and, instead of a
white spot after the beam passes through the prism, as at 8,
there appears a long, colored surface c, called the solar
spec
trum.
Dr. Wollaston supposes that there are but four colors, viz. :
red, green, blue, and violet, occupying spaces in the propor-
tion of 16, 23, 36, 28.

68
Calorific Rays - Daguerrcotype.
separate the
According to Sir D. Brewster, there are but three colors,
red, yellow, and blue, a mixture of which produces the others
The prismatic colors differ in their illuminating power.
This is greatest in the yellow and green, and diminishes each
way to the violet and red.
2. Calorific Rays. The calorific rays exist in the greatest
intensity in, and near the red rays, and diminish rapidly
towards the violet; the greatest heat is sometimes entirely
without the red rays; this, however, depends upon the kind
of substances used to separ
rays;
in some cases, it is
quite on the verge of the orange.
The refrangibility, then,
of the calorific rays is much less than that of the colorific.
This is shown also by the fact that, when the solar rays are
concentrated by a convex lens, the focus of heat is farther
from the lens than that of light.
3. Chemical Rays. On the side of the spectrum, a little
beyond the violet, are invisible rays, which have a peculiar
effect upon chemical changes. They are most powerful on
the verge of the violet, and diminish towards the red.
1. Photographic drawing depends upon the influence of
these rays.
Exp. Cover one side of a plate of glass with beeswax, colored with
lamp-black, and draw a picture on it by removing the wax with a sharp
point. If then a solution of salt in water be spread on a piece of white
paper, and the nitrate of silver in solution poured upon it, the chloride
of silver will be formed. Place the paper then over the glass, and the
sun's rays passing through, where the wax is removed, will form a
picture upon the paper, by changing the chloride black wherever they
strike it.
Exp. Soak a piece of white paper in a saturated solution of bichromate
of potassa, dry it rapidly, and put it in a dark room. Place over it
prints, dried plants, etc., and expose it to the sun; the objects will be
represented yellow on an orange ground. To fix the drawing, wash it
carefully, to dissolve the salt which has not been acted upon by the
light. The object will then appear white on an orange ground.
If sulphate of indigo be used with the bichromate of
potassa, it will give to the object and to the paper different
shades of green.
2. Daguerreotype. A method of fixing the images of ob-
jects on metal has lately been devised by Daguerre.

Magnetic Rays.
69
Exp. Expose a plate of silvered copper, well cleaned with dilute
nitric acid, to the vapor of iodine; an extremely thin coat of iodide of
silver will be formed. Place the plate in the Camera Obscura for eight
or ten minutes, in such a position that the light may come from the
object, and an inage of it be formed on the plate; then expose it, at an
angle of 48°, to the vapor of mercury; heat it to 167° Fahr., and the
images will appear. The plate should then be exposed to the action of
hyposulphite of soda, and washed in a large quantity of distilled
water.*
Magnetic Rays. Dr. Morrichini, of Rome, discovered
that the more refrangible rays possessed the property of
rendering iron magnetic; Mrs. Somerville. confirmed this
statement by magnetizing a sewing needle with less than
two hours' exposure to the violet rays; but others have not
been so successful, and it is questionable whether these rays
possess this property.
V. Absorption. The rays of light are separated by ab-
sorption. When light falls upon a substance, more or less
of it disappears like sensible caloric.
1. The different colors are absorbed variously by different
surfaces. This is the cause of the great variety of colors;
for, when all the rays are absorbed except the red, and these
only reflected, the body is red. Thus, in colored bodies, only
a part of the rays can be reflected ; and to the admixture of
the different colors in the reflected portion, is owing all the
beautiful variety of color.
2. The absorption of light varies with the chemical consti-
tution; hence, by the action of chemical agents upon each
other, every variety of color can be produced at pleasure.
Exp. Into a little chloride of calcium, in solution, pour a few drops
of sulphuric acid; a white solid will be formed.
Exp. Into a dilute solution of persulphate of iron pour the tincture
of gall; fine black ink will be formed.
Exp. Into an infusion of purple cabbage put a drop or two of sul-
phuric acid; a beautiful red will be produced.
Exp. Nitrate of mercury and infusion of gall will form an orange
color.
Exp. Nitrate of lead and hydriodic acid, yellow.
Exp. Vegetable infusion and an alkali, green.
Exp. Aquæ ammonia and sulphate of copper, blue.
Exp. Ferro-cyanuret of potassa and sulphate of iron, indigo.
Exp. Red and indigo, mixed, form violet.
3. When all the rays are absorbed, so that none can be
reflected, the body is black; for the same reason, everything
* See Jour. Franklin Inst. XXIV. 207.

70 Light. - Ignition - Phosphorescence.
is black in total darkness. If none of the rays are absorbed,
and all are reflected, the body is white.*
VI. Ignition and Incandescence.
The phenomena of
ignition and incandescence include all kinds of artificial
light, which is obtained by the combinations of inflammable
matter, or the heating of non-combustible bodies. Solids
begin to emit light in the dark at 700°, and in the light at
1000° F. Gases require a higher temperature; flame is in-
candescent gas. The color of the rays depends upon the
kind of substances and the degree of heat: the white light
of oil, candles, etc., when transmitted through a prism, has
but three primary colors— red, yellow and green. The
dazzling light emitted by lime intensely heated, gives the
prismatic colors almost as bright as the solar spectrum.
Different substances assume different colors when intensely
heated. Chemical rays exist very feebly in most artificial
light, but in the intense light of lime, under the compound
blowpipe, they are more easily detected.
VII. Phosphorescence. There are many substances in
nature which possess the property of shining in the dark,
without the emission of caloric. These are said to be phos-
phorescent, and are known by the term phosphori, (although
there is no phosphorus connected with the phenomena.)
1. Solar Phosphori. Many bodies acquire this property on exposure
to the solar rays for a few hours. Such, for example, is Canton's phos-
phorus, a composition made by mixing three parts of calcined oyster
shells with one of the flowers of sulphur, and exposing the mixture
for an hour to a strong heat in a covered crucible. Chloride of cal-
cium (Homberg's phosphorus) possesses the same property; also,
nitrate of lime, (Baldwin's phosphorus,) and a variety of other sub-
stances, such as carbonate of baryta, strontia and lime, the diamond,
fluor-spar or chlorophane, apatite, boracic acid, etc. Scarcely any
phosphori act unless they have been exposed to light.
When phosphorescence ceases, it can be restored by a
second exposure to the light, or by passing electric dis-
charges through the substance.
2. Phosphorescence from Moderate Heat. Chlorophane
and several mineral substances require to be heated before
* Colors have an important influence on the absorption and disen-
gagement of odorous matters. White bodies are the least absorbent,
and dark the most so.

Photometers.
71
they phosphoresce. Lime is a remarkable instance; when
heated, it gives out a dazzling white light, too intense to
look upon without injury to the eyes. Light is also emitted
during the crystallization of many salts, as the sulphate of
potassa and fluoride of sodium.
Exp. Put three drachms of the vitreous arsenous acid into a matrass,
with an ounce and a half of hydrochloric acid, and half an ounce of
water; boil the mixture for ten minutes, and then suffer it to cool
slowly. When crystallization commences, each little crystal will be
attended by a spark; on sudden agitation, great numbers of crystals
shoot up, accompanied with an equal number of sparks; if larger
quantities are taken, and the vessel shaken at the right moment, the
emission of light is so powerful as to illuminate a dark room.
3. Animal and Vegetable Phosphori. Some animal and
vegetable substances emit light at common temperatures,
without exposure to the sun's rays. This property is re-
markable in some fish, as the mackerel ; the light makes its
appearance just before putrefaction commences, and ceases
when it is completely established. Some species of decayed
wood possess this property in a remarkable degree.
VIII. Photometers. It is sometimes desirable to measure
the intensity of light, emitted from different objects, and an
instrument has been invented for this purpose, called the
Photometer, or light measurer. The principal one employed
for this purpose is that of Leslie.
It consists of a very delicate and small differential ther-
mometer, one bulb of which is made of black glass, and the
whole is enclosed in a small glass tube. The white ball
transmits all the light and heat, and is of course unaffected;
the black ball absorbs all the rays, and heats the air within,
so as to cause the liquid to rise. Its action of course depends
upon the heat produced by the absorption of light.
Some objections to this instrument have been stated by
Turner.
Count Rumford's Photometer determines the comparative
strength of lights, by a comparison of the shadows of bodies.
Sources of Light. These are similar to those of caloric-
the sun, stars, chemical action, mechanical action, and caloric.
IX. Nature of Light Light and caloric have been re-
garded by some as identical. Newton supposed that light

72
Electricity.
was a material, subtile fluid, which emanated from luminous
bodies in all directions in right lines, and produced the sen-
sation of vision, by falling upon the retina of the eye; this
is termed the Newtonian theory. But Descartes, Huygens,
and Euler, proposed a different theory, which has been lately
revived by Sir John Herschel and Prof. Airy. This theory
supposes that light is produced by vibrations in an elastic
medium, which pervades all space, and that vision is the
effect of these vibrations, meeting the retina, in the same
manner as pulsations of air impress the nerve of hearing,
and produce the sensation of sound.
At present, the
strongest evidence is in favor of this theory, which has
received the name of the undulatory theory. (See Sir J.
Herschel's article on Light in the Encyclopedia Metropol-
itana.) Either of the above theories answers the purpose of
classifying the facts, and it is not material which is adopted.
CHAPTER III.
ELECTRICITY.
The word electricity is derived from the Greek name for
amber,* a substance which possessed the property of at-
tracting light bodies when rubbed.
1. If a piece of sealing-wax, or a glass rod, be rubbed with a
dry woollen or silk cloth, each becomes capable of attracting
and repelling light substances. In this state each is said
to be electrified, or electrically excited. When friction is
applied to many other substances, they exhibit similar phe-
nomena. The cause of this attraction and repulsion is as-
cribed to an agent called electricity, and when it is excited
by friction, it is designated by the title of common elec-
tricity.
2. If a plate of copper and a plate of zinc, having copper
wires soldered to each, be immersed in acidulated water,
and the ends of the wires brought into contact, they will
* Ηλεκτρον. .

Common Electricity.
173
exhibit similar phenomena of attraction and repulsion. When
electricity is excited in this way, there is always a chemical
action between the metal and the liquid, and it is called
Galvanism, in honor of Galvani, who made the discovery;
also Voltaic electricity, from Volta, who first demonstrated
its existence as independent of the animal system.
SECT. 1. COMMON ELECTRICITY.
Common electricity is generally excited by the friction of
one substance upon another.
1. If a piece of sealing wax, or any resinous substance, be
rubbed with a silk cloth, and a pith ball, suspended by a
thread, be brought near it, the ball will be at first attracted,
and then repelled.
2. If a rod of glass, or other vitreous substance, be rubbed
in a similar manner, and brought near the ball, it will attract
it, while the sealing-wax will repel it.
3. If two balls be each electrified by the sealing-wax, or
by the glass, they will repel each other, but if one is electri-
fied by the wax, and the other by the glass, they will attract
each other; hence, when friction is applied to resinous and
vitreous bodies, opposite effects are produced. The state
induced by friction upon the glass, was called by Dr. Frank-
lin positive, and that induced upon the wax negative, and the
substances were said to be positively or negatively electrified.
Theories. 1. Franklin supposed that electricity pervaded
matter generally, and that friction tended to bring it upon
the surface of bodies, or drive it from them; that it was in
its nature self-repellent, but possessed a powerful attraction
for common matter; when a body was electrified positively,
it had more than its share of electricity; when it was electri-
fied negatively, it had less than its natural portion.
2. Du Fay supposed that there were two Auids: the one de-
veloped by the friction of the glass he called vitreous, which
answers to the positive electricity of Franklin, and the other,
developed by the friction of the wax, he called resinous, which
corresponds with the negative electricity of Franklin. Each
7

74
Electricity. - Gold Leaf Electrometer,
ca
Oy
fluid repels itself, and attracts the other. It follows from
this theory, that substances electrified by the same fluid repel,
and those electrified by the opposite fluids attract, each other,
and friction only tends to separate them.
The existence of the two fluids may be shown Fig. 29.
by the Gold Leaf Electrometer, * (Fig. 29,) which
consists of two strips of gold leaf suspended by a
brass cap and wire, in a glass cylinder. When
electrified with either kind of electricity, the leave
diverge.
But if, when the leaves diverge with negative
electricity, a substance excited positively be brought
near, the leaves will collapse.
Exp. Bring excited sealing-wax in contact with the brass knob
the leaves will diverge with negative electricity. Place now, excited
glass upon the knob, and the leaves will come together, because the
positive fluid restores the equilibrium. If pith balls be suspended by a
wire or thread, similar effects may be produced.
Some substances, such as glass and resin, retain the elec-
tricity upon their surfaces when excited, and are hence called
non-conductors of electricity.
Other substances, as the metals, do not retain electricity
upon their surfaces, unless they are surrounded by non-con-
ductors, but convey it away, or oppose no barriers to the
union of the two fluids; such bodies are called conductors of
electricity. The metals are all conductors; dry air, glass,
sulphur, and resins, are non-conductors; water, damp wood,
moist air, alcohol, and some oils, are imperfect conductors.
The non-conductors are called insulators.
Some substances exhibit signs of electricity when heated,
such as tourmalin, topaz, diamond, beryl.
Electrical Machine. The instrument by which the phe-
nomena of common electricity may be best exhibited, is the
electrical machine † (Fig. 30,) which consists of a cylinder,
or plate of glass G, revolving on an axis, and subjected to the
friction of a rubber R of leather or silk, upon which is
spread a thin coat of amalgam, composed of tin, mercury,
* Ηλεκτρον and pletpov, a measurer of electricity.
+ In the absence of an electrical machine, many experiments may be
performed with a rod of glass, or sealing-wax, two inches in diameter,
and rubbed with a silk handkerchief.

Electrical Machine.
75
Fig. 30.
R
fu
า)
insulated by a glass pillar, and communicates with the ground
by a brass chain, C. Attached to the machine is a cylindrical
metallic conductor, P, which is also insulated by a glass pillar.
When the machine is in operation, vitreous electricity
flows from the rubber and glass, by means of fine points, to
the prime conductor, P, and resinous electricity passes in an
opposite direction. If the hand be placed upon the con-
ductor, currents of electricity will pass in opposite directions,
the vitreous passing into the body from P, and the resinous
down the chain C to the ground. But if the hand be held
at a little distance from the conductor, a spark will dart
through the air, and cause a prickling sensation, accompanied
by a slight report, with light and heat. The sound is pro-
duced by the collapse of the air, as the fluid forces a passage
through it; and the light and heat are supposed to result from
the sudden condensation of the air, as in the fire syringe.
Induction. If an insulated body be brought near the prime
conductor, it will manifest signs of electricity opposite to
that of the conductor, on the side nearest the conductor, and
similar to the conductor on the other side, while the centre
of the body will be neutral. The electricity, in this case,
is
induced by the presence of the electrified conductor; and

76
Electricity.- Induction - Theory.
3
the process is called induction. Several insulated conductors
placed contiguous, will exhibit the same phenomena if a
communication be made between the last and the ground.
Thus, (Fig. 31,)
Fig. 31.
let A represent the
positive conductor
of an electric ma-
B
chine, b and c in-
sulated conductors,
with a chain pass-
ing to the ground.
The conductor b will be electrified by induction, as will be
indicated by the attached balls. Thus 1, being positive, will
attract the balls 2, which are rendered negative by induction.
The balls 3 are also rendered positive, 4 negative, and 5
positive, while the centres b c will remain neutral.
Theory. The phenomena of induction led Faraday to
propose a theory of attraction and repulsion. The reason
why an excited body attracts another is, that it induces in
it an opposite electrical state. He considers induction an
essential function, both in the development and continuance
of electrical currents; that it consists in a polarized state of
the particles, or positive and negative points, induced by the
presence of an electrified body.
Application of the Theory. According to this theory, an
excited body attracts light substances, because it induces in
them an opposite state of electricity.
1. On moving the hand towards the prime conductor, it is
electrified negatively by induction; when a spark is received,
the equilibrium is restored.
2. When a cloud, positively or negatively electrified,
passes over a tower, or a tree, it induces an opposite state in
them, and a stroke of lightning follows in consequence of the
attraction between the two accumulated fluids; hence the
utility of lightning-rods to form a communication between
the clouds and the ground.
3. The action of the Leyden Jar is due to induction. It
consists of a glass jar, lined on the inner and outer surfaces,
save a few inches near the mouth, with tin foil. Through the
stopper, made of dry wood or sealing-wax, a brass rod com-

Electrometers.
77
municates with the inner surface. When positive electricity
is applied to the inside, it drives off the same fluid on the
outer surface, and induces the negative fluid. These fluids
exert a strong mutual attraction upon each other, through
the glass, and enable both to accumulate in larger quantities
than they would do on separate conductors. When a com-
munication is made between the inner and outer surfaces,
the equilibrium is suddeniy restored, accompanied by a
sharp report. When several jars are connected by their
outer surfaces, and also by their inner surfaces, they consti-
tute an electrical battery.
4. The action of the Electrophorus Fig. 32.
(bearer of electricity) (Fig. 32) de-
C
pends upon the same principle. It may som
be constructed by pouring melted resin
into the cover of a firkin, taking care,
when it cools, to render the surface even.
Adapt to this a circular piece of board
covered with tin foil, and fix a glass rod
in the centre for a handle. This instru-
ment may be used instead of the machine for charging Ley-
den Jars.
obom
Electrometers, or Electroscopes. These are instruments for
detecting the presence of electricity, as in the Gold Leaf
Electrometer, (page 74,) or for determining the degree of its
tension, or attracting and repelling power. For this last
purpose, the Balance Electrometer is used.
Totoong
a
Fig. 33.
D
Caz
a
©
а
B
Sie sur
contre
B E
G
Thus A (Fig. 33) is a Leyden jar, which may be con-
y*

78
Laws of the Accumulation of the Electric Fluid.
nected with the prime conductor of an electric machine; B,
a brass ball connected with D, E; C, another ball, with a
chain, G, connecting it with the table or the outside of the jar;
D, a brass rod balanced at the centre, and insulated by the glass
post H; E is a ring which may be placed at any distance
from F, bringing the ball in contact with B. If, now, the jar
be positively electrified, the ball on the end of E will be re-
pelled, C will be electrified negatively by induction, and
there will be a powerful attraction between C and the ball
on the end of D, which will bring them together, and the
equilibrium will be restored. The force of attraction will be
measured by the distance between the balls and the weight
applied at E. With a powerful electrical battery, successive
vibrations may be produced in the beam, and a bright spark
and loud report produced at each contact of the balls.
Laws of the Accumulation of the Electric Fluid.
1. Free electricity is always accumulated upon the surface
of an insulated conductor, and does not penetrate its sub-
stance; hence the quantity does not depend upon the quantity
of matter in the conductor, but upon the extent of surface.
2. The mode in which electricity is distributed over the
surface of conductors, depends upon their form. On a sphere,
it forms a uniform stratum. On an ellipsoid, the stratum is
thickest on the extremities of the longer axis, and, as these
extremities approach to the form of points, the accumulation
increases till the tension becomes so great, that it flows off
into the atmosphere; hence electricity cannot be retained on
a conductor which has points attached to it.
3. This tendency to escape is due to the repulsion of its
particles.
4. Coulomb proved by his Torsion Electrometer, that the
repulsion of two bodies similarly electrified, and the attraction
of two oppositely electrified, varies inversely, as the square
of the distance between them.
SECT. 2. VOLTAIC ELECTRICITY, OR GALVANISM.
History. In the year 1791, Galvani, an Italian Professor
of Anatomy at Bologna, discovered that if a silver probe were
made to touch the crural nerve of a recently killed frog, and
a strip of zinc the muscle, violent contractions would be
duced at each contact of the two metals - the same effect as
pro-

2 Simple Voltaic Circles.
79
is produced by an electric spark. Hence he concluded that
the phenomena were due to electricity, generated by the
animal system. Some years after, Prof. Volta, of Pavia, dis-
covered that the animal system was not necessary to the de-
velopment of this kind of electricity, which he proved by the
construction of a pile of insulated plates, of different metals,
called the Voltaic pile. This discovery has given to this form
of exciting electricity the epithet voltaic.
1. But the identity of the agent concerned in galvanism, and
of that in the common electrical machine, is now a matter of
demonstration. Magnetism is doubtless due to the same
agent, and probably chemical affinity, which reduces the four
subjects to one, and renders it much more simple, and easy
to classify effects which were once supposed to originate from
as many distinct agents. See
I. Simple Voltaic Circles. Exp. Place a piece of zinc
upon the tongue, and a piece of silver under it: whenever the
projecting edges of these metals are brought into contact, a
peculiar sensation will be perceived, and, if the plates are
large enough, a flash of light. This effect is not due to elec-
tricity generated by the animal system, but to that developed
in the metals; for if the same plates,
or larger plates, be placed in water,
Fig. 34.
(Fig. 34,) and the connection made, с Z
electricity will be excited; feeble in-
deed, but in sufficient quantities to be
detected by a proper apparatus. If,
however, a few drops of sulphuric or
nitric acid be added to the water, and
the ends of the plates C and Z brought
into contact directly, or by means of wires soldered to the
plates, bubbles of hydrogen gas will rise from the surface of
the copper plate C, and electricity will be developed in larger
quantities. The currents will continue to circulate from one
plate to the other, as long as the wires are kept in contact,
but will cease when they are separated. This is a case of a
simple voltaic circle. The direction of the positive current
is indicated by the position of the arrows.
When the wires
are in contact, the circuit is said to be closed, and a current
of positive electricity flows through the water from the zinc
plate Z to the copper C, and from the copper along the con-

80
Electricity. - Compound Voltaic Circles.
ducting wires to the zinc. A current of negative electricity,
on the theory of two fluids, passes in an opposite direction.
When the wires are separated, the circuit is said to be broken.
The contact may be made above the water, or in it, or the
plates may touch each other throughout, or be soldered to-
gether; in either case electricity will be excited; but if one
plate is out of the liquid, no currents can be produced.
A simple voltaic circle may be formed of one metal and
two liquids, provided a stronger chemical action is induced on
one side of the plate, than on the other. Simple voltaic cir-
cles may also be formed of various materials; but, generally,
they consist of one perfect and two imperfect conductors
of electricity, or of two perfect and one imperfect conductors.
Metals and prepared charcoal are perfect, water and
aqueous solutions imperfect conductors. But, whatever be
the construction, chemical action seems absolutely necessary
to the development of voltaic currents.
The most common and convenient form Fig. 35.
of the simple battery, is that of two cyl-
inders of copper, C. (Fig. 35,) the one
within the other, separated about one
inch, with a bottom soldered on, so as to
contain the exciting liquid, a, between
them, and a cylinder of zinc, Z, placed
between the two cylinders of copper, and insulated by ivory
handles. The two plates are furnished with wires, terminated
by the cups b b, which contain a globule of mercury.
The
connection is made by means of wires dipped into the mercury
in the cups. Or, the copper and zinc may be coiled around
each other, so that each surface of zinc may be opposed to
one of copper, but separated from it by a small interval.
By thus exposing a large surface of zinc to a similar sur-
face of copper, Dr. Hare was enabled to melt the most
refractory metals, and from this circumstance gave it the
name of Calorimotor.
II. Compound Voltaic Circles. Compound circles consist
of a series of simple circles, for the purpose of increasing
the intensity of voltaic currents. The first combination of
this kind was made by Volta, and is called the voltaic pile.
TU

Compound Voltaic Circles.
81
in use.
1. This pile consists of zinc and copper plates, Fig. 36.
(Fig. 36,) placed alternately one above another,
with strips of woollen cloth moistened with salt
water between each pair. By connecting the top
and bottom plates, currents of electricity will be
set in motion.
2. But other forms of voltaic circles are now
The most convenient is that invented
by Wollaston. It consists of any convenient
number of zinc and copper plates, so arranged,
that each zinc plate is surrounded by two of copper.
A (Fig. 37) is a trough to contain the exciting liquid ; B
a case passing around the plates, and connected by chains to
the windlass C, by means of which the plates can be lowered
into the liquid, or raised to any position required.* EE are
small hand-vices attached to the poles. The zinc plates are
confined in copper cases, insulated by wood at each end.
The copper cases are separated of an inch, by pasteboard,
which, with the wood, is saturated by oil and wax. The
connection between the zinc and copper plates is made by
strips of copper soldered to the zinc of one pair, and to the
copper of the adjacent pair; by this construction, the power
of the battery is increased nearly one half.
Fig. 37.
с
E
As each zinc plate is connected to the adjacent copper
plate, the currents are urged along from one to the other, in
opposite directions, till they meet at the poles.
The size and number of plates may be varied at pleasure.
The largest battery ever constructed is that of Mr. Children,
* In some batteries, the plates are stationary, and the trough is raised
and lowered. This is the most convenient construction, especially in
large batteries.

82
Electricity. — Theories of Galvanism
the plates of which were 6 ft. long and 2 ft. 8 inches broad.
The most convenient size is 4 inches by 6. A battery con-
taining 200 or 300 plates, and thrown into vigorous action, is
nearly as powerful as one much larger.*
one much larger.* The battery of
Dr. Hare is called a Deflagrator, from its surprising power
of burning the metals.
The direction of the currents in this apparatus is the same
as in the simple circles : positive electricity passes from the
zinc through the liquid to the copper plates, and is given off
at the copper pole of the battery, while negative electricity
takes the opposite direction, and appears at the zinc or
negative pole.
During the action of the battery, all the hydrogen evolved
in the process is given off at the surface of the copper, and
the weight of the hydrogen during any given time, and that
of the zinc dissolved, will be as 1 to 32,3, which is the ratio
of their chemical equivalents.
This shows the close con-
nection between electricity, thus excited, and chemical
affinity
Theories of Galvanism.
On this subject there are three theories: 1. The first
originated with Volta, who conceived that electric currents
are set in motion, and kept up, solely by contact of the dif-
ferent metals. He regarded the interposed solution merely
as a conductor to convey the electricity from one point to
another.
2. The second theory was proposed by Dr. Wollaston,
who supposed that chemical action was the sole cause of
exciting and continuing the voltaic currents; and the fact
that no sensible effects are produced by a combination of
conductors, which do not act chemically upon each other, is
the strongest proof of its truth: even in the voltaic pile,
the energy of the action depends upon the oxidation of the
zinc.
* In experimenting with the battery, the plates should not be im-
mersed in the liquid but a few minutes at a time; by raising and low-
ering them for each experiment, their vigorous action will be kept up
much longer; or the troughs may be so constructed, that, by a partial
revolution, the exciting liquid may be withdrawn from the plates, or
thrown upon them at pleasure.

Laws of the Action of Voltaic Circles. 83
3. The third theory was suggested by Sir H. Davy, and is
intermediate between the two preceding. He supposed that
the electric equilibrium was disturbed by contact of the
metals, and the electric currents kept up by chemical action.
The theory of Wollaston is now generally embraced.
Laws of the Action of Voltaic Circles.
Electricians distinguish between quantity and intensity in
Galvanism, as in ordinary electricity.
Quantity refers to the amount of the electric fluid set in
motion; tension, or intensity, to the cnergy or effort with
which a current is impelled. Common electricity has great
tension ; voltaic, great quantity, --- and this is the principal
difference between them.
1. In the broken circuit, there is a strain to establish an
electric current, because without this, oxidation cannot take
place. There exists between the exciting fluid and the zinc,
a desire, as it were, for chemical action, which cannot be
gratified until, by closing the circuit, a door is opened for the
escape and circulation of electricity. This strain or tension
is great, according as the affinity between the exciting fluid
and the zinc is great
. Currents of higli tension are urged
forward with greater impetuosity than feeble ones, and hence
they more readily overcome obstacles to their passage.
2. Currents from a single pair of plates have not a high
tension; but if the plates are large, a great quantity of elec-
tricity is set in motion.
The condition which causes a high tension is an extended
liquid conductor, along the whole line of which successive
pairs of plates are arranged; each acted upon chemically by
the exciting liquid, and urging on the current in the same
direction. But the quantity in this case may not be great ;
for, although its tension is increased by the force which each
plate gives to the current as it passes, the quantity which
passes along the wire, according to Faraday, is exactly equal
to that which passes through one of the cells in which the
plates are immersed.
3. The energy of voltaic currents is measured either by
their power of deflecting a magnetic needle, or by that of
chemical decomposition. The deflection of the needle depends

84
Electricity. --- "Effects of Galvanism,
upon quantity; hence a single pair of plates will deflect the
needle more than a number of small ones combined; but de
composition depends upon quantity and intensity together
,
The decomposing power of the battery, however, does not
increase in the ratio of the number of plates, but as the
square root of the number, so that, when the number varies
as 1 to 4, the decomposing power is as 1 to 2.
The deflecting power of a single pair of plates varies in-
versely as the square root of the distance between them.
Thus, if a plate of zinc be placed at one, four, and nine
inches from a plate of copper, the deflecting powers will be
in the ratio of 3, 2, 1.
4. The velocity of common electricity through perfect con-
ductors, is surpassed only by that of light, being, according to
Wheatstone's Experiments, about 118,000 miles per second,
From some experiments, it is infered that the velocity of
voltaic electricity is somewhat less. Hence this agent has
been employed to communicate intelligence from one place
to another. The Electro-Magnetic Telegraph, by which this
is effected, depends upon the velocity of electricity and its
power to deflect the magnetic needle.
Effects of Galvanism.
I. The effects of common and voltaic electricity have many
points of resemblance.
1. If a zinc and copper plate be immersed in dilute nitric
acid, and the wire attached to the zinc plate be made to
touch a gold leaf electrometer, the leaves will diverge with
negative electricity, and if the wire of the copper plate be
applied, it will indicate positive electricity. This effect is
much greater when a battery of several pairs of plates is
employed. It appears to be due to the disturbed equilibrium
in the zinc plate; the chemical relation of which to the acid
renders the metal positive, at the expense of the attached wire,
while the copper plate, induced by the contiguous zinc, be-
comes negative, at the expense of its wire, which becomes
positive.
12. A Leyden jar may be charged from either wire of an
unbroken circuit, provided a large quantity of electricity be
developed, connected with high tension. This effect depends
upon the number of plates and the energy of the action.
3. Voltaic, like common electricity, passes through the

Effects of Galvanism.ro
85
air, and other non-conductors, in the form of sparks, accom-
panied with a report, and the development of light and heat.
Hence it will inflame gunpowder, phosphorus, hydrogen and
oxygen, and other inflammable substances.
4. Its tension, however, is so feeble, compared with com-
mon electricity, that it has, according to Mr. Children, a very
small striking distance; i. e., the space of air through which
the spark will pass is comparatively small. With a battery
of 1250 pairs of four-inch plates, he found the striking dis-
tance to be go of an inch. If the air be rarefied, the distance
will be increased, and diminished by condensation.
5. The effect of voltaic electricity upon the animal sys-
tem is similar to that of common electricity.
6. Both kinds also deflect the magnetic -needle, and pro-
duce chemical decomposition.
II. One of the most surprising effects of voltaic currents
is their power of igniting the metals.
Excp. Attach to each pole of the battery strips of metallic leaves,
and bring them in contact; the metals will burn with the most vivid
scintillations. (See Fig. 37.)
The color of the light varies in different metals. Gold
leaf burns with a white light, tinged with blue, and yields
a dark brown oxide. Silver emits an emerald-green light,
of great brilliancy; copper, a bluish-white light, with red
sparks; lead, a beautiful purple ; and zinc, a brilliant white
light, tinged with blue and red. If the communication be
made with charcoal points, (that from the box-wood is the
best,) the light is equal, if not superior, in intensity, to that
emitted during the combustion of phosphorus in oxygen gas,
and the heat is sufficient, it is said, to partially fuse the car-
bon, a substance which is fusible by no other means of pro-
ducing heat.*
Theory. The heating power seems to be due, for the
most part, to the quantity of electricity developed; hence, for
melting wires, a calorimotor is preferable to a compound bat-
tery. The heat is supposed to arise from the difficulty with
which the electric currents pass along the conductors; but
* On examining the points after they have been subjected to the
action of a powerful battery, one will present a conical appearance, like
the head of a pin, the other a corresponding cavity. The matter thus
transposed has been supposed to be partially melted; but probably it is
nothing but earthy matter in the carbon.
3

86
Electricity. - Chemical Effects of Galvanism.
as the substances are good conductors, the effect will take
place only when the quantity of electricity transmitted, is out
of proportion to the extent of surface over which it has
to pass.
As heat and light are produced in vacuo, under water, or
in
gases which do not contain combustible matter, these phe-
nomena cannot be attributed to combustion, but to the pro-
duction of light and heat by the electric fluid itself. The
effects of common electricity from the electric machine,
and in the case of lightning, are so similar to those above
described, that there can be no doubt of the identity of the
agents concerned in their production.
III. Chemical Effects of Galvanism.
The phenomena
which accompany chemical combinations are similar to those
produced by voltaic electricity. But the agency of voltaic
currents to effect the decomposition of chemical compounds
is a most important and useful discovery, which was first made
by Carlisle and Nicholson.
1. The first substance decomposed by the gal- Fig. 38.
vanic battery was water. The water for decom-
position is put into a small vessel, a, (Fig. 38.) 5
The tubes h o, after being filled with water, are
inverted in the vessel, passing through holes in the
stopper; n and p are platinum wires passing
through the sides of the vessel into the open ends
of the tubes. When the poles of the battery are
connected with the wires, the positive with P,
and
the negative with n, hydrogen gas is disengaged
at the negative, and oxygen at the positive wire.
The two gases will rise up in the tubes in small bubbles, and
displace the water. By measuring the gases, it will be found
that there will be exactly two measures of hydrogen in the
tube h to one of oxygen in the tube o. If the gases are col-
lected in the same tube and exploded in the eudiometer, they
will entirely disappear, and water will again be formed. By
this means, the composition of water, both by analysis and
synthesis, is accurately ascertained.
This important discovery led to similar trials upon
substances. Other compounds, such as acids, salts, and alka-
other

couver Chemical Effects of Galvanism.ba
87
lies, were subjected to the agency of galvanism, and all were
decomposed — one of their elements appearing at the positive,
the other at the negative pole. In these decompositions, it
was found that the same kind of body always went to the
same pole. The metals, inflammable substances in general,
alkalies, earths, and the oxides of the common metals, were
uniformly found at the negative wire, while oxygen, chlorine,
and the acids, were found at the positive pole. This led to
a division of substances into Electro-positive, and Electro-
negative - a distinction, however, which is not found, by later
experiments, to accord with facts.
2. The transfer of chemical substances from one vessel to
another was noticed by Sir H. Davy. This transfer may be
shown by two wine-glasses, (Fig. 39.)
Put a solution of sulphate of soda into one, Fig. 39.
n, and distilled water into the other, P; then
connect them with moistened amianthus or n
ve
cotton thread. If, now, the negative pole of
the battery is connected with n, and the pos-
itive with p, the acid will pass over into the cup p containing
the distilled water — if the poles are reversed, the alkali will
pass over into this cup. If, instead of distilled water, infusion
of purple cabbage be used, the presence of the acid will be
detected by the red color which it will give to the infusion,
and that of the alkali by its changing the infusion to green.*
But the effect in this experiment, and in those where three
vessels are used, (the middle one of which, although contain-
ing a very delicate test of the presence of an acid or of an
alkali, will suffer them to pass through it without detection,)
can be accounted for on the principle that a part of the salt
passes over into the cup by capillary attraction; as it has
Fig. 40.
*
A very simple apparatus for showing the changes of
color when salts in solution are subjected to galvanic
action, is shown in Fig. 40, which consists of a glass tube,
bent in the form of the letter U. Fill both legs with a
neutral salt colored with the infusion of purple cabbage ;
on immersing the poles p and n, the color may be trans-
ferred from one leg to the other as often as the poles are
changed.
U

88 Electricity. - Chemical Effects of Galvanism.
been proved by Faraday that decomposition never takes
place unless the electric fluid actually passes through the sub-
stance. Please
It was in pursuing these researches that Davy made his
great discovery of the decomposition of the alkalies and
earths, which, until that time, had been considered simple
bodies.
Theory. The theory of decomposition, proposed by Davy,
was this: He conceived that the poles of the battery were
centres of attraction to one element of the compound, and of
repulsion to the other; hence, when the two poles were im-
mersed in water, the oxygen of the water was attracted by
the positive, and repelled by the negative pole, while the hy-
drogen was repelled by the positive and attracted by the neg-
ative pole. The elements, thus acted upon by four forces,
were separated, and made to appear at their respective poles.
But this theory does not account for all the phenomena.
If it were true, we should expect decomposition to be effected
by one pole alone, as it exerts the attractive and repellent
influence; but this is never the case.
Mr. Faraday has lately revised this part of the subject, and
not only added much that is new, but shown that many prin-
ciples, especially the above theory, are erroneous.
He contends that the poles have no attractive or repulsive
tendency, but simply afford a path for the voltaic currents
to enter the liquid. Instead of poles, he calls them elec-
trodes,* which means the way or door for electric currents,
and may be air, water, metal, or any other substance capable
of conducting the currents to and from the substance to be
decomposed. The point where the positive current enters
the liquid, he calls the anode,t and that where it quits it, the
cathode. I
When a compound is decomposed by galvanism, it is said
to be electrolyzed, 9 and substances capable of decomposition
are called electrolytes; the elements of an electrolyte are
*
From ηλεκτρον and oδoς, α 10ay.
+ From éva, upwards, and odos, the way in which the sun rises.
# From xata, downwards, the way in which the sun sets.
$ From nextpov and avw, to unloose or set free.

Results of Faraday's Investigations.
89
called ions. * Anions are the ions which appear at the anode ;
cations, those that appear at the cathode. The anions are
the electro-negative substances, such as oxygen, chlorine,
acids, etc.; the cations, the electro-positive, such as hydro-
gen, alkalies, metals, etc.
The following are the principal results of Faraday's inves-
tigations : -
1. All compounds, contrary to what has been hitherto
supposed, are not electrolytes; that is, are not directly de-
composable by the voltaic currents. But many bodies may
be decomposed by secondary action. Thus water is directly
decomposed by an electric current; but nitric acid is decom-
posed by secondary action — the decomposition of the water
contained in it, aids the decomposition of the acid. Very
numerous secondary actions are produced in this way, because
the disunited elements, separated by direct action, are pre-
sented in their nascent form, which is peculiarly favorable to
chemical action.
2. Most of the salts or secondary compounds are resolva-
ble into acid and oxide; but in the binary compounds, such
as acids and oxides, the ratio of combination has an influence.
which has been hitherto overlooked. No two elements ap-
pear capable of forming more than one electrolyte. The
proto-chloride of tin is readily decomposed, but the by-chlo-
ride is not. Hence substances which consist of a single
equivalent of one element, and two or more of another, are
not electrolytes, that is, are not decomposed directly by
electricity.
3. Most of the simple substances are ions, that is, capable
of forming compounds decomposable by galvanism.
4. A single ion, by itself, has no tendency to pass to either
of the electrodes, that is, it is indifferent to the voltaic cur-
rents.
5. There is no such thing as a transfer of the ions, in the
sense supposed by Davy. In order that the elements of water
should appear at the two electrodes, there must be a row of
particles between them.
6. The air, or the surface of water, may constitute an elec-
trode, as well as metals.
7. Electro-chemical decomposition cannot occur unless a
current of electricity actually passes through the compound;
* From 10v, going, neuter participle of the verb to go.
8*

90 Theory of Electro-Chemical Decomposition.
сор-
that is, the compound must be a conductor of electricity
,
On this principle many substances, by change of state, resist
decomposition. Water is easily decomposed, but ice is not:
many solid substances, also, are not electrolytes, because they
are not conductors. Chemical compounds differ in the elec-
trical force required for their decomposition; some require
but a feeble current, others a powerful one.
8. The conduction of the electric currents in the cells of a
battery depends upon decomposition. If the zinc or the
per be attacked chemically by a substance which is simple, or
a non-conductor, no currents can be set in motion.
9. Electro-chemical decomposition is perfectly definite;
that is, in the voltaic circle 32.3 parts of zinc are dissolved
during the evolution of one part of hydrogen. This is in the
ratio of their chemical equivalents. The same is true of all
electrolytes. Hence Mr. Faraday has given to the quantities
of electricity, requisite to effect the decomposition of various
substances, the name of electro-chemical equivalents. This is
a new and important discovery; it seems to prove that the
cause of chemical combination or affinity is electricity
.
Hence, in order to estimate the quantity of electricity circu-
lating in a voltaic apparatus, it is only necessary to collect the
gas evolved from the acidulated water during any given time.
CA
Theory of Electro-Chemical Decomposition. We have al-
ready noticed the theory of Davy, which supposes that all
substances are in one of two states of electricity, and that the
poles have an attractive and repulsive force; but Mr. Faraday
has shown that this theory cannot be true. All substances
are indifferent when by themselves, but assume one of the
two states when brought in contact. Only one substance is
absolutely negative — oxygen; and but one absolutely posi-
tive
- potassium : between these extremes, they may be made
to assume either positive or negative states. To account for
the decomposition of water, we must conceive of a line of
particles between the two electrodes, along which the current
passes. When a particle of oxygen is evolved at the positive
electrode, its hydrogen is not transferred at once to the op-
posite electrode, but unites with the oxygen of the contiguous
particle of water, on the side towards which the positive
current is moving; then it passes to the next, and so on, until

Magnetic Effects of Electricity.
91
it arrives at the pole. A similar row of particles of oxygen
start from the negative electrode at the same moment, and
combine successively with the particles of hydrogen as they
pass them on their way to the positive pole or electrode. * It
is supposed that other compounds are decomposed by a
similar
process.
Magnetic Effects of Electricity, or Electro-Magnetism.
History. It had been noticed for a long time that, when a
ship, for example, was struck with lightning, the magnetic
needle often had its poles destroyed or reversed, and that the
iron often became magnetic. This led to the supposition,
that electricity might be employed to communicate the mag-
netic properties to iron or steel ; but no results of importance
were obtained until the winter of 1819, when Prof. Oersted,
of Copenhagen, made his famous discovery, which forms the
basis of a new and
very important branch of science.
I. Influence of Voltaic Currents upon the Magnetic Nee-
dle. The discovery made by Oersted was, that the me-
tallic wire, or any part of a closed voltaic circle, causes a
magnetic needle, when brought near it, to deviate from its
natural position, and assume positions depending upon the
relative position of the needle and the wire.
Thus, suppose a magnetic needle freely suspended with its
poles pointing north and south. (See fig. 41.)
1. İf, now, a positive current pass from north to south in
the same plane with the needle, but a little above it, the north
pole will turn to the east, and the south pole to the west.
2. If the current pass under the needle, the north pole
moves west, and the south east.
3. If the current pass on the west side of the needle, and
in the same horizontal plane, the magnet will have a tendency
to move in a vertical direction, the north pole being elevated,
and the south depressed.
4. If the current pass on the east side, the north pole is
depressed, and the south elevated.bg
5. If the current flow from south to north, the needle will
move in opposite directions.
*
The
quantity of electricity sufficient to decompose a single grain
of water would be equal to a powerful flash of lightning.

92
Magnetic Effects of Electricity, or
The deflection is rarely 45°, in consequence of the mag-
netism of the earth; but if that force is counteracted, as it
inay be, by suspending two magnets near each other, of equal
power, with their poles reversed, the declination will be 90°;
hence the tendency of a magnetic needle is to stand at right
angles to an electric current.
6. If the wire be placed in a plane, perpendicular to the
one in which the magnet moves, and the positive current
ascends or descends to the centre of the needle, no action
will take place; but if it be moved towards the north or south
poles, they will be attracted or repelled. Hence the plane in
which a needle moves is always perpendicular to that in which
the voltaic currents circulate.
7. The phenomena of Electro-Dynamic action result
wholly from electricity in motion, and depend upon quan-
tity alone; hence a simple circle of large plates is best fitted
for exhibiting it.*
From the above facts it will be seen, that the magnetic
needle may be employed, not only to ascertain the existence
and direction of voltaic currents, but also to measure their
force. The instruments used for these purposes are called
Galvanometers or Multipliers. As it is proved by experi-
ment that every part of a wire in a closed circuit exerts an
equal force upon the poles of a needle, if we can increase
the number of points, the combined force will be greatly
increased. This can be done by coiling the wire into the
form of a circle or rectangle; each coil will exert its own
force, independent of its neighbor, and the united force will
depend upon the num-
ber of coils. Thus (Fig.
Fig. 41.
41) NP are the two ends PN
of a copper wire bent in
W
the form of a rectangle,
in the centre of which,
в | 4
and in a plane perpendic-
ular to the plane of the
wire, is placed a mag-
netic needle. A graduate
ated circular plate meas-
1
a
SA
W
* The simple battery, Fig. 35, p. 80, is best fitted for experiments on
this subject. The exciting liquid should be a solution of sulphate of
copper.
bat

Electro-Magnetism.
93
ures the degree of declination, which indicates the quantity
of electricity circulating along the wires. It will be seen,
that if the positive current pass above the needle from north
to south, that is, from P to a, and then pass around the south
pole from A to B, there will be double the effect produced.
By increasing the number of coils, the deflection of the
needle will be much greater. This constitutes the Electro-
Magnetic Multiplier of Schweigger.
If the directive power of the needle be destroyed, or if the
currents are sufficiently powerful, the needle will stand at
right angles to the direction of the currents. Then, if, at the
moment it has attained this point, the currents be sent in an
opposite direction, it will perform a revolution. Thus, by
changing the direction of the currents, a needle
may be made
to revolve rapidly.
Te
Her
If the magnet is fixed, and the rectangle suspended free to
move, it will exhibit the same phenomena while the voltaic
currents are passing around it. ballora
alat
BV
Fig.
acento arba
11. Bolog orko ontslae te
42.
ei
y
3210
zĮ
["
S
N
M
M
ali
Samoa

94
Magnetic Effects of Electricity, or
nes around
The Revolving Rectangle is constructed on this principle
.
MM (Fig. 42) is a permanent horse-shoe magnet; C, a ree-
tangular coil of copper wire, connected at each end to an
axis, by which means it may be made to revolve; ZP are two
cups, to form a connection with the poles of a battery; the
wires bb are connected with the cups, and press on opposite
sides of the cylindrical metallic pole-changer, which revolves
between them. The pole-changer consists of two pieces of
silver, with a small space between them; one of these pieces
is connected with one end of the wire of the rectangle, and
the other piece with the other end; a is an arch of brass to
support the rectangle and the wires. If the two cups be
connected with the battery, P with the positive, and Z with
the negative pole, the positive current will pass along the
wire b next to N, and from the wire to one side of the pole-
changer, and thence several times around the rectangle to
the wire b next to S.
When the positive current is passing from P around this
rectangle, one side is impelled towards one pole of the magnet,
and the other towards the other pole. When the sides arrive
in the plane of the poles, the force still continues to act, and
they are forced by, and complete half a revolution, standing
again at right angles to the poles of the magnet, the point at
which they commenced their revolution : at this point the
pole-changer sends the currents in opposite directions, and
the revolution is continued. Reverse the current, by chang-
ing the battery wires, and the rectangle will revolve in an
opposite direction.
II. The influence of voltaic currents on soft iron and steel
was noticed by Davy and Arago about the same time. If an
iron or steel needle be suspended in the galvanometer instead
of the common needle, at right angles to the conducting
wires, permanent magnetism will be communicated to the
steel, and the iron will become powerfully magnetic, as long
as the currents circulate, but will lose this property when
the circuit is broken. Davy succeeded in producing a similar
effect by a discharge from a common electric battery.
1. This effect can be exhibited in the most satisfactory
manner by coiling an insulated copper wire in the form of
a helix, d, (Fig. 43,) and connecting the two ends of the wire
bb with the cups CZ, into which the poles of a battery may

Electro-Magnetism.
95
71
S
KUID
CE
be inserted. Bars of soft iron or Fig. 43.
steel, placed in the coil, will become
magnetized the instant the voltaic cur-
rents circulate around the coil. If
the positive current flows from Z
7
6
around the helix, n will be the north
pole, and s the south pole. If it flow
from C, the poles will be reversed.
2. If a bar of soft iron (Fig. 44)
be wound with copper wire from c to
a in one direction, and from a to d in
an opposite direction, and currents of
electricity passed around the bar, by od
connecting the wires we
Fig. 44.
with a voltaic battery, the
d
bar will have three poles ; C
and d will be similar poles,
and a an opposite pole com-
6
mon to the other two, as
may be shown by bringing a
magnetic needle near each.
By changing the direction base
‘of the battery currents, the
poles are reversed; hence
the kind of pole depends upon the
Fig. 45.
direction of the voltaic currents.
3. Although soft iron does not re-
tain its magnetism, yet its magnetic
properties, while the voltaic currents D
are passing around it, are truly sur-
prising
B
If a soft iron cylinder, two inches in
diameter, and bent in the form of a
horse-shoe magnet D, (Fig. 45,) be
wound with copper wire, and the ends
BC connected with the battery, it will
be converted into a powerful magnet.
On applying the armature A, it will
sustain several hundred pounds. Mag-
nets of this description may be made
to sustain from 200 to 2000 lbs. It
will be seen that the principle is the
same as in the helix; and, as in the mul-

96
Magic Circle.
T т
56
tiplier, by increasing the number of coils, the magnet becomes
more powerful, but the force does not increase directly as the
number of coils; for each additional coil is farther from the
axis of the iron bar, and the power it exerts is inversely as
the square of the distance from the axis.
4. The Magic Circle, with two iron ar- Fig. 46.
matures, acts also on the same principle.
r (Fig. 46) is a coil of insulated copper
3
wire; ab the two ends which may be con-
nected with the battery. When the wires
b a are connected with the battery, and the
two armatures are brought into contact, one
of them passing through the ring, they adhere
to each other very strongly, and, although
they weigh less than 3 lb., they will sustain a weight of 56 lbs.
without separation. The voltaic currents not only communi-
cate magnetism to the iron and steel placed in the ring, but
the helix itself becomes magnetic while transmitting the cur-
rents, as is proved by its attracting iron filings. These and
other facts, developed by voltaic currents, seem to prove the
identity of the magnetic and electric fluids.
5. Vibrating Magic Circle. MM (Fig. 47) is an electro-
magnet, which may be used instead of a permanent magnet;
C, a coil of coarse wire suspended from the post S; one end of
the wire a dips into the cup e, which is connected with the post
S, and which also communicates with p; the other end of the
wire d is connected with the other cup, which is insulated
from the post S,
and into which
Fig. 47.
also one of the
poles of
the
e
battery may be
immersed; con-
nect the other
pole of the bat-
tery with p, and
current of
electricity will
pass along the
post S to the
cup e; as the
wire a dips into
it, the current
old
M
a

Volta-Electric Induction.
97
will pass down the wire b around the coil
C, and then up
the
wire d to the other cup; as the currents circulate, the coil
will be attracted to the pole of the magnet M; this will lift a,
and break the circuit, and the coil will fall back beside the
pošt S; a will again be immersed in e, and the coil be again
attracted upon M. Thus vibrations are produced as long as
the currents of electricity circulate.
III. Volta-Electric Induction. The fact that an electri-
cally-excited body induced electricity in other bodies brought
near it, (page 75,) led Faraday to inquire whether electricity
in motion would not have the same effect. This fact he soon
established.
If a copper wire be wound in the form of a helix, and the
ends connected with a battery, and then another wire be
wound around this, but insulated from it, and the ends con-
nected with a galvanometer, currents of electricity will be
induced in the insulated wire, as often as the battery current
is broken. All the effects of galvanism may be produced by
the insulated wire.
The phenomena of Volta-Electric Induction may be ex-
hibited in the most satisfactory manner by the
Fig. 43.
MI
3
ET
5
begro
9

98
Volta-Electric Induction.
Separable Helices, (Fig. 48,) an apparatus very well fitted
for illustration, for producing sparks, and imparting shocks
of almost any degree of intensity.
b (Fig. 48) is a hollow coil of coarse wire fixed upon a
stand, Z; one end of the wire is connected with the cup, and
the other with the steel break-piece, * which is fixed to the
stand, by the side of the coil; a is a coil of fine wire, which
may be placed over the coil b; d is a bundle of wires, which
may be slipped into the copper case c, and placed in the
centre of the coil b.
Fig. 49.
Com
a les
ou
of
7 en
Fig. 49 represents this apparatus entire. The following
are the principal facts which it is fitted to exhibit :-
Exp. Connect one pole of the battery with the cup on the left of c,
(Fig. 48,) and move the other pole along the break-piece; vivid sparks
will be produced at each interruption.
Exp. Remove from the wires d the copper case c, and insert them
gradually in the coil b while the currents are circulating, and the
sparks on the break-piece will increase in brilliancy until the wires
reach the bottom, when the greatest effect will be produced.
* A break may consist of air, or any non-conductor, so connected
with a conductor, that, when the wire conveying the voltaio current
passes from the conductor to the non-conductor, the circuit may be
broken; and it is only at the moment of interrupting the battery current
in the inner, that electricity is induced in the outer coil,

Magneto-Electric Induction.
99
Exp. Place the coil a upon b, and let the currents circulate as before.
If the handles e f, (Fig. 49,) which communicate with the extremities
of the wire forming the coil a, be held in the hands, powerful shocks
will be felt as the wire conveying the battery current passes across the
break-piece. As the outer is insulated from the inner coil, the shocks
do not proceed from the battery current, but from currents induced in
the wire of the outer helix. Currents thus induced produce all the
phenomena of the battery currents.
Exp. A single wire* will increase the power of the shocks, and by
increasing the number of wires, the sparks will increase in brilliancy,
and the shocks will become more and more powerful. 2
Exp. If the copper case be placed upon the wires, the effect will be
the same as when no wires are used.
IV. Magneto-Electric Induction.
The power
of the
magnet to induce electricity greatly exceeds that of vol-
taic currents.
Tig, 50.
n
-lo
labore
MAS
e
The apparatus best fitted to exhibit this effect is the Mag-
neto-Electric Machine, (Fig. 50,) which consists of a perma-
nent horse-shoe magnet, SN, supported by pillars upon the
stand Z, and an armature, g, wound with copper wire, and
made to revolve upon an axis, c, near the poles of the magnet,
by means of the wheel h; one end of the wire is soldered to
the axis, by which means it is connected with a break-piece,
against which the wire e presses; the other end of the wire
Fine wires answer a better purpose than a solid bar; if, however,
the bar be slit lengthwise down to the axis, the effect will be nearly
equal to the wires, and if the copper case be sawed open lengthwise,
it will not destroy the effect of the wires.

100
Theory of Electro-Magnetism, etc.
is soldered to a silver ferule, a, insulated from the axis, against
which the wire b presses; the wires eb communicate with
the
cup
into which the wire p is inserted; the wire n is con-
nected with the axis by means of the post on the right of b;
P and n therefore represent the two ends of the wire which
surrounds the armature. When the armature is set in motion
by the multiplying-wheel h, its magnetic state is continually
changing. When the two extremities of the armature are
midway between the poles of the magnet, the armature is
neutral. As they advance towards the poles, they acquire a
gradually-increasing polarity, until they are opposite the poles,
and gradually diminish, as they pass the poles, until they are
midway again between the poles, when the armature becomes
neutral, as before. By this revolution, a current of elec-
tricity will be induced in the wire which surrounds the arma-
ture, and will pass from the break-piece to the ferule, by
means of the wire e b, which connects them; excepting,
when the end of the wire e is passing across the break-piece,
then there will be induced in the wire which surrounds the
armature a secondary current, which passes by sparks at each
point of interruption, or at the wires p n, if they are brought
+ nearly into contact. By pressing the hands, previously moist-
ened, upon the handles connected with p n, powerful shocks
will be felt at each interruption. Deflagrations may also be
produced, and decompositions effected, and generally the
electricity thus induced produces effects precisely similar to
those from the voltaic battery. The phenomena of elec-
tricity, thus produced, are sometimes called Magneto-Elec-
tricity.*
V. Theory of Electro-Magnetism and Magneto-Electricity.
In order to understand the theory of M. Ampere, by which
the phenomena of electro-magnetism and magneto-electricity
may be best explained, it is only necessary to keep in view
the following principle, which lies at the basis of the theory:
When two positive or two negative currents are passing in
the same direction, and parallel, they attract, and when pass-
ing in opposite directions, they repel each other.
* The best apparatus for experiments upon electro-magnetism and
magneto-electricity, is manufactured by Daniel Davis, Jr. No. 11,
Cornhill, Boston.

Theory of Electro-Magnetism, etc.
101
If, now, we suppose that all magnetic bodies, and the earth
itself among the number, derive their magnetic properties
from currents of electricity circulating, in reference to their
axis, in one uniform direction of revolution, we can account
for all the phenomena of Magnetism, Electro-Magnetism, and
Magneto-Electricity. Yordamotores de Vos
Fig. 51.
To make this view clear. Suppose that
around the cylinder of steel, (Fig. 51,) at right
angles to the axis, currents of positive electricity
are constantly circulating in a direction opposite
to that in which the sun moves. The cylinder
will be a magnet, n the north pole, and s the
south pole, and, if it be poised upon a pivot, it
will differ in nothing but in form from a mag-
netic needle.
fleto
Application of the Theory. 1. The reason
that the needle turns to the east when the
positive current passes above it from north to
south is, that the currents in the magnet, and those in the
wire, move in different directions. The needle is repelled,
and turns so that the currents may coincide.
2. When the positive current passes under the needle, it
moves to the west, because then also the two positive currents
coincide.
3. When it passes on either side in the same horizontal
plane, it tends to a vertical motion, for the same reason as
above; but if the positive current passes from south to north,
the phenomena are all reversed.
4. When it passes around the poles in a vertical plane, in
the same direction in which the sun appears to move, the
needle will perform one half a revolution, because the cur-
rents move in opposite directions, and the needle revolves so
that the currents in it may coincide with those in the con-
ducting wire.
5. Bars of steel and soft iron become magnetic when
placed in the helix around which currents of electricity
circulate, because similar currents are induced in them.
9*

102
Thermo-Electricity.
6. If we suppose positive currents of electricity to be
passing around the earth in the same direction in which the
sun appears to move, they would convert it into a magnet,
the north pole of the earth corresponding to the south pole of
the magnetic needle; hence, if soft iron or steel bars are placed
in a north and south direction, they will become magnets by
induction, the positive currents passing from west to east,
because then they would coincide with the same currents in
the earth which pass from east to west; hence the reason
that a magnetic needle stands north and south, is, that the
currents of electricity circulating around the earth, and those
circulating in the needle, will coincide only when the needle
takes that direction.
VI. Thermo-Electricity. Thermo-electric phenomena re-
sult from currents of electricity excited in metals by heat.
The existence of these currents was first demonstrated in
1821 by Seebeck.
If a magnet be suspended in a rectangle formed of a bar
of antimony or bismuth, having its extremities connected
with copper wires, and heat applied to one end of the bar,
the needle will be deflected in one direction, and in an
opposite direction when heat is applied to the other end.
Similar effects are produced when either end is cooled below
the natural temperature. Other metals, treated in the same
manner, exhibit similar phenomena, but bismuth and an-
timony are the best. Prof. Cumming has shown that a
rotary motion may be produced by placing platinum and
silver wires, soldered together in a circular form, upon a
magnet, and applying heat.
VII. Nature of Electricity. Some suppose that there is
no transfer of any thing in what are called electric currents,
but a process of induction passing progressively along among
the molecules of a conductor. Others ascribe them to waves
of vibrating matter, just as the phenomena of light and
caloric are explained, by the undulatory theory.
VIII. Uses of Electricity. 1. Both voltaic and common
electricity have been employed in medicine ; in some cases,
with highly beneficial effects. It acts powerfully upon the

Electro-Magnetic Telegraph.
103
as
nervous system, and has been the means of restoring sen-
sation to parts of the body which had become paralytic;
so powerfully does it act upon the vital energies, that persons
who have been deprived of life, either by some accident, or
by design, have been resuscitated by its agency. Its influ-
ence is constant and universal in the animal, vegetable, and
mineral kingdoms. loog
2. Attempts have been made to employ voltaic electricity
a motive power in the arts, to supersede the use of
steam; but all attempts hitherto have been unsuccessful. Suf-
ficient power has been generated to turn a small lathe; and it
is to be hoped that an apparatus will yet be constructed to
render available the great force which this agent is capable
of exerting. This force depends upon the property of the
voltaic currents to communicate magnetism to soft iron,
thus producing a powerful attraction, and the property of the
iron to change its poles, and consequently its attracting and
repelling power as currents circulate in different directions.
(See Fig. 42.)
3. Electro-Magnetic Telegraph. A most beautiful and
useful application of voltaic electricity, to communicate in-
telligence from one place to another, has lately been made,
in the Electro-Magnetic Telegraph. Two stations are taken
at some distance apart; at one of the stations is the battery,
with wires extending to the other station, and connected with
a magnetic needle in such a way that, when the wires are
attached to the battery, a motion is produced in the needle,
to which is attached a pencil, to mark certain characters
which are agreed upon as symbols of ideas.
The wires at the second station may be connected with an
electro-magnet, upon the poles of which an armature, having a
letter or word, may be attracted the moment the currents circu-
late. In this case, there must be as many electro-magnets as
there are letters employed. The experimenter at the first sta-
tion inserts the wires a, for example, in the battery, and the
observer at the second station sees the armature move upon the
poles of the electro-magnet, raising the letter a; the wires con-
nected with the letter 6 (or any other letter) are then inserted,
and b rises. In this way any word may be spelled. A pencil
may be attached to the armatures, to mark in a line all the a's,
and in another line all the b's, and so of all the other letters;
hence the words may be written down so as to be easily read.
Intelligence may thus be communicated to any distance that
is desired with the rapidity of lightning.

104
Electricity. - Electrography,
4. Electrography. A still more recent application of
voltaic electricity has been made to the “production of
perfect metallic casts or copies of medals, copperplates, and
other works of art." The discovery appears to have been
made about the same time, by Prof. Jacobi, of St. Petersburg
,
and Mr. Spencer, of Liverpool. The instrument by which
this effect is produced is the
Electrotype; and the effect depends upon the decomposition
of some metallic salt, by which the metal is precipitated upon
the object to be copied, either forming a mould for the cast
,
or raising lines which may be used for making impressions
on paper or other materials. *
Fig. 52.
Fig. 52 represents one form of the
ads
electrotype, and the mode of taking
impressions. A is a glass vessel, in
which a division is made by casting
across it plaster of Paris, (earthen
ware, a bladder, or any porous mem-
А.
brane, as thick pasteboard, will answer
the same purpose.) Into one of the
partitions is put a saturated solution
of sulphate of copper, and into the
other acidulated water. The object
C to be copied is soldered to one end of a wire, d, and
piece of zinc, Z, to the other end; the object is then immersed
in the cupreous solution, and the zinc into the acidulated
water. The deposit of metallic copper then commences
upon the object c, copying, with the most scrupulous exact-
ness, every line, and even the shades of polish. In about
two or three days, a complete mould may be obtained.
The copper mould is separated from the matrix by gentle
heat.
ON
ఆం
a
Theory. The metallic salt and the water are both decomposed. The
sulphate of copper is resolved into sulphuric acid and oxide of copper,
the water into oxygen and hydrogen. The acid and oxygen go to the
zinc, and the hydrogen and the oxide of copper to the copper pole, the
hydrogen unites with the oxygen of the oxide of copper, and the me-
tallic copper is deposited upon the metal or object to be copied.
* For a description of this process, see Journal of Science, Vol. xl.
No. 1; also, Part IV. of Griffin's Scientific Miscellany.

TESTY
PART II.
iwifrog
CHEMICAL AFFINITY.
AUTO
entre
In all those phenomena, which appropriately come under
the observation of the chemist, chemical affinity is the great
cause to which they are referred. Other agents, as light,
heat, electricity, cohesion, etc., modify its action, and some
knowledge of them is therefore an essential preparation for
the study of this, — the great subject of chemistry. The de-
tails, to which we shall attend in the examination of particu-
lar substances, are, almost exclusively, but the effects of this
principle. The student, therefore, should be familiar with
the circumstances which modify its action, its varieties or
different modes of operation, its effects, and especially the
laws in accordance with which these effects are produced.
Chemical Afinity is an attraction, which acts only at in-
sensible distances, between particles of different kinds.* Co-
hesion is distinguished from it, by acting only between par-
ticles of the same kind, as well as by being governed by dif-
ferent laws.
Varieties of Chemical Affinity.
Although this power is the same in all cases, it will facili-
tate the progress of the student to distinguish some of the
* A late writer (Griffin, Chemical Recreations) maintains that there
is no such thing as chemical affinity, because we know merely that
bodies combine. We might as well deny that any force or power ex-
ists because we see only, its effects. From the fact that bodies do com-
bine, we infer that some power causes them to combine, although,
indeed, we know nothing of it, except in its effects.

106
Varieties of Chemical Affinity.
different cases in which it operates. Between many sub-
stances it does not exist at all, as is seen in mixing oil and
water. The most simple case is the direct union of two sub-
stances, as when oxygen gas and iron unite, and form iron
rust. This is called Simple Affinity. The combination of
alcohol with camphor is another example.
Exp. But if water be added to this solution of camphor, the alcohol
will combine with the water, and desert the camphor, which again ap-
pears free, or is technically said to be precipitated. As the alcohol
appears to choose the water in preference to camphor, such cases are
called examples of single elective affinity.*
The following are examples of the same kind :-
Exp. Into a solution of sulphate of copper (blue vitriol) immerse a
clean iron wire; the sulphuric acid (oil of vitriol) will elect the iron,
and the copper will be precipitated, forming a metallic coating upon
the wire.
Exp. Into a solution of protonitrate of mercury put a sheet of cop-
per, or cents, well cleaned with dilute sulphuric acid; the nitric acid
will elect the copper, and the metallic mercury will be precipitated,
and form a covering over the cents, which will give them the appear-
ance of silver.
But, in other cases, two compounds mutually decompose
each other, and form two new compounds.
Exp. Thus, if carbonate of ammonia and hydrochlorate of lime be
mingled, each will be decomposed. The former consisting of carbonic
acid and ammonia, and the latter of hydrochloric acid and lime, the
carbonic acid will unite with the lime, and the hydrochloric acid with
the ammonia, forming carbonate of lime, and hydrochlorate of ammo-
nia. This change may be very easily understood from the annexed
formula, in which the symbols are used.t
© + Am.
Ö abandons Am. and goes to Ca; at the
same time HCl abandons Ca, and goes to Am.;
and the results are ☺ + Ca and HCl + Am.
HCl + Ca.
* Elective affinity is the basis of chemical science; for if each sub-
stance attracted every other with the same force, when combination
had once been effected, the decomposition of many, if not of most
substances, would be impossible; hence there would be but few
changes in matter which would come under the investigation of the
chemist.
+ i=Carbonic acid, and Am.=Ammonia; HCI=Hydrochloric
acid, and Cå.=Lime.

Operation of Chemical Affinity.
107
Exp. To a solution of alum (sulphate of alumina and potassa) add
a solution of acetate of lead. Sulphate of lead and acetate of alumina
are formed by a double decomposition. The sulphate of lead will be
precipitated, and the acetate of alumina will remain in solution.
Exp. Nitrate of ammonia and sulphate of soda will mutually decom-
pose each other. In all cases of double decomposition, the alkali in one
of the compounds will just neutralize the acid in the other, so that, if
any delicate test of an acid or an alkali (as vegetable infusion) be
placed in the mixture, no effect will be produced upon it; hence, as
the quantities of acid and of alkali, in all neutral salts, are just suffi-
cient to saturate each other when double decomposition takes place,
these quantities are called equivalents.
Such cases are examples of double elective affinity * Cases
are more numerous, however, in which the changes are much
more complicated; but they may all be referred to the three
modes stated above.
Circumstances which modify the Operation of Chemical
Affinity.
That one substance has a stronger affinity for some than
for others, cannot be doubted. But combination and decom-
position do not always depend upon the relative force of af-
finity alone.
Severay circumstances modify the operation
of this power. These are, cohesion, elasticity, quantity of
matter, gravity, and the imponderable agents.
I. Cohesion. In order that substances should combine
with each other, it is necessary that their particles should be
in contact. But cohesion holds together the particles of each
substance, so that they cannot be freely intermingled. Co-
hesion must, therefore, be destroyed to facilitate chemical
action. This may
be effected in three ways:-
1. By reducing the substance to powder.
Exp. Take two pieces of crystallized nitrate of copper; roll one of
them
up in tin foil; grind the other to powder, and wrap it in a piece
of the same metal; drop a little water upon both as they are rolled
· In a few minutes, that which is pulverized will combine with
the metal, and burst into a flame, while the other will not be affected.
Exp. Take two equal portions of chalk, and pulverize one; pour
up.
* Single and double elective affinity are the same in principle. The
only difference is, that, in the one case, a compound is decomposed by
a third substance, and but two affinities are in operation, while, in the
other, two compounds mutually decompose each other, and four affin-
įties are brought into action.

108
Operation of Chemical Affinity.
In this ex-
*:
dilute sulphuric acid on each, and the action will be rapid in the case
of the pulverized chalk, but moderate in the other case.
periment, one of the substances is in solution; and usually it will be
found insufficient to pulverize both substances, and resort must be had
to the second method.
2. By dissolving the body in some liquid.
Exp. Mix together tartaric acid and carbonate of soda; no action
will follow; pour on water, and they will be dissolved, and a violent
action ensue.
Solution is effected when a solid is put into a liquid, and
entirely disappears, leaving the liquor clear. The body
which thus disappears is said to be soluble ; the liquid is
called a solvent, and the compound liquor a solution. Water
is the principal solvent; alcohol, ether, oils, alkalies, and
acids, are also employed. When water, or any solvent, has
dissolved as much of any substance as it can, it is said to be
saturated, and the solution is called a saturated solution.
Solution should not be confounded with diffusion, which
is merely a mechanical mixture.
Exp. This distinction may be seen by mixing magnesia in water.
The particles of magnesia are suspended at first in the water, rendering
it turbid, and they would soon subside to the bottom; but if nitric acid bề
added, the magnesia will be dissolved, and the water will become clear.
Most substances are more soluble in hot than in cold
water; as a hot saturated solution cools, the water will not
therefore be able to hold in solution all of the substance
which had been dissolved, and it appears again in a solid
state. The power of cohesion has the ascendency over the
affinity of the liquid for the solid, and forms the latter into
crystals. Hence the phenomena of crystallization are owing
to the ascendency of cohesion over affinity.
By evaporation, also, the solid may be recovered from so-
lution. În either case, the crystallization is often confused,
especially when the process is rapid.
Insolubility has been found to exert a remarkable influence
on affinity, in the case of an alkali with two acids, or an acid
with two alkalies, one of which will form with the alkali a
soluble, and the other an insoluble compound. The one
which is insoluble is always formed in preference to the solu-
ble compound.
Exp. Thus, if nitric and sulphuric acids and baryta be thrown to-
gether in water, sulphate of baryta, which is insoluble, will be formed
in preference to nitrate of baryta, which is soluble.
It is obvious that, while the solution of one of the substances

Operation of Chemical Affinity.
109
is usually necessary, the solution of both will further facilitate
the action. It
Handle or aby
3. By heat. Fusion is there duction of a solid to a liquid
state by caloric, and facilitates chemical action by enabling
the particles to intermingle, and come within the sphere of
each other's affinity. In liquids a slight degree of cohesion
remains, and hence heat is applied to them with advantage.
A hot liquid will act more powerfully upon most solids than
the same liquid when cold. bongo mo
II. Elasticity. Cohesion, as we have seen, opposes
chemical action by keeping the particles out of the sphere
of each other's influence. Elasticity, or the gaseous state,
is still more unfavorable to the operation of affinity, because
the particles are removed too far from each other to be at-
tracted; hence most gases, though possessing a strong attrac-
tion for each other, will not combine unless they are in the
nascent state, that is, when in the act of assuming the gase-
ous form.
In this way elasticity not only prevents chemical union,
but it favors decomposition. to cart Bluz
1. When two highly-elastic gases combine, forming a
liquid or solid, the compound will be decomposed by a very
slight cause: the chloride of nitrogen is a familiar example.
It is an oily liquid, composed of two gases. A slight eleva-
tion of temperature will cause instant decomposition, even
with explosive violence. Generally all compounds which
contain a volatile principle are easily decomposed by a high
temperature. Hence caloric sometimes favors chemical action
by destroying cohesion, while at others it prevents it, and
favors decomposition by promoting elasticity.
2. There are some gases, however, which readily combine
at a high temperature, as in the case of gaseous explosive
mixtures. Oxygen and hydrogen gases require the heat of
flame to effect their union. The caloric, in such cases, ac-
cording to Berthollet, expands the gases in immediate con-
tact with the flame, which acts as a violent condensing force
to contiguous portions, and brings them within the sphere of
each other's attraction. The same explanation is applied to
the combination of gases effected by passing electric shocks
through them.
III. Quantity of Matter. Oxygen combines with lead in
10

110
Operation of Chemical Affinity.
three proportions, forming three distinct compounds. The
peroxide, or that which has the greatest quantity of oxygen,
is easily decomposed by heat; the second compound, in
which there is less oxygen, requires a higher temperature to
effect decomposition; and the third, which has the least oxy-
gen, will sustain the heat of our furnaces without yielding up
its oxygen. Hence, generally, when one substance combinés
with another in several proportions, the affinity is stronger in
the case of the less than of the greater portions.*
On this principie, also, when a salt is dissolved in water,
the first portions are dissolved more rapidly than the last, and
the force of affinity diminishes up to the point of saturation,
when it is overcome by the cohesion of the solid.
This principle led Berthollet to account for all chemical
changes without the aid of affinity, the existence of which he
was disposed to deny; but M. Dulong has found that the
principle of Berthollet is not in accordance with the results
of experiment.
IV. Gravity. The influence of gravity on chemical action
is seen when substances of different specific gravities com-
bine; as, when two liquids are put together, the heavier
liquid will sink to the bottom; or, when salt is dissolved in
water, the salt will remain at the bottom, and prevent the
particles of water from coming into contact with those of
the salt,
V. Imponderable Agents. The influence of caloric over
chemical phenomena has already been alluded to. It favors
chemical action in the case of solids, by destroying cohesion,
and opposes chemical action in the case of gases, by increas-
ing their elasticity. The influence of light has already been
noticed. Common electricity is often employed for the com-
bination of gases, and galvanism for decompositions; but the
same effects may be produced by either.
* In consequence of the influence of quantity of matter over chem.
ical changes, the chemist generally employs more of one substance
than is necessary to effect the decomposition of another.

Measure and Effects of Chemical Affinity.
111
Measure of Affinity.
Since some substances have a stronger affinity than others,
attempts have been made to measure its different degrees of
force. It was once supposed that its relative strength could
be ascertained by the order of decomposition, as may be ex-
plained from the following table:-
Sulphuric Acid
Baryta,
Lime,
Strontia,
Ammonia,
Potassa,
Magnesia.
Soda,
If to the sulphuric acid, united with the magnesia, forming
the sulphate of magnesia, ammonia be added, the acid will
leave the magnesia, and elect the ammonia, forming the sul-
phate of ammonia. If to this, lime be added, the acid will
desert the ammonia, and unite with the lime; this again will
be decomposed by the soda, and so on to baryta. Hence
sulphuric acid has the strongest affinity for the baryta, and
the force is in the order in which the several substances are
arranged.
Exp. This order may be shown experimentally thus: To a filtered solu-
tion of nitrate of silver add metallic mercury; the silver will be precip-
itated, and the nitric acid will combine with mercury, forming the nitrate
of mercury. Immerse in this a piece of clean sheet lead; the mercury
Suspend in the pastrim arel emne cloppet the read will be thrown down,
and the nitrate of copper will remain in solution.
In this place a sheet of bright iron, and in a short time the iron will
displace the copper, forming a solution of nitrate of iron.
this
present a piece of zinc; the iron will be separated, and the
zinc will combine with the acid.
Add liquid ammonia; the zinc will be separated, and nitrate of ammo
nia remain in solution.
To this pour lime water; the ammonia will be liberated in the forni
of a gas, and nitrate of lime remain in solution.
Add to this oxalic acid, and the oxalate of lime will be thrown down,
while a mixture of water and nitric acid remains.
Hence the practical chemist, when he wishes to decom-
pose any compound, is enabled to decide
upon
the substance
which will produce that effect.
But the circumstances which modify the action of chemical
affinity are so numerous, that the order of decomposition is
not, in every case, the measure of affinity. To determine the
To

112
Effects of Chemical Affinity.
2
relative force of affinity in doubtful cases, observe the ten-
dency of several substances to unite with the same, under
the same circumstances; and then notice the apparent facility
of decomposition, when these compounds are exposed to the
same decomposing agent.
Dk
- od
side
ber
Effects of Afinity.
ORD
The changes which accompany the action of affinity are
changes of chemical properties — of color, form, temperature,
and specific gravity.
I. Change of Chemical Properties. It is one of the most
remarkable facts in chemistry, that, when two bodies combine
chemically, the compound is generally possessed of properties
entirely different from those of the components.
Exp. 1. Pour sulphuric acid upon magnesia, and the compound will
be Epsom salts, entirely unlike either.
Exp. 2. Burn oxygen and hydrogen gases, and water will be
formed, which is wholly different from either of its constituents.
There are some cases in which affinity produces com-
pounds without much change of properties, as in the case
of solution ; but the force of affinity in such cases is very
feeble.
Exp. Salt dissolved in water, and camphor in alcohol, are instances.
II. Change of color is often the effect of affinity.
Exp. 1. To the chloride of calcium add nitrate of silver, both in
solution ; a white precipitate will be formed, which is the chloride of
silver. (See page 69.)
Exp. 2. To a solution of nitrate of lead add a few drops of hydriodic
acid, and a beautiful yellow pigment will be formed.
Exp. 3. Into an infusion of purple cabbage pour a few drops of any
alkali, and the color will become green ; add an acid gradually, drop
by drop,* and the purple color will be restored; add a few drops more
*
Fig. 53.
ilar purposes, the drop-
ping tube a (Fig. 53)
may be used. It is a
glass tube, with a bulb,
as a, with a small ap-
erture at the smaller
end, through which,any liquid may be drawn up into the bulb by pla-
cing the mouth upon the larger end. Having partially filled the bulb,
place the thumb over this end, and, by admitting the air slowly, the
liquid will drop out at the smaller end.
* For this and sim-

Effects of Chemical Afinity.
113
ܒܪܵܐ
of acid, and it will become red. By the gradual addition of the alkali,
the effects may now be reversed.
III. Change of form frequently accompanies chemical
combination.
Croce
Exp. 1. Take oxygen and hydrogen gases, and explode them; they
will form a liquid water. Hence chemical affinity converts gases into
liquids.
Seto
Exp. 2. If the two gases,
Fig. 54.
ammonia and the hydrochlo.
ric acid, be brought together You
in their nascent state, i. e.,
at the moment of their for-
mation, they will produce
the solid hydrochlorate of
ammonia. Hence chemical
affinity converts gases into
solids. The two gases may
be formed by putting hy.
drochlorate of ammonia and
om
lime in one retort, (Fig. 54,) and liquid hydrochloric acid in the other,
and applying heat; as the gases meet in the glass receiver b, they will
combine and form a white solid.
Exp. 3. Take chloride of calcium in solution, and pour in sulphuric
acid ; a solid precipitate — the sulphate of lime = will be thrown down
Hence affinity converts liquids into solids.
Exp. 4. Into a solution of pearlash or saleratus pour sulphuric
acid, and a portion of the liquid is converted into the form of a gas,
which escapes with effervescence.
Exp. Add one part of fuming nitric acid to two of alcohol; both liquids
will be converted into ammonia, and pass off in gas. Hence affinity
converts liquids into gases.
Exp. 5. Mix two solids, the nitrate of ammonia and sulphate of
soda; on rubbing them in a mortar, they will become liquid. Hence
chemical affinity converts solids into liquids.
Exp. 6. Explode gunpowder; it will be wholly converted into gas.
Hence chemical affinity converts solids into gases.
IV. Change of Temperature. The heat arising from the
combustion of fuel, is owing to chemical action.
Exp. Wet a piece of paper with spirits of turpentine and sulphuric
acid, and then throw on a few grains of chlorate of potassa; the paper
will instantly be in flames.
V. Change of Specific Gravity. In changes of gases into
liquids or solids, or of the latter into the former, there is, of
course, a great change of density. But where there is no
change of form, there is usually more or less of this change.
Exp. Mix 100 measures of strong sulphuric acid with 100 of water,
and the mixture will be less than 200 measures.
sho HOME
10 *

114
Laws of Chemical Affinity.
to brother
borte borila
Laws of Chemical Affinity.
The laws which regulate the action of affinity, constitute
the most important part of the whole subject; for they are the
foundation of modern chemistry. As they are expressed
mathematically, they have consequently imparted to it a high
degree of accuracy, and greatly elevated its rank as a science.
Most substances have been found to combine in definite pro-
portions, and with such the laws of affinity are chiefly con-
cerned; but there are numerous cases of apparently indefinite
proportions, which first demand a separate consideration.
I. Indefinite Proportions. Of these there are two cases,
in the first of which, any quantity of one substance may be
combined with any quantity of another. Thus a drop of
alcohol will combine with a quart of water, or a drop of water
with a quart of alcohol.
Tuomo
Exp. Take a large glass vessel, and fill it nearly full of water; color
it purple with the infusion of red cabbage; a drop of sulphuric acid will
change it red, or a drop of alkali will give it a green color, which shows
that both the acid and the alkali must combine with the whole of the
water.
In the second case, the proportions are indefinite within
certain limits. Thus with 24 lbs. of water, a pound or any
less quantity of common salt will combine, but if a larger
quantity of salt be employed, all the excess above a pound
will remain undissolved. The limit to the process is the
point of saturation. (See page 108.)
Ons
The most common instances of indefinite proportions are
solutions where the proportions are indefinite below the point
of saturation. Instances of unlimited indefinite proportions
are less numerous. It is important to observe, in these cases,
that the force of affinity is usually feeble, and the change of
properties slight. Thus, in the common liquors, the properties
of the alcohol are slightly modified by its combination with
water ; and in solutions there is also little change.
II. Definite Proportions by Weight. In the most numerous
and interesting cases of chemical combination, a certain
portion of one substance unites with one, two, three, or

Laws of Chemical Affinity.
115
-
Water
66
64
16 66
66
60
66
+
66
66
CG
14 56
14 6
16
66
24
64
06
32 66
46
more times a given weight of another. These cases are
usually characterized by a greater energy of combination,
and a much greater change of properties than those which
have been described. The great law of definite proportions
by weight may be thus stated :
DO
Gistedenfor
1. The proportions in which substances combine may be
expressed by fixed numbers, or by the multiples of these num-
bers. The following table is an illustration :-
is composed of Hydrogen 1 part + Oxygen 8 parts.
Binoxide of Hydrogen “
16
+
2. Protoxide of Nitrogen Nitrogen 14 «
Binoxide
16
Hyponitrous acid
Nitrous acid
14
Nitric acid
14 66
40"
A comparison of all the cases shows that hydrogen enters
into combination in less quantity relatively than any other
substance. It is therefore taken for a standard of comparison,
and in the above table appears as unity. The lowest ratio
in which oxygen combines with other substances is eight
times that of hydrogen. The lowest combining ratio of nitro-
gen is fourteen. If any simple substance does not combine
with hydrogen, its lowest combining ratio may be ascertained
from its combination with any other substance, whose ratio
has been determined. Thus from the above table the com-
bining ratio of nitrogen is seen in its compounds with oxy-
gen, whose ratio was ascertained in its compounds with
hydrogen. The lowest combining ratio is also called an
equivalent, or proportional. (See page 107.)
Inspection of the above table will show, that while eight is
the lowest combining ratio of oxygen, it combines also in the
ratio of 16, 24, 32, and 40 parts; that is, two, three, four,
and five times the lowest ratio, agreeable to the above-men-
tioned law.
HE
There are some cases in which substances do not unite
with one equivalent of one to one, two, or more equivalents
of another, but apparently of one to one and a half. Such
an irregularity conforms to the general law, on the supposi-
losted as beide

116
Laws of Chemical Affinity.
tion that two of the former unite with three of the latter. In
TO
some cases, also, two equivalents of one substance unite with
five of another.
The law of definite proportions by weight may be thus
illustrated algebraically :- If x and y be the equivalents of
any two substances, their compounds must be +y, 2+2 y,
x+3 y, x+4 y, etc.; sometimes we shall have 2 x+3 y,
and rarely 2 x+5 y.
It is evident from the above that the equivalent of any
compound is the sum of the equivalents of its constituents
,
each being multiplied by the number of times it enters into
the combination. Thus, in the above table, the equivalent of
water is 1+8=9, of nitric acid, 14+40=54, etc.
2. The second law of definite proportions is the follow-
ing: -
po to
Every substance has its constitution invariable. Thus
nitric acid is always composed of one equivalent of nitrogen
and five of oxygen. No other substances, and no cther
number of equivalents of these, by combination can form
nitric acid.molinster
Stadt
The same is true of every substance whose elements com-
bine in definite proportions. The least change of these de
terminate quantities will either form an entirely different sub-
stance, or a portion of that substance which is n excess will
remain uncombined; hence whatever be the circumstances
under which chemical substances are formed, whether formed
ages ago by the hand of nature, or quite recently by the
agency of the chemist, their composition is always inva-
riable.
Het dolore
The merit of establishing this law is due to Wenzel, a
Saxon chemist, who published his views in 1777. But Dr.
Dalton, an eminent English chemist, discovered the first law,
and deduced from the scattered facts a theory of chemical
union, embracing the whole science, and first published in
1803. Drs. Wollaston, Thompson, and other chemists, fol-
lowed out
It these views. But to no one, in this department, is
science so much indebted as to Berzelius.

Laws of Chemical Affinity.
117
66
66
66
66
50
66
66
66
66
66
56.
64
66
The application of these laws, in the arts, is of immense
importance. In the manufacture of compounds, they teach
precisely what proportions of the ingredients should be used.
If these are expensive, an excess of one would be a seri-
Dit
TO
ous loss.
III. Definite Proportions by Volume. The principal law
of definite proportions by volume is precisely similar to that
of definite proportions by weight, the parts being determined
by measure, as in the former case by weight. This law holds
true only in the case of gases
and
vapors. It is supposed
that substances which have not yet been made to assume
the form of a gas or vapor, would conform to this law, if
they should assume
such form. The law may be illustrated
by the following table:-
100 vols, carbonic acid gas combine with 100 of ammoniacal gas.
200
fluoboric
100
200
But there are two laws of definite proportions by volume,
which do not hold true to the same extent in definite
propor-
tions by weight. The first is, that a simple ratio of one to
two, one to three, &c., exists between the volumes of differ-
ent constituents in the same compound. This may be seen
in the above table.
The second law is, that, in combination, gases and vapors
are condensed by a portion, which is in a simple ratio to the
volume of one of the constituents.
The laws of definite proportion by weight and by volume
are not inconsistent with each other, for the specific gravity
always bears such a relation to the combining ratio by volume
as to establish their harmony. Thus hydrogen and oxygen
combine in the ratio of two of the former to one of the latter
by volume, and of one to eight by weight. But oxygen
is
sixteen times heavier than hydrogen, one volume of it is eight
times as heavy as two of the latter. In other words, the
compound ratio of the specific gravity and of the equiva-
lents by volume, is equal to the ratio of the equivalents by
weight.
solo ao logo
as

119
The Atomic Theory.
or
Atomic Theory
Existence of Atoms. The atomic theory supposes matter
to be composed of minute, indivisible atoms. Hypotheti-
cally, matter is infinitely divisible, that is, to Almighty power;
but in fact it is not infinitely divided. Sir Isaac Newton re-
garded it as probable, “that the primitive particles, being
solids, are incomparably harder than any porous bodies com-
pounded of them, even so very hard as never to wear,
break in pieces; no ordinary power being able to divide what
God himself made one in the first creation."
Theory of definite Proportions by Weight. When sub-
stances combine in their lowest equivalents, they unite atom
to atom, (Fig. 55;)
Fig. 55.
in higher proportions,
one atom of one to
two, three, or more
atoms of the other.
This theory exactly accounts for the facts of definite propor-
tions; for if in one compound we have one atom of A
joined to one of B, and in another one of A joined to
two of B, through the whole mass, the sum total of B in the
latter case will be exactly twice as much as in the former
bisa អំបង
Atomic Weight. If in a compound of one grain of hydro-
gen with eight of oxygen there be an equal number of atoms
of each, an atom of the latter will be eight times as heavy as
an atom of the former. In this way we know the relative
weights of the atoms of all substances, whose equivalents are
known. As the numbers are the same, the terms are often
interchanged.
The absolute weight and magnitude of atoms cannot be
determined. Dr. Thompson calculates that a cubic inch of
lead contains more than 883,492,000,000 atoms.
The shape of atoms is matter of hypothesis. They are
generally supposed to be spheroidal.
case.

Isomerism. — Cause of Chemical Affinity
119
Isomerism.
It was formerly supposed that when two elements combine
in the same ratio, they must always give rise to the same
compound; but it has of late been discovered that this is not
always the case. Thus there are 3 compounds of oxygen
and-phosphorus, whose composition is identical, each being
composed of 31.4 parts by weight of phosphorus, and 40
parts by weight of oxygen; and yet these substances differ in
their properties. The same is true of the two cyanic acids.
Berzelius has applied to such compounds, as a class, the
general term iscmeric, from two Greek words,* which ex-
presses an equality in the ingredients; and to distinguish the
isomeric bodies from each other the terms para † and meta
are prefixed.
To reconcile the phenomena of isomerism with the theories
of chemical combination, we have only to suppose that the
same elements may combine in different ways, so as to give
rise to compounds essentially distinct; for example, we may
suppose that the 2 atoms of phosphorus and the 5 atoms of
oxygen, which form 3 isomeric bodies, may be grouped dif-
ferently; thus, 2 atoms of oxygen may first unite with the
2 of phosphorus, and this compound unite with the other
3 atoms of oxygen, or 4 of oxygen may unite with 1 of
phosphorus, and 1 of oxygen with 1 of phosphorus: these two
compounds may then combine, and form a different sub-
stance from the first, although both contain the same number
of atoms of each element. It is evident that these groups
may be varied still further; hence the kind of substance may
depend upon the order in which the atoms are united. In a
few cases, the equivalents of isomeric bodies differ : olefiant
gas and etherine are an example. The equivalent of olefiant
gas is 14.24, and that of etherine 28.48, or exactly double.
Cause of Chemical Affinity.
The cause of affinity is probably electricity. In those
cases where the electrical state of substances can be ascer-
tained, they are always found to be oppositely electrified,
骨
​Igos, equal, and repos, part.
# Tlopa, near to.

Cause of Chemical cm.
120
Affinity.
when combination takes place. Voltaic electricity is the
most powerful decomposing agent, and the whole phenomena
of electro-chemical decomposition seem to prove the identity
of affinity and electricity. This view accords best with the
simplicity every where observed in the laws of nature. By
ascribing the phenomena of electricity, galvanism, mag-
netism, and chemical affinity, to the same agent, we seem to
we progressing in the chain of causation nearer to the great
and ultimate cause, the agency of God. Some suppose that
what we call the agents and laws of nature, have no real
existence as distinct powers. They deny the agency of
second causes, and ascribe every operation of nature to the
immediate
that there are
real agents or causes dependent upon God, but possessed of
power in themselves, to act as second causes, or subordinate
agents, in the various phenomena of matter. Whichever
view we take, we must, in the end, refer the ultimate cause
to the impulse of the divine will; although, for the mere
purposes of scientific classification, something, perhaps, is
gained by the introduction of second causes.
power
of God. Others suppose
persoon
Boldog biks to

PART III.
PONDERABLE BODIES
Specific Gravity means the relative weight of different
substances, compared with some standard. In the case of
solids and liquids, the weight of the body is compared with
water as unity ; i. e., if a given quantity of water by measure
be weighed,* and that weight represented by 1, the weight
of an equal quantity by measure of any other substance is
compared with it. In the case of gases, air is taken for the
standard of comparison, or for unity, and an equal quantity
of any other gas is weighed, and compared with it.
There are several methods of ascertaining the specific
gravities of bodies.
1. One of the best, if the body is a Fig. 56.
solid, is to weigh it in the air, and then
in water, in a manner represented in
Fig. 56. If the body weighs 100 grains
in the air, and 60 grains in water, then,
to ascertain its specific gravity, institute
the following proportion: As 100 — 60, Y
or 40 : 100.: :1: 2.5; hence the sp. gr.
of the body is 2.5, or two and a half
times as heavy as water. If the solid is
lighter than water, suspend to it a body
heavier than water, whose specific gravity
is known, and then weigh it as in the first instance,
2. To ascertain the specific gravity of liquids, the Areon-
eter is a convenient instrument. It consists of a tube,
A cubic foot of distilled water weighs 62.5 lbs.
11

122
Nomenclature.
a, (Fig. 57,) graduated with numbers, upon the end Fig. 57.
of which are two balls, the lower filled with mer-
cury. If the instrument sink in distilled water to
1, it will sink below that mark in liquids which
are lighter than water, and will remain above it
in those which are heavier. The specific gravity
of each liquid is thus ascertained by the numbers
on the scale. be
The specific gravity of liquids is also ascertained
by the use of a small bottle containing just 1000
grains of water; by filling it with any other liquid, its weight
will express directly its specific gravity.
3. The specific gravity of gases is more difficult : a given
portion of air is carefully weighed in a thin glass flask; the
air is then exhausted, and the flask weighed; the difference
gives the weight of the air; this is taken for unity, and the
weight of an equal quantity of any other gas is compared
with it'; thus, 100 cubic inches of dry air, at 60° F. and
30 in. barometer, weigh 31.0117 grains; 100 cubic inches of
oxygen weigh 34.109 grains. Now, to ascertain the sp. gr.
of oxygen, institute the following proportion:
As 31.0117 : 34.109 : :1, the sp. gr. of air, to 1.1025,
of
sp. gr. of any other gas may be
found in the same way.
o bogata
Nomenclature.
The study of particular substances has been greatly facili-
tated by the introduction of the nomenclature. By the use of
systematic names, expressive of the constitution of substances,
the recollection of the name will call to mind the constitu-
tion ; while, on the other hand, if there be any difficulty in
remembering names, the constitution will at once show what
the name must be. Hence, although compounds are very
numerous, the student can have no difficulty in remembering
their names and constitution, for the one neces
cessarily suggests
the other.
The present nomenclature was introduced in 1787 by the
French chemists. It resulted from the labors of Lavoisier,
Berthollet, Guyton-Morveau, and Fourcroy. Since that time,
it has undergone but a few slight changes. The former no-
the sp. gr.
oxygen. The

Nomenclature.
123
...
menclature, if such the entire want of system could be
called, was barbarous in the extreme; fanciful names were
introduced, and often many such were attached to the same
substance.
1. Simple Substances. The names of such elementary sub-
stances as had long been known, remain unaltered, as of
gold, iron, etc. Those which have been discovered within
the period of modern chemistry, have received names ex-
pressive of some obvious property; thus the name oxygen
signifies a generator of acids ; iodine, violet-colored, from
the beautiful color of its vapor ; chlorine, green, from the
color of the gas.
The following are the names of the simple
substances, with their symbols annexed : ='bloin abia
00 folto at 10 bobaudos
Oxygen,
0. Cadmium,
Cd.
Chlorine,
.Cl. Tin, (Stannum,)
Sn.
Iodine,
...1. Cobalt,
...Co.
Bromine,
Br. Nickel,
Ni.
Fluorine,
.F. Arsenic,
As.
Hydrogen,
.H. Chromium,
.Cr.
Nitrogen,
.N. Vanadium,
V.
Carbon,
..C. Molybdenum,
.Mo.
Sulphur,
....S. Tungsten, (Wolfram,)
.W.
Phosphorus,
.P. Columbium, (Tantalum,)
..Ta.
Boron,
.B. Antimony, (Stibium,)
Silicon,
...Si. Uranium,
....U.
Selenium,
.Se. Cerium,
Ce.
Potassium, (Kalium,) .K. Bismuth,
Bi.
Sodium, (Natrium ) .Na. Titanium,
Ti.
Lithium,
L. Tellurium,
Te.
.
Barium,
Ba. Copper, (Cuprum,).
Cu.
Strontium,
... Sr. Lead, (Plumbum,)
.Pb.
Calcium,
Ca. Mercury, (Hydrargyrum,)....Hg.
Magnesium,
. Mg. Silver, (Argentum,) .Ag.
Aluminium,
...Al. Gold, (Àurum,)
. Au.
Glucinum,
.G. Platinum,
Pl.
Yttrium,
Y. Palladium,
Pd.
Thorium,
Th. Rhodium,
.R.
Zirconium,
Zr. Osmium,
Os.
Manganese,
Mn. Iridium,
Ir.
Iron, (Ferrum,)
.Fe. Latanium.
La
Zinc,
Zn.
2. Acid Compounds. The names of acid compounds have a
peculiar construction. All the acids formed by combination
of oxygen with other substances, including a great majority
of the whole number, take the name of the other substance,
(which is called the base,) changing its termination. If there
....
.Sb.

124
Non clature.
be two oxygen acids formed with the same substance, the
stronger, which contains more oxygen, takes the termination
ic, and the weaker, ous.
In the case of more numerous
acid compounds, the prefix hypo signifies inferiority, as in
the following of oxygen with sulphur, beginning with the
stronger, and proceeding to the weaker :-
Sulphuric acid,
Sulphurous acid,
Hyposulphuric acid, Hyposulphurous acid.
Sometimes the prefix per is used to indicate an additional,
but indefinite quantity of oxygen. Thus perchloric acid
contains more oxygen than chloric acid.
Acids which do not contain oxygen receive names which
are compounded of the names of their constituents, the first
enunciated terminating in o, and the last in ic; as, chloro-
carbonic acid. Often the first is shortened ; as, fluo-boric, in-
stead of furo-boric: this is the case with the hydrogen acids;
as, hydrochloric acid, hydrosulphuric acid.
3. Primary Compounds which are not Acids. In such com-
pounds, the names are composed of the names of their con-
stituents. In the compounds of oxygen, chlorine, iodine,
bromine, and fluorine, with other substances, they are first
enunciated, and receive the termination ide; as, oxide of iron,
chloride of iron, iodide of mercury, bromide of carbon,
fluoride of zinc. In their compounds with each other, the
order of enunciation is not essential, although it is com-
monly that in which they are above mentioned; thus we
may say, chloride of bromine, or bromide of chlorine; but the
former is more common.
Compounds of the other non-metallic substances with each
other and with the metals, receive names of similar construc-
tion, except that the termination uret takes the place of ide ;
as, carburet of iron, biçarburet of hydrogen, sulphuret of
arsenic.
In many cases, one substance unites with another in
several proportions, and the compounds are designated by
numeral prefixes-proto the first, bi (formerly deuto was used).
the second, ter the third, quadro the fourth, etc., and per the

Nomenclature.
125
CG
CG
corper.
copper.
copper.
manganese.
66
=l66
2 "
oxygen
and 1
and 1
and 1
and 1
- 3
60
66
jodine
chlorine
6
66
66
um, etc.
highest degree, but indefinite; sesqui signifies one and a half.
If, however, the last enunciated substance, or base, be in two
or more proportions, the dividing prefixes di, tri, etc., are
used; subsequi indicates one and a half of the base.com
The following table exhibits all the cases of the use of
numeral prefixes:
Triphosphuret of copper =1 equiv. phosphorus and 3 equiv. copper.
Dinoxide of copper
conner Oxygen
and 2
Subsesquiphosphuret of copper
phosphorus and 11
Protoxide of copper G=i, oxygen and 1
Sesquioxide of manganese
Binoxide of manganese
oxygen
manganese.
Teriodide of nitrogen
nitrogen.
Quadrochloride of nitrogen
nitrogen.
Peroxide of iron=iron oxidated in the highest degree.
Many metals, whose names terminate in um, merely change
ium or um into a to indicate the state of protoxide. Thus
potassa = protoxide of potassium, lithia = protoxide of lithi-
The protoxide of calcium has long been known by
1
the name of lime.
Alloys, or compounds of metals with each other, not being
09
yet reduced to the laws of definite proportions, have no sys-
tematic names.
Some primary compounds, whose combinations are analo-
gous to those of simple substances, receive simple names,
which in composition receive the termination uret, and follow
the rules above given. These are ammonia and cyanogen.
Another primary compound, water, forms compounds which
are called hydrates ; as, hydrate of lime.
4. Secondary Compounds, or Salts. These are formed by the
combination of acids with other primary compounds, which
are called, in reference to them, bases. The name of a salt
is composed of the names of the acid and base. If the name
of the acid have a termination ic, it is changed into ate; ous
is changed into ite. Numeral prefixes are used according
to the rules which have been given, as in the following ex-
amples:
Dinitrate of the protoxide of lead = 1 eq. nitric acid and 2 eq. protoxide of lead.
Sesquisulphate of potassa
:15" sulphuric acid & 1 6 potassa.
Bisulphate of peroxide of mercury = 24
perox. of mercury.
Tersulphate of alumina
--
Protonitrate of mercury
16
and 1 16
C6 of mercury.
66
= 3
and i a
and 1 6 alumina.
CG

126
Notation.
As the acids never unite with the metals directly, but gen-
erally with their oxides, and sometimes other compounds, in
the case of the oxides, the name is abbreviated : thus, by
protonitrate of mercury is always understood protonitrate of
the protoxide of_mercury. Also, the prefix proto is often
understood, and we say, nitrate of mercury. totul
There are many secondary compounds, little known, how-
ever, except to the chemist, called sulphur salts, and haloid
salts, whose nomenclature follows the rules of primary com-
pounds which are not acid.
Notation.
Notwithstanding the great advantages of the chemical no-
menclature, a much greater help is given to the student in
the notation. By this, as in algebra, long and intricate pro-
cesses are exhibited to the eye at a glance, and the relations
of the constituents in complicated compounds easily compre-
hended. Each element is represented by a symbol consisting
of its initial, or, in the case of two or more which have the
same initial, of the initial and one of the following letters,
as on page 123, where the symbols of all the elementary
substances are given. In the case of potassium, sodium,
tin, iron, and several others, the symbols are derived from
the Latin names.
The symbols of compounds are composed of the symbols
of their constituents, algebraically connected; as, Fe+CI,
chloride of iron. In primary compounds, the sign + is often
omitted. Coefficients are used to show the number of equiv-
alents; as, N +4Cl, quadrochloride of nitrogen; or, if several
symbols are written together without the sign +, an index is
substituted for the coefficient, because the coefficient multi-
plies all which come between it and the next sign. Thus
the symbol of the substance last mentioned may be written
NC14.
Cyanogen, ammonia, and water, although compounds, have
simple symbols, like the elements; thus we have Cy, Am, and
Aq, Aqua,) instead of NC, H’N, and HO.

Notation.
127
The symbols of oxygen and sulphur are abbreviated. The
symbols for the compounds of oxygen are written thus :-
N for N +50, N for N +40, N for N+30, etc., each dot
indicating an equivalent of oxygen. A comma is used in the
same manner for the compounds of sulphur; thus, V for PS.
In place of the coefficient 2, a dash is often drawn through or
beneath the symbol. This is very convenient in the case of
half equivalents; as, Mn, signifying 2Mn+30, that is, Mn+
130, sesquioxide of manganese. In compounds of compli-
cated constitution, it is often necessary to multiply several ·
terms by one number, or to connect them as a whole to
another term. This is done, as in algebra, by the use of
vincula or parentheses ; thus (K+25) + Aq, shows that Aq
is combined with K+25, as with one substance; but if the
parentheses were omitted, thus, K+28+ Aq, the symbol
would indicate a combination of three distinct substances,
each one with the other. Also in 2(K+2S), the first coeffi-
cient belongs to what is within the parentheses as to one
substance.
If the student will, for practice, explain the constitution and
give the names of the compounds in the annexed table, he will
become familiar with the rules of nomenclature and notation.
The following table contains the names, equivalents, and
symbols of the thirteen non-metallic elements, and the sym-
bols of their compounds with each other, in the order in
which they are described in work :
Oxygen, equiv. 8; symbol, O.
Chlorine,
CI, CI+O, CI+ 40, CI+ 50, CI +70.
Iodine,
66 126.3
I, 1+50, 1+ 70, 3C1 + I.
code
Bromine,
Br, Br + 50 or Bros.
Fluorine, 18.68
Hydrogen, “
E SH, H+0 or H, H+20 or H, H+CI,
(H+I, H+ Br, H+F or HF.
N, NO or N, NO2 or N, NO3 or P, NO4
Nitrogen,
66 14.15
or N, NO3 or N, NC14, N1, NH3.
this
66
35.42
66
78
66
66
F.
1
66

128
Chemical Substances.
Oxygen.
od
[C, C, C, C+C1, C4C15, C²CI, CC13, C+
Carbon, equiv. 6.12; sym. CHH, C10H8, HCy, Cyo, Cy3O®H, Cyci,
Cl, CH2, CºH2, CH4, C6H3, CH, CH,
CyCl, HCys?, Cys?, H’Cys2.
Sulphur, 166 16.1
u SS, SO?, SO3, SOP, SOS, S’CI, SCI, HS,
HS?, CS2
SP, P20, P30, P203, P205, PPC13, P2C15, PI,
Phosphorus,' 15.7
PP, PBr, PŻBr", H3P2.
Boron,
66 10.9
B, B+30, B+3C1, B + 3F.
s Se, Se +0 or Se, Se +20 or Së, Se +30
Selenium,“
66
39.66
or Se.
Silicon,
66 22.5
Si, Si +0, Sici, SiBr, Sis, SiF.
10 doing on to
Photod CHAPTER I.
ent
CHEMICAL SUBSTANCES.
These substances will be arranged in three classes: 1st,
non-metallic elements, and their primary compounds, with
each other; 2d, metals, with their primary compounds; and
3d, secondary compounds, or salts.
Class I. Non-metallic Elements and their Primary Com-
pounds with each other.
I161 บส นอร์ 3 2511
kontor SE
El Oro
Sect. 1. OXYGEN.
Symb. O. Equiv. ? wgt. 8.
Sp. gr. { 16.021 Hyd. = 1
History. Oxygen was discovered by Dr. Priestley, of Eng-
land, August, 1774, by exposing the red oxide of mercury to
the solar focus. It was also discovered by Scheele, a Swe-
dish chemist, in 1795, and the same year by Lavoisier, of Paris,
neither being acquainted with the discovery by the others,
The honor of the discovery, as is usual in such cases, is as-
cribed to Priestley, who called it dephlogisticated air; Scheele
gave it the name of empyreal air; Condorcet, vital air; and
Lavoisier, oxygen. This latter name was suggested from the
belief that it was the only acidifying principle in nature. It
1.1024 Air -1.

Pneumatic Cistern.
129
is derived from two Greek words,* signifying a generator of
acids. It has since been found, however, that, although
present in most acids, it is not the only substance capable
of forming acid compounds. But, as a great majority of acids
are oxygen acids, the name is not inappropriate.
Natural History. Oxygen is the most abundant substance
known. It forms of the atmosphere, & part of water. By
far the greater part of the solid crust of the earth is composed
of oxydized
d substances, and it will not be far from the truth,
if we estimate oxygen to constitute of all the matter with
which we are acquainted.
Processes.
Oxygen can easily be obtained from the oxides
of metals, and from some of the salts. The oxides of man-
ganese and of lead, and the chlorate of potassa, are most
commonly used. The separation is effected by exposing
these substances to a red heat, in an iron retort, connected
by a pipe with the pneumatic cistern.
For the collection of gases which are not absorbed by
water, the
Pneumatic Cistern is
duo deb
Fig. 58. hoding on
generally employed. It
consists of an oblong
box, C, (Fig. 58,) made
w
water-tight; bb, two
shelves to support
ceivers, as r; w, a well
1
filled with water, across
which a board is placed,
also to support receiv-
ers, with small holes to
Hea
let the gas through as it
comes from the retort, which is placed over the side of the
box. The shelves b b may be made for gasometers, or gas-
holders ; and in that case they are boxes open at the bottom
of the cistern, with stop-cocks passing through one corner in
the top of each. These are made air-tight by a lining of
sheet lead. When they are filled with water, the gas is in-
troduced, by means of a lead pipe, through an aperture in the
79
C
. * Οξυς and γεννάω.
† If we suppose the sun and planets, with the stellary systems, to be
composed of matter similar to our earth, the quantity of oxygen which
actually exists must be immeasurably great.

130
Oxygen.
side of each, near the bottom; as it rises up, it displaces the
water; l is a lamp-stand and retort,* as it is connected with
the cistern.
Theory. To understand the theory of the process by man-
ganese, it is necessary to notice the composition of its three
oxides.
Manganese.
Oxygen.
Protoxide, 27.7 or 1 equiv. + 8 or 1 equiv. : 35.7
Sesquioxide, 27.7
+ 12 or 1}
: 39.7
Peroxide, 27.7
+ 16 or 2
: 43.7
The oxygen may be separated from the binoxide in two
16
66
ways : -
1. By simply exposing it to a red heat. In this case, the
binoxide
parts with equiv. of oxygen, and is converted into
sesquioxide. 1 oz. of manganese will yield 128 cubic inches
of
oxygen.
2. By putting it, in fine powder, into a glass flask, with an
equal weight of concentrated sulphuric acid, and heating the
mixture by a spirit lamp, the manganese parts with one equiv.
of oxygen, and the sulphate of the protoxide of manganese
remains. About twice the quantity of gas is obtained by
this process, 1 oz. yielding 256 cubic inches of gas. But the
former method is most convenient in practice.
For these processes, the manganese should be previously
ascertained to be free from carbonate of lime, which yields
carbonic acid gas on being heated.| Oxygen obtained in
this
way
is not quite pure, but is sufficiently good for all pur-
poses of experiment.
The
gas
obtained from chlorate of potassa is much purer,
but more expensive.
It may be easily obtained by subjecting the salt to a dull
red heat in a green or white glass flask, made without lead,
* Retorts are either plain, as in Fig.
Fig. 59.
58, or tubulated, as Fig. 59. A Florence
flask will answer a good purpose, if a lead
tube is fitted to it. See Fig. 60.
+ The cistern may be made of wood,
or, what is better, of copper, of any con-
venient dimensions. One five feet long,
twenty inches wide, and twenty inches
in height, is sufficiently large for com-
mon purposes.
# It may be freed from carbonate of lime by washing it in dilute
hydrochloric acid.
a

Physical and Chemical Properties. 131
or in an iron retort.* It first becomes liquid, and is then
resolved into oxygen and chloride of potassium.
Theory. The chlorate of potassa is composed of chloric acid and
potassa, and the theory of the process may be thus explained : KO+
CLO3 are resolved into K + CL, which remains in the flask, and 6
equiv. of oxygen, which are collected over the cistern. One ounce of
chlorate of potassa will give about 640 cubic inches of oxygen.
Physical Properties. Oxygen is transparent, colorless,
tasteless, and inodorous. In the simple state, it always exists
in the form of a gas. It cannot be condensed to a liquid
or a solid, by pressure or cold. It refracts light the least
of all substances; is a non-conductor of electricity; is the
only substance whose electric state is absolutely negative;
and of course it always goes to the positive pole in the
galvanic circuit. Its specific gravity is 1.1026; conse-
quently, 100 cubic inches, when the thermometer is at 60°
Fahr. and the barometer at 30 inches, will weigh 34.1872
grains. It is a little heavier than atmospheric air.
Chemical Properties. Oxygen possesses more extensive
powers of combination than any other substance, It
may
be
made to combine with all the simple substances. For acids
and alkalies it has little affinity, because these substances
have already received their proportion of it. Some of its
combinations with the metals, and with combustibles, are
very energetic.
Exp. 1. Let down a pendent candle into a jar of the gas, (Fig. 61,)
and it will burn with great brilliancy.
* The iron retort is an iron bottle with Fig. 60.
a long neck. After the salt or the man-
ganese is put into it, it may be placed de
in a furnace, and a lead pipe, as b or a, maata
(Fig. 60,) adapted to the mouth, by
means of a cork, a, a. The cork is first
perforated by a hot, sharp iron, and en-
larged, so as exactly to fit the tube, by a
round file; it is then pressed into the
mouth of the bottle. The other end OL
may then be conveyed to any part of
Б
the pneumatic cistern, or to the gas-
ometers. This is the simplest mode of
ko
connecting apparatus together; and it
may be done either with glass or lead
tubes.
of the

132
Oxygen. --- Theory
MIG
Exp. 2. Blow out a candle, leaving a red wick, Fig. 61.
and let it down into a jar of the gas, when it will be
relighted with a slight explosion. This process may
be repeated several times in rapid succession with
the same jar of gas.
Exp. 3. "If a bit of lighted phosphorus, in a capsule,
be immersed in this gas, (Fig. 62,) it will burn with
great energy and intense brilliancy. Substitute for
the phosphorus a small ball formed of turnings of
zinc, in which a small bit of phosphorus is enclosed,
and set fire to the phosphorus, as before. The zinc Fig. 62.
will be inflamed, and burn with a beautiful white
light. Metallic arsenic, moistened with spirits of
turpentine, and various other metals, in fine powder,
may be burned in a similar manner. Homberg's
pyrophorus flashes spontaneously, like inflamed gun-
powder.
Exp. 4. If iron wire, with a small lighted match
attached to one end, be let down into a tubulated
bell glass of oxygen, it will burn rapidly; and if a
watch-spring be used, (Fig. 63,) the bell glass will Fig. 63.
be filled with beautiful star-shaped scintillations.
Exp. 5. Or, let a stream of oxygen upon ignited
charcoal, upon which is placed the end of a watch-
spring; it will burn with great brilliancy, and throw out
immense numbers of the star-shaped scintillations.
Exp. 6. Put a small bit of phosphorus into a test-
glass tube, and fill the tube with warm water, so as to
melt the phosphorus. Direct, now, a stream of oxygen
gas from the gas bag, or a bladder, to which a tube
is attached, upon the phosphorus. A brilliant combus-
tion will be produced under water.
All substances, by combustion in oxygen, increase in weight,
in the proportion of about of a grain for every cubic foot of gas.
Exp. 7. Fill the bowl of a tobacco-pipe with iron wire, coiled in a
spiral form, and carefully weighed; heat the bowl of the pipe red hot,
and then attach the pipe to a bladder filled with oxygen gas. By
forcing a stream of the gas through the pipe, the iron will burn, and
will be found, when weighed, to be heavier than before. When com-
pletely oxidized, 100 parts of iron will gain an addition of about 30.
Theory. In these experiments, the oxygen combines with
the combustible substance, and forms a compound, which,
being now oxidized, is incapable of further combustion. In
case of the iron, an oxide is formed, the weight of which is
exactly equal to that of the iron and the oxygen together. In
case of the phosphorus, an acid is formed, which is absorbed
by water, if present, or appears as a fine powder. The heat
and light appear to arise from the condensation of the gas.
* In the case of combustion, the common opinion that the matter is
destroyed, is erroneous. If the products are collected, they will be
found equal in weight to the substances burned. It is a universal law
that no particle of matter is annihilated.

Chlorine.de
133
The combination of oxygen with other substances is called
oxygenation, and if the compound be an oxide, oxidation.*
Oxygen is slightly absorbed by several substances; 100 cubic
inches of water absorb three or four cubic inches of the gas.
The relation of oxygen to animal life is very intimate and
important. It is the only substance which will, for any length
of time, support respiration. No animal can live without it.
If confined in gases destitute of oxygen, death is the certain
consequence. A few years since, 148 persons were confined
in a prison called " Black Hole,' in Calcutta, for a night, and,
although there were two windows open in the west end of the
building, only twenty-three were found alive in the morning.
Pure oxygen gas is generally destructive to animal life.
The animal confined in it lives too fast; breathing becomes
difficult, and if it remain for any time, death will ensue.
If the quantity be small, it will support life longer than the
same quantity of common air. A bird will live five or six
times as long in a few gallons of oxygen as in the same
quantity of confined air. In order to its most salutary
effects, it should be diluted with nitrogen, as we find it in the
atmosphere. The Creator has, in this respect, adapted it to the
support of life, as any thing which destroys the relation thus
established, renders it deleterious to the animal constitution.
Uses. Oxygen has been used with good results in certain
diseases, such as paralysis of the thorax, and general debility.
Its effect upon the blood is to change it from dark red to a
bright vermilion.
Taldea Sect. 2. CHLORINE.
bet DOO
Symb, Cl. Equiv. by woot.35.42.
2.47 Air
.
History. Chlorine was discovered by Scheele in 1774,
and described under the name of dephlogisticated marine
-1.
Sp. Gr. 33.42 Hyd. =1
* It has been customary with many to call oxygen, and some other
kindred substances, “supporters of combustion," while the substances
with which they combine are called combustibles. But the supporters of
combustion and the combustibles are alike essential to the combustion,
and both are consumed in the process. Indeed, if the latter be in ex-
12

134
Chlorine. — History.
acid. The French chemists called it oxygenized muriatic
acid, afterwards contracted to oxy-muriatic acid. This name
implied a theory of its composition, suggested by Berthollet,
that it was a compound of muriatic acid and oxygen. Gay
Lussac and Thenard, in 1809, first suggested that it might
be a simple substance. Sir H. Davy, after subjecting it to
the most powerful decomposing agents, without in the least
affecting its character, denied its compound nature, and
maintained that, according to the true logic of chemistry, it
should be regarded as a simple body. The views of Davy
were for a long time combated. Drs. Murray and Thomp-
son in England, and Berthollet, Gay Lussac, and Thenard in
France, engaged with great warmth in the controversy.
But the name chlorine, suggested by Davy from a Greek
word * signifying green, not implying any theory as to its
nature, came gradually into use, and the contest subsided.
It is now universally regarded as a simple substance.
The introduction of chlorine into the class of simple
bodies changed entirely the views of chemists relative to the
theory of combustion. Previous to the discovery of oxygen,
the Stahlian theory of combustion was generally adopted.
According to this theory, combustion was the escape from
combustibles of a certain principle called phlogiston, which
pervaded most bodies.
Soon after the discovery of oxygen,
Lavoisier made an attack upon the phlogistic or Stahlian
theory, and proved that combustion was produced by the
union of oxygen with some combustible body. But when the
properties of chlorine were investigated, and it was viewed as
a simple substance, it was found to produce all the phenomena
of combustion. Hence the theory of Lavoisier, that combus-
tion was owing to the union of oxygen with a combustible, was
extended; and the phenomena of combustion are not referred
to any more specific cause than intensity of chemical action.
Natural History. Chlorine is one of the constituents of
common salt, and therefore exists in the ocean in large quan-
tity. Other compounds in the mineral kingdom are numerous.
cess, a portion of it will remain, while the former will be entirely con-
sumed. Generally, the supporter of combustion, as it is called, is a gas
which envelops the combustible; but there is no scientific distinction.
Χλωρος. .

Physical and Chemical Properties.
135
nese.
Processes. 1. It may be obtained in the form of a gas, by
the action of hydrochloric acid upon the binoxide of manga-
Take the latter, finely powdered, in a retort, and pour
on twice its weight of concentrated hydrochloric acid. Collect
the gas over the cistern in inverted bottles containing warm
water, or, more conveniently, over a small cistern of warm
water. The water should be raised to 70° or 80° Fahr., as
cold water rapidly absorbs the gas. Apply a moderate heat ;
and, when the bottles are filled, they should be stopped with
ground glass stoppers smeared with tallow.
Theory. In this process, the binoxide of manganese is
decomposed into protoxide and oxygen. A part of the acid
combines with the protoxide, and another is decomposed, its
hydrogen uniting with the oxygen, and forming water, and
the chlorine is set free. In other words, the MnO2 and HCI
are converted into MnO + HCl, and HO, which remain in
the retort, and Cl, which comes over.
2. The cheapest mode of obtaining chlorine is the follow-
ing :- Put eight ounces of common salt, with three ounces
of pulverized peroxide of manganese, and five ounces of
sulphuric acid, diluted with equal weights of water, into a
Florence flask or retort, and apply heat as before. The
MnO2, Na+Cl, and 2503 are converted into Mno+
SO3, NaO + SO3, and Cl.
Physical Properties. Chlorine gas is of a greenish-yellow
color; has an astringent taste, and a disagreeable odor; is a
non-conductor of electricity, and goes to the positive pole in
the galvanic circuit. By the pressure of four atmospheres,
or 60 lbs. to the square inch, it is condensed into a yellow
liquid, and into a solid by the reduction of the temperature
below 32°. * 100 cubic inches of this gas at 60° Fahr., and
30 barometer, weigh 76.5988 grains.
Chemical Properties. Chlorine unites with many sub-
stances with great energy, producing combustion; but its
range of affinity is more limited than that of
oxygen.
* Mr. Faraday succeeded in condensing it in a bent tube, sealed
hermetically. The pressure is produced by the accumulation of the gas
evolved by the affinities between the materials in the short end of the
tube. The experiment is attended with the hazard of breaking the tube,
and should not be attempted, unless the hands and face are protected.

136
Chlorine.
Exp. 1. If a small lighted taper be immersed in a jar of the gas, the
taper will burn for a short time with a small red flame, evolving large
quantities of smoke, and then go out. The reason is, that the flame is
mostly composed of carbon and hydrogen; the chlorine unites with the
hydrogen, but not with the carbon; the latter is therefore precipitated
in the form of smoke, and soon puts the light out.
Exp. 2. Into a tall glass vessel, filled with chlorine, throw finely-
pulverized antimony; the metal will burn as it falls through the gas.
Exp. 3. A rag wet with oil of turpentine will instantly be inflamed,
when immersed in the gas.
Exp. 4. Introduce phosphorus into a jar of chlorine; the phosphorus
will soon ignite, and burn with a pale-green flame.
Exp. 5. Instead of the phosphorus, drop in a few drops of liquid
ammonia; the ammonia will be decomposed; a flash and a white
smoke will be instantly produced.
Several other metals and combustibles combine with chlo-
rine with such energy as to exhibit the phenomena of com-
bustion.
Chlorine is readily absorbed by water. Recently-boiled
water, when cold, absorbs twice its bulk, but gives it off when
heated.
Exp. Into a jar furnished with a well-fitted glass stopper, and filled
with cold water, let up chlorine gas enough to displace half the water;
stop it tight, and shake it, and most of the gas will be absorbed by the
water. Open the jar under more cold water, which will rush into it to
fill the vacuum occasioned by the absorption of the chlorine; then re-
peat the process once or twice, and the water will be saturated with
chlorine, and possess most of its properties. If the water in this ex-
periment be at the temperature of 320 Fahr., the chlorine will form a
definite solid compound with it, in yellow crystals, which will be seen
on the sides of the jar. The crystals are composed of 35.42 or 1 atom
of chlorine, and 90 or 10 atoms of water.
Chlorine forms with hydrogen, if the vapor of water be
present, a mixture which explodes violently when exposed
to the direct rays of the sun, or even in a bright day with-
out such exposure.
Exp. Mix, in a dark place, equal measures of hydrogen and chlorine.
Expose the mixture to the light of day, and a slow action will take
place. Cover the glass with a black cloth, to which a string is attached,
and place the vessel in the direct rays of the sun. Rersove the cloth
by means of the string, taking care to have some object, as a door, be-
tween you and the receiver; as soon as the rays of light strike the
mixture, a violent explosion will occur, and an acid compound will
be formed.
Chlorine possesses remarkable bleaching properties.
Exp. 1. Immerse in the gas strips of calico, flowers, etc., and they
will be bleached in a short time; or the saturated water may be used.

Uses of Chlorine.
137
Exp. 2. Pour some of the saturated water into
a small quantity of
ink, and the color will be discharged; or put into it some writing,
which will become invisible, but will be restored if immersed in a solu-
tion of prussiate of potassa. Printers' ink will not be affected; and
hence chlorine water may be used for removing blots from books.
Chlorine is not an acid; for it does not redden vegetable
purples, and it combines directly in definite proportions with
the metals, which is not true of any acid. It is not alkaline.
Chlorine is very destructive to animal life. A few bubbles
of gas, in the atmosphere of a room, will bring on coughing.
Half a gill undiluted in the lungs would cause death. If
diluted largely with air, it irritates the throat and lungs, and
if pure, destroys their texture. Pelletier is said to have fallen
a victim to its effects. The antidote is ammonia.
Uses. 1. The bleaching properties of chlorine are turned
to great account in the art of bleaching. Both the gas
and
the water saturated with it were employed as early as 1784–5
for bleaching cloths; but it proved injurious to the workmen.
In 1789, the gas was condensed in a solution of pearlashes,
and went by the name of “ Liquid javelle.” But this sub-
stance soon gave place to Mr. Tennant's preparation of the
chloride of lime, in 1798. Since that period, most of the
bleaching of cotton and linen goods has been effected by this
substance. The articles to be bleached are first steeped in hot
water, boiled in a weak alkali, and then immersed in a solu-
tion of the chloride of lime. They are next taken out, and
washed in water ; sometimes diluted sulphuric acid is applied
to increase their whiteness; and, finally, they are boiled in
pearlashes and soap, to render them free from the odor of
chlorine. Chloride of soda, magnesia, and potassa, are some-
times used, but they are more expensive. *
Theory. The theory of this process, perhaps, would be better un-
derstood after learning the composition of water; but it can be given
* The advantages of this mode of bleaching, over the one formerly
employed, are very great. By the old method, large fields in the
vicinity of every manufactory were devoted to the purpose of spread-
ing the cloths. These fields are now devoted to agriculture. It re-
quired also several weeks, and even months, to complete a process
which may now be performed in as many days. In the former case,
they were dependent upon the light of the sun and fair weather;
in the latter, they are independent of the weather, and of the seasons
of the year.
12*

138
Chlorine and Oxygen.
here with a little explanation. Water is necessary to the bleaching
effects of chlorine. It is composed of oxygen and hydrogen. The
chlorine, having a strong affinity for the hydrogen, decomposes the
water, and leaves the oxygen to combine with the coloring matter.
The coloring matter may also contain hydrogen, and thus be directly
decomposed by the chlorine. The coloring matter is rendered soluble
by combination with oxygen, and is removed by the alkali. The pro-
cess of bleaching by chlorine is but one out of many useful con-
tributions of science to art.
1.2. Another use of chlorine arises from its disinfecting
agency. It seizes hold of every species of animal and vege-
table effluvia, and decomposes them. Hence its utility in
contagious diseases. The chloride of lime is used for this
purpose. Moisten the dry chloride with water, and place it
in the infected apartment, which will soon be purified. It is
thus very useful for dissecting-rooms, for cleaning drains,
sewers, vessels, and even the atmosphere, when charged with
miasma. Its use in medicine is mostly confined to the puri-
fication of apartments of the sick. The chloride of soda is,
however, used in certain cases of inflammation, such as
ulcers, mortification, and cutaneous diseases. It is also used
as a wash for the teeth.* The compounds of chlorine with
the metals are called chlorides.
Chlorine and Oxygen.
The compounds of chlorine and oxygen are held together
by very feeble affinities, and are never met with in nature.
They cannot be made to combine directly, unless they are in
the nascent state, that is, at the instant of their formation.
Hypochlorous Acid. Symb. Cl+O or CIO. Equiv. 35.42+
8=43.42. Sp. gr. 3.0212. It was discovered by H. Davy,
in 1811, and called euchlorine from its being of a brighter
color than chlorine.
Preparation. Put two parts of the chlorate of potassa and one of
hydrochloric acid into a retort, and apply the heat of water under
200° Fahr. Collect over mercury; or it may be more conveniently
prepared for experiment by placing the materials in a flask,
* So many and great are the advantages of cleanliness and pure air,
that chloride of lime should be kept in every family, especially in cities
and large towns; but an apartment in which it has been used should
be thoroughly ventilated before it is again occupied, or weak lungs may
be seriously injured.

Chlorine and Oxygen.
139
Fig. 64.
a, (Fig. 64,) connected by a glass tube, bent twice
at right angles, with a tall receiver, b. Apply
heat as before; the gas, being heavier than the
air, will displace it, and fill the receiver.
Theory. The hydrochloric acid and the chlo-
ric acid in the chlorate of potassa mutually decom-
pose each other, and the results are water and the
hypochlorous acid. 2 equiv. HCl, and one of
KO+C10s, are converted into KO, 2 Aq, and
3CIO.
17
If the gas be collected over mercury, the chlorine unites
with the mercury, and the acid remains in a pure state.
Properties. Greenish yellow color, more brilliant than
chlorine; odor like burned sugar; absorbed rapidly by water,
and gives to it an orange color ; bleaches vegetable sub-
stances; gives vegetable blues a red tint before destroying
them; does not unite with alkalies, and hence has been con-
sidered as a protoxide of chlorine; highly explosive, the heat
of the hand being sufficient often to explode it. Many sub-
stances take fire in it spontaneously.
Exp. A rag dipped in spirits of turpentine will kindle in it with a
slight explosion.
Exp. Phosphorus explodes in it spontaneously. Fifty measures of
this gas, and eighty of hydrogen, form an explosive mixture.
Chlorous Acid. Symb. Cl +40, or C104 Equiv. 35.42
+ 32= 67.42. Sp. gr. 2.3374. Discovered by Davy, in
1815, and soon after by Count Stadion, of Vienna, and has
been heretofore described as peroxide of chlorine.
Preparation. Make a paste of strong sulphuric acid and chlorate of
potassa; put it into a retort, and apply the heat of warm water under
212° Fahr. Collect over mercury, or as in Fig. 64. For the purposes
of experiment, take a wine or champagne glass, and put into it a few
grains of chlorate of potassa ; then pour on sulphuric acid; the
soon fill the glass. As the gas often explodes spontaneously, this is the
safest mode of collecting it. The preceding compound may be formed
in the same way.
Properties. Color, bright orange-green, richer than the
preceding compound; aromatic odor; is absorbed rapidly by
water, and gives it its peculiar color; bleaches powerfully,
and is more explosive than hypochlorous acid.
Exp. Put a bit of phosphorus into a wine glass filled with the gas.
It will instantly ignite, with a slight explosion.
Chloric Acid. Symb. Cl +50, or C105. Equiv. 35.42+
40 = 75.42. It was first noticed by Mr. Chenevix, and ob-
tained in a separate state by Gay Lussac.
gas will

140
Iodine.
Preparation. To a dilute solution of chlorate baryta add dilute
sulphuric acid sufficient to combine with the baryta. Pure chloric acid
will remain after the baryta subsides.
Theory. The sulphuric acid has a stronger affinity for baryta than
the chloric acid with which it has combined, decomposes it, and leaves
the chloric acid.
Properties. Sour to the taste; reddens vegetable blue
colors, but possesses no bleaching properties, by which it is
distinguished from the preceding compounds. It may be
concentrated by gentle heat into an oily liquid of a yellow
tint, emitting the odor of nitric acid. In this state, it sets
fire to paper and dry organic matter, and converts alcohol
into acetic acid.
Perchloric Acid. Symb. Cl+70 or C107. Equiv. 35.42
+56=91.42. Sp. gr. 1.65, water=1. It was first described
by Count Stadion, of Vienna.
Process. It may be obtained by heating a mixture of 1 part of water,
3 of sulphuric acid, and 5 of perchlorate of potassa. At a temperature
of 284°, white vapors arise in the receiver, which are soon condensed into
a colorless liquid. By admixture with sulphuric acid, and distillation,
it crystallizes in elongated prisms.
It is a very stable compound; absorbs moisture from the
air powerfully, and boils at 392° Fahr. When thrown into
water, it hisses like red-hot iron.
SECT. 3. IODINE.
Sp. Gr. $ 4.948 Water=1.
=1.
Symb. I. Equiv. by vol. 100.
?" wgt. 126.3.
8.702 Air
History Iodine was discovered in 1812, by a manu-
facturer of saltpetre — M. Courtois, of Paris. The substance
in which it was first noticed, was the residual liquor after the
preparation of soda from the ashes of sea-weeds. This dark-
colored liquor possessed the peculiar property of powerfully
corroding metallic vessels; on the application of sulphuric
acid, he noticed that it threw down a dark-colored substance,
which was converted into a violet-colored vapor on the ap-
plication of heat. This attracted his attention, and he gave
some of it to M. Clement, who, in 1813, described it as a
new body. Gay Lussac and Davy soon after proved it to be
a simple non-metallic substance, analogous to chlorine. The

Physical Properties.
141
name iodine is derived from a Greek word, * significant of
the beautiful violet color of its vapor.
Natural History. Iodine exists in nature but in small
quantities. It is found mostly in sea-weeds, in sponges, in
the oyster and some other mollusca, in many salt and mineral
springs, both in Europe and America. Vauquelin found it in
combination with silver; marine animals and plants derive it
from sea-water. Most of the iodine of commerce is obtained
from the impure carbonate of soda, called kelp. This is
nothing but the ashes of sea-weed, great quantities of which
are prepared on the shores of Scotland. Iodine exists, in
combination with sodium and potassium, in the liquor which
is left after the carbonate of soda crystallizes.
Process. Iodine may be obtained by lixiviating the pow-
dered kelp in cold water. Evaporate the lye till the car-
bonate of soda crystallizes; take the residual liquor, and
evaporate it to dryness; pour on to this 1 its weight of sul-
phuric acid; it may then be put into a common retort, to
which is attached a globe receiver, and the retort heated;
violet-colored fumes will soon arise, and be condensed in
the receiver, in the form of opaque crystals, of a metallic
lustre. These are to be washed in water, and dried on a
filter of unglazed paper.
Physical Properties. Iodine, at the common temperature,
is a soft, pliable, opaque solid, of a bluish-black color, and
of a metallic lustre. It is generally found in small crystalline
scales, resembling micaceous iron ore, or the scales from a
smith's forge. But it may be made to crystallize in large
rhomboidal plates, whose primary form is a rhombic octohe-
dron, by saturating hot alcohol, or hydriodic acid, with it,
and evaporating in the open air. It is very acrid to the
taste, and has the odor of chlorine. Like O and Cl, it is a
non-conductor of electricity, and goes to the positive pole in
the galvanic circuit. It acts as a powerful poison to the
animal system; fuses at 225°, and boils at 347° Fahr. If
moisture be present, it volatilizes at the common temperature,
*
Ιώδης. .
00 Olidata

142
lodine.
and sublimes rapidly under 212°. The rich violet vapor of
iodine is remarkably dense, more than eight times as heavy as
air. One hundred cubic inches would weigh 269.8638
grs.
Exp. This vapor may be shown by putting a few grains of the
iodine into a glass flask, and applying a gentle heat.
Chemical Properties. Iodine has an extensive range of
'affinity. Like chlorine, it destroys vegetable colors, though
in a less degree, and, like oxygen and chlorine, it unites
directly with the metals and with non-metallic combustibles
with great energy.
Exp. Drop a bit of phosphorus upon a few grains of iodine, con-
tained in a wine-glass, and it will be instantly inflamed.
The compounds thus formed resemble those of oxygen and
chlorine. It has little affinity for metallic oxides. It is not
inflammable, but a supporter of combustion. The im-
ponderables have no effect to change its character, and hence
it is regarded as a simple body. It is largely soluble in
alcohol, and but sparingly soluble in water, requiring seven
thousand times its weight of water for solution.
Tests. Starch is a very delicate test of iodine. It gives to the solu-
tion a deep blue color. A liquid containing 1500oy part of its weight
of iodine, receives a blue tinge from a solution of starch.
Iodine is sometimes adulterated with black lead. This may be de-
tached by dissolving it in alcohol, when the lead will not be held in
solution.
Uses. Used in medicine in the form of a hydriodate of
potassa, for certain glandular diseases. The goitre is a kind
of wen growing from the neck, which is very common in
Switzerland, in the treatment of which iodine has been of
great service.
Its vapor is irritating to the lungs, and produces copious
secretions in the eyes and nostrils. The compounds of
iodine with non-metallic combustibles are termed iodurets;
its compounds with the metals, iodides.
Iodine forms with oxygen three, perhaps four compounds:
1. Oxide of iodine, {composition unknown.
2.
3. Iodic acid, 1 eq. 1, 126.3+5 eq. O, 40=166.3 eq.
Symb. I+50 or 105.
4. Periodic acid, 1 eq. I, 126.3+7 eq. O, 56 = 182.3.
Symb. I +70 or 107.

Bromine.
143
The first two compounds, oxide of iodine and iodous acid,
are yet doubtful. The first is described by M. Sementini, of
Naples, and the second by Mitscherlich. The oxide is a
yellow solid, and the acid a similar liquid, but their properties
have not been examined.
Iodic Acid was discovered by Davy and Gay Lussac about
the same time. Davy, who first obtained it in a pure state,
called it oxiodine.
Preparation. When iodine is brought in contact with the hypochlo-
rous acid, two compounds are formed. The one is a volatile orange-
colored substance, chloride of iodine, and the other a white solid, which
is iodic acid. Apply heat to expel the chloride, and the iodic acid re-
mains in a pure state. (See Turner, for other processes.) In this
state, it is anhydrous iodic acid, that is, destitute of water.
Properties. It exists as a white, semi-transparent, crystal-
line solid, of a strong, astringent, sour taste, and no odor;
fuses at 500° Fahr., and is resolved into oxygen and iodine.
It is soluble in water, with which it combines, and forms
hydrous iodic acid; deliquesces in moist air ; reddens vege-
table blues, and finally destroys them. With charcoal, sul-
phur, sugar, and similar combustibles, it forms detonating
mixtures.
Periodic Acid was discovered by Ammermuller and Mag-
nus, and is obtained from the periodate of silver, by adding
cold water. It has decided acid properties, and is analogous
in composition to perchloric acid.
Chloriodic Acid was discovered by Davy and Gay Lussac.
It may be formed by the direct union of chlorine and iodine.
If the iodine is fully saturated with chlorine, it forms a yellow
solid ; but if the iodine is in excess, the color is a reddish
orange. It is easily fused, and converted into vapor; deli-
quesces in the air; forms a colorless solution in water; very
sour to the taste; reddens vegetable blues, and finally de-
stroys them; does not unite with alkalies, and hence has
been considered a chloride of iodine.
Souberaine has lately distinguished a compound of 3 eq.
of chlorine and 1 of iodine.
harun med ei
SECT. 4. BROMINE.
C
Symb. Br. Equiv. {!
S by. vol. 100.
Water =1.
wgt. 78.4.
History. Bromine was discovered in 1826; by M. Balard,
a young French chemist, of Montpellier, who named it muride,
th
$ 3.
67
Sp. gr. 25.4017 Air
= 1.

144
Bromine.
because obtained from the sea; but, in order to correspond
with chlorine and iodine, it was called bromine, from a Greek
word,* signifying rank odor.
Natural History. It exists in nature in very
small
quan-
tities. It is found in sea-water and marine plants, combined
with sodium and magnesium. It is found in every sea whose
waters have been tested for it, and in many mineral and salt
springs.
Process. It is obtained by passing a current of chlorine
gas through the bittern of sea-water, and agitating the liquor
with a portion of sulphuric ether. The ether dissolves the
bromine, from which it receives a beautiful hyacinth-red tint,
and, on standing, rises to the surface. Agitate this solution
with caustic potassa, and the bromide of potassium and bro-
mate of potassa will be formed. Evaporate the liquor, and
the bromide of potassium will be left, from which the bromine
may be distilled.
Physical Properties. Bromine, at common temperatures
,
is a deep reddish-brown colored liquor, of a disagreeable odor
and caustic taste; and, like oxygen, chlorine, and iodine, is a
non-conductor of electricity, and a negative electric; boils at
116.5° Fahr., and congeals at -4° Fahr. into a brittle solid
.
It volatilizes at the common temperature and pressure.
Exp. This may be shown by pouring a few drops of the liquid into
a glass flask; it will soon be converted into a beautiful vapor, some-
what resembling the vapor of iodine, having a density of 5.54. 100
cubic inches at 60° Fahr. should weigh 167.5158 grains.
Chemical Properties. Its chemical properties are very
analogous to those of chlorine and iodine. It readily bleaches
litmus paper, and discharges the blue color of indigo. A
lighted taper burns for a few moments in the vapor of bro-
mine, with a flame green at its base and red at the top, and
is then extinguished:
Bromine unites with great energy with many combustibles.
Exp. Pour a few drops of bromine into a strong wine-glass, and then
pour upon it tin or antimony, in fine powder, from a glass fastened to
-
farlota
Βρωμος. .

Fluorine.
145
::
the end of a long rod; the metals will be instantly inflamed. If potas-
sium be used, it will cause a violent explosion.
Bromine is soluble in water, alcohol, and ether; the latter
is the best solvent. With water at 32° F., it forms a hydrate,
in crystals of a fine red color. It gives to a solution of starch
an orange color. Chlorine will displace it from all its com-
binations with hydrogen. It acts powerfully upon the animal
system, and is very poisonous; a single drop upon the beak
of a bird, destroys it instantly.
Bromic Acid (Symb. Br + 50 or BrO5. Equiv. 78.4+
40=118.4,) may be obtained by pouring sulphuric acid
upon a dilute solution of bromate of baryta, and evaporating
the solution.
Properties. It has scarcely any odor, acrid to the taste,
though not corrosive. It first reddens litmus paper, and then
destroys the color.
Chloride of Bromine may be formed by transmitting a current of
chlorine through bromine, and condensing the disengaged vapors by
a freezing mixture. It is a volatile liquid, of a reddish-yellow color,
less brilliant than bromine. Its vapor is a deep yellow, taste very dis-
agreçable, and odor penetrating, causing a discharge of tears from the
eyes. Soluble in water which possesses bleaching properties.
Bromides of Iodine. Bromine and iodine unite and form two com-
pounds.
The proto-bromide is a solid easily converted by heat into a reddish-
brown vapor, which, on cooling, is condensed into crystals of the same
color, and of a form resembling fern leaves. By the addition of bro-
mine to these crystals, they are converted into a liquid resembling a
strong solution of iodine and hydriodic acid; but the nature of it is not
satisfactorily established.
SECT. 5. FLUORINE.
Symb. F. Equiv. 18.68, eq. vol. 100.
Fluorine is a name applied to a substance which has not
as yet been obtained in a simple state. It is inferred from
the nature of its compounds to be similar to oxygen, chlorine,
bromine, and iodine. It has a strong affinity for hydrogen
and the metals.
Natural History. It exists abundantly in nature, in fluor-
spar combined with calcium, (fluoride of calcium.) Baudri-
13

146
Hydrogen.
mont is said to have obtained it, mixed with hydrofluoric and
fluosilicic acid gases, by treating a mixture of fluoride of cal-
cium and peroxide of manganese with strong sulphuric acid.
It appears to be a gaseous body, similar to chlorine.
SECT. 6. HYDROGEN.
Sp. gr.{1.
vol. 100.
Equiv.<by
Symb. H.
= 1.
0.0689 Air
C# wgt. 1.
Hyd. -1.
History. The name hydrogen is formed from two Greek
words,* and means a generator of water. It was known for
many centuries, but was first distinctly described by Mr. Cav-
endish, in 1776. Nine years previous, Dr. Black discovered
carbonic acid gas, which was the first gas discovered, except
the atmosphere, and hydrogen was the second.
Natural History. Hydrogen is a very abundant substance.
It forms į part by weight of water. Its chief repository,
therefore, is the ocean; but it is widely disseminated through
the animal, vegetable, and mineral kingdoms. It is the basis
of most liquids.
Processes. 1. Water is always employed for obtaining
hydrogen. It is composed of oxygen and hydrogen, and the
object is to decompose it by presenting some substance, with
which the oxygen will combine, and leave the hydrogen to
escape in the form of a gas. Iron is such a substance, and
will decompose the water slowly at common temperatures ;
the oxygen combining with it, and forming the well-known
substance called iron rust. But if the temperature of the iron
be raised to 1000°
Fahr., and the va-
Fig. 65
por of water passed
over it, it will de-
B.
compose it more
I
ICT
rapidly. For this
purpose, clean iron
turnings, or bright
iron wire, are pla-
ced in the centre
* C
Υδωρ and γεννάω. .

Processes ---- Theory.hr
of a gun-barrel, C, (Fig. 65,) open at both ends, and passed
through a furnace, b. Into one end the vapor of water is
made to pass from the retort a, and the other end is con-
nected by a lead pipe with the pneumatic cistern. As the
vapor passes over the iron, its oxygen combines with it, and
its hydrogen passes over into the receiver h*
2. It is more conveniently obtained by putting small
pieces of zinc,† or iron turnings, into a glass or lead retort,
and pouring on one part of sulphuric acid, diluted with four
parts by weight of water, and collecting as above.
Theory. In this process, the oxygen of the water unites
with the zinc, and forms oxide of zinc, which combines with
the acid, while the hydrogen of the water escapes. This was
formerly supposed to be a case of what was called disposing
afinity, in which the acid disposed the oxygen and zinc to
unite, that it might combine with the compound; for it has
no affinity for them separately. This is sufficiently absurd.
The process commences with zinc and water alone, without
the aid of the acid, and is immediately arrested by the forma-
tion of a coat of oxide of zinc, which protects the zinc from
the action of the water. The acid dissolves away this coat-
ing of oxide as fast as formed, and thus the action of the
metal and the water is uninterrupted.
For every nine grains of water which are decomposed, one
grain of hydrogen will be set free. Eight grains of oxygen
will unite with twenty-eight of iron, forming thirty-six of the
protoxide of iron. One ounce of iron will yield 782 cubic
inches, and one ounce of zinc 676 cubic inches of hydrogen.
Impurities. The hydrogen, obtained in these processes, is not quite
pure. That from the iron contains a volatile oil, produced by the hy-
drogen and the carbon in the iron; this may be removed by passing
the gas through alcohol. When zinc is employed, and it is generally
* If the water and the iron are weighed before the experiment, and
the iron and the hydrogen after it, the increase in the weight of iron
and the weight of the hydrogen is just equal to that of the water.
In this way the exact composition of water is determined analytically,
and is found to be 8 parts of oxygen to 1 of hydrogen, and 1 vol. of the
former to 2 of the latter.
† The zinc may be conveniently prepared by pouring a stream of the
melted metal into cold water.

148
Hydrogen. — Physical Properties.
preferred,) the impurities result from the sulphur which it generally
contains - hydrosulphuric acid is formed, and there are also traces of
metallic zinc and carbureted hydrogen. These, except the last, may
be removed by passing the hydrogen through pure potassa. When
hydrogen of great purity is required, distilled zinc should be used.
Physical Properties. Hydrogen gas is colorless, tasteless,
and, when perfectly pure, inodorous. But as it is generally
obtained, it has a fetid odor, arising from the oily matter
which it contains, and the hydrosulphuric acid. It is a pow-
erful refractor of light, and has never been condensed to a
liquid
It is the lightest body in nature. It is sixteen times lighter
than oxygen, 36 times lighter than chlorine, 200,000 times
lighter than mercury, and 300 000 times lighter than
platinum!
Exp. Fill a gas bag with
Fig. 66.
hydrogen,* (Fig. 66 ;) con-
nect it with a bubble-pipe,
and inflate soap bubbles with
the gas; they will 'ascend
O
rapidly, being forced up by
the superior weight of the
air. Or, if a jar of hydrogen
be removed from the cistern,
and inverted in the open air,
the gas will immediately escape.
In consequence of its extreme lightness, hydrogen is used
for filling balloons.
O
Fig. 67.
a
The method of filling gas bags with
gases from the pneumatic cistern, is repre-
sented in Fig. 67. b is the cistern contain-
ing water; the receiver has a stop-cock in
its top, upon which another stop-cock, C,
connected with the bag a, may be screw-
ed. The receiver is filled with gas, and,
the stop-cocks being both open, is pressed
down into the well, and the water presses
the gas into the bag. Then, by closing
both stop-cocks, the bag may be removed
from the receiver.
-

Chemical Properties.
149
2
Aerostation. Roger Bacon. first suggested the pos- Fig. 68.
sibility of navigating the air by mechanical contri-
*vances; but nothing of consequence was effected until
1782. The substance first employed to raise balloons
was rarefied air, confined in a silk bag. Since the
discovery of hydrogen, it has been universally em-
ployed for this purpose. Balloons are made of various
shapes and capacities. The spherical form (Fig. 68)
is the best, for the reason that a given quantity of can-
vass, or silk, made in the form of a sphere, will contain
more than any other form, and hence offers the least
resistance to the air. The substance employed for bal-
loons is either varnished silk or gold-beaters' skin, and
the size varies from 1 to 40 feet in diameter. They
are generally covered with a net, n, connected by cords to a small boat,
€, in which the aëronaut is stationed when he ascends. The hydrogen
is prepared by putting iron turnings, sulphuric acid, and water, into
several large casks, and connecting each with the balloon; the hydrogen
is then rapidly evolved, and the balloon tied down until ready for use.
Chemical Properties. Hydrogen has a strong affinity for
many substances, and the energy of its combinations fre-
quently produces the phenomena of combustion.
Hydrogen is a combustible body, but not a supporter of
combustion.
Exp. Plunge a lighted taper into an inverted jar of hy- Fig. 69.
drogen ; the gas will instantly be inflamed at the mouth of a
the jar, and burn with a blue light; but the taper, if wholly
immersed in the gas, will be extinguished, and relighted
again when the wick touches the flame.
Exp. Burn a jet of hydrogen. If the hydrogen be
forced rapidly through a tube, b, (Fig. 69,) with a small
orifice, ignited at the orifice, and cylinders of glass, as a, or
other substances, put over the flame, musical tones will be
produced. "The tones will vary with the size and kind of 10 ha
tube,
Exp. Mix two measures of hydrogen with one of oxy-
gen, and apply the flame of a candle to a small portion
confined in an exploding tube, or gas pistol, a, (Fig. 70;)
there will be a violent explosion. This effect is also pro- b
duced by mixing one part of hydrogen with three of com-
mon air; but the explosions are much more violent when
two vols. of hydrogen and one of oxygen are mixed, and Fig. 70.
ignited with the flame of a candle; or by the electric
spark. Soap-bubbles may be formed and exploded as they
A large bladder, filled with the mixture, may also be
exploded by piercing it with a sharp wire on the end of a
long rod, having about it ignited tow.
a
ou
Exp. This mixture also explodes when suddenly com-
pressed by the fire-syringe; this is owing to the develop-
ment of its latent caloric, or because the particles are then
brought within the sphere of each other's attraction; but
the experiment is hazardous.
rise.
13*

150
Hydrogen and Oxygen.
Theory. In these experiments, the report arises from the
collapse of the air, a vacuum being formed by the sudden
condensation of the gases.
The musical tones arise from
continued explosions produced by the union of the hydrogen
and the
oxygen
of the air.
Exp. When a stream of hydrogen gas is brought in contact with
spongy platinum, it is immediately set on fire. This heat is supposed to
be due to the condensation of the gas upon the surface of the plati-
num, by which its latent caloric becomes sensible, and inflames the gas.
This singular fact was discovered by Prof. Doebereiner, of
Jena, in 1824. The sponge is prepared by dissolving plati-
num in nitro-muriatic acid, and then precipitating it with
ammonia. Rhodium and iridium produce the same effect.
This property has been applied to the construction of lamps,
by which light can be easily and conveniently produced.
Under pressure, the combustion of hydrogen produces a very
intense heat.
Exp. Burn a jet of hydrogen, and throw on iron filings; they will be
ignited, and produce beautiful scintillations. One pound of hydrogen,
in burning, will develop sufficient heat, according to Dalton, to melt
320 lbs. of ice.
Relations to Animals. An animal soon dies when confined
in it. This is not owing to the noxious properties of the
hydrogen, since an atmosphere of oxygen and hydrogen will
support respiration for a considerable time; but is due to the
fact, that it excludes the oxygen, and thus suffocates. An
atmosphere of oxygen and hydrogen has the singular property
of producing a most profound sleep.
Hydrogen and Oxygen.
Protoxide of Hydrogen, or Water. 1 eq. H 1 +1 eq. 08
=9 eq. Symb. H+0 or Aq. Sp. gr. = 1.
Process. Water is the sole product of the combustion of
hydrogen gas in common air, or oxygen. This may be shown
by burning a jet of hydrogen in a large globe receiver; or,
what will render the effect more striking, by burning a jet of
2 vols. of hydrogen to 1 of oxygen, with the compound
blowpipe: the sides of the receiver will soon become hazy,
from the deposition of water upon its interior surface; and if
the process be continued, large drops will form and run down
the sides. This fact was first demonstrated by Mr. Caven-

Physical and Chemical Properties. 151
dish, by burning the gases as above; and the weight of the
water produced was exactly equal to that of the gases con-
sumed.
Physical Properties. These are well known. It is trans-
parent, colorless, inodorous, and tasteless; slightly com-
pressible by a very strong pressure; elastic; converted into
vapor by heat; boils at 212° F., and congeals at 32° F. It is
the standard of weight, with which all solid and liquid bodies
are compared ; its specific gravity is therefore 1. One cubic
inch weighs 252.458 grs. It is 815 times heavier than the
atmosphere, which is the standard of weight for gaseous
bodies.
Chemical Properties. 1. Water has the power of ab-
sorbing a great number of gaseous bodies. It always con-
tains air.
Exp. This may be shown by placing it under the receiver of an air-
pump, and exhausting the air, when bubbles of air will rise up through
the water.
It is the air contained in water from which fishes obtain
the oxygen necessary to purify their blood.
At the mean temperature and pressure, water will absorb,
according to Henry and Dalton, of
Carbonic acid gas,
1 vol. | Carbonic oxide,
Sulphureted hydrogen, 1 " Carbureted hydrogen, at
Nitrous acid,
1 Nitrogen,
Hydrogen,
Oxygen,
27
But if the gas be passed through the water under great
pressure, a greater quantity will be absorbed. Carbonic acid
gas, for example, is absorbed according to the pressure ap-
plied, to an unlimited extent.
2. Water is one of the most powerful solvents in nature.
It enters into combination with various bodies; sometimes in
indefinite proportions, as in solutions; at others in definite pro-
portions, as in the acids, some of the metallic oxides, and many
salts, in whose crystallization it is taken up, and in which it
is therefore called the water of crystallization. The definite
64 vol.
66
Olefiant gas,
64
66
66
66
8
66

152
Hydrogen and Oxygen. I
הון
יתרונות
compounds are called hydrates.* The affinity of water for
some substances is so strong, that it cannot be entirely
separated from them without at the same time decomposing
the substance.
Composition of Water. This has been Fig. 71.
accurately determined, both by analysis
and synthesis. By synthesis, by burning
6
2 vols, of hydrogen and 1 of oxygen, the
product is water. Also, by exploding 2
vols, of hydrogen and one of oxygen, in a
strong glass tube, or Eudiometer, a, (Fig.
71,) over mercury, by the electric spark,
there will be a perfect vacuum produced,
Ea
and the mercury will rise, and fill the tube.
Instead of inflaming the gases by the
electric spark, spongy platinum may be
employed to produce a combination of
the oxygen and hydrogen.
Exp. Take three parts of spongy platinum, one of pipe-play,
moistened with water, and a small quantity of hydrochlorate of am-
monia, make it into a small ball, and ignite it, to separate the water
and ammonia. Introduce it, while hot, into the mixture, and the
oxygen and hydrogen will combine slowly, without explosion. If the
gases are mixed in the proportions of 1 vol. of oxygen to 2 of hy-
drogen, they will wholly disappear, and water will be the only product.
Water may be decomposed by the galvanic battery, and the
products are 2 vols. of hydrogen to 1 of oxygen. The same
results are obtained by passing its vapor over red-hot iron,
and collecting the products.
Compound Blowpipe. This apparatus was invented by Dr.
Hare, in 1804. The best construction for experimental pur-
poses is the following: A,B, (Fig. 72,) are two cylinders of
wood or copper open at the top; c, d, two similar cylinders
open at the bottom, placed within the others, leaving spaces
of of an inch in width between them, and passing around
cylinders of wood which nearly fill them. The spaces i, e, are
filled with water, and the gases are conducted by a lead pipe
into c and d, which are the gasometers. As they are filled,
they are lifted up by the weights.† The tubes h, 0, connect
* The term hydrous is prefixed to substances containing water, and
anhydrous to those deprived of it.
† A method for raising and depressing the gasometers has lately
been devised, which answers a better purpose than weights. A bar or

Hydrogen and Oxygen.
153
Fig. 72.
SI
VADS
S
ho
Am
SEADUSE
B
6
the gasometers with the blowpipe; the gases are let out by
means of stop-cocks. d, being filled with oxygen,
the
gas
passes in the tube o through the centre of the blowpipe; c,
at the same time, being filled with hydrogen, the gas passes in
the tube h to the side of the blowpipe, and issues at the
point, so as to encircle the oxygen. By igniting the two
gases, as they issue from the pipe, the heat is so intense as to
melt the most refractory substances. It is only surpassed by
that from a powerful galvanic battery. In burning the metals
under the blowpipe, an opportunity is afforded for many in-
teresting and beautiful experiments.*
Binoxide of Hydrogen. Symb. H+20 or HOP. Equiv. 1+16=17.
Sp.gr. 1.452, water=1. This singular compound was discovered
Thenard in 1818, and is sometimes called oxygenized water, and peroxide
of hydrogen. It is formed by the action of hydrochloric acid upon the
peroxide of barium.
Properties. The binoxide of hydrogen is a colorless, transparent
liquid, without odor, caustic to the skin, giving it a white stain, and
possesses powerful bleaching properties. When heated to 59° Fahr.,
it is decomposed so rapidly as to cause explosion; the same effect is
also produced by throwing it on to several of the oxides of metals,
such as the peroxide of silver, lead, mercury, gold, and some others.
rod of iron is fastened by one end to the centre of the gasometers.
The other end passes up through the cross-bar S; on one side of this
bar are teeth, which fit into a cog-wheel, and the gasometers are raised
and lowered by a crank attached to the wheel.
* In experiments with the blowpipe, the hydrogen should first be
inflamed, and then the oxygen let out gradually, until the substance to
be melted is fully ignited; the hydrogen may then be shut off, and the
combustion kept up by oxygen
alone,

154
Hydrogen and Chlorine.
Hydrogen and Chlorine — Hydrochloric Acid.
Symb. H+Cl. Eq. by vol. 200, by, wgt. 35.42+1=
36.42. Sp. gr. 18.21 Hyd.=1, 1.2694 air=1.
History. This compound has been long known under the
names of spirit of salt, and muriatic acid; but was dis-
covered in its gaseous state by Dr. Priestley, in 1772.
Natural History. It issues from the craters of volcanoes,
and is found in the warm springs of Mexico; it exists in com-
bination with ammonia, (the hydrochlorate of ammonia.)
Process. 1. It can be obtained in the gaseous state, by
simply heating the common hydrous hydrochloric acid of
commerce in a glass flask, or retort, and collecting the gas
over mercury.
2. Put equal parts of common salt and sulphuric acid into
a retort, and collect as above.
Theory. Salt is a' chloride of sodium, and sulphuric acid is com-
posed of real acid and water; the oxygen of the water goes to the
sodium, and forms soda, which unites with the acid, and the hydrogen
of the water unites with the chlorine, forming hydrochloric acid. Na
+ CI, SO3 and HO, are converted into NaO+SO3 and HCl.
Instead of collecting the gas over mercury, it may be col-
iected in large vials or bottles, in the following manner :-
Put the materials into a flask, a, (see Fig. 64, and connect
the flask with a glass tube, bent twice at right angles, and
extending to the bottom of a bottle or receiver, b; as the gas is
heavier than the atmosphere, it will expel it, and fill the bottle
.
By the application of ammonia to the mouth of the bottle, a
white cloud will arise when the bottle is filled. *
Liquid Hydrochloric Acid. This is obtained in the arts
by passing the gas through water ; for this purpose Woulfe's
apparatus may be employed.
It consists of several bottles, b, c, d, e, (Fig. 73.) The first
bottle is connected, by a lead tube, with a glass retort, a, which
contains the materials; b is one third filled with water; the
tube from b descends to the bottom of c, and the gas passes
up through the water. As soon as the water is saturated,
* All gases that are heavier than the atmosphere, may be collected
in this way, and those that are lighter may be collected by inverting
the bottle, and pressing the air down, instead of lifting it up.

Physical and Cremical Properties.
155
Fig. 73.
Db
manner.
the gas passes through the tube to the bottom of d, and as-
cends again through the water; thence to e, in a similar
Through the centre of each bottle there is a safety
tube, extending nearly to the bottom, to prevent the danger
that might arise from a too sudden evolution of gas. The
gas presses upon the surface of the water, and forces it up
the centre tubes, which prevents it from bursting the bottles.
The acid in the first bottle is thrown away; the rest is the
acid of commerce. The bottles should be surrounded with
ice, to aid the absorption : water will thus absorb 480 times
its volume, and the solution has a density of 1.2109.
Physical Properties. Hydrochloric acid gas is colorless,
of a pungent odor, and acid taste, a little heavier than the
air ; sp. gr. 1.269 ; under a pressure of forty atmospheres, or
600 lbs. on the square inch, it is condensed into a liquid.
Chemical Properties. It possesses decidedly acid proper-
ties, changes the vegetable infusions red, and combines with
alkalies, and forms salts. It supports combustion feebly, and
extinguishes a lighted taper, the flame of which assumes a
greenish hue before it goes out. Water absorbs it rapidly.
Exp. A drop or two of cold water, introduced into a flask of the
acid, will absorb it readily; and if a jar of it be inverted over water,
the water will rush in with nearly the same violence as into a vacuum.
Exp. So strong is its affinity for water, thať a piece of ice introduced
into a jar of it over mercury, will be dissolved almost as soon as if
thrown into a furnace.
It is readily decomposed by voltaic electricity, the hydrogen
appearing at the negative and the chlorine at the positive
pole. A discharge of ordinary electricity will decompose it,
but, according to Henry, the second shock causes it to com-
bine again. It is decomposed by those substances which

156
Hydrochloric Acid.
yield oxygen readily, such as the peroxide of manganese,
cobalt, and lead; the oxygen combines with the hydrogen of
the acid, and sets the chlorine at liberty.
It is nearly as suffocating, when taken into the lungs, as
chlorine, causes spasms of the glottis, and combines with the
saliva, or water, and forms the liquid acid.
Constitution. It was formerly supposed to be a simple
body, combining with oxygen to form oxymuriatic acid, now
found to be chlorine. But its composition may be determined
synthetically, by mixing equal portions of hydrogen and chlo-
rine in a glass tube, and exposing them to the solar rays,
when they instantly combine, with explosion, and hydrochlo-
ric acid is the only product; or their union may be effected
by passing an electric spark through the mixture contained
in the eudiometer.* If the gases are mixed, they will com-
bine slowly in diffuse daylight. The light from the point, of
charcoal, at the poles of a galvanic battery, has the same
effect as the sun's rays.
Uses. Hydrochloric acid is one of the three great acids
used in the arts; it is used for preparing the chloride of tin
for dyers, as a re-agent in various chemical processes, and
in medicine as a tonic.
Impurities. The acid of commerce is not quite pure, containing
the chloride of iron, and chlorine. This gives the liquid a yellow
color; but, when perfectly pure, it is limpid.
Hydriodic Acid. Symb. H+I. Eq. 126.3+1=127.3. .
Sp. gr. 4.3854, air=1. Discovered by Gay Lussac, of Paris.
Preparation. It may be obtained by passing iodine vapor
and hydrogen gas through a red-hot porcelain tube. But a
more convenient process, by which it may be obtained for
the purposes of experiment, is to put a small bit of phosphorus
into a glass tube, filled with water, and drop upon it a few
grains of iodine.
Theory. The iodine unites with the phosphorus, forming
the periodide of phosphorus, and then the water and the
periodide mutually decompose each other. The oxygen of
* The fact being established that hydrochloric acid is composed
of hydrogen and chlorine, the old theory that oxygen was the only
acidifying principle is proved false; there are many acids of hydrogen
which have no oxygen in them. They are called hydracids,

Hydrofluoric Acid.
157
the water unites with the phosphorus, and the hydrogen with
the iodine, giving rise to phosphoric and hydriodic acids; the
latter passes over in the form of a colorless gas, and may be
collected in a receiver of common air; it may be passed
through water, and absorbed by it. It cannot be collected
over mercury, because it acts upon it.
Properties. Hydriodic acid is a colorless, transparent gas,
very sour to the taste, and gives an odor like hydrochloric
acid; reddens vegetable blues without destroying them, and,
when mixed with air, produces dense white fumes; has a
strong affinity for water; is decomposed by several of the
metals, such as potassium, sodium, zinc, iron, and mercury,
and even when exposed to the air.
Uses. This acid may be employed to form pigments.
Exp. Take some of the salts of lead (acetate or nitrate of lead) in
solution, and pour on hydriodic acid; it will decompose the salt, and
form paints of a yellow color.
Tests. The most delicate test of this acid is bichloride of
platinum, a single drop of which, in solution, will give to a
liquid containing the acid, a reddish-brown color, and a dark
precipitate will subside.
Exp. Starch is also a sure test. A few drops of sulphuric acid will
give to a solution of the acid, mixed with a cold solution of starch, a
blue color.
Hydrobromic Acid. Symb. Br + H or BrH. Eq.78.4+1
=79.4. Sp. gr. 2.7353. Discovered by M. Balard, and may
be obtained by immersing a red-hot iron into a mixture of
the vapor of bromine and hydrogen; the combination takes
place slowly, without explosion; or it may be formed, for ex-
perimental purposes, by a process similar to that for obtaining
hydriodic acid, using bromine instead of iodine.
Properties. It is colorless, with an acid taste and pungent odor;
irritates the glottis, so as to excite coughing ; exposed to moist air, it
yields white dense vapors, and is rapidly absorbed by water; decom.
posed by chlorine instantly; nitric acid also effects its decomposition.
Hydrofluoric Acid. Symb. F+H or FH. Eq. 18.68 +1
19.68. Sp. gr. 1.0609.
History. First procured in a pure state in 1810, by Gay
Lussac and Thenard.
Process. It is formed by the action of sulphuric acid on
fluor-spar, (fuoride of calcium.) This mineral is pulverized,
14

158
Nitrogen.
put into a lead or silver retort, with twice its weight of sul-
phuric acid, and heat applied. The acid will distil over, and
must be collected in a vessel of the same material, surrounded
with ice, to condense the acid.
Theory. The hydrogen of the water in the sulphuric acid combines
with the fluorine in the mineral, and the oxygen with the calcium ;
the sulphuric acid unites with the oxide of calcium: the products are
hydrofluoric acid, and sulphate of the protoxide of calcium. Ca, F, SO
and HO are converted into Cað + 503 and FH.
Properties. At 32° F. it is a colorless liquid, and remains
in that state at 59°, if preserved in well-stopped bottles; but,
exposed to the air, it assumes the gaseous form, unites with
the water of the atmosphere, producing white fumes. Its
affinity for water is greater than strong sulphuric acid. Its
vapor is much more pungent than chlorine or any of the irri-
tating gases; the most destructive to animal matter of any
known substance, a single drop of the concentrated acid
causing deep and almost incurable ulcers. It is distinguished
for the remarkable property of acting on glass. It readily dis-
solves silex, and an acid is produced called the fluo-silicic
acid; and hence it cannot be preserved in glass vessels.
Uses. It is used for etching on glass.
Exp. For this purpose, prepare some resin or beeswax, and form
a coat over the glass; then, with a pointed instrument, remove the
coating where you wish the glass to be etched; pour on the acid,
and in a few minutes the etching is completed. Then, by wash-
ing the glass in water, and removing the coating, the figures will
appear. The liquor in the retort will answer for this experiment, es-
pecially if used within a day or two after the acid and the fluor-spar
are mixed.
SECT. 17. NITROGEN.
Equiv. by vol. 100
Sp. gr. 14.15
Symb. N.
S 0.9727 Air =1
wgt. 14.15.
Hyd. = 1
History. Nitrogen was discovered by Dr. Rutherford, of
Edinburgh, in 1772. Three years after, Lavoisier discovered
that it was a constituent of the atmosphere. Scheele also
made the same discovery. It was called by Lavoisier azote,
(from two Greek words, *) because it deprived animals of life;
but this is not the only gas which is azotic. Its present
name, nitrogen, is derived from nitre, (nitrate of potassa.)
* A and com

Physical and Chemical Properties. 159
Natural History. Nitrogen exists in all animals, in fun-
gous plants, and constitutes of the atmosphere; also in
some hot springs in Scotland, and in the Alps. It is also
evolved from certain springs in the state of New York.
Process. It may be obtained from the atmosphere, either
by burning out the oxygen of a confined portion of air with
some combustible, or by abstracting the oxygen in a more
gradual way, by its affinity for some of the simple substances.
Exp. 1. Put a small piece of phosphorus in a cup
which will float on water, (Fig. 14,) and invert over Fig. 74.
it a receiver of common air. On igniting the phos-
phorus, it will unite with the oxygen, and burn until
all the oxygen is consumed, forming white fumes —
the pyrophosphoric acid. This acid, in a short time,
will be absorbed by the water, which will rise and’fill
the jar 1 full. This is sufficiently pure for common
experiments, but contains vapor of phosphorus and
carbonic acid, which may be removed by passing the
gas through pure potassa.
Exp. 2. Make a paste of flowers of sulphur and iron filings, and invert
over it a receiver; the oxygen will combine slowly with the iron, and
leave the nitrogen. A stick of phosphorus will produce the same ef-
fect. If the proto-sulphate of iron, charged with the binoxide of nitro-
gen, be substituted for the paste, the process is more rapid.
Exp. 3. It may also be obtained by pouring nitric acid on fresh
muscle, and subjecting it to a moderate heat.
Theory. On account of the strong affinity of oxygen for
these substances, it leaves the nitrogen, and combines with
them.
Physical Properties. Nitrogen is colorless, tasteless,
inodorous, not condensed into a solid by pressure or cold.
100 cubic inches weigh 30.1650 grains.
Chemical Properties. Water, recently boiled, absorbs 13
volumes of the gas.
Nitrogen will not support combustion.
Exp. Put a lighted candle into a jar of it, and it will be immediately
extinguished; hence it does not support
Respiration. No animal can live in it, not because of the
active properties of the gas, but because it excludes the
oxy-
gen. It kills by its negative properties, for which it seems
alone to be distinguished. The effect is like that of
drowning
Nature of Nitrogen. Nitrogen has been supposed by

160
Nitrogen and Oxygen.
some, among whom is Berzelius, to be a body composed of
oxygen and an unknown base. But this base has never been
exhibited in a separate state; and, until that is done, it must
be regarded as a simple substance.
Although pure nitrogen is the most inert of substances,
some of its compounds are among the most active and useful.
Nitrogen and Oxygen.
Common Air. Symb. 2N+0. Equiv. 28.30+8 =
36.30, eq. vol. 4N +0. Sp. gr. = 1. The earth is sur-
rounded by a gaseous fluid or atmosphere, consisting chiefly
of common air, extending about forty-five miles from its sur-
face, and revolving with it around the sun.
Physical Properties. The atmosphere is a permanent,
elastic fluid, transparent, inodorous, and tasteless.
The air is very compressible and elastic
Exp. The compressibility of the air may be shown by the fire-syringe,
by which it may be compressed into a very small compass. If 100
measures of confined air, under pressure of 1 lb., be subjected to double
the pressure, or 2 lbs., it will be diminished to 50 measures; double
this pressure, or 4 lbs., will compress it to 25 measures. On the other
hand, if the pressure be diminished, its elasticity will restore it to its
former state. Then, if } lb. be applied to the 100 measures, it will ex-
pand to 200 measures. Halve this, or of a pound, and the volume
will be double, or 400 measures. The same is true of all other gaseous
bodies, while they retain their gaseous state. Hence the following
law, that
The volume of air and of other gaseous fluids is inversely
as the pressure applied.
Exp. The elasticity of the air may be further shown by putting a
bladder, half filled with air, under the receiver of an air-pump, and
exhausting the air from the receiver; the external pressure being thus
taken off, the air within the bladder will expand, fill the bladder, and
even burst it. This force is often so great, as to burst the strongest
vessels. Hence the danger of forcing too much air into the ball of an
air-gun, or carbonic acid into a soda fountain.
Winds. In consequence of the great elasticity and compressibility
of the air, it gives rise to the phenomena of winds. It is subject to the
laws of elastic fluids in general; as one portion therefore becomes ex-
panded by heat, the colder or more dense portions rush rapidly into
its place, and force it to ascend. From the same properties, also, vi-
brations are easily produced in it, which give rise to the sensation of
sound, musical tones, etc.
Pressure of the Air. That the air had weight, was first
noticed by Galileo, in 1640. Torricelli, his pupil, carried out

Common Air.
161
his suggestions, and in 1643 invented the barometer, * by
which variations of pressure could be accurately measured.
The exact weight of the atmosphere is of great importance
in physical and chemical researches, and has been accurately
determined by Dr. Prout.
At the level of the sea, its pressure
is 15 lbs. on every square inch of surface.
Exp. This pressure may be illustrated by exhausting the air from
the receiver of an air-pump; the pressure on the external surface of
the receiver will fix it immovably to the plate.
The body of a man sustains constantly a pressure of about
14 tons !
As we ascend above the level of the
sea, the mercury sinks
in the barometer, because the column of air is shorter ; hence
the height of mountains may be measured in a very expeditious
manner. Aëronauts in this manner determine the height to
which they ascend.t
Extent of the Atmosphere. The height of the atmosphere,
as estimated by the phenomena of refraction, is found to be
about forty-five miles. Above that height, no refraction takes
place in the rays of light. Dr. Wollaston estimates its ex-
tent, by the law of the expansion of gases, at forty miles ;
that is, the weight of the particles of air (gravity) will over-
come their elasticity at that height.
Composition of the Atmosphere. Chemists are not agreed
whether the atmosphere is a chemical or a mechanical com-
pound. The proportions 20 or 21 parts of oxygen and 79 or
80 of nitrogen in 100 never vary, from whatever parts of the
earth, or regions of the atmosphere, it may be taken. Gay
Lussac brought air from an altitude of 21,735 feet, and its
composition did not vary from that on the surface of the earth.
Exp. That the atmosphere is composed of 4 parts of nitrogen and
1 of oxygen, by measure, may be shown by a graduated.glass tube of
* Torricelli first filled a glass tube three feet in length with mercury,
and, on inverting it in a vessel of the same liquid, found that the mer-
cury fell about six inches; hence the atmosphere sustained a column
of mercury of about thirty inches. The space abandoned by the
mercury is called the Torricellian vacuum, and is the most perfect
that can be formed.
+ There seems to be a constant relation between the pressure of the
atmosphere and the weather. During a storm, the mercury in the
barometer sinks, indicating that the atmosphere is lighter, and rises
again when fair weather returns, proving its greater weight. Invalids
often complain of the oppressive weight of air in foul weather; the
fact, as we have seen, is the reverse; they feel a difficulty in respira-
tion, because the air is too light. The same difficulty is felt by aëro-
nauts, and those who ascond high mountains.
}{{ব 39?
14*

162
Nitrogen and Oxygen.
//
known capacity, and bent as in Fig. 75. Put a bit of Fig. 75.
phosphorus into the bent end, and place the open
end in a vessel of water, keeping the finger over the
end to prevent the air from escaping. Bring now
near the phosphorus a red-hot iron; the phospho-
rus will be inflamed, and will burn out the oxygen
of the air; phosphoric acid will be formed, and
absorbed by the water; the latter will rise, and fill/
the tube 1-5th full; the remaining 4-5ths is nitro-
gen.
This uniformity in the composition of the
atmosphere has been regarded as a decisive
proof of its chemical constitution. But it has
been shown by Dalton, that it is the results of
a mechanical, rather than of a chemical law.
This law may be illustrated in the following manner :-
Exp. Take two strong glass tubes closed at one end, and fill the
one with oxygen and the other with hydrogen gas. Close the tube con-
taining oxygen with a cork, through the centre of which is inserted a
small glass tube. Having inverted the tube containing the oxygen,
place upon it that containing the hydrogen, so that one cork shall close
both tubes; let them remain in an upright position. As the oxygen in
the lower vessel is sixteen times as heavy as the hydrogen in the upper,
we should expect that each would maintain its position; but the fact
is otherwise. They mutually intermingle, as is proved by their forming
explosive mixtures in both tubes.
Similar experiments have been made upon a great number
of gases, and it is uniformly found that, after a little time, they
will distribute themselves equally through the space occupied
by both, whatever be their difference of density; hence it was
inferred by Dalton that different gases are vacuums in respect
to each other; that is, that one gas does not prevent the en-
trance of another into the space which it occupies, any more
than the vacuum of an air-pump, although it will flow
more slowly in the former than in the latter case.
and vapors follow the same law; hence there are as many at-
mospheres around the earth as there are gases upon its
surface, each occupying the same space which it would oc-
cupy if it were entirely alone.
This tendency to diffusion renders it difficult to confine
gases in bladders, or even over water in the pneumatic cistern.
Exp. By placing hydrogen gas in a glass tube, one end of which is
stopped by plaster of Paris, over water, the hydrogen will force itself
out through this plaster so rapidly as to prevent the entrance of the
air, and the water will rise in the tube; but, as the water rises, the at-
mospheric pressure is such as to force the air into the tube, and the
water will fall. By igniting the gas, it will explode ; which shows that
there has been a mingling of the air with the hydrogen.
All gases

Protoxide of Nitrogen.
163
Impurities. The air usually contains other gases; car-
bonic acid and watery vapor are the most abundant. The
quantity of water is determined by the hygrometer. It never
amounts to more than one per cent. Carbonic acid rarely
exceeds Todo. Traces of hydrochloric acid are frequently
found in the vicinity of the ocean, and of nitric acid in rain
water, produced by lightning.
The air near cities often contains other substances, organic
matter, sulphuric acid, and ammonia. The odoriferous par-
ticles of flowers, and other vegetable and mineral substances,
are often detected in it.
It was formerly supposed, that the healthy state of the air
depended upon the proportion of oxygen in it; hence the
origin of the term eudiometry, which was applied to the
process of analyzing the air; but, since the oxygen of the
air is found to be constant, it is now applied also to the
modes of ascertaining its purity. This is effected either
by exploding a given portion of air with hydrogen in the
eudiometer, (see page 152,) or by placing in a portion of
confined air some substance to abstract the oxygen.
Uses of the Air. The utility of the atmosphere in the economy of
nature cannot be too highly rated. It is absolutely essential to animal
and vegetable life. Its constitution is one of the most beautiful illus-
trations of the wisdom and goodness of the Creator.
Protoxide of Nitrogen. Symb. NO. Equiv. 14.15+8=
22.15. Sp. gr. 1.5239. 100 cubic inches weigh 47.2586 grains.
History. Discovered by Priestley, 1772, and named by
him dephlogisticated nitrous air. Davy called it nitrous oxide.
Process. This gas may be formed by decomposing nitrate
of ammonia.
Exp. Put a few grains of this salt into a glass retort, and apply
heat. At a temperature of between 4000 and 500° Fahr. it liquefies,
bubbles of gas begin to appear, and in a short time brisk effervescence.
The gas may then be collected in the ordinary way over warm water,
and suffered to remain a short time, until the water absorbs the nitrous
acid which is often formed with it.
Theory. The changes which take place may be thus ex-
plained: the NH3 + NO5, containing 2N, 50, and 3H, are
converted into 3HO, or water, and 2NO.
Properties. The protoxide of nitrogen is a colorless, in-
odorous gas, of a sweetish taste, and does not affect the vege-
table blues; it is not, therefore, an acid or an alkali.

164
Nitrogen and Oxygen.
It supports combustion almost as powerfully as oxygen gas,
Exp. A candle is relighted in the same manner as in oxygen gas.
Iron wire, charcoal, and most combustibles, burn in it. Phosphorus
burns with nearly the same brilliancy as in oxygen gas.
Exp. Mix equal volumes of the protoxide and hydrogen gas, and it will
form an explosive mixture, which may be exploded in the gas pistol
by flame, or the electric spark ; but generally it requires the temperature
of the substance to be raised to a higher degree than oxygen, because
the heat is necessary to decompose the gas, so that its oxygen may
unite with the combustible, and its nitrogen escape into the air.
Respiration of this Gas. When respired, it is a powerful
stimulant. Its effects upon the animal system were first in-
vestigated by Sir H. Davy in 1799. In his experiments on
the effects of respiring the various gases, he breathed nine
quarts of this gas for three minutes, and twelve quarts for
four. No quantity would support respiration for a longer
period. The effects are pleasurable in the highest degree,
resembling the first stages of intoxication. The effect varies
very much with temperament, but generally gives an unusual
propensity to muscular action, a rapid flow of vivid ideas,
and the more prominent traits of character are made still
more
prominent.
This excitement continues but for a few minutes, and gen-
erally is not succeeded by the languor and exhaustion conse-
quent upon other stimulants.* Its effects, however, upon some
temperaments, have proved decidedly injurious. It is hoped
that so powerful a stimulant will be applied to some good use
in medicine.lt
Binoxide of Nitrogen. Symb. N +20, NO2 or N. Eq.
14.15 +16=30.15. Sp. gr. 1.0375.
History. Discovered by Dr. Hales; but its properties were
first investigated by Dr. Priestley, in 1772, who gave it the
name of nitrous air. Nitric oxide and nitrous gas have also
been applied to it.
Process. It may be formed by the action of dilute nitric
acid (2 parts of water to 1 of acid) upon copper filings, or
* It may be administered from a silk or India-rubber bag, furnished
with a stop-cock, by repeatedly breathing it from the bag and back
again, as long as it will support easy respiration.

Nitrous Acid.
165
mercury. Place the materials in a retort, and collect over
water.
Theory. In this process, the nitric acid is decomposed. 3 equiv. of
oxygen unite with the copper, forming the peroxide of copper, and 2
equiv. of oxygen combine with the nitrogen, and form the binoxide; the
peroxide of copper is then united to some undecomposed nitric acid,
and forms the nitrate of copper. Cu and 2N0 are converted into
CuO3+ NO5 and NO?.
Properties. This gas is colorless, and slightly absorbed
by water. It is perfectly irrespirable, exciting spasms in the
glottis, which immediately closes to prevent its passage into
the lungs. It extinguishes most burning bodies, although
phosphorus and charcoal, introduced in a state of vivid com-
bustion, burn with increased brilliancy, owing, doubtless, to
its decomposition, which is easily effected by heat or elec-
tricity
Binoxide of nitrogen has a strong affinity for oxygen.
Exp. Pass oxygen into a jar of it, and red fumes will be formed.
This is a test of the gas. Atmospheric air will produce a similar ef-
fect;* hence it may be used to separate the oxygen from the nitrogen
of the air.
Hyponitrous Acid. Symb. N +30, NO3 or N. Equiv.
14.15 +24=38.15. This compound was discovered by
Gay Lussac, and is said to be formed when 400 measures of
binoxide of nitrogen are mixed with 100 of oxygen, both
quite dry. When the resulting orange fumes are exposed to
a cold of zero, Fahr., they are condensed into a liquid.
Properties. The anhydrous acid is colorless at zero, and
green at common temperatures. It is so volatile, that, in open
vessels, the green fluid wholly and rapidly passes off in the
form of an orange-colored vapor, density of 1.72. In the
manufacture of sulphuric acid, it exerts an important agency,
by forming with water and sulphuric acid a crystalline com-
pound, the production of which seems essential to the
process.
Nitrous Acid. Symb. N +40, NO4 or N. Eq. 14.15+
32 = 46.15.
History. Known for some time under the name of fuming
nitrous acid. Its true nature has been ascertained by Davy,
Gay Lussac, and Dulong.
* Owing to this property, an attempt has been made to introduce it
into eudiometry; but the results are not perfectly satisfactory.

166
Nitrogen and Oxygen.
Processes. 1. It is formed by adding oxygen gas in excess
to the binoxide of nitrogen over mercury, and putting a strong
solution of potassa into the receiver before mixing the gases ;
red fumes appear, and combine with the potassa.
2. It may be obtained in the form of a gas, by exhausting
a glass globe of air, and introducing 100 volumes of oxygen
to 200 volumes of the binoxide of nitrogen.
3. The best mode is to expose, in an earthen retort, nitrate
of lead, carefully dried, to a red heat, and collect the gas in
a tube surrounded by ice. For the purposes of experiment,
it may be formed by introducing oxygen, or common air, into
a jar of the binoxide, over water; deep orange-red colored
fumes appear, which are rapidly absorbed by the water; or
by simply taking up a jar of the binoxide, and exposing it to
the air. In each case, nitrous acid is formed, and may be
known by its red fumes.
Properties. The vapor is of an orange-red color, rapidly
absorbed by water. At common temperatures, the liquid is
orange-red; below 32°, yellow, and nearly colorless at zero,
Fahr.; density, 1.451; anhydrous, exceedingly volatile, pun-
gent to the taste, and powerfully corrosive, giving a yellow
stain to the skin.
It has decided acid properties, + both in the gaseous and
liquid states.
Exp. Into a long glass tube, filled partly with vegetable infusion,
and partly with the binoxide, introduce a few bubbles of oxygen; the
infusion will immediately turn red, owing to the formation of nitrous
acid, and the absorption of it by the infusion.
Respiration of Nitrous Acid. It is highly suffocating and
poisonous, exciting great irritation and spasms in the glottis
,
even when moderately diluted with air.
Nitric Acid. Symb. N +50, NO5 or N. Equiv. 14.15
+40= 54.15.
History. This acid was first discovered in distilling a
mixture of nitrate of potassa and clay, by Raymond Lully,
* If collected over water, it is converted into nitric acid; if over
mercury, it is decomposed, and the mercury is oxidized.
+ Some chemists believe it to be a compound of nitric and hyponi-
trous acids, from the fact that, when it is added to an alkaline solution,
the products are a nitrate and a hyponitrite of the base.

Nitric Acid.
167
a
a chemist of the Island of Majorca. Basil Valentine, in the
15th century, describes a process of obtaining it, and calls it
the water of nitre. Its composition, however, was first de-
termined by Mr. Cavendish, in 1785, by exposing oxygen and
nitrogen in a glass tube over mercury, in which some water
was present, to the action of the electric battery. It has
since been examined by Davy, Dalton, Henry, Berzelius, and
Gay Lussac.
Process. Gay Lussac ob-
Fig. 76.
tained nitric acid by adding the
binoxide of nitrogen slowly to
an excess of oxygen over water.
By this process, it is found to
be composed of 250 volumes of
oxygen to 100 of nitrogen. But
b.
the usual process for obtaining
it, is to heat, in a large tubulated
retort, a, (Fig. 76,) a mixture id
of 3 parts of nitre (nitrate of po-
tassa) and 2 of sulphuric acid, *
and condensing the gas in the
globe receiver 6, by dropping
ice-cold water from the tunnel t upon the tube of the retort,
or by surrounding the receiver b with ice. The liquid, as it
is condensed, passes into the bottle C.
Impurities. The acid of commerce is not perfectly pure; three
acids are generated in the process - the nitrous, hyponitrous, and nitric.
It also contains hydrochloric and sulphuric acids Nitrous acid gives
it a color varying from yellow to orange and green, and may be ex-
pelled by heat; the hydrochloric may be detected and separated by a
few drops of the nitrate of silver, with which it will combine and form
a white solid. The sulphuric acid is separated by re-distilling it with
nitre.
Properties. Nitric acid, in its most concentrated state, is
a white or limpid liquid, specific gravity of 1.55, and of a
peculiarly nauseous odor. It boils at 243°, and freezes at
--50° Fahr.
E,
* The London College of Physicians employ equal weights of nitrate
of potassa and sulphuric acid. The Edinburgh and Dublin Colleges
employ 3 of nitre to 2 of acid. According to Thompson, the strongest
acid is obtained from 6% parts of sulphuric acid to 123 of nitre; the
specific gravity of which is 1.55.

168
Nitric Acid.
DVC
Chemical Properties. It is one of the most energetic of
substances. It acts upon the skin, and gives it a yellow
stain; it is eminently-poisonous; has a very strong affinity
for water, and cannot be wholly separated from it, before
decomposition takes place.
It acts as a supporter of combustion ; in this case, it is
decomposed, and the oxygen combines with the combustible.
Exp. Pass hydrogen and nitric acid through an ig- Fig. 77.
nited porcelain tube ; a violent detonation will be pro-
duced, which is due to the combination of the oxygen of
the acid and the hydrogen.
Exp. Pour strong nitric acid on dry, powdered char-
coal; the charcoal will be ignited, with the evolution
of dense fumes.
Exp. Phosphorus takes fire in it, (Fig. 77,) sometimes
with violent explosion.
Exp. Pour nitric acid on to some of the essential oils,
as spirits of turpentine, and they will be inflamed.
The acid in these experiments should be pour-
ed from a wine-glass, attached to the end of a
long rod.
Nitric acid unites with various metals, such as iron, tin,
copper, with great energy, and is decomposed by them. It
also suffers decomposition by boiling it in contact with
sulphur, or by exposing it to the solar rays.
the color changes to a yellow, and deep orange, in conse-
quence of the formation of nitrous acid. The action of
the binoxide of ritrogen produces the same effect, as may
be shown by passing it through nitric acid. In consequence
of its yielding up its oxygen so readily, it is one of the most
powerful oxidizing agents.
Uses. It is used extensively in chemistry and the arts;
for etching on copper, and as a solvent of tin to form a mor-
dant for some of the finest dyes; in metallurgy and assaying,
to bring the metals to their maximum of oxidation ; in medi-
cine, as a tonic. The nitric acid of commerce is water,
and called double aqua fortis; another kind, & water, is called
simply aqua fortis.
Nitrohydrochloric Acid. This is the aqua regia of the
alchemists, and is formed of 1 part of nitric to 4 of hydro-
In this case,

Nitrogen and Chlorine.
169
chloric acid. It possesses the remarkable property of dissolv-
ing gold and platinum, but does not form a distinct class
of salts.
Nitrohydrofluoric Acid. This acid is formed by a mixture
of nitric and hydrofluoric acids, and dissolves metals, which
are not dissolved by the preceding acid, and is therefore an
important re-agent.
Hea
Nitrogen and Chlorine.
Quadrochloride of Nitrogen. Symb. N +4Cl or NCI'.
Eq. 14.15 + 141.68 = 155.83. Sp. gr. 1.653. Discovered
in 1811 by Dulong, and subsequently examined by Davy and
others.
Process. This very extraordinary substance may be formed by the
union of nitrogen and chlorine in their nascent state, or the chlorine
may be obtained in a jar, and inverted over a solution of 1 part of hy-
drochlorate of ammonia to 12 of water; a part of the chlorine unites
with the hydrogen of the ammonia, forming. hydrochloric acid, and
another portion unites with the nitrogen of the ammonia, and forms
the quadro-chloride of nitrogen, which appears in the form of yellow,
oily drops on the surface of the solution.
Properties. A yellow, oily liquid, of an irritating and pe-
culiar odor; it retains the liquid state below zero, Fahr. It
may be distilled at 160° Fahr., but explodes between 200° and
212°, and suffers decomposition. It is one of the most explo-
sive substances yet known. A drop of the size of a pea,
brought in contact with phosphorus, or with any of the oils,
will explode with great violence. It is dangerous to experi-
ment with it, even in so small portions. Dulong lost an eye
and a finger, and Davy had both eyes injured by exploding
small quantities of it. As it is liable to explode without
any assignable cause, great care should be used in its prepa-
ration.
Nitrogen and Iodine. oodaloor
03
Teriodide of Nitrogen. Symb. N +31 or NI. Eq. 14.15+
378.9=392.24. This compound, discovered by M. Cour.
tois, is obtained in a similar manner with the preceding.
Exp. Put iodine in a solution of ammonia, and there will be precip-
itated a blackish powder, which may be thrown, in the course of half
an hour, upon a filter, Washed and dried. When dry, it explodes by
the slightest touch, or even spontaneously.
15

170
Nitrogen and Hydrogen.
to ਦਾ ਸ
Nitrogen and Hydrogen.be
Ammonia. Symb. N+3H or NH”. Eq. 14.15+3=
17.15.
athy
History. This substance was known to the alchemists by
the names of hartshorn, volatile alkali, spirit of sal-ammo-
niac, etc., but was first noticed as a distinct gas by Dr. Priest-
ley, who
gave
it the name of alkaline air. The name ammo-
nia is derived from one of the salts from which it was pro-
cured, the hydrochlorate of ammonia, or sal-ammoniac, and
this from the temple of Jupiter Ammon, in Lybia, from
which place it was first obtained.
Process. Mix together equal parts of pulverized Fig. 78.
hydrochlorate of ammonia and recently-slacked lime
in a common retort, and apply heat. The gas may
be collected over mercury, or, in consequence of its
being lighter than the air, the materials
may put
into a Florence flask, a,' (Fig. 78,) to which is at-
tached a long glass tube. Invert over it a receiver,
r, and the gas will displace the air, and fill the re-
ceiver; (for a test of the gas, hydrochloric acid
may be used, which prodaces a white cloud.) It
may also be obtained by simply heating the com-
mon aqua ammonia of commerce. The liquid ammonia, or
aqua ammonia, is prepared by passing the gas through water
in Woulfe's apparatus, in the same manner as in the prepa-
ration of hydrochloric acid. (See page 154.)
Theory. When lime and the hydrochlorate of ammonia are used,
the hydrochloric acid deserts the ammonia, and combines with the lime,
leaving the former to escape in the gaseous form.
Properties. Ammonia is a colorless gas, of a strong, pun-
gent odor; becomes a transparent liquid under pressure of
6.5 atmospheres, and at a temperature of 50° Fahr. It cannot
support respiration in its pure state, but may be inhaled with
safety when mixed with the air.
It is inflammable, but extinguishes the flame of most burn-
be
ing bodies.
Exp. A candle immersed in this gas, burns with increased flame,
tinged with yellow before it goes out. When expelled from an orifice

Nitrogen and Hydrogen.
171
surrounded by oxygen gas, and ignited, it burns with a pale yellow
flame. The products are water and nitrogen.
It has a strong affinity for water and for alcohol.
Escp. A few drops of water, introduced into a jar of the gas over
mercury, will instantly absorb it, and the mercury will rise.
Ice placed in a jar of it over mercury, is melted rapidly.
Alcohol absorbs several volumes of this gas, and the solu-
tion has a strong odor, commonly called spirits of hartshorn.
The decomposition of ammonia is effected by chlorine and
iodine.
Exp: Place a flask of ammonia over a bottle with a wide mouth,
containing chlorine gas. The gases will instantly combine, as will be
seen by a sheet of white flame.
Theory. The chlorine unites with the hydrogen of the ammonia,
forming hydrochloric acid; and this unites with some undecomposed
ammonia, and forms hydrochlorate of ammonia, and will be deposited
on the sides of the flask in a solid state.
Ammonia, both in the gaseous and liquid form, possesses
decided alkaline properties.*
Exp. Place a jar of ammoniacal gas on a plate containing vegetable
infusion, and the infusion will become green.
Uses. Ammonia is used in the arts and in medicine. In
chemistry, it is employed to neutralize acids.
Exp. Colors changed by acids may often be restored by ammonia.
Hence clothing spotted by acids, especially woollen clothes, may have
the color restored by moistening the spots with the liquid ammonia.
In medicine, it is used as a tonic. It is a powerful and
* This introduces to us a new class of bodies — the alkalies. Am-
monia is the only one the base of which is not a metal, and there is
still some doubt whether its base, nitrogen, is not a body with a me-
tallic base. This view corresponds best with the general analogy of
other compounds. The alkalies generally have the following prop-
erties :
1. Caustic to the animal organs, corrode woollen cloth, and are gen-
erally powerful solvents of animal matter.
2. Volatilized by heat, but, excepting ammonia, are not easily de-
composed by it.
3. Combine with acids, and form salts.
4. All soluble in water.
5. Unite with oils, and form soaps.
6. Taste acrid, very different from acids.
7. Change some vegetable blues to green. This last property is a
convenient one to distinguish them from acids. One of the best tests
of acids and of alkalies, is an infusion of purple cabbage, which is
changed to red by acids, and to green by alkalies.

172
Carbon.
Jana
grateful stimulant, producing the useful effects of alcohol,
without its injurious consequences. Ammonia is the sub-
stance employed for smelling-bottles. *
Equiv.<by wgt
.
y vol. 100.
Sp. gr.
Sect. 8. CARBON.
blon
Symb. C.
$ 3.52 Water =1.
6.12.
26.12 Hyd. = 1.
Natural History. Carbon is one of the most important
and useful of substances. Like all other substances of ex-
tensive utility, it is widely diffused. It exists abundantly in
the animal, vegetable, and mineral kingdoms. The greater
part of the substance of trees, and of animal bodies, is car-
bon. It is rarely found quite pure in nature, and cannot
be formed perfectly pure by art. The only pure carbon is
the diamond.
The diamond is found in the East Indies and in Brazil,
S. A. They generally occur in alluvial soils, in detached crys-
tals, the primitive form of which is the regular octohedron,
but sometimes have twenty-four, and even forty-eight faces.
They are of various colors, brown, black, red, blue, and green,
or colorless and transparent; the latter are the most valued.t
The diamond is the hardest body in nature. It is a powerful
refractor of light, a property which led Newton to predict its
combustion. Lavoisier first proved it to contain carbon, by
exposing it in oxygen gas to the solar focus. The product
was carbonic acid. In 1807, the combustion of the diamond
in oxygen was found by Allen and Pepys to be attended by
the same results as that of charcoal. Davy confirmed these
results by comparing the combustion of the diamond with
that of various kinds of charcoal. Another proof of its iden-
tity is the fact, that diamond converts iron into steel in the
same manner as charcoal.
* To prepare a smelling-bottle, it is only necessary to put a small
quantity of quick lime and hydrochlorate of ammonia into a small bot-
tle, and keep it corked tight, only when it is used.
† Diamonds are of various sizes; some are as large as a pigeon's
egg, and the value increases with the size, in a very rapid ratio.

Carbon.
173
or five
Uses. The diamond is the most valued of gems; used in
jewelry, and for the purpose of cutting glass.
The other kinds of carbon are the following :-
Plumbago. This is carbon nearly pure, containing four
per cent. of iron. It is sometimes called black lead,
and used for pencils, crayons, etc.
It is found native in
primitive formations, and is next to the diamond in purity.
Anthracite is a species of fossil coal, the next in purity.
Bituminous coal is similar to the preceding, with the addi-
tion of bitumen, when the bituminous and volatile matter is
driven off by heat; it is called coke, which is nearly pure
carbon.
Peat is an impure kind of carbon, containing uncarbon-
ized vegetable matter, mixed with earthy substances.
Lampblack is a kind of carbon which is obtained by the
combustion of turpentine, pitch-pine, camphor, and almost
any species of combustible matter, containing carbon. It is
deposited from flame in the form of a fine black powder.
For use in the arts, it is chiefly made by turpentine manufac-
turers, from the refuse resin. This is burned in a furnace,
and the smoke, carrying up the carbon, is conducted to a
room hung with sacking, upon which the lampblack is depos-
ited. It is collected and sold without further preparation.
It is used extensively as a paint -- that from camphor is the
best.
Ivory black is a kind of lampblack obtained from burning
bones, sometimes called animal charcoal.
Charcoal. If wood be burned in the open air, nothing
remains but ashes; but if the air is mostly excluded, so that
it undergoes a smothered combustion, a black, brittle sub-
stance remains, called charcoal, which is nearly pure carbon
Processes. 1. For the common purposes of fuel, it is pre-
pared by forming the wood into a conical pile, and covering
it with earth. The combustion is slow, in consequence of
the small quantity of air which is admitted; the volatile parts
are driven off, and the carbon remains.
2. It is also prepared by distillation of wood, in large iron
15*

174
Carbon.
cylinders. This is the mode of preparing it for the manufac-
ture of gunpowder. Beside the charcoal, two valuable sub-
stances, the pyroligneous acid and tar, are obtained.
3. But the purest charcoal is prepared by charring wood
under sand or melted lead. It should be put immediately
into bottles, corked tight, to exclude the air.
Properties. Carbon is a black, brittle, shining, inodorous
substance, easily pulverized, a good conductor of electricity,
and a bad conductor of caloric.
It is the hardest substance in nature. Common charcoal
appears soft, but this is in consequence of its pores. If
rubbed upon glass, it will scratch it.
It has the property of absorbing various gaseous bodies,
Exp: Heat a piece of charcoal, and plunge it into mercury until
cool, then place it under a glass receiver over mercury. In the course
of twenty-four or thirty-six hours, it will absorb of ammonia 90 times
the volume of the charcoal:
Hydrochloric acid,
85 ) Olefiant gas,
35
Sulphurous acid,
85 | Carbonic oxide,
9.42
Hydrosulphuric acid,
55 | Oxygen,
9.25
Protoxide of nitrogen,
40 Nitrogen,
7.5
Carbonic acid,
35 | Hydrogen,
1.75
The gases will be given up again by heating the charcoal,
or partially by plunging it into water.
Theory. This power cannot be attributed wholly to chemical action,
but is due to the porous texture of the charcoal; and the gases appear
to be absorbed in the same manner that sponges and other porous
bodies absorb liquids. The property is most remarkable in the com-
pact varieties, such as that from box-wood, where the pores are numer-
ous and small. By reducing it to powder, this power is diminished,
In plumbago, and in the diamond, it is wholly wanting.
But how does this account for its absorbing more of one gas than of
another ? Chemical affinity has doubtless some influence, but it is
mostly due to the elasticity of the gases. Those gases, easily converted
into liquids, are absorbed in greater quantities than those more perma-
nent; hence vapors are absorbed more easily than gases, and liquids
than ether. Hence, too, charcoal, when exposed to the air, or other
gases, increases in weight.*
.
* The increase varies with the kind of wood from which it is made.
According to the experiment of Allen and Pepys, charcoal from fir
gains 13 per cent.; lignumvitæ, 9.6 per cent. : that from
Box,
14. Oak,
Birch,
16.3 Mahogany,
.. 18.
16.5

Properties.
175
The absorption is the most rapid during the first twenty-
four hours; it absorbs oxygen from the air more rapidly than
nitrogen.
It also absorbs the odoriferous and coloring principles
from most animal and vegetable substances.
Exp. Pass ink through pulverized charcoal, and the color will be
discharged. Red wines, rum, and brandy, may be rendered colorless
by filtration through it.
It is used extensively for refining sugar, and for preparing
colorless crystals of citric acid, and other vegetable produc-
tions. Stagnant water, and most animal and vegetable sub-
stances, in a putrescent state, will be cleansed and purified
by this substance; hence its use to purify docks, vessels, etc.
Putrescent meat is purified by rubbing it with charcoal ;
and, generally, all substances subject to putrescence may
be preserved for a long time, by surrounding them with
charcoal.
In consequence of this property, it is used in medicine as
an antiseptic in putrescent diseases. Animal charcoal is the
best for these purposes, and as its efficacy depends upon iis
power of absorption, it should be heated, to expel all the gas,
before it is used, or kept in well-stopped bottles as soon as
prepared.
It is very combustible. It requires a strong heat to ignite
it, but then it will burn for a long time, the oxygen of the
air uniting with it and forming carbonic acid. *
In conse-
quence of this
property, it is one of the most useful substances
in nature.
It is the most durable substance known. Grains of wheat
and rye charred in Herculaneum by the volcanic eruption,
A. D. 79, were easily distinguished from each other, eighteen
centuries afterward; an arrow head has been charred, and
even the form of the feather preserved. The stakes driven
down in the bed of the Thames, by the Britons, to prevent the
army of Julius Cæsar from passing the river, were discovered
about fifty years since, and were all charred to a consider-
able depth. They were as perfect as when driven; were
made into knife-handles, and sold as antiques at a high
price. Farmers char their troughs and posts to prevent
decay.
* Large quantities of powdered charcoal often ignite spontaneously,
owing, doubtless, to the small quantity of potassium which is gener-
ally found in connection with it.

176
Carbon.
It is infusible by any degree of heat, except that from a
powerful galvanic battery; and in this case there is reason to
doubt whether there is a fusion of any thing but of some im-
purities in the carbon.
Uses. The uses of carbon have already been stated, and
are generally well known. It is one of those substances
which are indispensable to the wants, to the existence of our
race; and the Creator has given us, in its character and
abundance, the most decisive proofs of his wisdom and
benevolence.
Carbon possesses extensive powers of combination, and
forms a class of substances of great and permanent utility in
chemistry, the arts, and the common business of life.
Carbonic Oxide. Symb. CO or C. Equiv. 6.12+8=14.12.
Sp. gr. 0.9727, air = 1.
History. Discovered by Priestley by the distillation of
charcoal with the oxide of zinc; but its composition was
first determined by Mr. Cruickshank.
Process. The best and most convenient mode of obtain-
ing this substance, is to put 2 parts of well-dried chalk,
pulverized, to 1 of iron filings, into a gun-barrel, and raise
the temperature to a red heat. The gas may then be col-
lected over water; it may be obtained, also, by heating the
oxides of several of the metals with powdered charcoal.
Theory. Chalk is composed of carbonic acid and lime. One equiv-
alent of oxygen contained in the acid, goes to the iron, and converts
the acid to the carbonic oxide; oxide of iron and lime remain, or CO?
+ CaO and Fe are converted into FeO, CaO, and CO.
Properties. A colorless, insipid gas, of an offensive odor.
It is highly inflammable, and burns with a pale blue flame
when a lighted taper is plunged into it, but does not support
combustion. A mixture of 1 part of oxygen to 2 of the
gas is explosive; the result is carbonic acid. It is destruc-
tive to animal life ; an animal immersed in it soon dies.
When diluted with air, it causes fainting and giddiness.
Carbonic Acid. Symb. C +20, CO2 or C. Equiv. 6.12
+16= 22.12. Sp. gr. 1.5239, air=1.
History. Discovered in 1757 by Dr. Black, who called

Carbonic Acid.
177
it fixed air.* This was the first gas known, except the
atmosphere, and laid the foundation of pneumatic chemistry.
Natural History. Carbonic acid exists very abundantly
in nature, generally in combination with lime, forming the
carbonate of lime, or marble.
Process. It is obtained by the combustion of the diamond
in oxygen gas, by burning charcoal in the air, or oxygen;
but it is more easily obtained by decomposing some of the
carbonates. Take pulverized carbonate of lime (marble or
chalk) in a glass retort, and pour on sulphuric or hydro-
chloric acid, diluted with five or six parts of water, and
collect over water, or in a globe receiver, in the same man-
ner as hypochlorous acid gas. (See page 133.)
Theory. In this process, the sulphuric acid combines with the lime,
forming the sulphate of lime, and liberates the carbonic acid. SO3,
CO2 + CaO are converted into SO3 + CaO and CO2
Properties. It is colorless, inodorous, and elastic, requir-
ing a pressure of thirty-six atmospheres, 540 lbs., to the
square inch, to condense it into a liquid more than 14 times
as heavy as atmospheric air, and hence may be poured from
one vessel to another, like water.
It is neither a combustible nor a supporter of combustion.
Exp. Into a jar of carbonic acid, let down a pendent candle. It will
be extinguished as soon as it reaches the gas, or it may be poured upon
the candle from a vessel. The flame does not cease from want of oxy-
gen, since four measures of air and one of carbonic acid will extin-
guish flame; hence a positive influence is exerted upon it.
It is rapidly absorbed by water.
-
Exp. If a small quantity of water be agitated in a bottle containing
carbonic acid gas, it will soon absorb it, and acquire acid properties.
Recently-boiled water will absorb one volume of the gas at the com-
mon temperature and pressure, but increases in its absorbing power in
proportion to the pressure applied. It absorbs twice its volume when
the pressure is doubled, three times its volume when the pressure is
trebled, etc.
* Its composition was first demonstrated-synthetically by Lavoisier,
who obtained it by the combustion of charcoal in oxygen gas. Smith-
son Tennant proved its composition analytically by passing the vapor
of phosphorus over chalk, heated to redness in a glass tube.
f If intended to be kept long, it should be transferred from the cis-
tern in bottles, as the water rapidly absorbs it.

178
Carbon.
Water may be acidulated with it, by employing Woulfe's
apparatus, in the same manner as with hydrochloric acid.
(See page 154.) In the common soda fountains, the water
is confined in a strong brass or copper vessel, and charged
with the gas by a forcing-pump. The pleasant, pungent
taste and sparkling appearance of fermented liquors, soda,
and Seidlitz waters, and the waters of many mineral springs,
are due to the carbonic acid which they hold in solution.
The water saturated with it makes a pleasant and healthful
drink.
But the gas escapes on exposure to air and heat. Hence
all such drinks soon become insipid.
If the pressure is removed, the escape Fig. 79.
of gas is much more rapid.
Exp. Place a tumbler of water, (Fig. 79,) satu-
a
rated with this gas, under the receiver a of an
air-pump b, and exhaust the air. The gas will
escape so rapidly as to present the appearance
of boiling. Any of the fermented liquors will
produce similar phenomena.
water saturated with the acid
be rapidly congealed, the frozen water
has the appearance of snow, its bulk
being greatly increased by the immense
number of bubbles formed by the liber-
200
It is an acid, as shown by chemical tests.
Exp. Put a piece of litmus paper into water saturated with it, and
it is turned red; but by heat, or exposure to the air, the color returns,
owing to the escape of the acid.
This is not the case with any other acid; the colors they
form are generally permanent, unless changed by alkalies.
The best test of carbonic acid is lime water, which is ren-
dered turbid by the gas.
Theory. Carbonic acid unites with the lime which the water holds
in solution, and forms the carbonate of lime, which is soluble in water,
and is precipitated in fine powder. This gives to the water a milky
appearance. If; however, you continue to add carbonic acid, it will
dissolve the carbonate, and the water will become clear again, carbon-
ate of lime being very soluble in excess of carbonic acid.
Solidification of Carbonic Acid. It has lately been ascer
If the
ated gas.

Carbonic Acid.
179
tained, that when the gaseous carbonic acid is subjected to a
pressure of thirty-six atmospheres, it is condensed into a
liquid, and at —85° into a solid resembling compact snow.
Relations to Animal Life. Although water saturated with
carbonic acid proves a healthful and invigorating drink, the
free acid cannot be taken into the lungs without producing
almost instant death; in fact, the glottis closes at its ap-
proach, and will not suffer it to enter. If it be diluted with
air, it acts upon the system as a narcotic poison ; an animal
thrown into it is usually suffocated.+ Carbonic acid is
heavier than the air, and hence often remains in wells and
deep pits, where it is generated, and called by the miners
choke-damp. Before descending, a candle should be let
down, and if it will not burn, life cannot be supported. The
acid may be absorbed by pouring down large quantities of
water; it may be partially expelled by exploding gunpow-
der near the bottom;' or it may be drawn up with large
buckets.
Production of Carboric Acid. Causes are in constant
operation to form carbonic acid, and throw it off into the
* Mr. Faraday first condensed carbonic acid into a liquid by placing
carbonate of ammonia in one end of a strong glass tube, bent twice at
right angles, and sulphuric acid in the other end, which is sealed her-
metically. When the acid is poured upon the ammonia, it combines
with it and liberates the gas, which, by the pressure, is condensed;
but this process is attended with much danger, from the bursting of
the tube. A safer method has been contrived by Thillorier, in which
the gas is condensed in a strong metallic cylinder. By allowing the
liquid acid to escape through the stop-cock, it expands so rapidly as to
become frozen, owing to the absorption of its sensible caloric. A re-
duction of temperature to -162° is said to have been produced by this
means. The solid acid thus formed is about the weight of carbonate
of magnesia, perfectly white, and of a soft, spongy texture. It evapo-
rates so rapidly that mercury, and even alcohol, (sp. gr. .820,) are frozen.
According to the experiments of Mitchell, of Philadelphia, the greatest
cold produced by the solid acid in the air was –1090, and under an
exhausted receiver -136°. The pressure at 32° was 36 atmospheres,
at 66°, 60 atmospheres, and at 86º, 72 atmospheres, or 1290 lbs. to the
square inch. When obtained in a liquid form in a glass tube, it is
colorless and extremely fluid In attempting to open the tubes at one
end, they uniformly burst into fragments, with violent explosions.
† Caution. This gas is always produced in burning charcoal; and
hence the danger and criminality of placing pans of hot coals in
sleeping apartments, or in rooms not ventilated by a chimney. The
acid gradually mixes with the air, causing drowsiness, and even death,
before the person can escape. Every year adds new proofs, in the loss
of many lives, to the folly and danger of such practices.

180
Carbon.
atmosphere. It is evolved in great quantities from the earth
from ordinary combustion, and by the respiration of animals
.
In the two last cases, the oxygen of the air is consumed, and
carbonic acid takes its place; hence we should expect, if
there were nothing to counteract this process, that the whole
atmosphere would, in time, be rendered unfit to support
respiration ; but not more than nooo part of the atmosphere
is carbonic acid. In places near cities, or where it is evolved
from the earth, the proportion may be greater. This ten-
dency, however, may be counteracted by the vegetable king.
dom. During the daytime, plants absorb carbonic acid, de-
compose it, retain its carbon, and throw off its oxygen. In
the night, the process is reversed; oxygen is consumed, and
carbonic acid is thrown off; but more of oxygen is emitted
in the daytime than is consumed in the night; more carbonic
acid also is consumed during the day than is given off dur-
ing the night. The balance from this process is needed to
meet the demands of the animal kingdom, which constantly
consumes oxygen, and generates carbonic acid in the process
of respiration. Thus the equilibrium of the atmosphere is
preserved, and both kingdoms flourish together.
Exp. That carbonic acid is given off in respiration, may be shown
by breathing with a quill through lime water, which will become tur-
bid. This fact enables us to understand the process of
Respiration. The blood, in its progress through the sys-
tem, becomes filled with carbon, which gives to it a dark
color. When it passes into the lungs, the air is brought in
contact with it; the carbon unites with the oxygen, forming
carbonic acid, which is expelled, and the blood is changed
to a bright red; it is now fitted to nourish the system. Some
suppose that the oxygen enters into the blood, and that the
combination takes place during the course of circulation; but
whichever theory be adopted, carbonic acid is thrown off,
and oxygen is consumed. Hence, in crowded assemblies,
great quantities of this gas are formed, and, as a consequence,
dulness and fainting often ensue. Hence, also, the neces-
sity of having large public rooms well ventilated.
Dichloride of Carvon (Symb. C’Cl. Equiv. 12.24 + 35.42=47.66)
was discovered by M. Julin. It occurs in small, soft, adhesive fibres,
of a white color, of a peculiar odor, resembling spermaceti, and is taste-
less; burns with a red flame, emitting much smoke, and fumes of hy.
drochloric acid
gas.
Protochloride of Carbon. Symb. CCI. Equiv. 6.12 + 35.42=41.54.
It is obtained by passing the vapor of perchloride of carbon through a

Compounds of Carbon.
181
heated glass tube, filled with fragments of rock crystal, to increase the
heated surface. It is a limpid, colorless liquid; density, 1.5526.
Chloride of Carbon. Symb. C4C1. Equiv. 24.48 +177.1=201.58.
Discovered by Liebig, and sometimes called the new chloride of
Liebig; obtained by boiling chloral with a solution of lime, potassa, or
baryta. It is a limpid, colorless liquid, similar in odor and appearance
to the oily fluid which chlorine forms with olefiant gas; density, 1.48;
boils at 141° Fahr
Perchloride of Carbon. Symb. C²C13. 12.24 +.106.26=118.5. Dis-
covered by Faraday. When olefiant gas is mixed with chlorine, com-
bination takes place between them, and an oil-like liquid is formed,
consisting of carbon, hydrogen, and chlorine. Expose this liquid, in a
jar of chlorine, to the solar rays, and hydrochloric acid is set free, and
the chlorine unites with the carbon.
Properties. At common temperatures, it is a colorless, transparent
solid, of an aromatic odor, resembling that of camphor; fuses at 320°,
and boils at 360°.
Chloro-carbonic Acid. Symb. O+C+Cl. Equiv. 8+6.12+ 35.42.
= 49.54. This singular compound of oxygen, chlorine, and carbon,
affords a somewhat unusual instance of two acidifying principles
uniting with one base to form an acid. It was discovered by Dr.
Davy, who called it Phosgene gas. It is formed by exposing equal
volumes of chlorine and carbonic oxide to the solar rays, when rapid
but silent combustion takes place, and they contract to one half their
volume.
Properties. A colorless gas, with a strong odor; reddens litmus pa-
per, and combines with four times its volume of ammoniacal gas. Wa-
ter and several of the metals decompose it.
Chloral (Symb. C°C1604 Equiv. 299.60) is a new compound of
carbon, oxygen, and chlorine, discovered by Liebig, and prepared by
the mutual action of alcohol and chlorine. It is a colorless, transparent
liquid, of a penetrating, pungent odor, nearly tasteless, oily to the
touch ; density, 1.502, and boils at 2010
Periodide of Carbon was discovered by Serullas, and is obtained by
mixing an alcoholic solution of pure potassa and of iodine. It forms
crystals of a pearly lustre, sweet to the taste, and of a strong, aromatic
odor, resembling saffron.
The Protiodide is formed by distilling a mixture of the preceding
compound with corrosive sublimate. It is a liquid of a sweet taste, and
penetrating, ethereal odor.
Bromide of Carbon. Formed by mixing 1 part of periodide of
carbon with 2 of bromine: two compounds are formed, the bromide
of carbon and the sub-bromide of iodine; the latter is removed by a
solution of caustic potassa. It is liquid at common temperatures, but
crystallizes at 32° Fahr.; sweet to the taste, and of a penetrating, ethe-
real odor; distinguished from the protiodide by the vapor which it emits
on exposure to heat.
16

182
Carbon and Hydrogen.
Carbon and Hydrogen.
Two compounds of carbon and hydrogen have been known
for some time, but of late the number has been increased to
at least twelve.
Dicarburet of Hydrogen. Symb. C+2H or CH². Equiv.
6.12 +2=8.12. Sp. gr. 0.5593, air = 1.
History. This substance is generally known under the
name of light carbureted hydrogen. The names heavy in-
flammable air, the inflammable air of marshes, and hydro-
carburet, have also been applied to it; but, taking carbon as
the electro-negative element, it is more agreeable with the
principles of nomenclature to call it a dicarburet of hydrogen.
Dalton first ascertained its real nature, but it was subse-
quently examined by Davy, Thompson, and Henry.
Process. This gas is formed naturally by the decomposi-
tion of vegetable matter in marshes. It may be obtained by
inverting a receiver in almost any stagnant pool, and stirring
the sediment at the bottom. In this state it contains one
twentieth part of carbonic acid, and one fifteenth of nitrogen;
the former may be removed by lime water or pure potassa.
This is the best mode to obtain the pure gas.
It is formed also by the distillation of mineral coal, con-
taining carbonic acid and olefiant gas; the former may be
removed by lime water, the latter by chlorine.
Properties. Colorless, tasteless, and nearly inodorous.
Water absorbs ob of its volume. It extinguishes all burning
bodies, but is highly combustible. It burns in a jet with a
yellow flame, brighter than hydrogen ; destructive to animal
life when respired; partially decomposed by a very intense
heat.
Exp. Mixed with rather more than twice its volume of oxygen, it is ex-
plosive ; exactly two volumes of oxygen are consumed, and the prod-
ucts are carbonic acid and water.
Exp. Mixed with chlorine, and exposed to the solar light, it is de
composed, and hydrochloric and carbonic acids are formed; though the
products will depend upon the quantity of chlorine.
Olefiant Gas, or ļ Carburet of Hydrogen. Symb. 2C+
2H. Equiv. 12.24 +2= 14.24." Sp. gr. 0.9808, air =1,
و

Carbon and Hydrogen.
183
History Discovered in 1796 by some associated Dutch
chemists, who called it olefiant gas from its forming an oil-
like liquid with chlorine. It has been called hyduret of car-
bon, bicarbureted or percarbureted hydrogen; but carburet
of hydrogen accurately designates its composition, and is, on
this account, preferable.
Process. Mix in a large retort 1 measure of alcohol with
2 of concentrated sulphuric acid, and apply the heat of a
spirit lamp. The mixture soon turns black, and rises up in
the retort; the gas is rapidly disengaged, and may be col-
lected over water or mercury; carbonic and sulphuric acids
are formed during the process, and may be separated by pure
potassa or lime water.
Theory. Alcohol is a compound of olefiant gas and water. The
sulphuric acid unites with the water, and the gas is evolved. C²H30
and SO3 are converted into SO3, HỎ, and C?H? At the commence-
ment of the process, ether is formed, which differs from alcohol by hay-
ing 2 equiv. of olefiant gas combined with water, while alcohol has but
1. The ether is condensed in the cistern.
Properties. It is a colorless, tasteless gas, and has scarcely
any odor when pure. Water absorbs of its volume. It
extinguishes a lighted taper when immersed in it, and there-
fore does not support respiration. It burns with a clear, white
light.
Mixed with oxygen, it is highly explosive.
Exp: Mixed with oxygen in the proportions of l volume of the gas
to 3 of oxygen, and kindled by flame, or the electric spark, it explodes
with great violence. This may be shown by the gas pistol. There is,
however, much danger of bursting the pistol; glass vessels should
not be employed to explode it.
Exp. Bubbles of the mixture may be passed up through the water
of the cistern, and exploded upon the surface; but care should be taken
that the fire is not communicated to the vessel containing the mixture,
through the bubbles as they rise.
It is decomposed by heat. By passing it through a porce-
lain tube at a low red heat, charcoal is deposited, and the
bicarburet evolved, which, at a white heat, is also decom-
posed. It is also resolved into hydrogen and carbon by a
succession of electric shocks.
Action of Chlorine. When 2 volumes of chlorine and 1
of olefiant gas are mixed and ignited, they burn rapidly,

184
Carbon. - Gas Lights.
and form hydrochloric acid, while the carbon is deposited;
but, if the gases remain at rest, they slowly combine, and form
an oily liquid, of a yellow color, called chloride of hydro-
carbon.
4 Carburet of Hydrogen, Etherine, (Symb. 4C+4H. Equiv. 24.48
+4=28.48. Sp. gr. 0.627, water=1,) was first obtained by
Faraday in the process of compressing oil gas into strong copper
globes, for the supply of portable gas. It is a highly volatile liquid,
the lightest liquid body known. At 60°, it is exceedingly combustible,
and burns with a brilliant flame.
Carburet of Hydrogen (Symb. 6C + 3H. Equiv. 36.72+3=
39.72. Sp. gr. 0.85) was obtained by Faraday from the same oil gas
liquid which yielded etherine. At common temperatures, it is a color-
less, transparent liquid, smells like oil gas, with a slight odor of almonds.
It is highly combustible, and forms with oxygen a powerful detonating
mixture.
Parraffine is a compound of carbon and hydrogen, obtained by the
distillation of the petroleum of Rangoon, and also by that of tar de-
rived from beech wood. It is a fatty substance, without taste or odor,
and burns with a pure white flame.
Eupione differs from the preceding compound only in containing a
smaller portion of carbon. It is obtained by distillation of the tar
derived from bones or horns. It is a tasteless, inodorous liquid, similar
to oils, but as limpid as alcohol.
Naphtha (Symb. 6C +5H. Equiv. 36.72+5=41.72. Sp. gr,
0.753) is obtained from coal tar by distillation. It is a volatile, limpid
liquid, of a strong, peculiar odor, and generally of a light yellow color.
It is very inflammable, burning with a white flame and much smoke.
It is used to preserve potassium.
Naphthaline (Symb. C10H4. Equiv. 61.2 +4=65.2) is obtained in
the same manner as the preceding compound. It is a white, crys-
talline solid, heavier than water, has an aromatic pungent taste, and
faintly-aromatic odor. With sulphuric acid, it forms a compound, first
described by Faraday in 1826, under the name of sulpho-naphthalic acid,
which has a bitter taste and acid properties.
Paranaphthaline (Symb. C'H Equiv. 91.8+6=97.8) is allied
to the preceding, and obtained from coal tar.
Idriuline is also similar, and obtained from a mineral in the quick-
silver mines at Idria, in Carniola.
Camphene and Citrene. Symb. C10H8. Equiv. 61.2+8=69.2.
Camphene is the basis of camphor; colorless, volatile, and inflammable;
odor like the oil of turpentine. Citrene is almost the sole ingredient
of the oil of lemons.
Gas Lights.
History. The gas, now so generally employed for the
purpose of lighting cities, is probably a mixture of several of

Gas Lights.
185
the preceding substances, composed mostly, however, of
olefiant gas. This gas was first employed for the purposes of
illumination by Dr. Clayton, in 1739, but was soon given up
for more than sixty years. The subject was investigated,
about fifty years since, by Mr. Murdock; and since that time
gas lights have come into general use, both in Europe and
America. The gas was obtained chiefly from the distillation
of coal; but that obtained from oil (spermaceti is the best) is
much purer, and possesses a greater illuminating power.
Gas from rosin is about equal to that from oil.
Process. When oil is used, several large cylindrical cast-
iron retorts are laid across a furnace, and partially filled with
brick and bits of iron, to increase the heated surface. The
oil is contained in a reservoir, and conveyed to the retorts by
separate tubes. When the retorts are heated to the proper
temperature, the oil is admitted by a stop-cock, in a. small
stream, so that it is immediately decomposed, and the gas
passes out of the retorts by other tubes, running into a large
one, which conveys it to the gasometer.*
When coal is used, the process is similar: the needs
to be purified by passing it through lime water, to deprive it
of carbonic acid and other impurities, which give it a very
disagreeable odor; 112 pounds of coal yield from 450 to 500
cubic feet of gas; sp. gr. 0.450 to 0.700; and į a cubic foot
of gas per hour is equivalent to a candle, six to the pound,
burning during the same time. But oil gas, though much
more expensive, possesses nearly twice the illuminating power
According to Henry, it requires vessels and tubes of but half
the size. 20 cubic feet of coal gas, or 10 of oil gas, is equal
to a pound of tallow.f
Portable Gas. In consequence of the greater cheapness
of gas lights, as compared with candles and oil, it seemed
gas
* The gasometer is made of iron, in some cases 40 feet in diameter
and 20 feet high, containing 20,000 cubic feet. This is immersed in
a vat containing water, and the air permitted to escape by a valve in
the top. When it is filled with water, the gas from the large pipe is
conducted to the bottom, and passes up through the water into the
gasometer, which rises as fast as it is filled. The gas is now con-
veyed in a cast-iron pipe, laid under ground, to which small pipes are
attached, branching off to every part of the city where it is wanted.
+ Coal gas costs about two thirds as much as oil gas, and about one
fifth as much as spermaceti candles.
16*

186
Carbon. — Fire-Damp.
desirable to contrive some method by which it could be made
portable. This object has been effected by what are called
portable lamps. The gas, by means of a forcing-pump, is
compressed into strong brass globes, and ignited as it escapes
through an aperture which is furnished with a stop-cock to
regulate the quantity. These can be carried about like com-
mon oil lamps. For this
purpose,
the
gas
obtained from rosin
is employed.
Fire-Damp. This term is applied to several gaseous com-
pounds of carbon and hydrogen, which are produced in the
mines of bituminous coal. It is mostly light carburcted hy-
drogen, and is produced by the decomposition of the water
by the coal. It issues from various parts of the coal beds, in
such quantities as to render the whole atmosphere of the mines
explosive, and often irrespirable. Hence the miners were
exposed to frequent explosion, and to suffocation. Many ex-
plosions have occurred in the coal mines of England: the
older mines extend miles under the ground, and, in some
cases, are several hundred feet deep. As the gases are
lighter than the air, they rise and mingle with the air near
the top, and gradually descend until they reach the miner's
lamp, when the whole is instantly exploded.* In conse-
quence of the great expense of human life, and the constant
fear of the miners, Sir H. Davy undertook the investigation
of the subject for the purpose of inventing some means of
safety. He went with the miners into the region of the fire-
damp, obtained specimens of the gas, and subjected it to
chemical examination. He found that the most explosive
mixture was 1 part of gas to 7 or 8 of air; 5 or 6 volumes of
air would explode but feebly, and above 14 volumes of air to
1 of gas did not explode at all. It was also found that it re-
quired the heat of flame to explode it. Iron at a red heat,
and even at a white heat, would not affect it. But the fact
which led immediately to the invention of the safety lamp,
had been observed by Dr. Wollaston, that “an explosive mir-
ture cannot be kindled through a glass tube so narrow as 7 of
an inch in diameter.” It was also noticed that the mixture
could not be exploded through fine wire sieves, or gauze
wire, which acts on the same principle as longer tubes.
* In 1812, an explosion occurred in Felling colliery, in Northumber-
land, by which ninety-two men lost their lives. The explosion was
heard three or four miles; thirty-two persons only were saved alive,
In 1815, a similar occurrence happened at Durham, and destroyed
fifty-seven persons; and in another, twenty-two lost their lives.

Carbon. -- Safety Lamp.
187
1
Fig. 80.
Exp. Place the gauze
wire a (Fig. 80) over a jet
of the gas, the flame may
be pressed down, and will
not pass through the wire.
Exp. Let a stream of
the gas pass through the
wire c; the gas may be ig.
nited on the top of the
wire, but will not communicate through it to the tube Fig. 81.
b. The same is true of flame,* by whatever substance
it is produced. The wires conduct off the heat, so
that they do not gain the temperature requisite to
ignite the gas.
Safety Lamp. This consists simply of a
common lamp, a, (Fig. 81,) with a gauze wire,
6, surrounding the flame. The wire should
have at least 625 apertures to the square inch.
Furnished with this lamp, the miners can
enter the mines in perfect safety from explo-
sion, but are exposed to suffocation, when
there is not sufficient oxygen in the mines to
support the combustion of the oil.
To enable the miner to escape from the Fig. 82.
mine when the atmosphere becomes such
as to extinguish the flame of the lamp, a
platinum coil may be inserted around the
wick. Thus, in the lamp b, (Fig. 82,) let
a platinum coil a be inserted around the
wick; when the flame ceases, the combus-
tion will con que slowly for hours, so as
to heat the platinum red-hot. This will
give sufficient light to enable the miner to 5
escape.
This is founded on the fact, that plati-
num wire or foil will, if heated, cause certain gases to com-
bine gradually, with the production of a red heat, but with-
out flame.
Exp. Pour a small quantity of ether into the lamp, and, having
heated the coil of platinum, plunge it into the ether; the heat, of the
wire will cause the vapor of ether and the oxygen of the air to com
* The flames of candles, lamps, gas lights, &c., are hollow, as may
be shown by holding a plate of glass over them. Flames formed by a
mixture of oxygen with the combustible are solid; hence the use of
the blowpipe, bellows, &c., to render the flame solid and increase the
heating power.
e
I E

188
Carbon and Nitrogen.
bine, so as to keep the wire red-hot, and sometimes even at a white
heat, when the ether will burst into a flame
Carbon and Nitrogen.
Bicarburet of Nitrogen, or Cyanogen. Symb. NC2 or Cy
Equiv. 14.15 + 12.24=26.39. Sp. gr. 1.804, air=1.
History. This gas was discovered in 1815, by Gay Lussac
It is sometimes called nituret of carbon, but bicarburet of
nitrogen expresses definitely its composition.
Process. It is obtained from the bicyanuret of mercury,
by heating the salt in a small glass retort, with a spirit lamp,
The retort should be covered with lute, to prevent its
melting. At a red heat, it is decomposed. The cyanogen
passes over in the form of a gas, and the mercury is sublimed,
and remains in the neck of the retort in small globules
Collect over mercury or air.
Properties. This gas is colorless, with a strong, pungent
odor; not a supporter of combustion, but burns itself with
a beautiful purple flame, resembling the peach blossom
Water, at the common temperature and pressure, absorbs 4.}
times its volume, and alcohol 25 times its volume. At the tem-
perature of 45°, and under a pressure of 3.6 atmospheres, it is
condensed into a limpid liquid, but resumes the gaseous
state when the pressure is removed. The most remarkable
chemical property of this substance is, that it acts like a
simple body in most of its combinations, forming substances
consisting of three elementary bodies, analogous to those
formed in other cases by two.
Cyanic Acid (Symb. Cy+0. Equiv. 26.39 +8= 34.39)
may be obtained by exposing cyanuric acid to a dull red heat.
It has a penetrating odor, pungent, and caustic to the skin,
producing great irritation of the eyes; very volatile, giving
off an inflammable vapor.
Fulminic Acid. This is isomeric with the preceding, i. e.,
identical in composition, but possessed of different properties.
It is called fulminic because its compounds of mercury and
silver are highly explosive.
Cyanuric Acid (Symb. Cy306H3. Equiv. 130.17) was
obtained by Serullas by gently boiling bichloride of cyanogen

Compounds of Carbon.
189
in water: cyanuric and hydrochloric acids are the results.
The hydrochloric is removed by evaporation, and the cyan-
uric deposited, on cooling, in oblique rhomboidal crystals.
The crystals are further purified by solution and evaporation.
Paracyanuric Acid is identical in composition with the
preceding, but different in properties; it results from the
spontaneous decomposition of hydrous cyanic acid.
Chloride of Cyanogen. Symb. Cy+Cl. Eq. 61.81. First obtained
in a pure state by Serullas, in 1829, by exposing bicyanuret of mercury
in powder, and moistened with chlorine gas in a well-stopped vial. It
congeals at zero in needle-shaped crystals; is liquid between 5° and
10°, but above this it is a colorless gas, of a very offensive odor, irri-
tating to the eyes, corrosive to the skin, and highly injurious to ani-
inal life.
Bichloride of Cyanogen. Symb. Cy+2C1. Eq. 97.23. Discovered
also by Serullas, by putting 155 grains of pure hydrocyanic acid into a
bottle containing sixty cubic inches of dry chlorine, and exposing it to
the solar rays. The acid is vaporized, and, in the course of a few
hours, a colorless liquid is formed on the surface of the bottle, gradu-
ally growing thicker, until, in the space of twenty-four hours, it sets
into a white solid, with shining crystals. This is the bichloride of
cyanogen. It is exceedingly poisonous, caustic to the taste, and pene-
trating odor, similar to the chloride.
Bromide of Cyanogen is similar to the preceding.
Hydrocyanic Acid, or Prussic Acid, (Symb. Cy+H.
Equiv. 26.39+1=27.39,) was discovered by Scheele, in
1782. Berthollet afterwards ascertained that it was a com-
pound of carbon, nitrogen, and hydrogen; but it was first
procured in a pure state by Gay Lussac.
Process. The best process is that of Vauquelin. Fill a
narrow tube, placed horizontally, with fragments of bicyan-
uret of mercury, and then pass a current of dry hydrosul-
phuric acid gas very slowly through it. Double decomposi-
tion ensues as soon as the gas comes in contact with the
bicyanuret, when hydrocyanic acid and bisulphate of mercury
are formed. When the bicyanuret becomes black, the acid
is expelled by a gentle heat, and collected in a receiver sur-
rounded with ice.
Properties. It is a limpid, colorless liquid, of a strong,
but agreeable odor, similar to that of peach blossoms. It
excites, at first, a sensation of coolness on the tongue, which
is soon followed by heat; but, when diluted, it has the flavor
of bitter almonds; exceedingly volatile; boils at 79°, and

190
Sulphur.
congeals at zero; unites with alcohol and water in all
proportions, but possesses very feeble acid properties.
It is a most virulent poison. A single drop, if placed on
the tongue of a dog, causes instant death. A girl swallowed
a small quantity of it diluted with alcohol, and fell instantly,
as if struck with lightning, and died in two minutes.
A professor of Vienna put drops upon his arm, and was
deprived of life in a few minutes. But though a most potent
poison in its pure state, when much diluted, it has been em-
ployed as a medicine, in cases of consumption, with beneficial
effects. This, like many other violent poisons, cannot be
employed for criminal purposes, without the almost certain
risk of being discovered. It exists in the laurel, peach, and
in beef-steak.
SECT. 9. SULPHUR.
Symb. S. Equiv. { boy wodt
. 16.66.
Sp: gr.
wgt. 16.1.
21.99
5 6.6558 Air =1.
Water=1.
Sulphur has been known from the remotest antiquity.
Natural History. It exists in nature, in a pure state, in
the vicinity of volcanoes. It collects in the craters, either in
fine powder or in crystalline solids; but it exists more abun-
dantly in combination with the metals, forming the sulphurets
of iron, copper, lead, silver, etc., from which it may be sub-
limed by heat, but is not quite pure. It is found also in many
mineral waters; in many minerals, such as gypsum, sulphate
of strontia, etc.; in all animals, and some plants.
Process. The sulphur of commerce exists in two states;
in rolls, called roll brimstone, and in fine powder, called flow-
ers of sulphur ; but the two varieties are readily resolved into
each other by the application of heat.
Exp. Heat a brick, or small iron cup, to nearly a red heat. Place
upon it roll brimstone, and invert over it a beil-glass receiver; the
sulphur will sublime,* i.e., pass into a fine powder, like vapor, and col-
* This may serve to illustrate the process of sublimation as applied
to other substances. Camphor and gum benzoin are easily sublimed
.
The process of converting mercury into vapor, and condensing it
, is
also called sublimation, although it is a liquid.

Sulphur. — Properties.
191
lect on the sides of the vessel. In this way the flowers of sulphur are
prepared.
Properties. Sulphur is a brittle solid, of a lemon-yellow
color, nearly tasteless, and inodorous, except when rubbed or
heated. It is a non-conductor of electricity, but becomes neg-
atively electrified by friction ; fuses at 216° Fahr.; possesses
the highest degree of fluidity between 230° and 280°, and is
of an amber color; at 320°, it begins to thicken, acquiring a
red tint; between 423° and 482°, it is so tenacious as to re-
main in the vessel when inverted; but, from 432° to its boiling
point, it grows fluid again, and sublimes rapidly from 550° to
600° Fahr.
When cooled from the several temperatures above named, it
possesses different degrees of consistency. Cooled suddenly
from the most fluid state, it is hard and brittle; but if plunged
into cold water between the temperatures of 320° and 482°,
it is soft, and may be drawn out like wax; cooled from the
boiling point, it is of a deep red-brown color, very soft and
transparent. It is prepared in this way for taking seals.
The native crystals are octohedrons, with rhombic bases;
those formed artificially occur in oblique rhombic prisms.
Exp. Melt a few pounds of sulphur in an
Fig. 83.
earthen crucible,* (Fig. 83,) and, when it is
partially cooled, pierce the crust so that the
fluid parts may flow out; on breaking the
mass when cooled, the interior will exhibit a
cluster of beautiful crystals. Fig. 81 rep-
resents a section of the crucible containing
the sulphur after it has cooled.
Sulphur is soluble in boiling oil of
turpentine, which is a test of its puri-
ty. Sulphur is highly combustible; it
burns with a pale blue flame, and com-
bines readily with the metals.
Exp. Mix copper or iron filings with sulphur, and heat them in a
glass tube, or crucible, by a spirit lamp. The sulphur will combine,
and form sulphurets of these metals.
Impurities. Sulphur contains some hydrogen in its purest
* There are four principal varieties of crucibles :- 1. Wedgwood crų.
çibles are made of a mixture of burned and unburned clay; 2. Black

192
Sulphur. - Sulphurous Acid.
state; but the more common ingredients are earthy sub-
stances and arsenic; the latter is tested by ammonia.
Uses. Employed extensively in the manufacture of gun-
powder, for seals, medallions, and as a cement for iron.
Used in medicine, for the diseases of the skin, humors, etc.
The milk of sulphur, which is sulphur combined with water,
and precipitated from some of its alkaline solutions by an
acid, occurs in a gray powder, and is sometimes used in
medicine.
Hyposulphurous Acid. Symb. 25 + 20. Eq. 32.2 +16=
48.2. It is difficult to procure this in a pure state. It may
be formed by digesting sulphur in a solution of any sulphite
It is distinguished b; uniting with the oxide of silver, which
separates the acid from soda.
Sulphurous Acid. Symb. S+20 or so? Eq. 16.1+
16= 32.1. Sp. gr. 2.2117, air=1.
History. Sulphurous acid appears to have been known
from an early period. Stahl first pointed it out as a distinct
substance; but its discovery in a pure state was made by
Priestley, in 1774, and accurately analyzed since, by Gay
Lussac and Berzelius. It exists in nature in the vicinity of
volcanoes, and issues from the fissures in the craters, and
from the lava, often in immense quantities.
Process. Burn sulphur in common air, or in dry oxygen
gas, over mercury; but the best method is to put 2 parts
of mercury and 3 of sulphuric acid into a retort, and
apply the heat of a lamp, and collect over mercury.
Theory. The sulphuric acid has 3 equiv. of oxygen, one of which
unites with the mercury, forming the oxide of mercury, which com-
bines with some undecomposed sulphuric acid, and forms the sul-
Fig. 84.
lead crucibles are formed by a mixture
of clay and plumbago ; 3. Hessian
crucibles are composed of a mixture
of sand and clay; 4. Metallic cruci-
bles are made of silver, platina, &c.
These latter are used with the spirit
lamp in analytical processes.
The
form of these vessels is represented
in Fig. 84. Metallic and porcelain
crucibles are generally provided with
covers and stands, as in the figure,
but the best stand is a piece of fire-
brick,

Sulphurous Acid.
193
phate of mercury, which remains in the retort, and the sulphurous acid
comes over in the gaseous state. The gas is heavier than the air, and
can be collected in a manner described on page 139, fig. 64.
Properties. A transparent, colorless gas, sour to the
taste, and pungent, suffocating odor, by which it is distin-
guished from all other gases; extinguishes burning bodies,
but is not combustible.
Exp. A candle immersed in a jar of this gas is instantly extin-
guished.
It is irrespirable, and fatal to animal life. When largely
diluted with air, it excites coughing, and uneasiness about
the chest; when perfectly pure, it excites spasms of the glot-
tis, which prevent its introduction into the lungs; of course,
an animal confined in it is instantly suffocated.
It reddens vegetable colors, and then discharges them.
Exp. Place a rose over an ignited sulphur match in the open air,
and it will turn white; hence it is used for bleaching straw, silk, and
for removing fruit-stains from woollen cloths, etc.
It has a strong attraction for water and oxygen. Water
absorbs it so rapidly, that, if a jar of the gas
be inverted over
it, the atımosphere will force the water into the jar with great
violence; recently-boiled water absorbs 33 times its volume.
Sulphurous acid will remain with dry oxygen without
change, but if water be present, it combines with oxygen,
and forms sulphuric acid. It instantly decomposes those
cxides, the metals of which have a weak affinity for oxygen,
such as those of gold, platinum, and mercury. Nitric acid
yields to it one proportion of oxygen, and converts it to sul-
phuric acid.
Liquid Sulphurous Acid. It becomes liquid by the pres-
sure of two atmospheres, and even by surrounding it with a
freezing mixture. In this state it is anhydrous, a little
heavier than water, (sp. gr. 1.45,) and boils at 14° Fahr.
By its evaporation, it produces so intense a degree of
cold, that mercury may be frozen, and several of the gases
rendered liquid.
Exp. Pour liquid sulphurous acid upon water contained in a shal-
17

194
Sulphur.
low vessel; the acid will boil, and its vapor will absorb so much
caloric that the water will soon be frozen.
Exp: Or pour it upon mercury in a shallow dish, and place it under
the exhausted receiver of an air-pump; the mercury itself will soon
congeal.
It may be obtained in the solid form in crystals containing
water, by passing the moist gas through a receiver, cooled
from 50° to 14° Fahr.
Uses. Sulphurous acid is often employed for ' bleaching
purposes, for whitening straw and silks, and for the barbarous
purpose of killing bees.
Hyposulphuric Acid. Symb. 28 +50. Equiv. 322+40
=72.2. This acid was discovered in 1819, by Welter and
Gay Lussac.
Process. It may be formed by passing sulphurous acid
gas through water containing peroxide of manganese. By
the interchange of elements, the sulphate of the peroxide and
the hyposulphate of the protexide of manganese are formed;
the latter remains in solution. The manganese is thrown
down by pure baryta, and the hypesulphate of baryta ob-
tained, which crystallizes by evaporation, and is then decom-
posed by sulphuric acid, by which the sulphate of baryta is
precipitated, and hyposulphuric acid remains in solution.
Properties. Colorless, inodorous, sour to the taste, red-
dens litmus, and cannot be wholly freed from water.
Sulphuric Acid. Symb. S +30, SO3, or S. Equiv. 16,1
+24=40.1.
Sulphuric acid was discovered by Basil
Valentine, near the close of the fifteenth century. It is
commonly called oil of vitriol, because it was first obtained
by the distillation of green vitriol, (sulphate of iron or cop-
peras.) It exists in nature abundantly in the sulphate of lime,
(gypsum.)
Process. Anhydrous sulphuric acid may be obtained from
the hydrous acid, manufactured at Nordhausen, in Germany,
from the protosulphate of iron, and called fuming sulphuric
acid. But the best method is that of Professor Mosander, of
Stockholm. Saturate the oxide of antimony with excess of
sulphuric acid, and then, by a slow heat, drive off the excess
-

Sulphurous Acid.
195
of acid, when the salt will crystallize as a dry sulphate of
antimony. Expose this salt to a dull red heat in a retort, and
the anhydrous acid will be driven off, and may be collected
in a dry receiver, surrounded with ice.
Properties. In this state, the acid has some peculiar prop-
erties. It is a white, opaque solid; fuses at 66° Fahr.; sp. gr.
1.99; boils between 104° and 122°, forming a transparent
vapor ; has a powerful affinity for water, so that, on exposing
it to the air, it flies off in white fumes.
Hydrous Sulphuric Acid, which is the crdinary acid of
commerce, may be obtained by several modes.
Exp. Burn a mixture of 8 parts of sulphur to 1 of nitre in a vessel
of oxygen gas containing a vegetable infusion; the acid will be ab-
sorbed by the water, and change the infusion red.
But the process for manufacturing this acid in the arts, is
done in chambers lined with sheet lead.* 8. parts of sul-
phur to l of nitre, coarsely bruised and mixed together,
are put upon iron plates, 1 lb. to 300 cubic feet of air. The
mixture is ignited by a hot iron, and the door closed. Water,
to the depth of 6 inches, covers the floor, and absorbs the
acid as fast as formed. The room is then ventilated, and the
process repeated every four hours, until the water is suffi-
ciently acid; or, by an improvement in the structure of the
room, the sulphur is burned in a separate room, and the air,
admitted continually, carries the acid vapor into the chamber,
where it is condensed by the water. This acidulated water
is then drawn off and concentrated by heat, in leaden boilers,
until it is of the specific gravity 1.450, and the concentration
is finished in glass or platinum dishes placed in sand baths.
Theory. By the combustion two gases are formed -- sulphurous acid
from the sulphur, and binoxide of nitrogen from the nitre. The latter
combines with the oxygen of the air, and is converted into the nitrous
acid. The sulshurous and nitrous acids then combine with the watery
vapor, and form a crystalline solid, composed of sulphuric acid, hyponi-
trous acid, and water. When this solid drops into the water, it is
instantly decomposed, the sulphuric acid is retained in the water, and
nitrous acid and binoxide of nitrogen escape. The nitrous acid thus
set free, as well as that formed by the binoxide and oxygen of the air,
again combines with the moist sulphurous acid, and forms the solid,
which sinks to the water, and is decomposed again. This process con-
* The usual size of the chamber is 20 feet long, and 12 wide; but
in one establishment in England, the chamber is 120 feet by 40, and 20
high, containing 96,000 cubic feet.

196
Sulphur.
tinues, until the whole is converted into sulphuric acid, and absorbed
by the water.
Properties. Hydrous sulphuric acid, when pure, is an
oily, limpid liquid, colorless, inodorous, intensely sour and
corrosive; destroys, by the aid of heat, all animal and vege-
table bodies, with the deposition of charcoal, and formation
of water ; hence the acid often attains a brown tinge by
charring substances which accidentally fall into it; boils at
620° Fahr., and freezes at -15°. When its specific gravity is
1.78, it congeals above 32°, and remains solid up to 45°;
but when mixed with twice its weight of water, it congeals
at -36º.
It has a powerful affinity for water. It combines with
the water of the air, even at boiling temperatures, so power-
fully that its greatest concentration can be effected only by
glass or platinum retorts with narrow mouths.
Exp.' 4 parts of sulphuric acid and 1 of water, each at 50°, when
poured together, have a temperature of 3000. The heat is occasioned
by the diminution of bulk, by which the insensible caloric becomes free.
Exp. 2 parts of acid and 3 of snow form a mixture which will
freeze water, and the thermometer will sink even to -23°. The cold
results from its affinity for water; it dissolves the snow to obtain it;
and the heat necessary to render the water liquid is absorbed from the
acid and the snow, and passes into an insensible state.
Exp. 1 part of snow to 3 of acid will produce a heating mixture,
because the condensation develops more heat than is required to melt
the snow.
The decomposition of sulphuric acid is effected by heat,
and by the non-metallic combustibles.
Exp. Pass hydrogen gas and sulphuric acid through a red-hot por
celain tube.
Exp. Heat this acid with charcoal, or put into it vegetable sub-
stances.
Exp. Expose the acid to the galvanic battery; the sulphur will
appear at the negative, and the oxygen at the positive pole. Its spe-
cific gravity never exceeds 1.850.
Its strength is tested by its specific gravity, and by the
quantity required to saturate a given portion of an alkali.
100 grains of the carbonate of soda will neutralize 92 of
pure sulphuric acid. It may be detected in any solution by
the chloride of barium, by which a white, insoluble solid is
precipitated — the sulphate of baryta.

. Sulphur and Hydrogen.
197
It is one of the most powerful of acids, reddens the vege-
table infusions, unites with bases, and forms salts, which are
called sulphates.
It is a most violent poison. The best antidote is dry mag-
nesia. If water be taken, it will produce a very great heat,
and thus increase its injurious effects.
Uses. It is one of the principal acids of chemistry and
of the arts, in which greater quantities are employed than
of any other acid; for the formation of most of the other
acids ; for the preparation of soda from salt, of alum from
sulphate of iron ; for obtaining chlorine and other gases; for
dissolving indigo for dyes. It is used in medicine as a tonic.
Dichloride of Sulphur (Symb. 28+ci. Eq. 67.62. Sp. gr. 1.687)
was discovered by Dr. Thompson, in 1804. Prepared by passing a
current of chlorine gas over flowers of sulphur, gently heated, till
nearly all the sulphur disappears. The dichloride is then obtained by
distillation in the form of a reddish liquid.
Iodide of Sulphur. First described by Gay Lussac. Formed by
heating 4 parts of iodine with 1 of sulphur. A dark-colored substance,
easily decomposed by heat.
Bromide of Sulphur is obtained by pouring bromine on sublimed
sulphur. The product is an oily liquid, of a reddish tint; odor resem-
bles the dichloride of sulphur.
Sulphur and Hydrogen.
Hydrosulphuric Acid. Symb. SH. Equiv. 16.1+1=
17.1. Equiv. vol. 100. Sp. gr. 1.1782, air=1. This sub-
stance was discovered by Scheele, in 1777, and has been
variously named, sulphureted hydrogen and hydrothionic
acid.
Process. It may be obtained from the sulphurets of the
metals. The one generally employed is the protosulphuret
of iron, which is a native product, but can be prepared by
heating 2 parts of iron filings with 1.4 of sulphur to a red
heat, in a covered crucible; upon this, in a retort, pour dilute
sulphuric acid, apply gentle heat, and collect over water.
Sesquisulphuret of antimony; treated in the same manner
with hydrochloric acid, will yield a purer gas; the former
contains a little iron and hydrogen.
Theory. The oxygen of the water unites with the iron, and its
hydrogen with the sulphur, and the sulphuric acid unites with the
oxide of iron; the products are hydrosulphuric acid and sulphate of
17*

198
Sulphur and Hydrogen.
а
the protoxide of iron. Fes, so and HO are converted into SO3 +
Feo, and SH.
Properties. It is a colorless gas, but has an excessively
op offensive taste and odor; it is this gas which gives the odor
to putrescent eggs, sewers, and the waters of sulphurous
springs. It extinguishes burning bodies, but burns with a
pale blue flame; forms an explosive mixture with oxygen,
and is so destructive to animal life that nobo part of this gas
in air destroys small birds; sio part killed a middle-sized
dog, and to part a horse. If placed on the cutaneous
surface of animals, it will prove fatal to them. Reddens lit-
mus feebly, but unites with bases and forms salts.
Water absorbs 3 volumes of the gas, and forms a colorless
die
liquid, similar to the gas in taste and odor. This water is
test of the metals. Nitric acid will cause a precipitate of
sulphur; and if poured into a bottle of the gas, a blue flame
will pervade the vessel, and sulphur and nitrous acid fumes
be produced. If exposed to the air, it deposits its sulphur
on the surface of the vessel ; but it is readily decomposed by
metals in solution; the sulphur combines with the metal, and
the hydrogen is liberated.
It is also decomposed by chlorine and iodine, because of
their great affinity for hydrogen. Hence chloride of lime is
used to purify places rendered noxious by this gas
. It is
partially decomposed by heat, in a porcelain tube.
Liquid Hydrosulphuric Acid. Mr. Faraday succeeded in condensing
the gas. Under a pressure of 17 atmospheres, it is colorless, limpid,
and excessively fluid; compared with it, ether appears tenacious and
oily. On breaking a tube under water, it rushed out violently, and
assumed the gaseous state.
Test. The best test of this gas is carbonate of lead. 1
part of the
gas
mixed with 20,000 of air will give a brown
stain to a surface whitened with the lead. Hence persons
who use preparations of lead to improve their beauty, on
coming into the vicinity of this gas, often change their color.
Exp. Write on paper with any of the salts of lead in solution, and
pass a stream of the gas over it; the writing will instantly appear.
Uses. In medicine for cutaneous eruptions, in the labora-
tory as a test of metals; hence its use in analytical processes,

Sulphur and Carbon.
199
-
CZ
wa
Production of Sulphur in Volcanoes by the Meeting of Sul-
phurous and Hydrosulphuric Acids. These acids are gener-
ated in volcanoes, and, as they meet, are decomposed, and
sulphur is deposited. This may be shown in the following
manner:
Let two small retorts
Fig. 85.
a, a, (Fig. 85,) pass into
a globe receiver, b, so
that their mouths shall
nearly touch each other.
Put the materials for sul-
phurous acid into one,
and for hydrosulphuric
acid in the other, and
apply heat; as the two
gases meet in the receiver, they will be decomposed, and the
sulphur will be deposited upon the interior surface, in fine
powder.
Hydrosulphurous Acid. Symb. 25 +H. Equiv. 33.2. Discovered
by Scheele, who called it supersulphureted hydrogen. The names
hydrothionous acid, per or bisulphureted hydrogen, and persulphuret of
hydrogen, have also been applied to it.
It is similar in taste and odor to hydrosulphuric acid, but not so
powerful; semi-fluid, inflammable, and easily decomposed by heat into
sulphur and hydrosulphuric acid.
Sulphur and Carbon.
Bisulphuret of Carbon, or Alcohol of Sulphur, Carbosul-
phuric Acid. Discovered accidentally by Professor Lampa-
dius, in 1776; but its true nature was first pointed out by
A Clement and Desormes.
Process. It is obtained by heating, in a close vessel, the native
bisulphuret of iron (iron pyrites) with one fifth of its weight of dry
wis charcoal. “The compound, as it is formed, should be conducted, by
means of a glass tube, into a vessel of cold water, at the bottom of which
it is collected. To free it from moisture and adhering sulphur, it should
be distilled at a low temperature, in contact with chloride of calci-
um.” - T.
Properties. A transparent, colorless liquid, remarkable
for its high refractive power, acid, pungent, and somewhat
aromatic taste, and fetid odor; specific gravity, 1.272, ex-
ceedingly volatile; boils at 110°; very inflammable, and
burns with a pale blue flame. With oxygen, its vapor
forms
an explosive mixture; with binoxide of nitrogen, it forms a

200
Cyanogen and Sulphur.
mixture which burns with dazzling brilliancy; dissolves in
alcohol and ether, and is precipitated by water; dissolves
phosphorus, sulphur, and iodine, giving to a solution of the
Îatter a beautiful pink color. It is decomposed by chlorine, .
Cyanogen and Sulphur.
Sulphuret of Cyanogen was discovered in 1828, by M. Lassaigne, by
the action of bicyanuret of mercury, in fine powder, upon half its
weight of bichloride of sulphur, confined in a small glass globe, and
exposed for two or three weeks to day light. A small quantity of crys-
tals, biting to the tongue, and of a penetrating odor, collected in the up-
per part of the vessel, which form red-colored compounds with per
salts of iron.
Bisulphuret of Cyanogen (Symb. 25+ Cy) was discovered by Liebig,
by exposing fused sulphocyanuret of potassium to a current of dry chlo-
rine gas; it forms a dry, yellow powder.
Hydrosulphocyanic Acid. Symb. S’CyH. Equiv. 59.59. Dis-
covered in 1808, by Mr. Porritt, who ascertained it to be a compound
of sulphur, carbon, hydrogen, and nitrogen. It is sometimes called
sulphocyanic acid, and may be formed by suspending sulphocyanuret
of silver or mercury in water, and by transmitting through it a current
of hydrosulphuric acid gas; sulphuret of silver or mercury, and hydro-
sulphocyanic acid, are generated; filter the solution, and expel the
excess of gas by heat.
Properties. A liquid, either colorless, or a shade of pink;
odor resembling vinegar; sp. gr. 1.002; boils at 216.5°; crys-
tallizes in six-sided prisms at 45.5° Fahr.; acid to the taste
,
and by the chemical tests. It also unites with alkalies.
Test of its Presence. A salt of the peroxide of iron, to
which it gives a deep blood-red solution; decomposed by
exposure to the air, and by chloric or nitric acid.
Cyanohydrosulphuric Acid (Symb. S'CyH?. Equiv.
60.59) may be obtained by passing a current of hydrosul-
phuric acid through a saturated solution of cyanogen in alco-
hol. The liquid acquires a reddish-brown tint, and numer-
ous small crystals, of an orange-red color, are generated. It
is considered by Liebig to be similar in composition to the
preceding, but to have one equivalent more of hydrogen.
Secr. 10.
PHOSPHORUS.
Sp. gr.
Symb. P. Equiv.
ş by vol. 25.
51.77 Water =1.
{ " wgt. 15.7.
{ 4.3261 Air =1.
History. Phosphorus received its name from the property
of shining in the dark.*
*
pās, light, and grégelv, to carry.

Phosphorus.
201
It was discovered by Brandt, an alchemist of Hamburg, in
1660. It was formerly obtained from urine, but the process
of obtaining it was for a long time kept secret, and small
quantities only were procured. Scheele obtained it from
bones, and invented the method now generally employed. It
exists in the bones of all animals, in the state of phosphate
of lime. A middle-sized man has about one pound of phos-
phorus in his bones.
Process. The bones are calcined in an open fire, reduced
to a fine powder, and digested for a few days with one half
their weight of sulphuric acid, with sufficient water to give
them the consistency of paste. The phosphate of lime is
decomposed, and the sparingly-soluble sulphate and soluble
superphosphate of lime are generated. The latter is then
dissolved in warm water, filtered and evaporated to the con-
sistency of sirup.
dhe gudalost
It is then mixed with 4 part of charcoal, in an earthen re-
tort lined with clay, heated in a furnace to a high tempera-
ture, when the vapor of the phosphorus comes over, and is
conducted by a tube into a bowl of water, where it is con-
densed into a reddish-brown solid. This is then fused in hot
water, and distilled in hydrogen, or passed through chamois
leather.
Properties. When pure, it is transparent and nearly col-
orless, or of a wax color; easily cut with a knife, and the sur-
face has a waxy appearance and texture ; fuses at 108°, and
at 550° is converted into vapor; soluble by the aid of heat in
naphtha, in fixed and volatile oils, and in the chloride of sul-
phur, sulphuret of carbon, and sulphuret of phosphorus. On
cooling a solution of the latter, it crystallizes in dodeca-
hedrons.
It is very inflammable. At common temperatures, it com-
bines slowly with the oxygen of the air, giving a luminous
appearance
in the dark.
Exp. If a stick be placed in a receiver of air, it will absorb the oxy-
gen,
and leave the nitrogen.
Exp. If a stick of phosphorus be dusted over with charcoal or resin,
and placed under the receiver of an air-pump, it will inflame on ex-
hausting the air.
Exp. By friction it instantly ignites, and hence is employed for
matches.

202
Phosphorus.
Exp. When ignited in oxygen, it
Fig. 86.
burns with great brilliancy. This
experiment should be conducted
in a large globe receiver, (Fig.
86,) filled with oxygen, and the
phosphorus placed in the centre
by a pendent copper spoon. Dense
white fumes of phosphoric acid are
formed; these often mingle with
the vapors of phosphorus and oxy-
gen, which renders the whole in-
flammable; and hence the danger
of breaking the receiver.
Exp. Let a stream of oxygen
gas upon phosphorus in a fused
state, under water, and flashes
of light will pass up through the
water.
Exp. Or put a few grains of chlorate of potassa into a glass of water,
in which is a piece of phosphorus, and from the dropping tube pour
on nitric or sulphuric acids; flashes of light will appear.
Exp. Drop a small piece into a glass containing a small quantity of
strong nitric acid; it will burn vividly, and often explode with great vio-
lence. (See Fig. 77.).
Exp. Sweet oil dissolves it by the aid of heat, and the phosphorized
oil can be put on the face and hair so as to render it luminous in
the dark.
Theory. In all these cases, the light results from the union
of phosphorus with oxygen; so strong is its affinity for oxy-
gen, that it should always be kept under water. If exposed
to the air, and held in the hands in a dry state, there is dan-
ger of its entering into a state of combustion, especially if
any friction is applied to it.
Relation to Animals. It is very poisonous; acts as an
excitant, and in large doses it proves fatal ; but it is used
sometimes as a medicine. It renders water poisonous in
which it is kept.
Phosphorus and Oxygen.
Oxide of Phosphorus. Symb. 3P+0. Equiv. 47.1+8=55.1. It
is obtained by burning phosphorus under hot water, by a jet of oxygen
gas. The substance which remains after combustion is of a red color,
without taste or odor ; insoluble in water, alcohol, ether, and oil; is
not volatilized at 6620 Fahr., but takes fire at a low red heat, in the air
and in chlorine gas. This substance has been examined by M. Pelouse,
and found to be an oxide of phosphorus.
Hypophosphorous Acid (Symb. 2P+0. Equiv. 31.4 +

Phosphoric Acid.
203
8=39.4) was discovered by Dulong, in 1816, and is obtained
by the action of water upon the phosphuret of barium. Hy-
pophosphite of baryta is formed soluble in water ; on filtering
the solution, and adding sulphuric acid to precipitate the
baryta, the hypophosphorous acid remains, and is concentra-
ted by evaporation into a viscid liquid, capable of crystalliza-
tion; this is the hydrate of the acid, and is a powerful deox-
idizing * agent.
Phosphorous Acid (Symb. 2P+30. Equiv. 31.4 +24=
55.4) was discovered by Davy, and may be obtained by sub-
liming phosphorus through the bichloride of mercury, in a
glass tube; a limpid liquid distils over, which is a compound
of phosphorus and chlorine. Put this into water, and the
hydrogen of the water unites with the chlorine, forming hy-
drochloric acid, and the oxygen of the water combines with
the phosphorus, forming the phosphorous acid. The solution
is then evaporated to the consistency of sirup, to expel the
hydrochloric acid, and the phosphorous acid crystallizes as
a hydrate. The anhydrous acid may be obtained by burning
the phosphorus in highly-rarefied air.
Properties. Sour to the taste, odor like garlic, and pos-
sesses acid properties; has a strong affinity for oxygen, and
is hence easily converted into phosphoric acid; precipitates
mercury, silver, platinum, and gold, from their saline solu
tions, in the metallic form.
Phosphoric Acid. Symb. 2P +50. Eq. 31.4 +40=
71.4. Under the term of phosphoric acid, three compounds
have formerly been described, affording a remarkable in-
stance of a class of bodies, called isomeric, which are identical
in composition, but possess different properties. The names
given to the three compounds are, phosphoric, pyrophosphoric,
and meta or paraphosphoric acids.
1. The Phosphoric Acid has hitherto been obtained only
in combination with water or an alkaline base.
Process. The superphosphate of lime is boiled for a few
* Bodies are said to deoxidize when they abstract oxygen from its
combinations with other bodies. They are said to oxidize when they
yield oxygen to other bodies,

204
Phosphorus.
minutes with excess of carbonate of ammonia, by which the
lime is précipitated as a phosphate. After filtration, the liquid
is evaporated to dryness, and then ignited in a platinum
crucible, to expel the ammonia and sulphuric acid.
Properties. Colorless, intensely sour, reddens vegetable
infusions powerfully, and neutralizes alkalies. In the state
of greatest concentration, it is composed of three equivalents
of water, and one equivalent of acid, and may be made to
crystallize in thin plates. It is remarkable for uniting
with bases, in the proportion of 1 equivalent of the acid to
3 of the base, or the oxygen of the base and the acid as
3 to 5.
2. The Pyrophosphoric Acid is obtained by exposing
concentrated phosphoric acid to a temperature of 145º.
Its properties are generally similar to the preceding, but
it is distinguished from it by yielding a snow-white pre-
cipitate, when neutralized with ammonia, and mixed wit!
the nitrate of the oxide of silver. It is remarkable for its
tendency to unite with 2 equivalents of a base to 1 of the
acid.
BO
3. Meta or Paraphosphoric Acid is obtained by burning
phosphorus in dry air, or oxygen gas. The acid appears in
small crystals, like snow, on the interior of the vessel. It is
formed, combined with water, by heating to redness the two
preceding acids; when fused, it cools into a brittle and
transparent solid, resembling ice, hence called glacial phos-
phoric acid, very deliquescent, and hence must be kept in
close bottles. It is distinguished from the others by uniting
1 equivalent of a base to l of the acid.
Phosphorus and Chlorine.
The Sesquichloride of Phosphorus (Symb. 2P+ 301.
Equiv. 31.4 +106.26 = 137.66. Sp. gr. 1.45) may be
formed by passing the vapor of phosphorus over corrosive
sublimate, in a glass tube, or by heating the perchloride with
the phosphorus.
Properties. It is a clear, limpid liquid, not acid by the

Phosphorus and Hydrogen.
205
water.
chemical tests, though it emits acid fumes when exposed to
the air. This is due to the affinity of the chlorine for the
hydrogen of the water contained in the air. When mixed
with water, mutual decomposition takes place, with evolution
of heat, and the formation of hydrochloric and phosphoric
acids.
The Perchloride of Phosphorus is formed by the spon-
taneous combustion of phosphorus in chlorine gas. Symb.
2P +5Cl. Eq. 208.5.
Properties. A white solid, volatile at a temperature below 2120 ;
heated under pressure, it fuses, and forms, in cooling, transparent,
prismatic crystals. Thrown into water, mutual decomposition ensues.
Iodides of Phosphorus. There appear to be three com-
pounds of iodine and phosphorus, produced by the spontane-
ous combustion of the two substances.
The Protiodide (Symb. P+I. Equiv. 142) has a yellow color,
fuses at 212°, sublimes by heat unchanged, and is decomposed by
,
The Sesquiodide (Symb. 2P+31. Equiv. 410.3) is a dark-gray
crystalline mass, fuses at 84º.
The Periodide (Symb. 2P + 51. Equiv. 662.9) is a black com-
pound, fusible at 1ì40.
Bromides of Phosphorus are formed by bringing phospho-
rus and bromine into contact, in a flask filled with carbonic
acid.
The Protobromide (Symb. P + Br. Equiv. 94.1) is a liquid formed
at the bottom of the flask, easily converted into vapor by heat, acts
energetically upon water, and mutual decomposition takes place.
The Perbromide (Symb. 2P + 5Br. Equiv. 423.4) is a yellow solid,
converted by heat into a red-colored liquid, and into a vapor of a simi-
lar tint. When cooled from fusion, it yields rhombic crystals. Emits
dense, penetrating fumes when exposed to the air, and is decomposed
by water and chlorine.
agente
godina od
3 procent
Phosphorus and Hydrogen. gratis
Die
Phosphuret of Hydrogen, (Symb. 2P + 3H. Equiv. 31.4
+3=34.4,) called also hyduret of phosphorus, was discov-
ered in 1812, by Sir H. Davy, by heating hydrated phospho-
rous acid in a retort.
Properties. It is colorless, with the odor of garlic; does
not take fire spontaneously in air, but instantly inflames in
18

206
Phosphorus.
chlorine gas, with a white light; forms with oxygen a det-
onating mixture.
Perphosphuret of Hydrogen is isomeric with the prece-
ding. It was discovered in 1783, by Gengembre, and has
been since examined by Dalton, Thompson, and others. The
names phosphureted hydrogen and hyduret of phosphorus
have also been applied to it.
Process. For the purposes of experiment, it is easily
prepared in the following manner: Fill a pint retort half full
of recently-slacked lime, and put into it a stick of phosphorus
two or three inches long, cut into strips. Then pour on a
strong solution of carbonate of potassa, filling the retort quite
full. Place the beak of the retort in the cistern, and apply
heat. *
The gas will soon form and inflame when it comes
in contact with the air, forming beautiful wreaths of smoke,
which rise up from the water.
Or it
may
be collected like
any other gas.
Properties. This gas is colorless, and has a highly-offen-
sive odor, and bitter taste; will neither support flame nor
respiration.
Fig. 87.
Кога бего, за
a
de vie
not
MID
Inflames spontaneously when admitted into air, and explo-
sively with oxygen gas. As the bubbles of the gas (Fig. 87)
rise through the
e water in
in the cistern b into the air, they
inflame successively, the phosphoric acid and vapor form a
series of rings, as c, of dense white smoke, continually
* The readiest mode of obtaining this gas is to heat phosphorus in
connection with quicklime, forming the phosphuret of lime. Drop
this into water acidulated with hydrochloric acid. The water is de-
composed, and its hydrogen and oxygen unite with the phosphorus,
and form hypophosphorous acid, phosphoric acid, and phosphuret of
hydrogen.tr
salo

Boron.
207
increasing in size as they arise, and producing one of the
most striking and beautiful appearances in experimental
chemistry. If a bubble of the gas is admitted into a receiver
of oxygen gas, a bright flash of light is seen, and the receiver
is jarred by the concussion. This is one of the most re-
markable properties of this gas, and distinguishes it from all
other gases. It is often produced by the decomposition of
bones, in swamps and graveyards, and gives rise to those
lights which are frequently seen about such places. It is the
real“ Jack o' the lantern,” or “Will o'the wisp.”
Water absorbs one eighth volume of this gas, and, if the gas
is suffered to remain over water for a few days, it loses its
spontaneous inflammability, but will inflame on the applica-
tion of a lighted taper.
to
Phosphorus and Sulphur.
Sulphuret of Phosphorus. The nature of this compound is
not accurately settled; it is formed by bringing sulphur in
contact with fused phosphorus. They act on each other
with great violence, producing a compound of a reddish-
brown color, which fuses at 16° Fahr., and is highly combus-
VER
old go aldstone
bbar som
oldinda
SECT. 11. BORON.
list
Daha
Symb. B. Eq. 10.9. Equiv. vol. 100. lotools
This substance was discovered in 1807, by Sir H. Davy,
by exposing boracic acid to a powerful galvanic battery; but
its properties were first investigated by Gay Lussac and The-
nard, who obtained it in greater quantity by heating boracic
acid with potassium.
The easiest method of obtaining it is to decompose boro-
fluoride of potassium by means of potassium and heat.
Properties. A dark olive-colored solid, without taste or
odor; a non-conductor of electricity; sp. gr. nearly 2; insolu-
ble in water, alcohol, ether, and oils; does not decompose
water at any temperature, and may be subjected to intense
heat in close vessels without change; heated to 600° in the
air, it ignites, and is converted into boracic acid. When
tible.

208
Boron and Oxygen.
heated with nitric acid, or with any substance which yields
oxygen freely, it passes into boracic acid.
Hind sat doet
Boron and Oxygen.
Boracic Acid. Symb. B + 30. Equiv. 34.9. Sp. gr.
1.479, water 1. This substance exists in nature in small
quantities in the Lipari Islands, and the hot springs of Lasso,
in the Florentine territory; in combination with soda, in
the well-known substance borax, the biborate of soda, used
by smiths as a flux. It is also a constituent of the minerals
boracite and datholite.
Process. To a solution of purified borax in boiling water,
add half its weight of sulphuric acid, diluted with an equal
quantity of water. On evaporation * and cooling, shining
crystals of boracic acid will be deposited; it may be purified
by repeated solution in hot water and crystallization. This
is a hydrate, containing 1 eq. of acid and 3 of water. The
anhydrous acid may be obtained by heating this in a plati-
num crucible.
Properties. The hydrous acid exists in the form of thin
white scales, without odor, and nearly tasteless, sparingly
soluble in water, which reddens vegetable blue colors, and,
like the alkalies, turns turmeric paper brown, soluble in boil-
ing alcohol, and gives a beautiful green color to flame.
The anhydrous acid is a hard, colorless, transparent glass,
absorbs water rapidly from the air, and should be kept in
well-stopped vials; exceedingly fusible, and communicates
this
property to the substances with which it unites. Hence
its use in the arts as a flux.
Fig. 88.
Fig. 88 represents the form of evaporating
dishes; some are made of clay and sand, oth-
ers of porcelain, glass, silver, platinum, and
gold. The substance to be evaporated is
poured into them, and they are placed in a
sand bath, which is simply a quantity of com-
mon sand contained in an iron vessel, and
connected generally with the furnace or fire-
place, so as to be kept constantly at a tem-
perature below the boiling point.

Selenium.
209
CA
bitov Boron and Chlorine.
.
Terchloride of Boron. Symb. B + 3Cl. Eq. 117.16. Pro-
duced by the spontaneous combustion of boron in chlorine
gas. It is rapidly absorbed by water, and unites with am-
·monia, forming a volatile fluid. It is also formed, according
to Despretz, by passing dry chlorine gas over charcoal and
boracic acid, ignited in a porcelain tube. It was first
noticed by Davy, and examined by Berzelius, Dumas, and
Despretz.
Boron and Fluorine.
Fluoboric Acid. Symb. B+3F Equiv. 66.94. Sp. gr.
2.3622. Discovered by Gay Lussac and Thenard, in 1810.
Process. Mix 1 part of pure boracic acid and 2 of fluor-
spar with 12 of sulphuric acid, in a glass flask, and apply heat;
or heat a strong solution of hydrofluoric and boracic acids in
a metallic retort.
Properties. 'A colorless gas, of a penetrating, pungent
odor ; extinguishes flame, reddens litmus powerfully, and
unites with bases forming salts called fluoborates.
It has a powerful affinity for water, which absorbs 700
volumes of the gas; becomes hot, fuming, and caustic;
attacks animal and vegetable substances with great energy.
Some doubt yeť exists concerning its true nature.
Boron and Sulphur.
Sulphuret of Boron is formed, according to Berzelius, by
burning boron in the vapor of sulphur. The product is a
white, opaque mass, readily decomposed by water.
SECT. 12. SELENIUM.
Portes
Symb. Se. Equiv. 39.6. Sp. gr. 4.32.
bis Selenium was discovered by Berzelius, in 1818, and
named Selenium, from Selene, the moon, because he at first
mistook it for tellurium.
Natural History. It is found in small quantities among
18*

210
Selenium.
the volcanic products of the Lipari Islands, in Clausthal in
the Hartz, combined with lead, cobalt, silver, mercury, and
copper. Berzelius obtained it from the iron pyrites of
Fahlun.
Process. Mix the native sulphuret of selenium with 8
times its weight of peroxide of manganese, and expose it to a
low red heat in a glass retort, the beak of which dips into
water. The manganese yields its oxygen to the sulphur,
and the selenium sublimes pure, or in the form of selenious
acid.
Properties. A brittle, opaque solid, without taste or odor;
its lustre is metallic, resembling lead in the mass, but the
powder has a deep red color; softens at 212°, and may be
drawn out into fine, transparent threads, which appear red by
transmitted light ; becomes fluid a little above 212°, and boils
at 650°, yielding an inodorous vapor of a deep yellow color;
sublimes, in close vessels, without change, and condenses
into dark globules, or into a cinnabar-red powder, if the ves-
sels are large. Heated in the open air, or in oxygen, it com-
bines with the oxygen ; under the blowpipe, it emits the
strong odor of horseradish.
ber
Selenium and Oxygen.
Oxide of Selenium (Symb. Se +0. Equiv. 47.6) is
formed by heating selenium in a limited quantity of air, and
washing the product to clear it from selenious acid. It is a
colorless gas, which gives the peculiar odor to the selenium,
when burned in the wick of a lamp.
Selenious Acid (Symb. Se + 20. Equiv. 55.6) is formed
by dissolving selenium in nitrohydrochloric acid. On evap-
oration, the acid is left as a white, crystalline solid, of a sour
and burning taste; dissolves readily in water and alcohol,
and attracts moisture from the air. It has distinct acid
properties, and its salts are called selenites. It is decom-
posed by all substances which have a strong attraction for
oxygen. Denna

Compounds of Selenium.
211
Selenic Acid (Symb. Se +30. Equiv. 63.6) was first
noticed by M. Nitzsch, and described by Mitscherlich in
1827.
Process. It is obtained by fusing nitrate of potassa or
soda with selenium; a metallic seleniuret with selenious acid,
or any of its salts. (For process, see Turner, 6th ed. p. 209.)
Properties. A colorless liquid: sp. gr. at 329°, 2.524; at
512°, 2.60. It is decomposed by heat at 536°, and is resolved
into oxygen and selenious acid; has a powerful affinity for
water, with which it combines, with the eyolution of as much
caloric as sulphuric acid and water. It dissolves zinc, iron,
copper, and gold; unites with bases, and forms salts analo-
gous, in composition and form, to those of sulphuric acid.
Chloride of Selenium is a white solid, obtained by placing
selenium in chlorine gas.
Bromide of Selenium is an orange-colored solid; soluble
in water, and obtained by dropping selenium into bromine.
The combination is violent, with the evolution of much heat.
നിന
Selenium and Hydrogen.
Hos out
Hydroselenic Acid. Symb. Se+H. Eq. 41. This acid
was discovered by Berzelius, and some doubt exists as to its
composition.
Process. It may be obtained by the action of hydrochloric acid upon
a concentrated solution of any hydroseleniate.
Properties. A colorless gas, with an odor resembling hy-
drosulphuric acid. It irritates the membrane of the nose,
exciting catarrhal symptoms, and produces temporary insen-
sibility. Water absorbs it readily, and the solution reddens
litmus, and leaves a brown stain upon the skin. On exposure
to the air, it is decomposed, but decomposes all the salts of
the common metals, forming seleniurets of the metal.
Selenium and Sulphur. Diador SV
Bisulphuret of Selenium (Symb. Se +25. Eq. 718) was
obtained by Berzelius, by adding hydrosulphuric acid' to a
solution of selenious acid, when it is precipitated as an
orange-colored powder ; fuses at 212°, sublimes at a high

212
Silicon.
sw
temperature without change; when heated in the open air, it
inflames, and is decomposed by nitrohydrochloric
acid.
Seleniuret of Phosphorus, or Phosphuret of Selenium, is
prepared in the same manner as the sulphuret of phosphorus.
It is a very fusible substance; imflammable, and decomposes
water slowly, yielding seleniuret of hydrogen, and one of the
acids of phosphorus.
SECT. 13.
SILICON.
Symbol, Si. Equivalent, 22.5.
Silicon was obtained by Berzelius, in 1824, by the action of
potassium on fluosilicic acid gas. It was at first called sili-
cium, and regarded as a metal, but it is destitute of the me-
tallic properties.
Properties. Silicon is a solid, of a dark brown color, and
a non-conductor of electricity.
Before ignition it is not oxidized, or dissolved by hot sul-
phuric or nitrohydrochloric acids, but is soluble in hydro-
fluoric acid, and in a hot, concentrated solution of caustic
potassa. It burns readily in air, and vividly in oxygen gas;
but after ignition, it is insoluble and non-combustible. It is
oxidized by heating it with nitrate of potassa, and explodes
when dropped upon fused hydrate of potassa, soda, or baryta,
in consequence of the evolution of hydrogen.
Silicon and Oxygen.
Silicic Acid, Silica. Symb. Si +30. Equiv. 22.5+
24=46.5.
19 Natural History. Silicic acid, also called silica, siliceous
earth, and silex, constitutes nearly 40 per cent. of the crust
of the globe. Hence it is the principal ingredient of exten-
sive mountain masses, of sand, and of several minerals, such
as quartz, flint, chalcedony, rock-crystal, etc. It is the most
abundant ingredient in nearly all soils.
Process. It may be prepared by heating rock-crystals, and
throwing them, red-hot, into cold water. og blogg 2009

haver og Compounds of Silicon.
213
e is solu-
Properties. When reduced to powder, it is white, insipid,
and inodorous. It is very infusible, requiring the heat of the
compound blowpipe to fuse it; insoluble in water, unless
presented in the nascent state; does not act upon test paper,
but in every other respect, has the properties of an acid. Its
combination with the fixed alkalies is effected by mixing
pure sand with carbonate of potassa. If 3 parts of the car-
bonate to 1 of sand are mingled, the fused silicate
ble in water; but if I part of the carbonate to 3 of sand
be employed and fused, the well-known substance glass is
formed, which is transparent, brittle, insoluble in water, and
affected by no acid except the hydrofluoric.
Every kind of common glass is a silicate, and the different
varieties are due to the proportions of the constituents, to the
nature of the alkali, or the presence of foreign matter. Thus
green bottle glass is made of materials containing iron;
Plate
glass, for mirrors, is made of the purest materials. Flint glass
contains red lead; and sometimes peroxide of manganese,
or nitre, is added to oxidize the carbon contained in the
materials.
Chloride of Silicon (Symb. Si+ Cl. Equiv. 57.92) is
prepared by burning silicon in chlorine gas. The product is
a limpid, volatile liquid, flying off in white vapor when ex-
posed to the air, with a suffocating odor resembling cyano-
gen; boils at 124° Fahr.
le of Silicon (Symb. Si+Br. Equiv. 100.6) was obtained by
Serullas, in the same manner as the chloride. It is a very dense, color-
less liquid, emitting dense fumes.
Sulphuret of Silicon (Symb. Si+S. Equiv. 38.6) is formed by heat-
ing silicon in the vapor of sulphur. It is a white, earthy substance,
instantly converted by the action of water into hydrosulphuric and
silicic acids.
Fluosilicic Acid (Symb. Si+F. Equiv. 41.18) is formed by bring-
ing hydrofluoric and silicic acids into contact.
It is a colorless gas,
which extinguishes flame, destroys animals immersed in it, and acts
powerfully upon the respiratory organs. Water acts upon this gas
with some change of properties, and the solution is called silicohy-
drofluoric acid.
,
Bromide
benistused on
so no
ც ცალმნენ და

214
Metals, with their Primary Compounds.
Hizobro o halat LE
RO ol
CHAPTER II.
Class II. METALS, WITH THEIR PRIMARY COMPOUNDS.
General Properties of Metals.be
Metals are the most important of substances. They are
distinguished from other substances by the following prop-
erties :
1. They are all conductors of electricity and of caloric.
2. When combined with oxygen, chlorine, iodine, sulphur,
and similar substances, and subjected to the voltaic battery,
they always go to the negative electrode or pole, and hence
are called positive electrics.
3. Metals are opaque; that is, they do not permit the light
to pass through them, although reduced to thin leaves.
4. They are good
reflectors of light, and possess a peculiar
lustre, which is termed the metallic lustre. Any substance,
which has the above properties, may be regarded as a metal.
Metals differ greatly in their Properties.
1. In their specific gravity. Most of the metals are re-
markable for their weight, such as gold and platinum, which
are more than nineteen times as heavy as an equal bulk of
water; while some, potassium and sodium, are lighter than
water.
2. In their malleability, or the property of being beaten
into thin leaves by hammering. Gold, silver, copper, tin,
platinum, palladium, cadmium, lead, zinc, iron, nickel, po-
tassium, sodium, and frozen mercury, are malleable. The
others are malleable only in a slight degree, or, like arsenic,
antimony, and bismuth, brittle. Gold is the most inalleable
of metals; one grain of which may be extended so as to
cover fifty-two square inches of surface, and to have a thick-
ness not exceeding 252020 of an inch.

General Properties of Metals.
215
2010
3. Ir their ductility, or the property of being drawn out
into wires. Most of the malleable metals are also ductile,
Gold, silver, platinum, iron, and copper, are the most ductile
Gold wire may be obtained so fine that it shall not exceed
sobo of an inch in diameter, and platinum rotor of an
inch. The tenacity of a metal is measured by the weight
which a wire of a certain diameter can support without
parting
4. In hardness. Titanium, manganese, iron, nickel, cop-
per, zinc, and palladium, are hard metals. Gold, silver, and
platinum, are softer than these, lead still softer, and po-
tassium and sodium yield readily to the pressure of the
fingers. Wobedioul to remontas gauloinen asia
5. In their structure. Many have a crystalline structure.
Iron is fibrous; zinc, bismuth, and antimony, are lamellated ;
gold, silver, and copper, are found naturally in crystals, and
others may be made to assume the form of crystals, when
they pass gradually from a liquid to a solid state. Most of
them, in crystallizing, assume the figure of a cube, the reg-
ular octohedron, or some form allied to it.
6. In their fusibility. All are solid, at the common tem-
perature of the atmosphere, except mercury, which is solia
at -40° Fahr. Mercury, potassium, sodium, cadmium, tin,
bismuth, lead, tellurium, antimony, and probably arsenic, are
fusible below red heat. The rest require a higher tempera-
ture to fuse them; and some of these, such as platinum, ceri-
um, rhodium, and columbium, require the heat of the com-
pound blowpipe to render them liquid.
7. In volatility. Cadmium, mercury, arsenic, tellurium,
potassium, sodium, and zinc, are volatilized by heat. Most
of the others may be exposed to the most intense heat of a
smith's forge, without being converted into vapor.cf
8. In their affinity for the other simple substances. Metals
generally have an extensive range of affinity; hence they
are rarely found in the earth in their simple or pure state, but
are generally combined with other bodies, especially with

216
Metals. - General Properties.
oxygen and sulphur, in which state they are said to be
mineralized.
It is a remarkable fact, that they are not disposed to com-
bine with compound bodies. They combine with each other,
and with other simple substances, generally in a few definite
proportions. bottom lines to si
* They all combine with oxygen, though with different de
grees of energy. Iron and copper are slowly oxidized at
common temperatures, while gold will sustain the most in-
tense heat of furnaces without oxidation. Potassium and
sodium will even decompose water, to obtain the oxygen, the
moment they come in contact with it. In all these cases,
they produce the phenomena of combustion. Hence they
are said to be combustible. With chlorine, iodine, bromine,
etc., they combine with more or less energy, giving rise
to the same phenomena. Some unite with oxygen in one
proportion only, but most have two or three degrees of
oxidation.
Metallic oxides may be reduced to the metallic state by
heat, by the united agency of heat and combustible matter,
by voltaic electricity, and by the action of the deoxidizing
agents on metallic solutions.
Many metals form acids with oxygen, as well as oxides;
but one only, arsenic, is capable of forming an acid, and not
an oxide.porn old, and to
Many of the metallic oxides combine with acids, and
form salts, and generally the protoxide is the only salifi-
able base.
BFT Beige
Oxides sometimes combine with each other, and form defi-
nite compounds. The action of the metals upon the simple
non-metallic substances will be noticed in their proper
place. Vhobused
The number of metals is forty-two; and the following table
contains their names, with the date at which they were dis-
covered, and the names of the chemists by whom the dis-
covery was made :
RSS

Table of the Discovery of Metals.
217
Names of Metals.
Authors of the Discovery.
Dates of the
Discovery
ora
1803.
Gold
Silver
Iron
Copper
Known to the Ancients,
Mercury
Lead
Tin
Antimony Described by Basil Valentine
1490
Bismuth Described by Agricola
1530.
Zinc
First mentioned by Paracelsus
16th century
Arsenic 2
Brandt
Cobalt
1733.
Platinum Wood, assay-master, Jamaica
1741.
Nickel
Cronstedt
1751.
Manganese
Gahn and Scheele
1774.
Tungsten D'Elhuyart
1781.
Tellurium Müller
1782.
Molybdenum Hielm
1782.
Uranium Klaproth
1789.
Titanium Gregor
1791.
Chromium Vauquelin
1797.
Columbium Hatchett
1802.
Palladium
Wollaston
Rhodium
Iridium
Descntils and Smithson Tennant
1803.
Osmium
Smithson Tennant
1803.
Cerium
Hisinger and Berzelius
1804.
Potassium
Sale
Sodium
Barium
Davy
Strontium
Calcium
Cadmium Stromeyer
1818.
Lithiam
Arfwedson
1818.
Zirconium Berzelius
1824.
Aluminium
Glucinium Wöhler
Yttrium
SO
Thorium
Berzelius
1829.
Magnesium Bussy
1829.
Vanadium Sefström
1830..
Latanium Mosander
1839.
to euer Groua
It will be found convenient, in studying the properties of
the metals, to arrange them in groups. They may be divided,
for this purpose, into the two following orders :-
Order I. Metals which, by oxidation, yield alkalies or earths.
- Order II. Metals, the oxides of which are neither alka-
lies nor
earths.org la variant
1807.
1828.
19

218
Potassium.
Metals.
-
ORDER I. includes twelve metals, which may be arranged
in three sections or divisions : -
Section 1. Metallic bases of the alkalies. These are,
Potassium,
Sodium,
Lithium.
Section 2. Metallic bases of the alkaline earths. These
are,
Barium, Strontium, Calcium, Magnesium
Section 3. Metallic bases of the earths.
These are,
Aluminium, Yttrium,
Zirconium.
Glucinium,
Thorium,
ORDER II. The metals belonging to this order are ar-
ranged in the three following sections :
Section 1. Metals which decompose water at a red heat :-
Manganese, Cadmium, Cobalt,
Iron,
Tin,
Nickel.
Zinc,
Section 2. Metals which do not decompose water at any
temperature, and the oxides of which are not reduced to the
metallic state by the sole action of heat :-
Arsenic,
Columbium, Titanium,
Chromium,
Antimony, Tellurium,
Vanadium,
Uranium, Copper,
Molybdenum, Cerium,
Lead.
Tungsten,
Bismuth,
Section 3. Metals, the oxides of which are decomposed by
a red heat :
Mercury,
Platinum, Osmium,
Silver,
Palladium, Iridium.
Gold,
Rhodium,
T.
Sect. 1. METALLIC BASES OF THE ALKALIES.
POTASSIUM. Symb. K. Equiv. 39.15. Sp. gr. 0.865.
to win overleg
History. The discovery of potassium, or kalium, as it
was at first called, was made by Davy, in 1807, and consti-
tutes an era in the history of chemical philosophy, as it led

Properties of Potassium.
219
to the discovery of the metallic bases of the other alkalies
and alkaline earths, and to the decomposition of a variety of
compounds which were before regarded as simple bodies.
The discovery was made by subjecting the hydrate of
potassa to the influence of a powerful galvanic battery of
200 pair of plates; oxygen appeared at the positive, and a
small globulę of a metallic lustre at the negative pole, which
proved to be the metal potassium.
Process. Potassium is obtained in small quantities by
galvanism; but the best method is that of M. Curaudau,
which was improved by Brunner, and modified by Wöhler.
The substance employed is carbonate of potassa, prepared
by heating cream of tartar to redness in a covered crucible.
This is raised to a high temperature, in connection with
charcoal, in an iron retort; the oxygen of the potassa com-
bines with the carbon, and the potassium distils over.
Properties. Potassium, at common temperatures, is a
soft, malleable solid, yielding to the pressure of the fingers,
like wax; of a decidedly metallic lustre; similar to mercury
in color; somewhat fluid at 70°, and perfectly liquid at 150°;
cooled to 32°, it is brittle; sublimes at a low red heat in
close vessels secluded from the air; a good conductor of
electricity and of caloric.
But its most remarkable property is its affinity for oxygen.
It oxidizes rapidly in the air or oxygen gas; but if a piece be
thrown upon water, it will decompose it rapidly, disengaging
so much heat that the potassium takes fire, and burns with a
beautiful purple flame. The evolution of hydrogen gas
causes it to move about upon the surface of the water, and,
combining with the potassium, augments the brilliancy of
the combustion.
Exp. Invert a wine-glass filled with water in the cistern, and in-
troduce a small piece of potassium ; it will rapidly decompose the
water, and the escape of hydrogen gas will displace the water in the
glass. This gas may then be ignited.
200
Exp. Heat a small piece of iron, and drop upon it potassium; then
invert over it a jar of oxygen gas.
Exp. Drop, a piece upon ice, and it will instantly inflame; a deep
hole is made in the ice, containing pure potassa.
Exp. To show that the action of potassium upon water produces an

220
Metals. — Compounds of Potassium.
alkali, drop a small piece into a bottle containing vegetable infusion,
and it will instantly turn it green. In consequence of its affinity for
oxygen, it must be kept under naphtha, or the essential oil of copaiba.
Remark. In the description of the metallic compounds,
the abbreviations symb. and equiv. will be omitted, and the
symbols and equivalents placed immediately after the names
GO
of the substances.
el
Tomat
Compounds of Potassium.
Protoxide of Potassium, (K +0. 47.15,) commonly called
potash, or potassa, is always formed when potassium is put
into water, or burned in oxygen gas. It exists in nature in
the minerals, feldspar, mica, and several others; in all vege-
tables, from which it is obtained by leaching their ashes, and
boiling the lye.
Properties. The pure potassa is a white solid, very caus-
tic, possessing powerful alkaline properties ; easily fused by
heat, but not decomposed; deliquesces in the air, and hence
is very soluble in water, forming with it a hydrate, which
retains the water under the most intense heat.
The Hydrate of Potassa contains 1 eq. of water, and is
similar in its properties to the anhydrous potassa. The
aqueous solution of the hydrate, aqua potasse, may
pad
be prepared by decomposing the with lime.
sh
Exp. Put quick lime, with half its weight of carbonate of potassa,
dissolved in 8 or 10 times its weight of water, into a clean iron vessel,
and put it into well-stopped bottles, to exclude the air, from which it
will absorb carbonic acid. If the solution is pure, it will not effervesce
with acids.
The solid hydrate may be made from this by evaporation, and further
purification by alcohol, which dissolves only the pure hydrate; the
alcohol is then driven off by heat. This was formerly called lapis
causticus, but the colleges of Edinburgh and London called it potassa
fusa.
Tests. Potassą may be distinguished from all other sub-
stances by the precipitates thrown down from its salts in
solution. pade och
Exp. 1. Take any of the salts of potassa in solution, and pour into
them tartaric acid ; a white precipitate will be thrown down - the bi-
tartrate of potassa.

ostale Compounds of Potassium.
221
Exp. 2. Chloride of platinum will give a yellow, and when dissolved
in alcohol, a pale yellow, precipitate.
Exp. 3. Alcoholic solution of carbazotic acid throws down yellow
crystals of carbazotate of potassa. This is the most delicate test.
*Uses. Potassa, being a very powerful alkali, is of great
use in chemistry and the arts. It forms the bases of most
soaps; the crude potash is employed for making glass.
b. Owing to its affinity for carbonic acid, it is used for ab-
stracting that substance from gaseous mixtures, and for
depriving them of moisture.
Teroxide of Potassium (K+30. 63.15) is formed when
potassium is burned in the air or oxygen gas.
It is an
orange-colored substance, caustic, alkaline, heavier than
potassium, and decomposed by galvanism and by water ; by
the latter it is resolved into the protoxide and oxygen; fuses
below a red heat, in which state it burns vividly, in contact
with combustibles.
Chloride of Potassium (K+ Cl. 74.57) was long known by the
names febrifuge salt of Sylvius, regenerated sea-salt.'
It may be formed by the spontaneous combustion of potassium in
chlorine, or by dissolving potassium in hydrochloric acid, and evapo-
rating the solution slowly to dryness.
Properties. It occurs in cubic crystals, colorless, of a
saline and bitter taste, insoluble in alcohol, and soluble in 3
parts of water at 60°, and in less at 212° Fahr.
Iodide of Potassium (K +I. 165.45) is formed by heating potassium
with iodine, or by heating the iodate of potassa.
Properties. Fuses readily, and is converted into vapor
below a red heat; deliquesces in air ; very soluble in water ;
dissolves in strong alcohol, and, by evaporating the solution,
yields colorless cubic crystals of iodide of potassium.se
Bromide of Potassium, (K + Br. 117.55,) formed by a
process similar to that for the iodide, (using bromine instead
of iodine,) and has similar properties; very soluble in water,
which, by evaporation, yields anhydrous cubic crystals;
easily fused, and decrepitates, like sea-salt, when heated.
Exp. Put a small piece of potassium into a wine-glass containing a
few drops of bromine; the two bodies will combine with explosive
violence.
be
Fluoride of Potassium (K+F. 57.83) is formed by
bine was
19 *

222
Metals. — Compounds of Potassium
merely saturating hydrofluoric acid with carbonate of potassa,
evaporating to dryness, and igniting to expel excess of acid.
Properties. It has a sharp, saline taste, alkaline to the
test papers, soluble in water, and the solution acts on glass.
It is obtained from its solution, by evaporation at 100°, in
cubes or rectangular four-sided prisms, very deliquescent.
od 18 barbie
Hyduret of Potassium. Discovered by Gay Lussac and
Thenard, and may be formed by heating potassium in hydro-
gen gas.
It is a gray solid, readily decomposed by heat or
water. Gaseous hyduret of potassium is produced when
hydrate of potassa is decomposed by iron, at a white heat.
It is a colorless gas, and burns spontaneously in air or oxy-
gen gas, but loses its inflammability by standing over mercury,
Nituret of Potassium consists, according to Thenard, of 100 parts of
potassium to 11.728 of nitrogen, and is formed by heating potassium
with ammoniacal gas. do
Sulphurets of Potassium. These are five in number, de-
pendent on the quantity of sulphur.
The Protosulphuret of Potassium (K+S. 55.25) is prepared by
burning potassium and sulphur in the air, or by decomposing the sul-
phate of potassa by charcoal or hydrogen gas at a red heat. Mixed
with powdered charcoal, it kindles spontaneously.
The Bisulphuret of Potassium (K + 2S. 71.35) is formed by ex-
posing a saturated alcoholic solution of hydrosulphate of sulphuret of
potassium, until a pellicle begins to form, and then evaporating to
dryness.
The Tersulphuret of Potassium (K+S. 87.45) is formed by heating
carbonate of potassa to low ſedness, with half its weight of sulphur,
known by the name of liver of sulphur.
20 The Quadrosulphuret of Potassium (K+48. 103.55) is prepared by
transmitting the vapor of bisulphuret of carbon over sulphate of potassa
heat, until carbonic acid gas ceases to be disengaged.
The Quintosulphuret of Potassium (K+5S. 119.65) is formed by
fusing carbonate of potassa with its own weight of sulphur.
The properties of the four last compounds are similar ;
they are deliquescent, have a sulphureous odor, and are
soluble in water. A solution of the last dissolves sulphur,
and renders it probable that other compounds may be
formed.
Orain
Phosphurets of Potassium. Several compounds exist, but
their composition is unknown. Obtained by burning potas-
sium in phosphureted hydrogen.
Oto
Seleniuret of Potassium. Formed by fusing potassium and
selenium together. They combine with explosive violence,
at a red
CI

Sodium.
223
De
and a crystalline, fusible compound results, of an iron-gray
color, and metallic lustre.
Cyanuret of potassium (K + Cy. 65.54) is formed by heating to red-
ness the anhydrous ferrocyanuret of potassium in an iron bottle.
30 Properties. Easily fused, and crystallizes in colorless
cubes ; pungent and alkaline to the taste, and poisonous, act-
ing like the hydrocyanic acid; deliquescent, and very solu-
ble in water ; used sometimes as a medicine.
Sulphocyanuret of Potassium K+Cy. 97.74. idmazat
SODIUM. Symb. Na. Equiv. 23.3. Sp. gr. 0.972. T
endedor
Sodium was discovered by Sir H. Davy, in 1807, a few
days after the discovery of potassium, and by a similar
process.
DATE
Process. It may be obtained in small quantities by gal-
vanism.
But the process of obtaining it from soda, now.
generally practised, is precisely the same as that for potas-
sium.
og 102 103
Properties. Sodium resembles potassium in many of its
properties. It is a white, opaque solid, of a metallic lustre,
resembling silver; yields readily to the pressure of the
fingers, and may be formed readily into leaves; fuses at 200°
Fahr., and is vaporized at a red heat.
Sodium has so strong an affinity for oxygen that it rapidly
decomposes water to obtain it, but does not inflame unless
the water is heated, in which case it throws out beautiful
scintillations, often with violent combustion,
add hautat
Exp. Thrown upon water, it moves about upon its surface, having
the appearance of a silver ball, gradually growing less till the whole
disappears.
Exp. Drop a piece of sodium into a test-tube partly filled with warm
water; it will soon burst into a flame, and often explode with violence.
It oxidizes in the air or oxygen gas, but not so rapidly as
potassium; hence, like that metal, it must be kept under
naphtha. The product of its combustion in oxygen, and its
action upon water, is soda, the alkaline properties of which
may be tested by dropping a small piece of the metal into a
bottle containing a vegetable infusion.

224
Metals. — Compounds of Sodium
to share
Compounds of Sodium.
Protoxide of Sodium, (NaO. 31.3,) commonly called soda,
and by the Germans natron, is formed by the oxidation of
sodium in air or water.
Properties. A gray solid, similar to potassa, which it
resembles in most of its properties ; very caustic, and has
powerful alkaline properties.
1. The hydrate has 1 eq. of water, and is easily fused. In
other respects, it is similar to the anhydrous soda; absorbs
carbonic acid from the air, and passes into carbonate.
It is distinguished from other alkaline bases by yielding,
with sulphuric acid, the well-known substance called Glau
ber's salts. All its salts are soluble in water, and are not
precipitated by any re-agent, and give a rich color to the
blowpipe flame. The soda of commerce is generally a car-
bonate prepared from the ashes of marine plants, in the
same manner as potash is from land plants.
as Uses. Employed for the manufacture of hard soaps, and
for culinary and medical purposes.
Sesquioxide of Sodium (2Na+30. 70.6) is formed when
sodium is heated to redness, in excess of oxygen gas. It has
an orange color, but no acid or alkaline properties. It is
resolved by water into soda and oxygen.
Chloride of Sodium. Na + Cl. 58.72. This substance is
formed by burning sodium in chlorine gas, or by saturating
soda with hydrochloric acid, and evaporating to dryness. It
is a very abundant natural product, under the name of rock
salt. It exists in sea-water
r and salt-springs, from which it
is obtained by evaporation. Great quantities are manufac-
tured on the sea-coast of New England, and at Salina, N. Y.
The water at the latter place, according to the analysis of
Beck, contains one seventh of its weight of pure dry chloride
of sodium.
bota
Properties. A well-known solid, crystallizing in regular
cubes, and by sudden evaporation, in hollow, quadrangular
pyramids. It is dissolved in 23 times its weight of water, at

Compounds of Sodium.
225
Samobor
60° Fahr.; gradually fuses when heated, and decrepitates
when thrown into the fire; is decomposed by carbonate of
potassa and nitric acid. The different kinds of salt, such as
stored, fishery, bay, &c., arise from its different forms, and
not from a difference of chemical constitution. It contains
small quantities of sulphate of magnesia and lime, and chlo-
ride of magnesium.
Uses. The utility of salt depends on its property of pre-
serving animal and vegetable substances from putrescence.
Iodide of Sodium, (Na+I. 149.6.) prepared in the same manner
as the iodide of potassium, exists in sea-water, salt-springs, and in the
residual liquor from kelp.
Bromide of Sodium, (Na+ Br. 101.7,) analogous to sea-salt, exists
in sea-water and salt-springs, and crystallizes in cubes.
2 Fluoride of Sodium (Na+F. 41.98) is formed by neutralizing hydro-
Auoric acid with soda; crystallizes in cubes, and when carbonate of
soda is present, in octohedrons. Nearly insoluble in alcohol; soluble in
twenty-five times
nes its weight of water; attacks glass vessels when
evaporated in them — a property which is common to most of the com-
pounds of fluorine.
Sulphuret of Sodium (Na+ S. 39,4) is obtained in the same manner
as the protosulphuret of potassa, and has similar properties.
The Cyanuret of Sodium (Na + Cy. 49.69) and the Sulphocycuret
of Sodium (Na + CyS?. 81.89) are similar to the corresponding com-
pounds of potassium.
attalus ollos
Chloride of Soda is prepared by passing a current of chlo-
rine into a cold solution of caustic soda. This liquor
has received the name of Labarraque's Disinfecting Soda
Liquid, and is used extensively in the arts, and in med-
the bus
icine.
Folie Theron DER
Properties. A liquid of a pale yellow color, with slight
odor of chlorine. Its taste is sharp, saline, and but little
alkaline; reddens turmeric, and then bleaches it. When
evaporated, it yields damp crystals ; decomposed by exposure
to the air.
Uses. It may be used for all the purposes of bleaching to
which chlorine was formerly applied, in medicine to purify
apartments, dissecting-rooms, for destroying the fetor of
ulcers, and for removing the offensive odors of sewers, drains,
and all kinds of animal putrescence.
Alloy of Sodium and Potassium 10 parts of potassium,
he gas

226
Lithium.
Metals.
and 1 of sodium, form an alloy which is liquid at zero, Fahr.,
and is lighter than naphtha, or rectified petroleum.
LITHIUM. Symb. L. Equiv. 6.44.
This substance was obtained by Davy, by means of gal-
vanism, as a white-colored metal, like sodium; but it oxidized
so rapidly that he was unable to examine its properties.
Compounds of Lithium.
Protoxide- of Lithium, Lithia, (L+0. 14.44,) was dis-
covered, in 1818, by M. Arfwedson, in the mineral petalite;
it exists in spodumene, lepidolite, and several varieties of
mica.
Process. One part of petalite to two of fluor-spar are
finely pulverized, and the mixture heated with four times
its weight of sulphuric acid, till the acid vapors are disen-
gaged. Sulphate of lithia and alumina are formed. These
salts are then dissolved in water, and boiled with pure am-
monia, to precipitate the alumina; filter and evaporate to dry-
ness, and then expel the sulphate of ammonia by a red heat.
The result is a pure sulphate of lithia, which must be
decomposed by acetate of baryta, and the acetate, by a red
heat, is converted into the carbonate, and this reduced to the
caustic hydrate, by boiling it with lime.
SEL
Properties. Similar to potassa and soda in its alkalinity
and chemical relations. It is distinguished from them by its
greater neutralizing power; when exposed to the air, it ab-
sorbs carbonic acid, and becomes opaque.
Chloride of Lithium (L+Cl. 41.86) is obtained by dissolving lithia
in hydrochloric acid, evaporating to dryness, and fusing the residue.
Properties. A white, semi-transparent solid, and, like
the chlorides of potassium and sodium, forms, by evaporation,
colorless, anhydrous, cubic crystals, which differ from those
chlorides in being very deliquescent, dissolving freely in
water and alcohol, and tinging the flame of alcohol red.
Fluoride of Lithium, (L+F. 25.12,) prepared by dissolving lithia in
hydrofluoric acid, and is a very fusible solid.

คงสงคราม
227
Barium
30,9
SECT. 2. METALLIC BASES OF THE ALKALINE EARTHS.
BARIUM. Symb. Ba. Equiv. 68.7.
to
19 Barium was discovered by Davy, in 1808.
Process. The process consisted in forming the carbonate
of baryta into a paste with water, placing a globule of mer-
cury in a small hollow made in its surface, and laying the
paste on a platinum tray, which communicated with the posi-
tive pole of a galvanic battery of 100 double plates, while the
negative wire was in contact with the mercury. The baryta
was decomposed, and its barium entered into combination
with the mercury. This amalgam was heated in a vessel
free from air, by which means the mercury was expelled,
and the barium obtained in a pure state. — T.
Properties. The metal, thus obtained, has a dark gray
color, with a lustre inferior to cast iron. It is much heavier
than water ; it even sinks in sulphuric acid. Its attraction
for oxygen is scarcely less than that of the preceding metals;
is converted into baryta by exposure to the air ; decomposes
water with effervescence, from the escape of hydrogen gas.
It has been obtained but in small quantities, and its proper-
ties are not accurately defined.
Compounds of Barium.
Protoxide of Barium, or Baryta, (Ba +0.76.7,) was
discovered by Scheele, in 1774, and called barytes or baryta,
from the great density of its compounds.
Process. It is the sole product of the oxidation of barium
in the air and in water. It is also obtained by exposing the
nitrate of baryta to a red heat, or the carbonate, mixed with
charcoal, to an intense white heat.
Properties. Baryta is a gray powder, (sp. gr. 4,) very dif-
ficult of fusion; has a sharp, caustic, alkaline taste, with
other alkaline properties; insoluble in alcohol, but has a
strong affinity for water, and slacks like lime, but with the
evolution of more intense heat, and is converted into a white,
bulky hydrate, which fuses at a red heat, but cannot be

228
Metals. — Compounds of Barium.
deprived of its water at the highest temperature of a smith's
forge. A saturated solution yields, on evaporation, trans-
parent, flattened, prismatic crystals, containing 10 atoms of
water to 1.of baryta.
This solution is an excellent test of carbonic acid, or other
gaseous mixtures in the atmosphere. The acid gives a
milky appearance to the clear solution, due to the solid car-
bonate of baryta, which is precipitated.
Distinguished by the fact, that all its so
soluble salts are
precipitated by alkaline carbonates, and by the insoluble
sulphate, which latter cannot be separated by any other acid.
Binoxide of Barium (Ba + 20. 84.7) is formed by conducting dry
oxygen gas over pure baryta, at a red heat. It is a grayish-white sub-
stance, employed by Thenard in obtaining the binoxide of hydrogen.
Chloride of Barium (Ba + Cl. 104.12) is prepared by decomposing a
solution of sulphuret of barium with hydrochloric acid, or by conduct-
ing chlorine gas over baryta, at a red heat. On concentrating the solu-
tion, the chloride crystallizes in flat, four-sided tables, beveled at the
edges like crystals of heavy-spar. They consist of l' eq. of the chlo-
ride to 2 of water.
Properties. Pungent and acrid to the taste. The crys-
tals do not change in moist air ; but in a very dry air, at 60°
they lose their water of crystallization, and are rendered
anhydrous at a full red heat ; decomposed by sulphuric acid
and alkaline carbonates.
Iodide of Barium (Ba +I. 195) is formed by acting on
baryta with hydriodic acid, and evaporating the solution.
Soluble in water, and forms colorless, needle-shaped crystals.
Bromide of Barium (Ba + Br. 147.1) is prepared by
boiling protobromide of iron with moist carbonate of baryta,
evaporating the filtered solution, and heating the residue to
redness. The produet crystallizes, by careful evaporation,
in white rhombic prisms, which have a bitter taste, are
slightly deliquescent, and soluble in water and alcohol. -T.
Fluoride of Barium couple 87.38) is prepared by
F.
digesting moist carbonate of baryta in hydrofluoric acid. It
is a white powder, soluble in nitric and hydrochloric acids.
Sulphuret of Barium (Ba+S. 84.8) is prepared by pass-
ing dry hydrosulphuric acid over pure baryta, at a red heat.
It dissolves readily in hot water, and deposits colorless
crystals on cooling. It may be employed for obtaining pure
baryta by a process described by Turner, 5th ed. p. 308.

Strontium.
229
Cyanuret of Barium (Ba + Cy. 95.09) is procured by
the action of hydrocyanic acid on baryta. It is slightly
soluble in water, has an alkaline reaction, and is decomposed
by the carbonic acid of the air.
Sulphocyanuret of Barium (Ba + CyS2. 127.29) is ob-
tained in the same way as the sulphocyanuret of potassium.
It is very soluble in water, and crystallizes in beautiful
needles, slightly deliquescent.
Phosphuret of Barium is formed by heating to redness anhydrous
caustic baryta, and throwing into it pieces of phosphorus. It decom-
poses water, and forms phosphuret of hydrogen.
STRONTIUM. Symb. Sr. Equiv. 43.8.
Strontium was discovered by a process similar to that for
barium, which it resembles in most of its properties; oxi-
dizes in the air ; decomposes water, by which process it is
converted into strontia.
Compounds of Strontium.
Protoxide of. Strontium (Sr+0. 51.8) was discovered
by Dr. Hope, in 1792 ; also by Klaproth.
Process. It was formerly extracted from strontianite, (a
carbonate of strontia,) found at Strontian, in Scotland;
hence its name. It may be prepared from the nitrate or
carbonate of strontia, in the same manner as baryta.
Properties. It resembles baryta in most of its properties.
A gray substance, pungent and acrid to the taste; slacked
with water, it produces intense heat, and is converted into a
hydrate which fuses readily, but the highest temperature of
a blast furnace will not separate the water; soluble in boil-
ing water, and crystallizes on cooling. The solution, like
baryta, is an excellent test of carbonic acid.
Peroxide of Strontium (Sr+20. 59.8) is prepared in the
same way as the peroxide of barium, and, like it, is em-
ployed to form binoxide of hydrogen ; decomposed by dilute
acids into strontia and oxygen. It is white, of a brilliant
lustre, inodorous, and nearly tasteless.
Chloride of Strontium (Sr+Cl. 79.22) is obtained in a
manner precisely similar to the chloride of barium; crys-
20

230
Calcium
Metals.
-
tallizes from its solutions in colorless prismatic crystais,
which are distinguished from baryta by being soluble in twice
their weight of water at 60°, and by the red tinge which it
gives to the flame of an alcoholic solution. The anhydrous
chloride fuses at a red heat, and yields a white, crystalline,
brittle mass on cooling. -T.
Todide of Strontium (Sr+1. 170.1) is prepared in the same manner
as iodide of barium. It is very soluble in water, fuses without decom-
position in close vessels, but is resolved into iodine and strontia, by a
red heat, in the open air.
Fluoride of Strontium (Sr+F. 62.48) is obtained in the same way as
the fluoride of barium. It is a white powder, sparingly soluble.
Protosulphuret of Strontium (Sr+S. 59.9) is similar in its proper-
ties, and modes of preparation, to the corresponding compound of
barium
CALCIUM. Symb. Ca. Equiv. 20.5.
Calcium was discovered by Davy, in 1808, by exposing
lime to the action of the galvanic battery.do
Properties. It is of a whiter color than barium, and is
converted into lime by oxidation. Its other properties are
unknown.
Compounds of Calcium.
Protoride of Calcium (Ca +0. 28.5) is generally obtained
by burning common limestone (carbonate of lime) in kilns,
for three or four days, to expel the carbonic acid. It is
then called lime, or quick lime. The purest lime is prepared
from the Iceland spar, or Carrara marble.
Properties. A brittle, grayish-white, earthy solid, of an
acrid, caustic, and alkaline taste; sp. gr. 2.3; difficult of fusion,
but promotes the fusion of other bodies, and is hence used
as a flux in smelting the ores of the metals. It has a strong
affinity for water, with which it combines with the disengage-
ment of heat, and forms the hydrate — a bulky, white sub-
stance, called slacked lime. This parts with its water at a
red heat, and is more soluble in cold than in hot water.
Lime Water. This is simply a solution of the hydrate, and
possesses similar properties, absorbs carbonic acid from the
air, and should therefore be kept in close vessels. It is a

Compounds of Calcium.
231
most delicate test of carbonic acid -
- a property already no-
ticed under carbon.
Uses. The uses of lime are well known for a cement, for
plaster, and as an anti-acid in medicine; a substance almost
indispensable in every civilized country, and hence the Cre-
ator has made it very abundant and widely diffused, (the
carbonate forming 7 part of the crust of the globe.)
Peroxide of Calcium (Ca+20. 36.5) is similar in prop-
erties, and in the mode of preparation, to the peroxide of
barium.
Chloride of Calcium (Ca+Cl. 55.92) exists in sea-water
and some saline springs, and may be formed by dissolving
marble in hydrochloric acid. On evaporation, the solution
yields colorless prismatic crystals, which consist of 10 equiv.
of water to 1 of the chloride; these are rendered anhydrous
by heat, and fuse at a red heat, but absorb the water again
from the air, and deliquesce, owing to their strong attraction
for water. It is much used for freezing mixtures with snow.
Soluble in alcohol, with which it forms a definite compound.
Iodide of Calcium (Ca+I. 146.8) is prepared by digesting
hydrate of lime with protoxide of iron. It is a white, fusible
compound, deliquescent, and very soluble in water; the solu-
tion will dissolve a large quantity of iodine, and, on evapo-
ration, yield the periodide of calcium, in black prismatic
crystals.
Bromide of Calcium (Ca+ Br. 98.9) is prepared in the
same manner as the iodide, which it resembles in its prop-
erties.
Fluoride of Calcium. Ca +F. 39.18. This is an abundant
natural product, generally called fluor-spar or Derbyshire
spar. It occurs in beautiful cubic crystals, the primary form
of which is an octohedron, used extensively for ornamental
purposes, and is justly celebrated for the variety and beauty
of its colors ; fuses at a red heat, insoluble in water, and is
decomposed by sulphuric acid; thrown in coarse powder on
hot iron, it emits beautiful phosphorescent light, varying from
red to purple and green. doled to
Protosulphuret of Calcium (Ca+S. 36.6) may be pre-
pared by exposing sulphate of lime to a strong heat in a
charcoal crucible. It is white, with a reddish tint, and pos-
sesses the remarkable property of becoming phosphorescent
by exposure to the light. It is the essential ingredient in
Canton's phosphorus.
Bolo

232
Metals. — Magnesium.
Bisulphuret of Calcium (Ca+2S. 52.7) occurs in orange-colored
crystals, prepared by boiling 3 parts of slacked lime, 1 of sulphur, and
20 of water, for a few hours, and setting the solution aside in bottles
corked tight for several days. When either of the above solutions is
boiled with sulphur, the solution contains calcium, with 5 equiv. of
sulphur -- the quintosulphuret of calcium, (Ca + 58. 101.).
Phosphuret of Calcium (Ca+P. 36.2) is formed by passing the vapor
of phosphorus over quick lime, at a low red heat. It is a brown sub-
stance, and, when thrown into water, forms, by mutual decomposition,
phosphureted hydrogen, hypophosphorous acid, and phosphoric acid.
Chloride of Lime. Ca +0+ Cl. 63:92. This substance,
commonly called oxymuriate of lime, or bleaching powder, is
prepared by exposing recently-slacked lime to an atmosphere
of chlorine. The gas is rapidly absorbed, and enters into
direct combination with the lime, although Dr. Ure thinks
that no definite compound is formed.
Properties. A dry, white powder, similar to quick lime,
having the odor of chlorine, which it readily yields up when
moistened with water; possesses powerful bleaching proper-
ties, for which purpose it is extensively used in the arts.
The strength of the chloride is estimated by the quantity of
indigo which a given portion of the bleaching solution will
deprive of its color. Used also in medicine, as a disinfecting
agent; it should be kept in every family. Se bolo
MAGNESIUM. Symb. Mg. Equiv. 12.7.
Magnesium was discovered and obtained in small quantities
by Sir H. Davy, by means of galvanism; but M. Bussy, in
1830, obtained it in greater abundance by the action of po-
tassium on chloride of magnesium.
Process. For this purpose, five or six pieces of potassium,
of the size of peas, were introduced into a glass tube, the
sealed extremity of which was bent into the form of a retort,
and upon the potassium were laid fragments of chloride of
magnesium; the latter being then heated to near its point of
fusion, a lamp was applied to the potassium, and its vapor
transmitted through the mass of the heated chloride. Vivid
incandescence immediately took place; and, on putting the
mass, after cooling, into water, the chloride of potasium, with
undecomposed chloride of magnesium, was dissolved, and
metallic magnesium subsided. - T.

Compounds of Magnesium.
233
Properties. A very malleable solid, of a white color, like
silver, and of a brilliant, metallic lustre. Dry, air and water
do not oxidize it, but moist air does; heated to redness in
oxygen gas, it burns vividly, and forms magnesia. In chlo-
rine gas it inflames spontaneously. To IT
Compounds of Magnesium. o forte
Protoxide of Magnesium, (Mg+0. 20.7,) commonly known
by the name of magnesia, is prepared by exposing the car-
bonate to a strong heat, to expel the carbonic acid.
Properties. A white, fusible powder, of an earthy appear-
ance, without taste or odor; sp. gr. 2.3; very infusible, and
sparingly soluble in water, requiring 5142 times its weight
at 60°, and 36,000 of boiling water to dissolve it. The prod-
uct is a hydrate. It changes vegetable infusions slightly,
but possesses the properties of an alkali, by forming neutral
salts with acids; absorbs water and carbonic acid from the
air, and should be kept in close bottles. It exists in nature
in serpentine, steatite, magnesite, and in sea-water, in con-
siderable abundance.
Chloride of Magnesium (Mg + Cl. 48.12) is prepared by
dissolving magnesia in hydrochloric acid, evaporating to dry-
ness, mixing the residue with its own weight of hydrochlorate
of ammonia, and projecting the mixture, in successive portions,
into a platinum crucible, at à red heat. The ammonia is
expelled, and the chloride remains a transparent, colorless
mass; very deliquescent, and soluble in water and alcohol.
Iodide of Magnesium (Mg +I. 139) is formed by dissolving magnesia
in hydriodic acid; known only in solution with water.
Bromide of Magnesium (Mg + Br. 91.1) is prepared by dissolving
in . It in ,
of a sharp taste, very deliquescent and soluble ; it is decomposed by a
strong heat.
Fluoride of Magnesium (Mg +F. 31.38) is formed by digesting mag-
nesia in excess of hydrofluoric acid; it is insoluble, and bears a red heat
without decomposition. log on to
to all solid
og
ben bolond to this
dos
in a stabla villor tai nuo abem sw-120x13359
&+F. 31.300
20
*

234
- Aluminium.
Metals.
Sect. 3. METALLIC BASES OF THE EARTHS.
ALUMINIUM. Symb. Al. Equiv. 13.7.
Sir H. Davy proved that alumina was an oxidized body,
and Wöhler succeeded in decomposing it, from which he ob-
tained the pure metal, aluminium.
Process. This metal may be obtained by heating the
chloride of aluminium with potassium in a covered platinum
or porcelain crucible. Intense heat is evolved during the
process. After cooling the mass, it is put into water, by
which the saline matter is dissolved; hydrogen gas, of
an offensive odor, is evolved, and a gray powder subsides.
This powder, after being washed in cold water, is pure
aluminium.
Properties. Aluminium, as thus prepared, is a gray powder,
similar to platinum, but when rubbed in a mortar, exhibits
distinctly a metallic lustre. Fuses at a higher temperature
than cast iron, and in this state is a conductor of electricity,
but a non-conductor
E.cp. Heated in the air to redness, it burns brilliantly, and forms
alumina ; but when introduced into oxygen gas, at a red heat, it burns
with such splendor, that the eye can hardly support the light, and with
so much heat, that the resulting alumina is partially fused into yellow
fragments, as hard as corundum, which not only scratch, but abso-
lutely cut glass.
Exp. Takes fire in chlorine gas at a red heat, but not oxidized by
water at common temperatures, nor attacked by cold sulphuric and
nitric acids ; soluble in solutions of potassa and ammonia, and in hot
sulphuric, or dilute sulphuric and hydrochloric acids.
r when cold.
ingen aninhos Compounds of Aluminium.
Sesquioxide of Aluminium (2A1+30. 27.4+ 24 = 51.4)
is the only known oxide of aluminium, and is commonly
called alumina; or aluminous earth.
Natural History. Alumina is very abundant in nature,
being found in every region of the globe, and in rocks of all
ages; hence it is one of the principal ingredients in most
soils. The different kinds of clay of which bricks, pipes, and
earthen-ware are made, consist mostly of hydrate of alumina.

Compounds of Aluminium.
235
Score
It is also found beautifully crystallized, in some of the most
beautiful gems. The ruby and the sapphire are nearly pure
alumina.ro me
Bonde
Process. It may be prepared for chemical purposes from
alum, which is a sulphate of alumina and potassa. Dissolve
pure alum in water, and precipitate the alumina by carbonate,
of ammonia. This, when washed in hot water and filtered,
is the hydrate, which may be rendered pure by a white heat
An easier process is to expose the sulphate of alumina and
ammonia to a strong heat, so as to expel the ammonia and
sulphuric acid. M. Gaudin has succeeded in forming rubies,
by mixing'ammoniacal alum with gobo part of chromate of
potassa, and exposing to a high heat.
Properties. Inodorous, tasteless, and possesses the proper-
ties both of an acid and an alkali ; insoluble in water, but has
a powerful affinity for it; when moistened, it forms a ductile
mass, which gives it its great utility in the arts. It is a re-
markable exception to the law, that heat expands all bodies.
There are probably several hydrates of alumina.
bars Y
Uses. Used for bricks, and various kinds of pottery.
Sesquichloride of Aluminium (2A1 +3C1. 133.66) was dis-
covered by Wöhler, by transmitting dry chlorine gas over a
mixture of alumina and charcoal, heated to redness. It is of
a pale, greenish-yellow color, partially translucent, of a highly
crystalline, lamellated texture, somewhat like talc, but with-
out regular crystals. On exposure to the air, it fumes slightly,
emitting an odor, like hydrochloric acid gas.
Exp: When thrown into water, it is speedily dissolved with a hiss-
ing noise, and so much heat is evolved, that the water, if in small
quantities, is brought into a state of brisk ebullition, and forms the
hydrochlorate of alumina.
Sesquisulphuret of Aluminium (2A1+3S. 75.7) is prepared by drop-
ing a piece of sulphur on to aluminium, strongly heated. It is a vitri-
fied, semi-metallic substance, of a dark color.
Sesquiphosphuret of Aluminium (2A1+ 3P. 74.5) is formed by heat-
ing aluminium in contact with the vapor of phosphorus; it is a black-
lustre, and, in the air, has the odor of phosphureted hy-
drogen.
Sesquiseleniuret of Aluminium (2A1 +38e. 146.2) is obtained by
heating to redness a mixture of selenium and aluminium. It is a
black, pulverulent substance, which acquires a metallic lustre when
tas mode 10 SOBY

236
-
Metals. — Glucinium
Yttrium.
ang GLUCINIUM. Symb. G. Equiv. 26.5. Sp. gr. 3.
Glucinium was obtained by Wöhler, in 1828, by the action
of potassium upon the chloride of glucinium. The process is
similar to that for obtaining aluminium. It appears in the
form of a gray powder, which acquires the metallic lustre by
burnishing, and is easily oxidized.
Sesquioxide of Glucinium, or Glucina, (2G+ 30. 77,)
was discovered by Vauquelin, in 1798. It is found only in
the minerals emerald, beryl, and cuclase.
Process. It is obtained by exposing beryl in fine powder,
with three times its weight of carbonate of potassa, to a strong
red heat. The fused mass is dissolved in dilute hydrochloric
acid, evaporated to dryness, re-dissolved in acidulated water,
and the alumina and glucina are thrown down by ammonia,
the precipitate macerated wy carbonate of ammonia, which
dissolves the glucina, and on boiling the filtered liquor, car-
bonate of glucina subsides; the carbonic acid is then expelled
by a red heat.
Properties. A white powder, without taste or odor, quite
insoluble in water. Pure potassa or soda precipitates it from
its salts; distinguished from alumina by being precipitated
from its solution with carbonate of ammonia, when the solu-
tion is boiled. Toronto
onda dola
YTTRIUM. Symb. Y. Equiv. 32.2.
Yttrium was prepared by Wöhler, in 1828, by a process
similar to that for obtaining glucinium.
Properties. It has a scaly texture, a grayish-black color,
and a perfectly metallic lustre. It is a brittle metal, and
burns with splendor in common air, and with still greater
brilliancy in oxygen gas. The result of this combustion is
the earth yttria, which was discovered in 1794, by Gadolin,
in a mineral at Ytterby, Sweden. It is of a white color,
soluble in sulphuric acid, and combines with sulphur, sele-
nium, and phosphorus. Its salts have a sweetish taste, and
some of them have an amethystine color.

Thorium - Zirconium.
237
THORIUM. Symb. Th. Equiv. 59.6.
This metal was procured by the action of potassium on the
chloride of thorium; decomposition being accompanied by a
slight detonation, On washing the mass, thorium is left, in
the form of a heavy, metallic powder, of a deep leaden-gray
color; and, when pressed in an agate mortar, it acquires
metallic lustre and an iron-gray tint. –T.
Properties. Thorium is not easily oxidized at common
temperatures, but burns with great brilliancy in the air. It
is not acted upon by alkalies, scarcely at all by nitric, and
slowly by sulphuric acid; but is readily dissolved by hydro-
chloric acid, with the disengagement of hydrogen gas.
Protoxide of Thorium, or Thorina, (ThO. 67.6,) was dis-
covered by Berzelius, in 1 1828, in a rare mineral from Nor-
way, called thorite. It is a white, earthy substance, soluble
in none of the acids, except the sulphuric, and is precipitated
from its solutions by the caustic alkalies as a hydrate, in
which state it absorbs carbonic acid from the atmosphere,
and dissolves in acids. Bitw o nie
to
It is distinguished from alumina and glucina, by its insolu-
bility in pure potassa, and from yttria, by forming with sul-
phate of potassa a double salt, insoluble in a cold, saturated
solution of sulphate of potassa.
gang tot by ZIRCONIUM. Symb. Zr. Equiv. 33.7.:
Los ದಿತಿ
Zirconium was discovered by Berzelius, in 1824.
Process. It is obtained by heating the double fluoride of
zirconia and potassa, carefully dried and mixed with potassium,
in a glass or iron retort. The mass is then washed in hot
water, and digested for some time in hydrochloric acid.
Properties. This substance exists in the form of a black
powder. It may be pressed out into thin, shining scales, but
its particles adhere very slightly. It is a non-conductor of
electricity. It takes fire, when heated in the open air, at a
temperature below a red heat; the product is zirconia.
Sesquioxide of Zirconium, or Zirconia, (2Zr +30. 91.4,) was dis-
covered by Klaproth, in 1789, from the Zircon, or Jargon, of Ceylon.

238
Metals. - Manganese.
17 parts of this substance, finely pulverized, and mixed with 21 of
litharge, may be fused, and a glass obtained, soluble in acids, from
which the zirconia is derived; or it can be formed directly by the com.
bustion of the metal in oxygen or common air.
Properties. A fine, white powder, inodorous and taste-
less; sp. gr. 4; exposed to a strong heat, it fuses, assuming a
light gray color; when cool, it is so hard as to strike fire with
steel, and to scratch quartz crystal.
ORDER II. METALS, THE OXIDES OF WHICH ARE NEITHER
ALKALIES NOR EARTHS.
Sect. 1. Metals which decompose Water at a red Heat.
MANGANESE. Symb. Mn. Eq. 27.7. Sp. gr. 8.013.
History. In 1774, Scheele described the black oxide of
manganese as “a peculiar earth.” Gahn subsequently dis-
covered that it contained a new metal, to which he gave the
name of magnesium, a term applied afterwards to the metallic
base of magnesia; and for which the words manganesium and
manganium have been substituted. The metal is not found
in the native or uncombined state, but its oxides are very
abundant.
Process. Make a paste with finely-pulverized oxide of
manganese and oil, and expose it to the heat of a smith's
forge, in a Hessian crucible, lined with charcoal, for the
space of two hours.
Properties. A hard, brittle metal, of a grayish-white color,
and granular texture; very infusible; not attracted by the mag-
net, except when it contains iron; soon tarnishes on exposure
to the air, and absorbs oxygen rapidly when heated to redness.
Decomposes water slowly at common temperatures, but rapidly
at a red heat.
Compounds of Manganese.
Protoxide of Manganese (Mn +0. 35.7) may be formed,
as shown by Berthier, by exposing the peroxide, sesquioxide,
or red oxide of manganese, to the combined agency of char-

Compounds of Manganese.
239
coal, and a white heat; or by exposing either of the oxides,
contained in a glass tube, to a current of hydrogen gas, at an
elevated temperature.
Properties. When pure, it is of a light green, or moun-
tain-green color, undergoing little if any change in the open
air, but oxidizes rapidly at 600° Fahr., and is instantly
converted into the red oxide, at a low red heat, and some-
times takes fire. It is the salifiable base of the metal, and is
contained in all its salts; hence its strong affinity for acids.
Sesquioxide of Manganese (2Mn +30, or Mn+110. 79.4) occurs
nearly pure in nature, and may be formed by exposing the peroxide to
a red heat. It is the chief residue of the usual process of obtaining
oxygen gas, but it is difficult to regulate the heat so as to obtain it in a
pure state.
into
Properties. The color is brown or black, according to
the source from which it is obtained; unites with nitric and
sulphuric acids, and is converted, by exposure to the air,
the peroxide.
Peroxide of Manganese. Mn+20. 43.7. This is a well-
known native product, commonly called black oxide of man-
ganese.
Properties. It occurs generally in masses, of an earthy
appearance, and black color, mixed with other substances;
but it is frequently found in small prismatic crystals. It is
not affected by exposure to the air or water, but yields oxy-
gen when heated to redness, and is the substance most
generally employed for that purpose, (see page 130 ;) does
not, unite with acids or alkalies.
Uses. Employed in the arts for coloring glass, in prepar-
ing chlorine gas, and in forming the salts of manganese.o
Red Oxide of Manganese. 3Mn +40. 115.1. This is
identical with the oxidum manganoso-manganium of Arfwed-
son, and occurs as a natural product. It may be formed arti-
ficially by exposing the peroxide or sesquioxide to a white heat.
Properties. Color, when finely rubbed, is nearly black
when warm, and brownish-red when cold. It is permanent
in the air at all temperatures, dissolves in small quantities by
cold sulphuric acid, and more rapidly by the aid of chlorine;

240
Metals. - Manganese.
the solution has an amethystine tint. It is the cause of the
rich color of the amethyst.
Varvicite. 4Mn +70. 166.8. Sp. gr. 4.531. Known only as a
natural production, and first noticed by Mr. Phillips among some ores
of manganese, found at Hartshill in Warwickshire. It resembles the
peroxide in color, for which it was first mistaken, but may be distin-
guished from it by its stronger lustre, greater hardness, more lamel.
lated texture, and by yielding water when heated to redness. It is
probably, like the red oxide, a compound of two oxides, consisting of
2 equivalents of the peroxide, and 1 of the sesquioxide of manganese,
with 1 of water. - T.
Manganic Acid. Mn+ 30. 51.7.
When peroxide of
manganese is mixed with equal weights of nitre, or carbon-
ate of potassa, and heated to redness, it fuses, and a green-
colored mass is formed, known by the name of mineral
chameleon, from the property of its solution to pass through
several shades of color.
Exp. On the addition of cold water, a green solution is formed,
which soon becomes blue, purple, and red; and ultimately a brown,
flocculent matter — hydrated peroxide of manganese — subsides. – T.
Theory. These changes are owing to the formation of
manganate of potassa, of a green color, which passes to the
permanganate of potassa, which is red, the blue and purple
being due to a mixture of these compounds; but the man-
ganic acid has not been obtained in a separate state, owing
to its ready decomposition.
Permanganic Acid. 2Mn +70. 111.4. This acid is
more permanent, though easily decomposed, even by contact
with paper or linen in filtering. It may be obtained from
the permanganate of baryta, by sulphuric acid.
Properties. Color red; decomposed by water at 86°;
oring matter is bleached by it, but particles of organic matter
floating in the air decompose it rapidly.
Protochloride of Manganese (Mn + Cl. 63.12) is prepared by evap-
orating a solution of the chloride to dryness, and heating it to redness
in a glass tube, while a current of hydrochloric acid gas is transmitted
through it; fuses at a red heat, and forms a pink-colored lamellated
mass on cooling ; deliquescent, and very soluble in water. -T.
Perchloride of Manganese (2Mn +7C1. 303.34) was discovered by
Dumas, and formed by putting a solution of permanganic into sul-
phuric acid, and adding fused sea-salt.
Properties. When first formed, it is a greenish-colored
vapor; but by passing it through a glass tube cooled to -5°,
Iron.
241

it condenses into a greenish-brown liquid, decomposed in-
stantly by water.
Perfluoride of Manganese (2Mn +7F. 186.16) was discovered by
Dumas and Wöhler. Prepared by mixing the mineral chameleon with
half its weight of fluor-spar in a platinum vessel, and decomposing the
mixture with fuming sulphuric acid.
bermedia
Properties. A yellowish-green gas, or vapor, which ac-
quires a beautiful purple-red color when mixed with air;
freely absorbed by water, giving to the solution the same red
tint; acts on glass with the formation of fluosilicic acid gas,
and the deposition of a brown matter, which acquires a deep
purple-red tint by the addition of water.
V
Protosulphuret of Manganese (Mn +S. 43.8) is found native in
Cornwall, England, and may be formed by igniting the sulphate with
one sixth of its weight of charcoal, in powder.com
Cyanuret of Manganese. Mn+ Cy. 27.7+26.39=54.09, equiv.
Phosphure and Carburet of Manganese may be obtained by heating
the metal in contact with phosphorus or carbon.
Alloys of Manganese. Manganese unites with several of
the metals, forming alloys of little importance. fasilia
IRON.
Symb.
Fe. Equiv.
28.
Sp. gr. 7.78.
History. Iron is decidedly the most important and useful
of the metals. It appears essential to a state of civilization ;
hence it is the most abundant, and widely diffused throughout
different parts of the earth. Hence, too, it seems to have
been made known to the first inhabitants of the earth, and
used in all ages where men have emerged even to the state
of barbarians. It was formerly called Mars.
Natural History. Iron is rarely found pure in nature.
Even meteoric iron is alloyed with cobalt and nickel; but its
oxides are very abundant. In combination with oxygen and
sulphur, it is so widely diffused, that few minerals can be
found that do not contain traces of it. It enters also into
plants and animals. The ores of iron are the red oxides,
including red and brown hematite, the black oxide, or mag-
netic iron ore, and the carbonate of the protoxide, either pure
or in the form of clay iron ore.
Process. The extraction of the iron from the ores is ef-
21 si lotuto Oi B Juget

242
Iron.
Metals.
fected by subjecting them, after being roasted and reduced to
a coarse powder, to the action of charcoal, lime, and caloric;
this is the cast iron, which contains some impurities, es-
pecially carbon. The malleable or wrought iron is prepared
from this, by continuing the process until the carbonaceous
matter is burned out ; it then becomes solid again, and is
put under a roller or hammer and drawn out into bars.
Steel is the wrought iron combined with carbon. The best
wrought-iron bars are surrounded by dry charcoal and heated
to a high temperature.
Properties. Iron has a peculiar gray color, and strong
metallic lustre, which is brightened by polishing, of which it
is capable of receiving a higher degree than any other metal.
It is less ductile and malleable than some others, but the most
tenacious of all; hence it may be drawn out into fine wire,
but not into thin leaves. Its texture is fibrous, and when
heated, is soft, and possesses the property of being welded to
other heated iron. When cooled suddenly, it is brittle, but
may be rendered malleable again by heat; it is very infusible,
and when combined with carbon, very hard. In this state,
it is capable of being made permanently magnetic: it is the
great repository of natural magnets, and the only substance,
save cobalt and nickel, which possesses magnetic properties.
Its uses in the arts are well known.
Compounds of Iron.
Protoxide of Iron. Fe +0. 36. The existence of this ox-
ide was first inferred by Gay Lussac; but Stromeyer obtained
it in an insulated form, by transmitting dry hydrogen gas
over the protoxide at a low temperature. It may also be
precipitated from its salts as a white hydrate by pure alkalies,
as a carburet by alkaline carbonates, as a white ferrocyanuret
by ferrocyanuret of potassium, and as a protosulphuret by
alkaline hydrosulphates. 10
Properties. Color dark blue, and communicates a blue
tint to substances melted with it. It is magnetic, and so
combustible, that it takes fire spontaneously in the open air,
and is converted into the peroxide. Its salts absorb oxygen
$o rapidly from the air, as to be useful in eudiometry. It is
Compounds of Iron.
243

commerce.
the base of the native carbonate, and the green vitriol of
an
Peroxide of Iron. 2Fe + 30 or Fe +110. 80. This is the
red hematite of mineralogists, a very abundant natural pro-
duction.
Process. It is made chemically by dissolving iron in nitro-
· hydrochloric acid, and adding an alkali.
The precipitate is of a brownish color, and is identical with
the mineral called brown hematite, and consists of 1 equiva
alent of the peroxide and 2 of water.
Properties. It is a brownish-red compound, not attracted
by the magnet. It is precipitated from its salts by the pure
alkalies. With ferrocyanuret of potassium it forms Prussian
blue ; with infusion of nutgalls it forms ink.
Tests of the presence of iron in any composition, may be made by
boiling it with nitric acid, which converts the iron into the peroxide;
the ferrocyanuret of potassium will then form a blue precipitate.
Black Oxide. (Fe +0)+(2Fe + 30.) 116. This com-
pound is called, by Berzelius, oxidum ferroso-ferricum, and
is supposed to be a mixture or combination of the two pre-
ceding oxides. Hebbet,
It occurs native, often in regular octohedral crystals. It
is formed also when iron is heated in the open air, or in con-
tact with moisture. It is not only magnetic, but is itself
often a magnet. With sulphuric acid, an olive-colored so-
lution is formed, containing two salts, the sulphate of the
protoxide, and peroxide, which may be separated from each
other by means of alcohol. The black oxide is the cause
of the green color of glass.
Protochloride of Iron (Fe + C1. 63.42) is formed by dissolving iron
in hydrochloric acid, evaporating to dryness, and heating the product
to redness, in a tube deprived of air. It is a gray, crystalline substance,
fusing at a red heat, and is easily converted into the hydrochlorate of
the protoxide of iron.
Perchloride of Iron (2Fe + 3Cl. 162.26) is formed by the combustion
of iron in chlorine gas. It is a yellowish-brown substance, crystal-
lizes in small iridescent plates, of a red color ; volatilizes at little above
2120; deliquesces readily, and dissolves in water, alcohol, and ether,
and is converted by water into the hydrochlorate of the peroxide of
iron.
Protiodide of Iron (Fe +1. 154.3) is prepared by digest-

244
Metals. -- Iron.
ing iodine in water and iron wire. On evaporating the solu-
tion to dryness, without exposure to the air, and heating it
moderately, it yields crystals of an iron-gray color and metal-
lic lustre, deliquescent, very soluble in water and alcohol,
and used in medicine as a tonic.
The Periodide of Iron (2F+31. 434.9) is obtained by exposing a so-
lution of the protiodide to the air. It is a volatile, red compound, colu-
ble in water and alcohol.
The Protobromide of Iron (Fe + Br. 106.4) and the Perbromide of
Iron (2Fe +3Br. 291.2) are formed in a similar manner with the iodides,
and have similar properties. Protofluoride of Iron. Fe +F. 46.68.
Perfluoride of Iron (2Fe + 3F. 112.04) is formed by dissolving per-
oxide of iron in hydrofluoric acid. As the acid becomes saturated,
crystals are formed in small, white, square tables, which are sparingly
soluble in water.
Protosulphuret of Iron (Fe +S. 44.1) is prepared by
heating equal parts of sulphur and iron-filings in a covered
Hessian crucible; considerable heat is evolved, and a yel-
lowish-gray substance is formed ; this is completely dissolved,
if pure, by dilute sulphuric acid, yielding hydrosulphuric
acid. It exists in nature, in the variegated copper pyrites,
and forms a black precipitate, when hydrosulphate of ammo-
nia is mixed with the sulphate of the protoxide of iron.
Sesquisulphuret of Iron (2Fe + 3S. 104.3) is formed by the action of
the hydrosulphuric acid on the hydrated peroxide of iron.
It has a yellowish-gray color, and dissolves in dilute sul-
phuric and hydrochloric acids, with the formation of hydro-
sulphuric acid and bisulphuret of iron.mod
Bisulphuret of Iron. Fe + 2S. 60.2. This is the iron
pyrites of mineralogists, and occurs abundantly in cubes, or
in some analogous form, of a yellow color, and metallic lus-
tre; sp. gr. 4.981, so hard as to strike fire with steel ; hence
its name.
It is dissolved by nitrohydrochloric acid, but by no other
acid, except the nitric. By heat, it is converted into magnet-
ic iron pyrites, if in close vessels, but exposed to the air, into
the peroxide of iron.
Magnetic Iron Pyrites. (57e+S) + (Fe +28.) 280.7.
This natural product appears to be composed of 5 equivs.
of the protosulphuret and 1 of the bisulphuret. It may
be formed as above. It is much more easily oxidized than
the bisulphuret.
Tetrasulphuret of Iron (4Fe +S. 128.1) and the Disulphuret of Iron
(2Fe + S. .72) may be formed by passing hydrogen.gas, at a red heat,
over the anhydrous sulphate of the protoxide of iron, to obtain the di-
&

Compounds of Iron.
245
sulphuret, and over the disulphate of the peroxide of iron, for the tetra-
sulphuret.
Properties. They exist in a grayish-black powder, soluble
in dilute sulphuric acid, with the evolution of hydrogen and
hydrofluoric acid gases.
Diphosphuret of Iron (2Fe +P. 71.7) is prepared by heating the
phosphuret in a covered crucible, lined with charcoal. W
Properties. It is a fused, granular substance, which re-
semblés iron in color and lustre, but is very brittle, and ren-
ders iron brittle, when contained in it, as it sometimes is.
Perphosphuret of Iron (3Fe + 4P. 146.8) is obtained by the action of
phosphureted hydrogen on sulphuret of iron, and resembles the pre-
ceding in most of its properties.
Carburets of Iron. Carbon and iron unite in several pro-
portions; only three seem worthy of notice – graphite, cast
or pig iron, and steel.
Dino
Graphite is known as a natural product, under the names
of plumbago and black-lead. There is not more than 10 per
cent. of iron, and often not 5.
Used for pencils, crayons,
crucibles, and for burnishing iron.
Cast Iron is a compound of carbon and iron, and is the
product of melting the ores of iron with charcoal. Its uses
are well known.
Steel is formed by filling a furnace with bars of the best
malleable iron, with layers of charcoal between, and subject-
ing them to strong heat away from the air; about 1.3 to 1.75
per cent. of carbon combines with the iron. This is the
substance used for the various purposes of the arts. It is
much harder than iron, but more brittle, and capable of a
less ductile and
malleable, but more firm in its texture,
higher polish. By fusion it forms cast steel. STE
-
Protocyanuret of Iron (Fe + Cy. 54.39) is prepared by mixing in
To You
taker
solution cyanuret of potassium with sulphate of protoxide of iron; on
exposure to the air, it passes to I Prussian
Protosulphocyanuret of Iron (Fe + CyS2. 86.59) is
pale
green solution to dryness in vacuo.
solving iron in hydrosulphocyanuric acid, and evanoting the di
ogno
to Sequisulphocyanuret of Iron (2Fe +3CyS?. 231.77) is prepared by
mixing the sulphocyanuret of potassium with any salt of the peroxide
of iron. It has a blood-red color, and is a very delicate test of the
presence of iron.
also
can blue.
21 *

246
?
Metals – Zinc
ZINC. Symb. Zn. Equiv. 32.3. Sp. gr. 7.00.
Zinc has long been known in the East, India and China,
but was first distinctly noticed in the sixteenth century, by
Paracelsus, under the name of zinetum. Henckel is the first
who obtained the metal from calamine, in the year 1721.
Von Swab first obtained it by distillation in 1742; and Mar-
graff published a process in the Berlin Memoirs in 1746.
Natural History. Zinc, like most of the metals, is rarely
found pure in nature, but is an abundant substance in com-
bination with oxygen, carbon, and sulphur.
Process. Commercial zinc, or spelter, is generally ob-
tained from calamine, native carbonate of zinc, or from the
native sulpkuret, called by mineralogists zinc blende. This
is oxidized by heating it in the open air, called roasting. It
is then distilled ; that is, it is heated in a crucible open at
the bottom and closed at the top, to which is affixed a tube,
which terminates just above a basin of water ; the gaseous
products, with the vapor of zinc, pass through the tube, and
the zinc is condensed. The first portions are impure, con-
taining cadmium and arsenic, which give the brown blaze;
when the blue blaze is seen, the zinc is collected.
tains now some impurities, which are removed by a white
heat in an earthen retort, to which a receiver full of water is
adapted.
) sed
g Properties. This metal is bluish-white, with a strong
metallic lustre and lamellated texture. It is a hard and brittle
bor
metal; but between the temperatures of 210° and 300° Fahr.,
it is malleable and ductile, and in this state is rolled out into
plates; fuses at 773° Fahr., and when slowly cooled, crystal-
lizes in four or six-sided prisms. It is easily pulverized
when heated to a certain temperature below redness, and
sublimes at a high temperature in close vessels, without
change.
Uses. Zinc is used extensively in the arts, for the construction of
voltaic instruments, and for covering buildings. It has been pro-
posed to use
se it for culinary vessels, water-pipes, and sheathing for
ships; but it is so easily oxidized and acted upon by the weakest
acids, that it is unfit for these uses.
It con-
Compounds of Zinc.
247

ness,
SULLA
1995 bist Compounds of Zinc.
Protoxide of Zinc, Zn +0. 40.3. This is the only known
oxide of zinc, formerly called flowers of zinc, nihil album,
and philosopher's wool.
Process. It is obtained by the combustion of zinc in the
open air, in oxygen gas, or by heating the carbonate to red-
It is found native in Franklin, New Jersey.
Exp. Melt zinc in a covered crucible, and when it is at a white
heat, remove the cover; it will burst out into a white flame, forming
the oxide.
The Hydrated Oxide of Zinc may be obtained by uniting
a rod of iron and zinc, and placing them in caustic ammonia,
in a close vessel.
Properties. At common temperatures it is white, but as-
sumes a yellow color when heated to redness ; insoluble in
water, and is a strong salifiable base.
The oxide is precipitated from its solutions, as a white hy-
drate, by pure potassium and ammonia, and as a carbonate
by alkaline carbonates.
Theo oxide is sometimes substituted
for white lead for paint; it is more durable, but not so white.
Berzelius describes a suboxide, and Thenard a binoxide,
but they are doubtful substances.
Det
Chloride of Zinc (Zn + Cl. 67.72) is formed by burning zinc-filings
in chlorine. It is colorless, fusible a little above 2120, and has so soft
a consistency at common temperatures, as to be called butter of zinc.
Iodide of Zinc (Zn + I. 158.6) is prepared by digesting iodine in
water with zinc-tilings.
Bromide of Zinc (Zn + Br. 110.7) is formed in a similar manner
with the preceding.
6129 hobia
Fluoride of Zinc (Zn +F. 50.98) is prepared by the action of hydro-
fluoric acid on the oxide of zinc. It exists as a white solid.
Sulphuret of Zinc (Zn+S. 48.4) is a native product,
known by the name of zinc blende. It may be formed by
heating sulphur with the oxide; it crystallizes in dodeca-
hedrons; lamellated structure; adamantine lustre; color red,
yellow, brown, or black. Cyanuret of Zinc. ZnCy. 58.69.
taget ni P690 (250)
3
a otro bene
mosaik
CADMIUM. Symb. Cd. Equiv. 55.8. Sp. gr. 8.604.
Tolos
History, Cadmium was discovered in 1817, by Stromeyer,
of Göttingen, in an oxide of zinc which had been prepared

248
Metals. — Cadmium.
for medical use. Dr. Clark detected it in the zinc ores of
Derbyshire, and in the common zinc of commerce, and
Mr. Herapath found it in considerable quantities in the zinc
works near Bristol, England.
Process. The following is the process of Stromeyer :
The ore of cadmium is dissolved in hydrochloric or sulphuric
acid in excess. The sulphuret of cadmium is precipitated
by hydrosulphuric acid. Nitric acid decomposes, this, and
forms a nitrate, which is evaporated to dryness. To a solu-
tion of this in water, an excess of carbonate of ammonia is
added, and the white carbonate of the oxide of cadmium is
precipitated, which, when subjected to a red heat, yields a
pure oxide. The metallic cadmium is obtained from the ox-
ide, by heating it with charcoal.
Properties. Cadmium resembles tin in its color and lus-
tre, but is harder and more tenacious; very ductile and
malleable; 1 melts
is at about the same temperature as tin, and
is nearly as volatile as mercury.
Heated in the open air, it
absorbs oxygen, and is converted into the
Oxide of Cadmium, (Cd +0. 63.8, which is the only
known oxide; is a strong alkaline base, forming neutral salts
with acids; insoluble in water ; fixed in the fire; and pre-
cipitated by all the alkaline carbonates, and by pure ammonia
a е
and potassa.
los
Chloride of Cadmium. Cd + Cl. 91.22. This compound
is formed by dissolving oxide of cadmium in hydrochlorie
acid. By concentration, the chloride crystallizes in four-
sided rectangular prisms, which lose their water of crystal-
lization by heat, and even in dry air; fused below redness,
and sublimes at a high temperature.
Iodide of Cadmium (Cd +I. 182.1) is formed in the same way as
the iodide of zinc; soluble in water and alcohol, and crystallizes in
large, colorless, transparent, hexagonal tables, which do not change in
the air, and have a pearly lustre. By heat they lose water, and then
fuse.
Sulphuret of Cadmium (Cd + S. 71.9) occurs in nature in
zinc blende, and is prepared by the action of hydrosulphuric
acid on the salts of cadmium. It has a
It has a yellowish-orange
color, and may be distinguished from the sulphuret of arsenic
by being insoluble in pure potassa, and by sustaining a white
heat without subliming to Shiza gita
Tin.
249

Phosphuret of Cadmium is a gray compound, very briitle and
fusible.
Men
am
TIN. Symb. Sn. Equiv. 57.9. Sp. gr. 7.2.
Tin was known to the ancients, in the time of Moses;
and was obtained, chiefly from Cornwall, England, and Spain,
at a very early period, by the Phænicians.
Process. The tin of commerce is obtained from the
native oxide by heat and charcoal, and in the form of block
and grain tin.
Stream Tin is the native oxide of Cornwall, which is
found in rounded pebbles, occasioned by the action of water.
Tin is seldom perfectly pure, containing a little copper, iron,
and arsenic. That from Malacca is the purest.
Tin Foil is often an alloy of tin and lead. Block tin is
less
pure than grain tin.se
Properties. Tin has a color and lustre resembling silver.
It is very malleable. Tin foil does not exceed To'oo of an
inch in thickness, but its ductility and tenacity are inferior to
many of the metals. When bent backward and forward, a
crackling noise is produced, by which it may be readily dis-
tinguished from Icad, zinc, etc. It fuses at 240° Fahr. When
heated to whiteness, it takes fire. If a drop of the fused tin
fall upon a board, it will divide into several globules, and
burn with a beautiful white light. The brilliancy of its sur-
face tarnishes slowly when exposed to the air at comnion
temperatures, but oxidizes at a high temperature.
Compounds of Tin.
Protoxide of Tin (Sn +0. 65.9. sp. gr. 6.666) is formed
by fusing tin for some time in an open vessel, or it may be
precipitated, as a hydrated oxide, from a solution of chloride
of tin, by an alkaline carbonate.
Properties. It is a gray powder, permanent in the air,
unless touched by a red-hot body, when it takes fire, and is
converted into the peroxide. It is dissolved in the strong
acids, and the pure, fixed alkalies. It readily absorbs oxygen
from the air and other compounds; hence it throws down

250
-
Metals.
Ta.
mercury, silver, and platinum, from their salts. With gold,
it causes the purple precipitate of Cassius ; by this charac-
ter it is readily distinguished. It is precipitated from its
solutions by hydrosulphuric acid as a black protosulphuret.
Sesquioxide of Tin (2n + 30. 139.8) is prepared by mixing recently-
precipitated and moist hydrated peroxide of iron with a solution of
protochloride of tin. The sesquioxide is precipitated in a slimy, gray
matter, of a yellowish tint, from oxide of iron; distinguished from the
protoxide by being soluble in ammonia.
Binoxide of Tin (Sn +20. 73.9) is prepared by the action
of nitric acid on metallic tin. The concentrated acid does
not act on the tin, but, on the addition of water, violent effer-
vescence takes place, and a white powder — the hydrated bi-
noxide of tin — is formed. The water is expelled by heat, and
the pure binoxide, of a straw-yellow color, results. The by-
drated oxide may also be precipitated from the protochloride
by potassa, ammonia, or the alkaline carbonates; but the
properties differ from that formed in the other way, the latter
being dissolved in the strong acids, while the former is not.
It acts the part of a feeble acid, uniting with the pure alka-
lies, and forming a class of compounds — the stannates.
Biroxide of tin is recognized by its being precipitated
from its solutions by hydrochloric acids as a bulky hydrate,
and by any of the alkalies or alkaline carbonates. When
melted with glass, it forms a white enamel.
Protochloride of
of Tin
(Sn + Cl. 93.32) is obtained by distilling equal
weights of tin and bichloride of mercury. It is a gray solid, of resin-
ous lustre ; fuses below redness, and sublimes at a high temperature;
crystallizes in small, white needles. A solution of the protochloride
may be prepared for deoxidizing purposes, by heating granulated tin
in strong hydrochloric acid, as long as hydrogen gas is evolved.
Bichloride of Tin (Sn+ 2Cl. 128.74) is formed by distilling 8 parts
of granulated tin with 24 of bichloride of mercury, or by heating the
protochloride in chlorine gas.
Properties. It is a colorless liquid, very volatile, yielding
white fumes in an open vessel; hence formerly called the
fuming liquor of Libavius; boils at 248°; sp. gr. of its
vapor, 9.1997; mixed with of its weight of water, it forms
a solid hydrate, but dissolves in a larger quantity of water.
Uses. The solution called permuriate of tin is used in dyeing, and
is prepared by dissolving tin in nitrohydrochloric acid.
Protiodide of Tin (Sn + I. 184.2) is prepared by heating granulated
tin with 25 times its weight of iodine. It is a brownish-red substance,
very fusible, volatile, and soluble.
Biniodide of Tin (Sn +21. 310.5) is prepared by dissolving the hy-

Cobalt.
251
drate of the peroxide, precipitated by alkalies, from the bichloride, in
hydriodic acid. It forms yellow crystals of a silky lustre.
Protosulphuret of Tin (Sn+S. 74) is prepared by pouring melted
tin upon its own weight of sulphur, and stirring rapidly with a stick.
It has a bluish-gray, or nearly black color, and metallic lustre ;-fuses
at red heat, and has a lamellated texture when cool.
Sesquisulphuret of Tin (2 Sn +3S. 164.1) is obtained by heating to
low, redness the protosulphuret with } of its weight of sulphur. It is
a deep grayish-yellow compound.
Bisulphuret of Tin. Sn + 2S. 90.1. This compound was formerly
called Mosaic gold, and may be prepared by heating a mixture of 2
parts of peroxide of tin, 2 of sulphur, and 1 part of hydrochlorate
of ammonia, in a glass or earthen retort, to a low red heat, till sulphur-
ous acid ceases to be evolved.
Properties. It occurs in crystalline scales, of a golden-
yellow color, and metallic lustre; soluble in pure potassa,
and its only solvent among the acids is the nitrohydrochlo-
ric acid. It is obtained, as a hydrate, by the action of hy-
drosulphuric acid, and the bichloride of tin, in solution.
low
Terphosphuret of Tin (Sn +3P. 105) is formed, according to Rose,
by the action of phosphureted hydrogen on a solution of protochlo-
ride of tin. It oxidizes rapidly in the air.
or
COBALT. Symb. Co. Equiv. 29.5. Sp. gr. 7.834.
sblad
Cobalt was discovered by Brandt, and derives its name,
Kobold, an evil spirit, from the belief of the German miners
that its presence was unfavorable to that of valuable metals.
Natural History. It exists in nature, generally, in com-
bination with arsenic. It is also a constant ingredient -in
meteoric iron, and is found combined with sulphur and other
combustibles.
For
Process. It may be obtained from the oxide, by heating
it in connection with charcoal, and then passing over it a
stream of hydrogen gas, to combine with the oxygen.
Properties. Cobalt is a brittle solid, of a reddish-gray
color, and weak metallic lustre; fuses at 130° Wedgwood,
and crystallizes when slowly cooled. It is attracted by the
magnet, and is susceptible of being rendered permanently
magnetic; absorbs oxygen when heated in open vessels. It
is also oxidized by nitric acid, and decomposes water at a
red heat.

252
Cobalt.
Metals.
Compounds of Cobalt.
Protoxide of Cobalt (Co+0. 37.5) is obtained by de-
composing the carbonate, by heat, in a vessel from which the
air is excluded.
Properties. It has an ash-gray color, and is the base of
all the salts of the metal, most of which are a pink-blue.
When heated, it absorbs oxygen, and is converted into the
peroxide. It is distinguished by giving a blue tint to borax
when melted with it.
Zaffre is an impure oxide of cobalt, obtained by heating
the arseniuret in a reverberatory furnace. When this sub-
stance is heated with sand and potassa, a beautiful blue-
colored glass is formed, known by the name of smalt, and
used in the arts for communicating the blue color to glass,
porcelain, and earthen-ware.
The protoxide is easily precipitated from its salts by alka-
lies; the precipitates are of a blue or pale pink color; dis-
solved in excess of alkali.
Oxide of Cobalt (3Co +40. 120.5) is probably a compound of the
peroxide and the protoxide.
Peroxide of Cobalt (2Co +30. 83) is obtained as a black
hydrate with 2 equivs. of water, when chloride of cobalt is
decomposed by chloride of lime. The water is driven off
by exposure to a he
a heat of 600° or 700°. It combines with
none of the acids, and, when strongly heated, is decomposed,
and resolved into the protoxide and oxygen.
Chloride of Cobalt (Co + Cl. 64.92) is obtained by dis-
solving metallic cobalt, or either of its oxides, in hydrochlo-
ric acid. The solution is of a pink color, and yields, on
evaporation, small crystals of the same color. When these
crystals are deprived of their water of crystallization, they
assume a blue color - a property on which is founded its
use as a sympathetic ink.
Exp. Write on paper with a dilute solution of the chloride, and
expose it to a gentle heat; it becomes blue. This solution is called
riate of cobalt; but Turner thinks it a chloride, analogous to several
other compounds generally described as muriates of the metals.
Exp. Draw the branches of a tree with India ink, and put on the
foliage with the chloride of cobalt. When cold, the foliage does not
appear, but shows itself on the application of heat. A landscape may

Compounds of Nickel.
253
be represented, in this manner, as wintry or vernal, according as the
heat is increased or diminished.
Sulphurets of Cobalt. Cobalt unites with sulphur in three
proportions.
The Protosulphuret (Co+S. 45.6) is formed by throwing fragments
of sulphur on red-hot cobalt; has a gray color, a metallic lustre, and
crystalline texture.
The Sesquisulphuret of Cobalt (2Co +3S. 107.3) is formed by pass-
ing a current of hydrosulphuric acid gas over the oxysulphuret, at a
red heat.
The Bisulphuret (Co+28. 61.7) is prepared by heating below red-
ness, in a glass tube, 2 parts of the carbonate of the oxide of cobalt,
intimately mixed with 3 of sulphur.
Subphosphuret of Cobalt (3Co +2P. 119.9) is obtained by the action
of phosphureted hydrogen on chloride of cobalt. It is a pulverulent,
gray solid.
NICKEL. Symb. Ni. Equiv. 29.5. Sp. gr. 8.2579.
Nickel was discovered by Cronstedt in 1751, in the kup-
fer nickel (copper nickel) of Westphalia. The term nickel
was applied to the ore because it looked like copper, but did
not yield it. It exists also in meteoric iron.
Process. Nickel may be extracted from the ore, — which
is an arseniuret of nickel, containing small quantities of
sulphur, copper, cobalt, and iron, or from speiss; also an
arseniuret which is obtained in forming srnalt from the
roasted ores of cobalt. This metal is obtained by heating
the oxalate or the oxide with charcoal in close vessels. *
Properties. Color white, intermediate between tin and
silver; strong metallic lustre; ductile and malleable; at-
tracted by the magnet, and, like iron and cobalt, may be
rendered permanently magnetic; a little less infusible than
iron; oxidized at a red heat, and by nitric acid.
Compounds of Nickel.
Protoxide of Nickel (Ni +0. 37.5) is formed by heating
the carbonate, oxalate, or nitrate, to redness, to drive off the
acid.
For processes, see Turner's Elements, p. 351,
0935%

254
Metals. - Arsenic.
Properties. Color at first an ash-gray, but, when exposed
to a white heat, it is of a dull olive-green. This is the
strong alkaline base of the metal, and nearly all the salts
have a green tint. Pure alkalies precipitate this oxide from
its salts, as a hydrate of a pale green color. The alkaline
carbonates and hydrosulphurets also precipitate it from its
salts, the former as a carbonate, the latter as a sulphuret of a
black color.
Sesquioxide of Nickel (2Ni +30. 83) is formed by transmitting
chlorine through water, in which the hydrate of the protoxide is sus-
pended. It has a black color, does not unite with acids, and is decom-
posed at a red heat.
Chloride of Nickel (Ni+CI. 64.92) is formed by the action of hydro-
chloric acid upon metallic nickel, or one of its oxides; an emerald-
green solution is formed, and, on evaporation, yields crystals of the
same tint, which deliquesce in moist air, and effloresce if the air is dry.
Protosulphuret of Nickel (Ni+S. 45.6) is formed by a similar pro-
cess with the protosulphuret of cobalt; occurs native in acicular
crystals - the haarkies of the Germans. When dry, it is of a grayish-
yellow color, while the precipitates are dark brown; soluble in nitric
or nitrohydrochloric acid. lot
Disulphuret of Nickel (2Ni +S. 75.1) is obtained by passing hydro-
gen gas over the sulphate of nickel at a red heat; color light yellow,
and is more fusible than the preceding.
Subphosphuret
of hydrogen on of Nickel (3Ni+2P. 119.9) is obtained by the action
subphosphate of oxide of nickel. Color black, solu-
ble in nitric acid, and burns with a flame under the blowpipe.
Cyanuret of Nickel (Ni+ Cy. 55.89) is obtained by mixing in solu-
tion a salt of nickel with cyanuret of potassium. A precipitate is
formed, of a pale, apple-green color, which becomes tinged with yellow
on drying.
Sect. 2. METALS WHICH DO NOT DECOMPOSE WATER AT
ANY TEMPERATURE, AND THE OXIDES OF WHICH ARE NOT
REDUCED TO THE METALLIC STATE BY THE SOLE ACTION
OF HEAT.
ARSENIC. Symb. As. Equiv. 37.7. Sp. gr. 5.8853.
Arsenic was first discovered by Dioscorides, who called
it Sandarac; but its properties were first investigated by
Brandt, in 1733.
Natural History. It exists in nature, in small quantities,
rarely in a metallic state. It is generally found in com-

Compounds of Arsenic.
255
bination with cobalt and iron, and occasionally with other
metals.
Process. Metallic arsenic is obtained by roasting the ores
in a reverberatory furnace; as the arsenic is expelled by heat,
it combines with oxygen, and condenses into thick cakes on
the chimney. These cakes are purified by a second sublima-
tion, and constitute the white oxide of arsenic- a virulent
poison. This substance is then mixed with twice its weight
of black flux, * exposed with charcoal to a red heat in a Hes-
sian crucible; and the metal is sublimed and collected in an
empty crucible, which is placed over the other, and kept cool
for the purpose of condensation. .
Properties. Arsenic is a very brittle metal, of a steel-gray
color, high metallic lustre, and of a crystalline structure.
When heated to 356°, it sublimes without fusion, and may be
collected in close vessels without change; but, when thrown
on a red-hot iron, it burns with a blue flame and white
smoke, giving off a strong odor of garlic- a property which
belongs to no other metal, unless it be zinc; when thus
heated in the open air, it is converted into the white oxide
of arsenic. Exposed at common temperatures of the air, it
oxidizes slowly, forming the substance called fly-powder,
which is a mixture of the oxide and the metal.
Arsenic detonates with some of the salts, and decomposes
them.
Exp. Take 3 parts of chlorate of potassa, and 1 of arsenic, finely
powdered, and cautiously mixed together.
1. Place a small quantity on an anvil, and strike it with a hammer;
the arsenic will instantly combine with the salt, producing an explosion
with flame.
2. Set it on fire, and it will burn rapidly. Pero
3. Throw it into concentrated sulphuric acid, and a bright flash of
light will be perceived at the moment of contact.
Uses. Arsenic is used in the arts. It renders glass
white.
en
nede
toline prots
Compounds of Arsenic.
Arsenious acid, (2 As + 30. 99.4, commonly called white
arsenic and white oxide of arsenic, may be formed by the
* Prepared by detonating, in a crucible, 1 part of nitre with 2 of
the crystals of tartar.

256
Metals. - Arsenic.
combustion of the metal; but the white arsenic of commerce
is obtained from the arseniurets of cobalt, by sublimation.
Properties. Arsenious acid is white, semitransparent,
and, when first formed, of a vitreous lustre and conchoidal
fracture. Its acid taste is owing to the inflammation which
it produces; it has a faint impression of sweetness. Its
sp. gr. is 3.7; has two crystalline forms, but is usually found
in six-sided scales, derived from a rhombic prism; soluble
in water.
It is one of the most virulent poisons known ; and, as it is
sometimes accidentally or intentionally taken, it is a frequent
cause of death, and a subject of judicial investigation. Hence
the importance of pointing out the most effectual modes of
detecting its presence.
Tests. The most valuable are the ammoniaco-nitrate of
silver, ammoniaco-sulphate of copper, hydrosulphuric acid,
and hydrogen gas.
1. Obtain as large a quantity of the liquid from the stom-
ach as possible. This, with parts of the stomach, should be
put into pure water, filtered and evaporated, so as to obtain
a concentrated solution; add to this, ammoniacal nitrate of
silver,* and if arsenic is present, a yellow — arseniate of sil-
ver - will be thrown down.
2. Add to the suspected liquid ammoniacal sulphate of
copper, and a green precipitate will be formed, called
Scheele's green.
3. Pass into the liquid, hydrosulphuric acid, and if arseni-
ous acid is present, orpiment, or the sesquisulphuret of
arsenic will be formed, giving to the liquor a yellow, turbid
appearance. This sulphuret should then be dried, mixed
with black flux, carefully introduced into a glass tube, and
heated by a spirit lamp; the sulphuret will be decomposed,
and metallic arsenic appear on the cool parts of the tube.
This is a very satisfactory test; but if, on heating the sub-
Prepared by dropping into a strong solution of nitrate of silver,
ammonia, till the oxide of silver, first precipitated, is nearly all dis-
solved.
+ Prepared in the same way with the preceding, by using the sul-
phate of copper, instead of the nitrate of silver.
Compounds of Arsenic.
257

stance
thus à
deposited, it rises up in white fumes, with an
alliaceous odor, and is deposited in white, octohedral crystals,
we may be sure that arsenic is present.
4. Introduce a quantity of the suspected liquid into a
Florence flask, having a jet pipe and a stop-cock attached,
with zinc and sulphuric acid; the water will be decomposed,
and the nascent hydrogen, in passing through the water con-
taining arsenious acid, will form arseniureted hydrogen;
and on burning the gas, as it issues from the jet, metallic
arsenic will be deposited on a plate of glass or porcelain,
held over the flame.byl ui ainden bis mit 70 pok
Any one of these tests, however, should not be depended
upon in a case where the life of a fellow-being is at stake, as
other metals, such as antimony, will sometimes present a
similar appearance; but if the suspected substance be tested
by each of the four ways mentioned, there can be no doubt
but that it contains arsenious acidentes la
Its action upon animals, whether taken into the stomach, or applied
to wounds, is attended by pain and vomiting; and if life be prolonged
beyond twenty-four hours, diarrhæa, a sensation of heat, and extreme
pain in the stomach and intestines, succeed, pulse feeble, countenance
anxious, skin livid, often attended by eruptions.
The best antidote is perhydrate of iron, with a small quantity of am-
monia. In cases rapidly fatal, extreme faintness, cold sweats, attended
with slight convulsions, are experienced. (See Christison on Poisons.)
Arsenic has the property of preserving from decay the bodies of
those poisoned with it. The stomach and intestines have thus been
found entire two years and a half after death.
Dedal
Arsenic Acid (2As + 50. 115.4) is formed by dissolving
arsenious acid in concentrated nitric, mixed with a small
quantity of hydrochloric acid, distilling in a glass vessel until
it acquires the consistency of sirup, and then heating nearly
to redness, in a platinum crucible, to expel the nitric acid.
Properties. It has a sour, metallic taste, reddens the vege-
table blue colors, and combines with alkalies, forming arse-
niates. It is decomposed by hydrosulphuric acid. This
acid is also an active poison.
ODPUR
132574
Protochloride of Arsenic (AsCl. 73.12) is prepared by heating in a
retort, to nearly 212°, arsenious acid, with ten times its weight of con-
centrated sulphuric acid, and throwing them in fragments of common
salt.
Sesquichloride of
f Arsenic (As-C13
. 181.66) is formed by the sponta-
neous combustion of powdered arsenic in chlorine gas. It is a color-
22 *

258
-Chromium.
Metals.
This gas
less, volatile liquid, giving off fumes, on exposure to the air; hence
called fuming liquor of arsenic.
Periodide of Arsenic (2As + 51. 706.9) is formed by gently heating
arsenic with iodine. It is a deep red compound, decomposed by
water.
Protohyduret of Arsenic (As +H. 38.7) is prepared by the action of
water on an alloy of arsenic and potassium.
Sesquibromide of Arsenic. 2As + 3Br. 310.6. When arsenic and
bromine are brought into contact, they instantly unite with vivid evo-
lution of light and heat.
Arseniureted Hydrogen. 2As + 3H. 78.4.
was discovered by Scheele. It is generally made by digest-
ing an alloy of tin and arsenic in hydrochloric acid. It is
colorless; nas a fetid odor resembling garlic; sp. gr. 2.695;
extinguishes burning bodies, but burns with a blue flame.
It is poisonous in a high degree, having proved fatal to M.
Gehlen. It is decomposed by chlorine, iodine, caloric, and
even atmospheric air; it forms with oxygen an explosive
mixture.
Protosulphuret of Arsenic. As + s. 53.8. This substance
exists in the mineral kingdom, and is called realgar. It
may be formed by heating arsenious acid with half its weight
of sulphur, until the mixture is perfectly fused. It is crys-
talline, transparent, and of a ruby-red color.
Sesquisulphuret of Arsenic. 2As +3S. 123.7. This in
the native state is called orpiment.
Process. It may be formed by fusing arsenious acid and sulphur;
but it is purer, if obtained by passing hydrosulphuric acid gas through
a solution of arsenious acid.
Properties. This substance has a rich, yellow color, and
is employed as a pigment. It is the coloring principle in
the paint called king's yellow.
Persulphuret of Arsenic (2As +5S. 155.9) is formed by passing
hydrosulphuric acid through a moderately strong solution of arsenic
acid. It resembles orpiment in color. The sulphurets of arsenic are
poisonous.
LE
CHROMIUM. Symb. Cr. Equiv. 28. Sp. gr. 5.9.
Chromium* was discovered in 1797, by Vauquelin, in a
beautiful red mineral, the native chromate of lead. It exists
*
Xpõud, color, from its remarkable tendency to form colored com-
pounds.
Compounds of Chromium.
259

also in chromate of iron, a native mineral found abundantly
in Europe, and also in this country.
Process. This metal has been obtained only in small
quantities, owing to its affinity for oxygen. The oxide may
be deprived of its oxygen, by heating it with charcoal in a
smith's forge.
Properties. A brittle metal, of a grayish-white color, and
very infusible. It is oxidized by heating it with nitre, and
converted into chromic acid.
Compounds of Chromium.
Sesquioxide of Chromium. 2Cr +30.-80. Exists native
in the emerald.
Process. It is prepared by dissolving chromate of potassa in water,
and mixing it with a solution of nitrate of mercury, when a yellow-
colored precipitate — the chromate of mercury — is formed. When this
salt is heated to redness in an earthen crucible, the mercury is driven
off, and the chromic acid is resolved into oxygen, and oxide of chro-
mium.
Properties. Oxide of chromium is of a green color, very
infusible, insoluble in water, and after being strongly heated,
resists the action of the most powerful acids ; heated with
nitre, it is converted into chromic acid. Fused with borax
or vitreous substances, it communicates to them a beautiful
green color. Hence its utility in the arts. It unites with
acids, and forms green-colored salts.
Chromic Acid (Cr+ 30. Equiv. 52) may be obtained
from the native chromate of iron.
Process. It is best prepared by transmitting the gaseous fluoride
of chromium into water contained in a vessel of silver or platinum;
when, by mutual decomposition of the gas and the water, hydrofluoric
and chromic acids are generated. — T.
Properties. This acid is black while warm, and dark red
when cold. When dry, according to Hayes, it is yellowish-
brown, very soluble in water, rendering it red and yellow.
When a heated concentrated solution cools, it deposits red
crystals, very déliquescent. The solution has an acid, astrin-
gent taste, and bleaches litmus paper. It destroys most vege-
table and animal coloring matters. Hence its use in calico-
printing. It is characterized by its color, and by forming
colored salts with alkaline bases.

260
.
Metals.
Vam
VanadiumSesquichloride of Chromium (2Cr +3C1. 162.26) may be prepared
by transmitting dry chlorine gas over a mixture of oxide of chromium
and charcoal, heated to redness in a porcelain tube ; when the sesqui-
chloride gradually collects as a crystalline sublimate of a peach-purple
coloratori
Terchloride of Chromium (Cr+ 3Cl. 134.26) is formed by the action
of fuming sulphuric acid on a mixture of chromate of lead and chloride
of sodium.
Oxychloride of Chromium. CrCl3 + 2Cr03. 238.2.
Sesquifluoridě of Chromium (2Cr + 3F. 112.04) is formed by dissolv-
ing the exide in hydrofluoric acid, and evaporating to dryness.
Terfluoride of Chromium. Cr+ 3F. 28 +56.04=84.04.
Sesquisulphuret of Chromium (2Cr +38. 104.3) may be obtained by
heating in close vessels a mixture of sulphur and the hydrated oxide.
It is of a dark-gray color, acquiring a metallic lustre by friction.
Protophosphuret of Chromium (Cr+P or CrP. 43.7) is prepared by
passing phosphureted hydrogen gas over the sesquichloride of chro-
mium at a red heat; a black compound, burning before the blowpipe,
with a flame of phosphorus.
tendong Stoties galesib daya
VANADIUM. Symb. V. Equiv. 68.5.
Vanadium was discovered by Sefstrom, in 1830. It de-
rives its name from Vanadis, a Scandinavian deity.
Natural History. It exists in the iron ore of Taberg,
Sweden, and is found in great abundance in the slag formed
by converting the cast iron of Taberg into malleable iron,
It was also found by Johnson, at Wanlock-Head, Scotland,
where it occurs as a vanadiate of lead.com
Bolto
ang apa ba
Process. It has been obtained in various ways — by heat-
ing vanadic acid with potassium, and by the decomposition
of the chloride of vanadium.*
Properties. When obtained by means of potassium, it is
a brittle, black substance; but when prepared by decompo-
sing the chloride, it is white, resembling silver, of a strong
metallic lustre. It is not oxidized by air or water; boiling
sulphuric, hydrochlorie, and hydrofluoric acids, do not affect
it, but it is dissolved by nitric and nitrohydrochloric acids,
and the solution has a fine, dark blue color.
guzo 1 * For processes, see Turner's Elements.
50

Compounds of Vanadium - Molybdenum.
261
Compounds of Vanadium.it, abon
Protoxide of Vanadium (V+0.76.5) may be obtained by heating
vanadic acid with charcoal or hydrogen gas. It is a dark brown, or
black, substance, soluble in nitric acid.
Binoxide of Vanadium (V + 20. 84.5) may be prepared by heating
to full redness 10 parts of the protoxide, with 12 of vanadic acid, in a
vessel filled with carbonic acid. It is black, very infusible, and insolu-
ble in water. Its salts have a blue color. It acts the part of an acid
by uniting with alkaline bases.
Vanadic Acid (v +-30. 92.5) is tasteless, insoluble in
alcohol, and very slightly soluble in water. It is easily de-
composed by heating it with combustible matter, and in solu-
tion by all deoxidizing agents. It unites with bases often in
two or more proportions ; most of its neutral salts are yellow.
It is distinguished from all other acids, except the chromic,
by its color, and from this acid by the action of deoxidizing
substances, which give a blue solution with the former, and
green with the latter.*
Jo te folosite bute bine
ind von Roberto
MOLYBDENUM. Symb. Mo. Equiv. 47.7. Sp. gr. 8.615.
Molybdenum was discovered in 1775.
Process. It was obtained from the native sulphuret, by
digesting it in nitrohydrochloric acid, and heating the mo-
lybdic acid, thus formed, in connection with charcoal.
Properties. It is a brittle metal, of a white color, and
very infusible. Its properties are imperfectly known.
Protoxide of Molybdenum (Mo + 0.55.7) is obtained by
precipitating the hydrochloric solution of molybdic acid by
zinc, when a brown hydrate is formed, giving dark colored
solutions with the acids.
Binoxide of Molybdenum (Mo+0. 63.7) is prepared by putting a
mixture of molybdate of soda and sal-ammoniac, in fine powder, in a
red-hot crucible, instantly covering it, and continuing the heat until
lybdenum com
* The bichloride of vanadium, (VCI?. 68.5+ 70.34= 139.34 ;) the
terchloride of vanadium, (VC13. 68.5+ 106.26=174.76 ;) the bibromide
of vanadium, (VBrº. 68.5+ 156.8=225.3;) the bisulphuret of vana-
dium, (VS?. 68.5+ 32.2=100.7;) the tersulphuret, (VS3. 68.5+ 48.3
=116.8.) are unimportant compounds, for a description of which, see
Turner's Elements, p. 365.

262
Metals. - Tungsten. 3
vapors of sal-ammoniac cease to arise. This is a deep brown anhydrous
powder, insoluble in acids.
Molybdic Acid (Mo +30, or M03 71.7) may be obtained
by roasting the native sulphuret in an open crucible, kept at
a low red heat, and stirred until sulphurous acid ceases to
escape. The yellow powder, thus formed, is treated with
ammonia; the filtered solution evaporated, again dissolved
in water and ammonia, and crystallized; the ammonia is
then expelled by gentle heat.
It is a white powder; sp. gr. 34.9 ; fuses at a red heat into
a yellow liquid ; slightly soluble in water.*
TUNGSTEN. Symb. W. Equiv. 94.8. Sp. gr. 17.5.
Tungsten is found native in the mineral wolfram.
Process. It is obtained by exposing a mixture of tungstic
acid and charcoal to a strong heat.
Properties. It is a very hard, brittle metal, resembling
iron in color, and, by the action of heat and air, converted
into tungstic acid.
GUR
Compounds of Tungsten.
Binoxide of Tungsten (W+20. 110.8) is prepared by
the action of hydrogen gas on tungstic acid, at a low red
heat. It has a brown color, resembling copper when
polished.
Tungstic Acid (W+30. 118.8) may be obtained by
heating the binoxide to redness in open vessels. It is of a
yellow color, insoluble in water, and has no action on litmus
paper.
Bichloride of Tungsten (W+201. 165.64) is formed by
heating tungsten in chlorine gas.t
* For the preparation of the protochloride of molybdenum, (MoCl.
83.12 ;) the bichloride of molybdenum, (MoCl2. 118.54;) the terchloride
of molybdenum, (MoC13. 153.96 ;) the tersulphuret of molybdenum,
(MOS3. 96,) and the persulphuret of molybdenum, (MoS4. 112.1,) the
student is referred to Turner's Elements, p. 369.
† For a description of the terchloride of tungsten, (WC13. 201.6 ;) bi-
sulphuret of tungsten, (WS?. 126;) and tersulphurct of tungsten, (WS.
143.1,) see Turner's Chemistry.

Columbium -- Antimony.
263
COLUMBIUM. Symb. Ta. Equiv. 185.
::
Columbium was discovered in 1801, by Hatchett, in a
black mineral in the British Museum, which had been sent
by Governor Winthrop to Sir Hans Sloane, from Haddam, in
Connecticut. *
Process. It is obtained by heating potassium with the
double fluoride of potassium and columbium.
Properties. Obtained in this way, it is a black powder,
and a non-conductor of electricity, but a perfect conductor
in a more dense state. It acquires a metallic lustre by pres-
sure; of an iron-gray color; fuses at a higher temperature
than glass; heated in the open air, it takes fire, and is con-
verted into columbic acid. It is easily dissolved into nitro-
hydrofluoric acid,
Compounds of Columbium.
Binoxide of Columbium (Ta + 20. 201) may be formed by exposing
columbic acid in a crucible, lined with charcoal, and luted to exclude
the air, for an hour and a half, to an intense heat. When reduced to
powder, it is a dark brown substance, not acted upon by acids, but con-
verted into columbic acid by fusion with potassa or nitre.
Columbic Acid (Ta + 30. 209) is formed from the native columbates,
by fusing the ores with three or four times their weight of carbonate of
potassa, and precipitating the white hydrate by acids.
Properties. Hydrated columbic acid is tasteless, insolu-
ble in water, and communicates a red tinge to moistened lit-
mus paper ; heated to redness, the water is expelled, and the
anhydrous columbic acid remainst
side
ANTIMONY. Symb. Sb: Equiv. 64.6. Sp. gr. 6.702.
Halden
History. Antimony was discovered by Basil Valentine,
in the fifteenth century. It derived its name from anti monk,
* Tantalum, discovered by Ekeberg, is identical with this metal.
# For a description of the terchloride of columbium, (Ta +3C1.
291.26 ;) the terfluoride of columbium, (Ta + 3F. 241.04 ;) and the sul-
phuret of columbium, composition uncertain, see Turner's Chemistry.

264
Metals. — Antimony.
from its having proved fatal to some monks, to whom it was
given as a medicine.
It is found native in Sweden, France, and the Hartz; but
generally occurs as a sulphuret.
Process. It may be obtained by heating the native sul-
phuret in a covered crucible, with half its weight of iron-
filings; the sulphur unites with the iron, and the metal ap-
pears in the bottom of the crucible. Procured in this way,
it is not absolutely pure, and, for chemical purposes, it should
be procured by heating the oxide with an equal weight of
cream of tartar.
Properties. A brittle metal, of a white color; fuses at
810°, and, on cooling, has a lamellated texture, and often
yields crystals; burns with great brilliancy when placed on
ignited charcoal, under a current of oxygen gas.
fonto
Compounds of Antimony.
Sesquioxide of Antimony (2Sb + 30. 153.2) is obtained
by subjecting antimony in a covered crucible to a white heat.
and then exposing it to the air; a white vapor arises, and
condenses in fine crystals of silver whiteness.
It is the only oxide which forms regular salts. It is the
base of emetic tartar, and the tartrate of antimony and po-
tassa. The test of antimony in solution is the hydrosulphuric
id, which yields an orange-colored precipitate.
Antimonious Acid (2Sb +40. 161.2) is generated when
the oxide is exposed to heat in open vessels. It is white
when cold, and yellowish when heated; very infusible and
fixed in the fire, by which it is distinguished from the oxide;
insoluble in water and in acids, after being heated to redness.
Antimonic Acid (2Sb + 50. 169.2) may be obtained as a
white hydrate, either by digesting the metal in strong nitric
acid, or by dissolving it in nitrohydrochloric acid, concen-
trating by heat to expel excess of acid, and throwing the
solution into water.
It is decomposed at a red heat, and converted into an
monious acid.
Sesquichloride of Antimony (2Sb + 3Cl. 235.46) is generated by the
spontaneous combustion of antimony in chlorine gas. It is a soft solid

Uranium.
265
called butter of antimony; easily fused, and deliquesces when ex-
posed to the air.*
Sesquisulphuret of Antimony. 2Sb +3S. 177.5. This is the princi-
pal ore of the metal, and hence is generally employed in making the
preparations of antimony. It is of an earthy appearance, but is some-
times found in acicular crystals, of a red-gray color and metallic lustre ;
sp. gr. 4.62. It may be formed artificially by fusing together antimony
and sulphur.
O.cysulphuret of Antimony is composed of 2 equiv. of 2 Sb +3S
and 1 equiv. of 2SbO3 =508.2. This occurs native - the red antimony !
of mineralogists. Glass, liver, and crocus of antimony are of a similar
nature.
Kermes Mineral is formed by boiling the sesquisulphuret with a
solution of potassa or soda. On neutralizing the cold solution, a simi-
lar substance, the golden sulphuret, is precipitated.t
Alloys. Printers' types are formed of 3 parts of lead, 1
of antimony, and a little copper.
Pewter is an alloy of 12 parts of tin, 1 of antimony, with
a small addition of copper. The white metal for teapots is
an alloy of 100 parts of tin, 8 of antimony, 2 of bismuth, and
2 of copper.
URANIUM. Symb. U. Equiy. 217. Sp. gr. 9.
Uranium was discovered by Klaproth, in 1789. It derives
its name from the planet discovered the same year, (Uranus.)
It exists in pitch blende, and is obtained from it by heating
the ore to redness, and digesting its powder in pure nitric
acid, diluted with 3 or 4 parts of water. Its properties are
not well known.
Protoxide of Uranium (U+0. 225) is obtained by de-
composing the nitrate of the sesquioxide by heat. It is of a
dark green color, very infusible, and readily oxidized by
nitric acid; used in the arts to give a black color to porce-
lain.
* Bichloride of antimony ; 2Sb + 4Cl. 270.88. Perchloride of anti-
mony; 2Sb + 5Cl. 306.3. Oxychloride of antimony; 2 equiv. of 2Sb +
3C1. and 9 equiv. of SbOP=1849.72. Bromide of antimony, composi-
tion unknown.
+ Bisulphuret of antimony; 2Sb +48. 193.6. Persulphuret of anti-
mony; 2Sb +5S. 209.7,
23

266
- Bismuth.
Metals.
Cerium
Sesquioxide of Uranium (20 + 30. 458) is of a yellow
color, and combines with acids and alkaline bases.
The Protochloride of Uranium, (U + Cl. 252.42;) the Sesquichloride
of Uranium, (20 +371. 540.26,) and the Sulphuret of Uranium, are un-
important compounds. (See Turner, page 380.)
CERIUM.* Symb. Ce. Equiv. 46.
Cerium was obtained, by Hisinger and Berzelius, from a
mineral called cerite. It exists also in the mineral called
allanite, as an oxide, which is very difficult to be reduced to
the metallic state. Vauquelin obtained a small globule, not
larger than a pin's head, which was not acted upon by any
of the simple acids, and but slowly dissolved by the nitro-
hydrochloric.
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Compounds of Cerium.
Protoxide of Cerium (Ce+0. Eq. 54) is a white powder,
insoluble in water. The salts, which are soluble, have an
acid re-action.
Sesquioxide of Cerium (2Ce +30. 116) is obtained from cerite, and is
a fawn-red substance, soluble in several of the acids.
Protochloride of Cerium. Ce + Cior CeCl. 46 +35.42=81.42.
Sesquichloride of Cerium. 2Ce + 3Cl or Ce’CH.92+106.26=198.26.
Protosulphuret of Cerium. Ce+S or CeS. 62.1. - (See Turner's
Chemistry, p. 381.)
BISMUTH. Symb. Bi. Equiv. 71. Sp. gr. 9.822.
Native Bismuth occurs in crystals, octohedra, or cubes,
containing arsenic and cobalt. It is also found combined
with sulphur and oxygen, from which it is obtained by the
aid of heat and charcoal.
Properties. It is a brittle solid, generally composed of
broad plates of a reddish-white color, very fusible; melts at
476° Fahr., and forms very fine crystals by slow cooling.
Exp. For this purpose, fuse a quantity of it in a crucible, and let it
cool until a crust is formed; break the crust and pour out the fluid be-
* So called from the planet Ceres, discovered about the same period,

Titanium.
267
neath; the inner surface will be lined with beautiful crystals. Under
the compound blowpipe it burns with much brilliancy, producing yellow
fumes of protoxide.
Protoxide of Bismuth (Bi +0. 79. Sp. gr. 8.211) may
be formed as above. It forms salts, most of which are white;
sublimes at a high temperature; fuses at a full red heat into
a brown liquid. If the nitrate of the protoxide be thrown
into water, a white precipitate is thrown down, formerly
called magistery of bismuth, and pearl white, which is some-
times used as a paint, for improving the complexion.
Sesquioxide of Bismuth (2Bi +30. 166) is formed by fusing potassa
with the protoxide of bismuth. It is a brown, heavy powder, little dis-
posed to unite with acids, or alkalies.
Chloride of Bismuth (Bi + CI. 106.42) is formed by the spontaneous
combustion of bismuth in chlorine gas, formerly called butter of bisinuth.
It is of a grayish-white color, and granular texture.
Bromide of Bismuth. Bi + Br. 71+78.4=149.4.
Sulphuret of Bismuth (Bi + S. 87.1) is found native.
TITANIUM. Symb. Ti. Equiv. 24.3. Sp. gr. 5.3.
Titanium was first noticed by Mr. Gregor, of Cornwall.
Klaproth gave it the name of titanium, after the Titans of
ancient fable. But its properties were determined by Wol-
laston, in 1822, who found it in the slag of an iron-smelting
furnace in South Wales.
Properties. Its color is red, resembling copper. It exists
in small cubes, which are so hard as to scratch rock-crystal,
and very infusible. It generally contains traces of iron.
The
pure metal is obtained by heating the chloride with am-
monia in a glass tube, when it appears in the form of a deep
blue colored powder, which is apt to take fire, if exposed to
the air when warm.
Compounds of Titanium.
Oxide of Titanium (Ti +0. 32.3) is obtained by exposing titanic acid
to a strong heat in a black-lead crucible. It is of a purple color.
Titanic Acid, (Ti + 20. 40.3,) also called peroxide of titanium, exists
in the minerals anatase and rutile, from which the acid is obtained by
the aid of heat and hydrosulphuric acid gas.*
* For processes, see Turner's Elements.

268
Tellurium.
Metals.
Properties. Titanic acid is of a white color; very infusi-
ble, and when once ignited, insoluble in acids, except in the
hydrochloric. It is a feeble acid, resembling the silicic. If
it is ignited with potassa, and dissolved in hydrochloric acid,
a solution of gall-nuts will produce an orange-red color, which
is very characteristic of titanic acid.
Bichloride of Titanium (Ti + 2Cl. 95.14) was discovered in 1824, by
Mr. George, of Leeds, by transmitting dry chlorine gas over titaniuni
at a low red heat.
Properties. A transparent, colorless liquid, which boils
at 212°. The density of its vapor is 6.615; combines with
water with explosive violence from the evolution of intense
heat; on exposure to the atmosphere, it emits dense white
fumes, of a pungent odor, similar to chlorine.
Bisulphuret of Titanium. Ti+2s. Eq. 24.3 + 32.2=
56.5.
TELLURIUM. Symb. Te. Equiv. 64.2. Sp.gr. 6.115.
Tellurium is a rare metal, found only in small quantities in
Transylvania and Connecticut. It was first noticed by Mül-
ler, in 1782, but its existence was more fully established in
1798, by Klaproth, who called it tellurium, from tellus, the
earth. It is found chiefly in combination with gold and
silver.
Properties. It is a brittle metal, of a bright gray color;
very infusible and volatile. Heated in the air, it burns with
a sky-blue flame, edged with green; placed upon charcoal
before the blowpipe, it inflames with violence, and flies en-
tirely off in gray smoke, having a peculiarly nauseous smell.
Compounds of Tellurium.
Tellurous Acid, (Te +20. 80.2,) also called oxide of tel-
lurium, is generated by the action of nitric acid on tellurium.
It is a white, granular powder, resembling in many of its
properties the titanic, and several other feeble acids. Its
aqueous solution reddens litmus paper.
The other compounds are the Telluric Acid, (Te +30. 88.2;) Chlo-
ride of Tellurium, (Te + Cl. 99.62 ;) Bichloride, (Te + 2C1. 135.04;)
Bisulphuret, (Te + 2S. 96.4;) Persulphuret and Hydrotelluric Acid,
(Te+H. 65.2.)

Copper.
269
DICE
COPPER. Symb. Cu. Equiv. 31.6. Sp. gr. 8.895.
Copper, from cuprum, a name derived from the island
Cyprus, has been known from the remotest ages.
Natural History. It is found native, and in combination
with other substances, especially with sulphur. The copper
of commerce is chiefly obtained from the native sulphurets.
It exists in great abundance in Cornwall, and other parts of
Europe, in Liberia, and in America.
Schoolcraft found, a mass of native copper about thirty
miles from Lake Superior, which weighs, by estimation,
2000 lbs.
Process. It may be obtained perfectly pure, by dissolving
the copper of commerce in hydrochloric acid, diluting the
solution, and immersing in it a clean plate of iron, upon
which the copper will be precipitated.
Properties. Copper is distinguished from all other metals,
except titanium, by its red color. It is very ductile and
malleable; melts at 1996° Fahr.; burns before the com-
pound blowpipe with a beautiful green flame, and if a fused
globule be thrown into a glass jar, two feet high, filled with
water, it will pass in full ignition to the bottom, and remain
some time at a red heat.
Uses. Copper is one of the most useful metals, being em-
ployed extensively in most of the arts of life.
Compounds of Copper.
Red, or Dioxide of Copper (2Cu +0. 71.2) is found
native in octohedral crystals.
Process. It may be prepared artificially, by heating, in a
covered crucible, a mixture of 31.6 parts of copper-filings
with 39.6 of the black oxide.
Properties. It resembles copper in color; sp. gr. 6.093;
soluble in ammonia, and the solution is colorless, but it
absorbs oxygen on exposure to the air, which produces a
blue color, owing to the formation of the black oxide.
23 *

270
Metals. - Alloys of Copper.
Black, or Protoxide of Copper. Cu +0. 39.6. This is the copper-
black of mineralogists, and is formed by the spontaneous oxidation of
other ores of copper.
Properties. It varies from a dark brown to a bluish-black
color, according to the mode of formation; combines with
most of the acids, and its salts have a green or blue tint. It
forms with ammonia a deep blue solution, which distinguishes
it from all other substances. The salts of the protoxide of
copper are mostly distinguished by their color. Metallic
copper is separated from the salts by a rod of iron or zinc.
Binoxide of Copper. Cu +20. 31.6+16=47.6.
Dichloride of Copper (2Cu + Cl. 98.62) is formed by the spontane-
ous combustion of copper-filings in chlorine gas. It is of various colors,
white, yellow, and dark brown, according to the mode of preparation;
soluble in hydrochloric acid, but not in water.
Chloride of Copper; Cu + Cl. 67.02. Diniodide of Copper; 2Cu +
I. 63.2 + 126.3=189.5. Sulphuret of Copper (Cu+$. 47.7) is a
constituent of copper pyrites, in which it is combined with protosul-
phuret of iron. Triphosphuret of Copper ; 3Cu + P. 110.5. Subse-
quiphosphuret ; 3Cu + 2. 126.2. Cyanuret of Copper; Cu + Cy.
57.99. Disulphocyanuret of Copper ; Cu + CyS?. 63.2+(26.39+
32. 2) =121.79. — (See Turner’s Elements, p. 389.).
Tests. The best mode of detecting copper in mixed liquids is the
hydrosulphuric acid. The sulphuret, after being collected, and heated
to redness in order to char organic matter, should be placed on a piece
of porcelain, and be digested in a few drops of nitric acid ; sulphate of
the protoxide of copper is formed, which, when evaporated to dryness,
strikes the characteristic blue tint on the addition of ammonia. – T.
Alloys. The alloys of copper are very important and use-
ful substances.
Brass is an alloy of copper and zinc. The best brass
consists of four parts of copper to one of zinc.
• Tutenag
contains in addition a little iron. Tombac, Dutch Gold, Si-
milor, Prince Rupert's Metal, and Pinchbeck, contain more
copper than brass. Bell-metal and Bronze are alloys of cop-
per and tin. The best proportion for bell-metal is 3 parts
of copper to l of tin; for bronze, 8 to 12 of tin to 100 of
copper. In these alloys, according to Dalton, the elements
combine in definite proportions.
Poisonous Properties of Copper. Copper vessels used for
culinary purposes should be coated with tin, as the oxide is
poisonous. This is done by making the surface of the copper
bright, rubbing over a little sal-ammoniac to prevent oxidation,
and then heating the vessel and rubbing it with rosin and tin.

Lead.
271
LEAD. Symb. Pb. Equiv. 103.6. Sp. gr. 11.352.
Lead was well known to the ancients. It is rarely found
native, but its ores are abundant, the most important of which
is the sulphuret or galena, from which the pure metal is
chiefly obtained* Berzelius obtained the metal perfectly
pure by heating the pure nitrate of lead, mixed with charcoal,
in a Hessian crucible.
Properties. The properties of lead are generally well
known. It is of a bluish-white color, soft, malleable, and
ductile; fuses at 612°, and by slow cooling, crystallizes in
octohedra. The proper solvent of lead is nitric acid.
Compounds of Lead.
Protoxide of Lead (Pb+0. 111.6. Sp. gr. 9.4214) is
prepared by heating the metal to a high temperature, and col-
lecting the gray film which forms on the surface. This is
exposed to heat in open vessels, until it acquires a uniform
yellow color, and constitutes the massicot, and when partially
fused, the litharge of commerce. This is always mixed with
the red oxide; it is obtained perfectly pure by adding ammo-
nia in excess to the nitrate in solution, washing the precipi-
tate in cold water, and, when dry, heating it to redness for an
hour in a platinum crucible.
Properties. Its color is red when hot, but acquires a rich
lemon-yellow when cold; fuses at a bright red heat, and, after
fusion, has a highly-foliated texture; insoluble in water; unites
with acids, and forms the base for all the salts of lead.
It is precipitated from its solutions by pure alkalies as a
* Process. The ore, in the state of coarse powder, is heated in a
reverberatory furnace, when part of it is oxidized, yielding sulphate of
protoxide of lead, sulphuric acid which is evolved, and free oxide of
leadThese oxidized portions then re-act on sulphuret of lead, by the
re-action of 2 equivalents of oxide of lead, and 1 of the sulphuret';
3 equivalents of oxide of lead and 1 of sulphuric acid result,
while 1 equivalent of the sulphuret and 1 of the sulphate mutually
decompose each other, giving rise to 2 equivalents of sulphurous acid,
and 2 of metallic lead. The lead of commerce commonly contains
silver, iron, and copper. -T.

272
Lead
Metals.
white hydrate, which is re-dissolved by potassa in excess, as
a white carbonate, which is the well-known pigment white
lead, by alkaline carbonates; as a white sulphate, by soluble
sulphates; as a dark brown sulphuret by hydrosulphuric acid;
and as a yellow iodide of lead, by hydriodic acid, or iodide
of potassium. — T.
Metallic Lead is separated from the salts of the protoxide
by iron or zinc.
Exp. In a solution of 1 part of acetate of lead in 24 parts of water,
contained in a glass bottle, suspend a piece of zinc by a thread. The
lead will be deposited upon the zinc in a form resembling a tree - a
peculiar appearance, called arbor Saturni.
Uses. Protoxide of lead enters into the composition of
flint-glass, and is employed for glazing earthen-ware and por-
celain.
Peroxide of Lead (Pb+ 20. 119.6) is formed by the action of nitric
acid upon the red oxide, or minium of commerce. It is of a puce color,
insoluble in water, and resolved by strong oxygen acids into a salt of
the protoxide and oxygen gas.
Red Oxide of Lead (3 Pb + 40. 342.8) is prepared by
heating lead in the air nearly to the point of fusion, by which
it is oxidized. It is then exposed to a temperature of 600°
or 700°, while a current of air passes across its surface. It
slowly absorbs oxygen, and is converted into the minium of
commerce. It is employed as a pigment, and in the manu-
facture of flint-glass, but does not unite with acids and form
salts.
Chloride of Lead (Pb+ Cl. 139.02) is obtained by adding hydro-
chloric acid to a solution of acetate or nitrate of lead. It is sometimes
called horn lead; dissolved in hot water, it appears, on cooling, in
small, acicular, anhydrous crystals, of a white color.
Iodide of Lead; Pb +1. 229.9. Bromide of Lead; Pb + Br. 182.
Fluoride of Lead; Pb + F. 122.28. Sulphuret of Lead ; Pb+S. 119.7.
Phosphuret of Lead and Carburet of Lead, composition uncertain. Cy-
anuret of Lead ; Pb + Cy. 129.99. — (See Turner's Elements, p. 393.)
The salts of lead are generally poisonous, of which the
carbonate is the most virulent.
Alloys of Lead. Common pewter is an alloy of 20 parts
of lead and 80 of tin. Fine solder consists of 1 part of lead
and 2 of tin, and is employed for tinning copper. Coarse
solder contains one fourth of tin, and is used by plumbers.
Pot metal is an alloy of lead and copper.

Mercury.
273
ARE REDUCED
Secr. 3. METALS, THE OXIDES OF WHICH
TO THE METALLIC STATE BY A RED HEAT.
MERCURY, or QUICKSILVER.
Symb. Hg. Equiv. 202. Sp. gr. 13.568.
Mercury was well known to the ancients. Its principal
ore is the sulphuret or native cinnabar, from which it is
separated by distillation with quick lime, or iron-filings.
Properties. Mercury is the only metal which retains its
liquid form at common temperatures. It is of a tin-white
color, and strong metallic lustre; boils at 662° Fahr., and
congeals at 40° below zero, in which state it is malleable,
and has an increased specific gravity 15.612. It is not tar-
nished by exposure to cold, moist air, unless it contain other
metals. It is sometimes adulterated with an alloy of lead and
bismuth, which renders it less fluid and volatile, leaving a
residuum when boiled in a silver spoon.
Mercury is not acted upon by any of the acids except the
sulphuric and nitric.
It is used for collecting those gases which are absorbed by
water; also for barometers, thermometers, and for forming
connections in voltaic circles.
Compounds of Mercury.
Protoxide of Mercury (Hg +0. 210) is prepared by
mixing calomel with pure potassa in excess in mortar, and
stirring it briskly to effect a rapid decomposition. The pro-
toxide is then washed in cold water, and left to dry in a dark
place.
Properties. It is a black powder, insoluble in water, com-
bining with acids, and bur feebly with alkalies. The alkalies
precipitate it from the solution of its salts, as a black protox-
ide. The best test of its presence is the hydrosulphuric
acid, by which it is thrown down as a black protosulphuret.

274
Metals. – Mercury.
Binoxide of Mercury (Hg+20. 218) is commonly
known by the name of red precipitate.*
Process. Peroxide of mercury may be prepared by dissolving mer-
cury in nitric acid, and exposing the nitrate thus formed to a tempera-
ture just sufficient to expel the whole of the nitric acid. It may also be
formed by exposing mercury in a matrass, with a long tube, to the
agency of heat and air, for the space of three or four weeks.
Properties. It exists in shining, crystalline scales, nearly
black when hot, and red when cold; slightly soluble in
water. The solution has an acrid, metallic taste, and is poi-
sonous.
This oxide is separated from all acids by the carbonated
fixed alkalies, and is reduced to the metallic state by copper.
Protochloride of Mercury (Hg + Cl. 237.42) is common-
ly called calomel, and was first mentioned in the seventeenth
century, by Crollius.
Process. It
may be obtained by bringing chlorine gas in contact
with mercury, but it is more commonly prepared by sublimation. This
is done by mixing 1 equiv. of the bichloride with 1 equiv. of mercury,
until the metallic globules entirely disappear, and then subliming.
To purify it from corrosive sublimate, which is always mixed with it,
when first prepared, it must be reduced to powder, and well washed,
when it will be fitted for chemical or medical purposes. The proto-
chloride is also found native, and called horn quicksilver.
Properties. When obtained by this process, calomel ex-
ists in semi-transparent, crystalline cakes, of a yellow color
when warm, but white when cold; sublimes a little below
a red heat, and a part of it is resolved into mercury, and
the bichloride. It is insoluble in water, and is decomposed
by the pure alkalies.
Used extensively for medical purposes; acts powerfully
upon the glandular system.
Bichloride of Mercury (Hg+201. 272.84) is formed by heating mer-
cury in chlorine gas. During the process, the metal burns with a pale
red flame. It is prepared for medical purposes by subliming a mixture
of bisulphate of the peroxide of mercury with chloride of sodium, or
sea-salt.
Properties. Bichloride of mercury, commonly called cor-
rosive sublimate, is a most virulent poison. It is white, semi-
transparent, and crystalline in its texture; taste acrid and
nauseous; more soluble in alcohol than in water ; sp. gr. 5.2.
It sublimes in the form of a dense, white vapor, when heated,
* This is the hydrargyri oxidum rubrum of the pharmacopolist.

Compounds of Mercury.
275
powerfully affecting the mouth and nose ; soluble in hydro-
chloric, nitric, and sulphuric acids, and is decomposed by
the alkalies, and several of the metals. *
Tests. Place a drop of the suspected liquid on polished gold, and
touch the moistened surface with the point of a penknife; the part
touched will instantly become white, owing to the formation of an
amalgam of gold.
Some animal and vegetable substances convert the bichloride into
calomel; the best is albumen, made by mixing the white of an egg in
water; hence the white of an egg is an antidote to poisoning by cor-
rosive sublimate.
Protosulphuret of Mercury. Hg + S. 218.1.
Bisulphuret of Mercury (Hg + 2S. 234.2) may be formed by fusing
sulphur with six times its weight of mercury, and subliming in close
vessels.
Properties. When thus obtained, it has a red color, and
is known by the name of factitious cinnabar. When reduced
to powder, its tint is greatly improved, and constitutes the
well known pigment, vermilion. The native cinnabar is a
bisulphuret, and is the principal ore of mercury.
Ethiops Mineral is a mixture of sulphur and the bisul-
phuret, and may be formed by triturating equal parts of sul-
phur and mercury, until the globules of mercury disappear.
Bicyanuret of Mercury (Hg + 2Cy. 228.39) is prepared by boiling a
solution of Prussian blue with an equal weight of peroxide of mercury
in powder, until the blue color of the pigment entirely disappears.
The solution, on evaporation, yields quadrangular prisms of bicyanuret
of mercury. It is colorless, inodorous, and highly poisonous.
Amalgams. Mercury combines with most of the metals,
and forms a class of compounds called amalgams.
amalgam of one part of potassium and seventy of mercury
is hard and brittle; on adding mercury to the liquid alloy
of potassium and sodium, solidification and combustion
ensue. Two parts of mercury, one of bismuth, and one of
lead form a liquid amalgam, from which cubic crystals of
bismuth are slowly formed. The combination of mercury
with those metals which are not easily oxidized, enables
them to combine with oxygen; hence gold and silver, in
combination with mercury, are easily oxidized by heat and
air. With tin, it forms an amalgam for coating mirrors.
* Pro iodide of mercury; Hg+I. 328.3. Sesquiodide; Hg?13. 782.9.
Binzodide ; HgIP 454.6. Protobromide ; HgBr. 280.4. Bibromide of
mercury; Hg + 2Br. 358.8. Iodureted bichloride of mercury; 20HgCl2
+ I. 5583.1. Todobichloride of mercury; 40HgCl² + HgI?. 11368.2.

276
Silver.
Metals.
SILVER.* Symb. Ag. Equiv. 108. Sp. gr.
10.51.
Silver has been known from the earliest ages. It is found
native, and in combination with other substances. The
native silver occurs in octohedral or cubic crystals, seldom
perfectly pure; it is generally found in primitive formations,
Peru and Mexico contain the richest mines of native silver
which are known.
Preparation. Pure silver may be obtained from standard
silver, by dissolving it in nitric acid and introducing a clean
piece of copper. The metal will be precipitated upon the
copper; this is then to be washed in pure water, and di-
gested in ammonia to remove the copper. A better pro-
cess is to decompose the chloride of silver by carbonate of
potassa.
Silver is often obtained from the argentiferous sulphuret
of lead, by a process called cupellation. Some of the ores
are also reduced by amalgamation with mercury, and the
mercury expelled by heat.
Properties. Silver has the clearest white color of all the
metals. Its lustre, when polished, is surpassed only by pol-
ished steel; so malleable that it may be extended into leaves
less than a ten thousandth of an inch in thickness, and so
ductile that it may be drawn into wire finer than the human
hair. It fuses at 1873° Fahr., and appears extremely brilliant
* Lat. argentum.
+ This process is conducted in the following manner :- -The lead is
kept at a red heat, in a flat furnace, with a draught of air playing on
its surface. The lead is thus rapidly oxidized, while the silver is un-
affected. As fast as the oxide is formed, it melts and runs off through
an aperture in the sides of the furnace; so that, in the end, the lead is
all removed. The button of silver which remains is then melted in a
small furnace resting on a porous earthen dish made with bone ashes,
called a cupel, the porosity of which is so great that it absorbs any por,
tions of litharge which may remain on the silver. The cupel is prepared
by driving pounded bone ashes into a small brass mould by means of
a pestle. It should then be removed and dried on paper. The cupel
is then placed in a muffle, which is made of clay, arched above, and
closed on all sides except the front. The whole is then placed in a
cupelling furnace, which has an opening in one of its sides to receive
the mufile. This is a very important process, and much used by re-
finers and assayers, in the analysis of alloyed silver,

Compounds of Silver
277
It is not oxidized by air or moisture, but is tarnished by
sulphurous vapors, which act slowly upon it; it burns with
a fine green light, and throws off fumes of oxide when ex-
posed to the action of voltaic currents. None of the pure
acids act upon it but the sulphuric and nitric; the latter is
its proper solvent, with which it forms the nitrate which,
after fusion, is the lunar caustic.
Use. Silver is one of the precious metals, and is used as
a coin, and for various purposes of art.
Oxide of Silver (Ag +0 or Ag0. 116) is best formed by
mixing a solution of pure baryta with the nitrate dissolved
in water; it is of a brown color, insoluble in water, and
easily reduced by a red heat.
Fulminating Silver is a compound of oxide of silver and ammonia.
Process. Precipitate nitrate of silver by lime water; and, after wash-
ing and drying the precipitate, put it into a vessel of pure ammonia
for twelve hours; a black powder will be thrown down, which, when
carefully dried, explodes violently by the gentlest heat, or by slight
friction. Great care should be taken in its preparation, and it should
be preserved in small quantities in paper boxes.
By heating the solution, a more dangerous compound is formed.
A compound similar to the above, but less dangerous, is formed by
dissolving silver in nitric acid, and adding to the solution successive
portions of alcohol. This substance is used in the preparation of small
balls called torpedoes.
Chloride of Silver (Ag + Cl. 143.42) is the horn silver
of mineralogists.
Process. It is formed by mixing liydrochloric acid with
a solution of oxide of silver. When first precipitated, it is
white, but becomes almost black by exposure to the solar
rays; insoluble in water, but very soluble in ammonia, by
which it is usually distinguished from other chlorides. It is
often employed in analysis as the means of ascertaining the
amount of chlorine present in various compounds.
Iodide of Silver (Ag +I. 234.3) is a greenish-yellow substance.
Sulphuret of Silver. Ag + S. 124.1. This is the silver glance of
mineralogists. Silver has a strong affinity for sulphur. On passing a
current of hydrosulphuric acid gas through a solution of lunar caustic,
a dark brown precipitate subsides, which is a sulphuret of silver.
Cyanuret of Silver (Ag + Cy. 134.39) is a white, curdy substance.
Alloys of Silver Silver is alloyed with most of the metals.
With steel, it forms an alloy used in cutlery ; with copper,
24
Den

278
Metals. - Gold
it forms the silver plate and coin,* which is the most useful
of its alloys; with mercury, it forms an amalgam, sometimes
employed for plating copper.
Thermometer scales and
clock dials are usually silvered by an alloy of chloride of
silver, chalk, and pearlashes.
Hata
GOLD. Symb. Au. Equiv. 199.2. Sp. gr. 19.257.
Gold was known to the ancients, and has always been
highly valued, as the most precious of the metals.
Natural History. Gold occurs native, alloyed with a little
silver or copper. It crystallizes in cubes and octohedra; it
is found in large quantities in alluvial soils, and in the beds
of certain rivers, especially on the western coasts of Africa
and Peru, in Brazil and Mexico, in Europe and the United
States. I
Process. Gold is generally separated by amalgamation
and cupellation, but the best mode is to fuse the gold with
silver, so that the latter shall constitute of the mass ; nitric
acid will dissolve the silver, and leave the gold. This process
is called quartation.
To obtain gold perfectly pure, dissolve standard gold in
nitrohydrochloric acid; evaporate the solution to dryness,
re-dissolve it in distilled water, filter, and add to the solu-
tion sulphate of the protoxide of iron; a black powder falls,
which, when washed in dilute hydrochloric acid and distilled
water, yields, on fusion, a button of pure gold. o
Properties. Gold is distinguished from all other metals
by its yellow color; it exceeds all others in ductility and
malleability; it may be beaten into leaves not exceeding
292000 of an inch in thickness; it is very flexible and soft ;
fuses at 2016° Daniell, and appears of a brilliant green color.
* The standard silver of Great Britain contains 11% of
pure silver,
and 18 of copper; that of the United States, 1 part by weight of
copper, and 9 of silver. The dollar weighs 4121 grs., and the dime
414 grs.
+ Lat. aurum.
# The gold from all the mines in the United States, in 1836, amounted
to 467,000 dollars, 148,100 dollars of which were from North Carolina.

Compounds of Gold.
279
It is not easily oxidized, even in the state of fusion; but, on
subjecting a fine wire to an electric discharge, a purple
powder is produced, which is probably an oxide; it is readily
dissolved by nitrohydrochloric acid.
Protoxide of Gold (Au +0. 207.3) is formed by adding
a cold solution of potassa to the protochloride; a precipitate
falls, of a green color, which changes spontaneously into me-
tallic gold and teroxide.
Binoxide of Gold (Au+ 20. 215.2) is formed by the combustion of
gold.
Teroxide of Gold (Au +30. 223.2) is the only well-
known oxide of gold.
Process. Dissolve 1 part of gold in the usual way, render it quite
neutral by evaporation, and re-dissolve in 12 parts of water; to
of ,
twice its weight of water, and digest at about 170°; carbonic acid
gradually escapes, and the hydrated teroxide, of a brownish-red
color, subsides. After being well washed, it is dissolved in colorless
nitric acid of sp. gr. 1.4, and the solution decomposed by admixture
with water.
The hydrated teroxide is thus obtained quite pure, and is rendered
anhydrous by a temperature of 212° Fahr. – T.
Properties. The hydrate is yellow, but the anhydrous
teroxide is nearly black, insoluble in water, and completely
decomposed by solar light, or a red heat. With alkalies it
acts the part of a weak acid, and was called by Pelletier
auric acid. When the teroxide is kept in ammonia for the
space of a day, a detonating compound of a deep olive color
is formed. It is composed of 1 equiv. of gold, 2 of nitro-
gen, 6 of hydrogen, and 3 of oxygen.
The Fulminating Gold is a similar compound.
Process. Add pure liquid ammonia to the dilute chloride.
The precipitate which is formed will be re-dissolved if too
much alkali is used; filter the liquid, and wash the sediment
several times in warm water; dry it by exposure to the air,
and preserve it in small paper boxes.
Exp. Hold, on the point of a knife, a small portion of the powder
over the flame of a spirit lamp, and it will detonate violently.
Exp. Place two or three grains on a sheet of copper, and explode it;
it will force a hole through the copper; a spark from the electrical
machine, or from a fiint, will not affect it; but the slightest friction will
cause it to explode; hence the danger of forming it, or of putting it up
in large quantities.

280
Metals. - Gold.
Protochloride of Gold. Au + Cl. 234.62.
Terchloride of Gold (Au +3Cl. 305.46) is obtained by
concentrating a solution of gold, in ruby-red crystals. This
is the compound from which pure gold is obtained, and also
most of the preparations of gold.
Exp. When a strong aqueous solution of the terchloride is shaken
with an equal volume of ether, two fluids result, the lighter of which
is an ethereal solution of gold.
Exp. When a piece of charcoal is immersed in the aqueous solution,
and exposed to the solar rays, it is covered with metallic gold.
Exp. Ribbons are gilded by moistening them in this
solution, and
exposing them to a current of hydrogen gas.
Exp. Add the protochloride of tin to a dilute aqueous solution of
gold, and a purple-colored precipitate, the purple of Cassius, is thrown
down. On fusing this powder with sand and borax, it forms a purple
enamel, which is used for giving a pink color to porcelain.*
Alloys of Gold. Gold forms alloys with most of the
metals. With tin it forms a whitish brittle alloy. On
this account the old chemists called tin diabolus metal-
lorum.
With lead, it forms a very brittle alloy. Even the fumes
of lead destroy the ductility of gold. With copper, it forms
the alloy used for standard gold; which is perfectly malleable
and ductile, harder than pure gold, and resists wear better
than any other alloy, except that of silver; sp. gr. 17.157.
The standard gold of the United States is an alloy of 1 part
of an alloy of copper and silver, and 9 parts of pure gold,
The British “sovereign.” is 22 carats fine, that is, 22 parts
of pure gold, and 2 of copper and silver.
Water-Gilding. Mercury and gold combine, and form an
amalgam much employed in gilding. It is applied to the
surface of silver, and the mercury driven off by heat.
Porcelain is gilded with gold powder, obtained by de-
composing the chloride of gold; applied with a pencil,
and burnished after exposure to the heat of a porcelain fur-
nace.
* Iodides of gold are formed by the action of iodide of potassium on
the terchloride of gold. Protiodide of gold ; Au +I. 325.5. Teriodide
of gold; Au + 31. 578.1. Tersulphuret of gold ; Au +3S. 247.5.
* Platinum.
281

20 volt PLATINUM. Symb. Pl. Equiv. 98.8. Sp. gr. 21.25.
Platinum is a very rare metal. It occurs native in Brazil,
Peru, and other countries of South America, in rounded or
flattened grains, mingled with other metals. It is found in
larger quantities in the Ural Mountains.sk
Properties. Platinum is the most dense of the metals, of
a white color, resembling silver. It is malleable, and so duc-
tile that it may be drawn into wire not exceeding Tour of
an inch in diameter. It is soft, and easily welded, conduct-
ing caloric with less facility than many other metals. It is
not attacked by any of the pure acids. Its solvent is chlo-
rine, or nitrohydrochloric acid. It is fused before the com-
pound blowpipe, and by voltaic electricity.
Bodenllow
Spongy Platinum* has the remarkable property of causing
oxygen and hydrogen gases to combine. Platinum foil will
produce similar effects. This is due to the attraction of the
gases for the platinum, and the repulsive power of the gases
themselves. They are thus so condensed upon the surface
as to bring the particles of the gases within the sphere of
each other's attraction.
Exp. Let a jet of hydrogen and oxygen upon a piece of spongy
platinum ; the gas will soon be inflamed.
Protoxide of Platinum (Pl + 0. 106.8) is prepared by digesting pro-
tochloride of papun in a solution of
Binoxide of (P1+ 20 or Plo?. 114.8) is prepared with diffi-
culty. According to Berzelius, it should be prepared by exactly de-
composing sulphate of binoxide of platinum with nitrate of baryta, and
adding pure soda to the filtered solution, so as to precipitate about
half of the oxide, which falls as a bulky hydrate, of a yellowish-brown
color.
Sesquioxide of
le of Platinum. 2P1+.30. 221.6. This oxide, of a gray
color, is prepared by heating fulminating platinum with nitrous acid.
Protochloride of Platinum (P1+ Cl. 134.22) is formed when the
bichloride is heated to 450°; half of its chloride is expelled, and the
protochloride, of a greenish-gray color, remains.
Bichloride of Platinum. P1+2C1. 169.64. This chloride is obtained
by evaporating the solution of platinum in nitrohydrochloric acid to
dryness, at a very gentle heat, when it remains as a red hydrate,
which becomes brown when its water is expelled. -- (See Turner,
page 408.)
* The sponge is prepared by adding ammonia to a solution of the
chloride, and heating the precipitate to drive off the ammonia and
chlorine.
24 *

282
- Platinum.
Metals.
Protiodide of Platinum. Pl+I. 225.1.
Biniodide of Platinum (P1 + 21. 351.4) is prepared by the action of
iodide of potassium on a rather dilute solution of bichloride of platinum.
It is a black powder, tasteless, inodorous, and insoluble in water.
Protosulphuret of Platinum (Pl+ s. 114.9) is prepared by heating
the ammoniacal chloride with half its weight of sulphur, until all the
sal-ammoniac and excess of sulphur are expelled.
Bisulphuret of Platinum (P1 + 2S. 131) is prepared by dropping a
solution of bichloride of platinum into a solution of sulphuret of po-
tassium.
Fulminating Platinum may be prepared by the action of
ammonia in excess on the sulphate of protoxide of platinum.
It explodes at 420° with a very loud report, but does not
explode by percussion.
Palladium, Rhodium, Osmium, and Iridium; are found
associated with platinum, but exist in small quantities.
Palladium (Pd. 53.3. Sp. gr. 11.5) was discovered by
Wollaston, and resembles platinum in color and lustre.
Rhodium (R. 52.2. Sp. gr. 11) was also discovered by
Wollaston. It is, when fused, of a white color, hard, and
extremely brittle. It attracts oxygen at a red heat, and a
mixture of peroxide and protoxide of rhodium is formed,
not acted upon by any of the acids, unless alloyed with other
metals.
Osmium (Os. 99.7. Sp. gr. 7 to 10) was discovered by
Tennant, in 1803. It is a black powder, which acquires
metallic lustre by friction. When heated in the open air, it
takes fire, and is readily oxidized and dissolved by fuming
nitric acid.
Osmic Acid (Os +40. 137.7) is formed by the oxidation
of osmium by acids, by combustion, or by fusion with nitre
or alkalies. Its vapor is very acrid, exciting cough, irritating
the eyes, and producing a copious flow of saliva.*
Iridium (Ir. 98.8. Sp. gr. 15.3629) was discovered by
Tennant, in 1803, and about the same time by Descotils, of
France. It is the most infusible of all metals, very brittle,
and when polished resembles platinum.t
* For other compounds of osmium, see Turner, 5th ed. p.
412.
| Iridium forms with oxygen four oxides, and with chlorine four
chlorides. (See Turner, 5th ed. p. 414.

Salts.
283
Latanium (La) is a metal recently discovered by Mosander.
It is prepared by calcining the nitrate of cerium, mixed with
nitrate of latanium.
CHAPTER III. to all
esposal botti di
Class III. Salts, OR SECONDARY COMPOUNDS.
Salts comprise a very extensive class of compounds, in
which acids combine with oxides, or with other compounds
having similar properties. The oxide which combines with
the acid, is termed a base, or salifiable base. I till
The substances hitherto described are either simple bodies,
or, with a few exceptions, compounds of two simple elements,
and are hence called binary compounds.
Salts, on the other hand, are composed of three or more
simple bodies, and are hence termed secondary compounds.
As salts, under favorable circumstances, readily assume regu-
lar crystalline forms, it seems proper, before proceeding to
describe them, to present the subject of crystallization in
general.
cosastolat
SECTION 1. CRYSTALLIZATION.
Most bodies, under favorable circumstances, may be made
to assume the form of a regular geometrical solid. The
process by which such a body is produced is called crystal-
lization; the solid is termed a crystal; and the science, the
object of which is to study the form of crystals, is crystal-
ography. The condition, by which this process is peculiarly
favored, is the slow and gradual change of a fluid into a
solid, the arrangement of the particles being at the same time
undisturbed by motion. This is exemplified during the slow
cooling of a fused mass of sulphur or bismuth, or the spon-

284
Salts. — Crystalography.
taneous evaporation of a saline solution. The numerous crys-
tals found in the mineral kingdom are due to the same cause.
The surfaces which limit the figure of crystals are called
planes or faces. The lines formed by the junction of two
planes are called edges, and the angle formed by two such
edges is a plane angle; a solid angle is the point formed by
the meeting of at least three planes. — T.
The forms of crystals are exceedingly diversified; they
may be divided into primary and secondary forms.
The primary forms are fifteen in number, and may be
distributed as follows:- 1. Prisms; 2. Octohedrons; 3. Do-
decahedrons.
I. The prisms have either a six-sided base, or a four-sided
base.
Patos da
(1.) Right Prisms. To
Fig. 89.
The bases are either right * or oblique,
and the prisms are named according to
their bases.
1. The Hexahedron, or Cube, (Fig.
89,) is a figure bounded by six
square
faces, and all the angles of its edges are
equal to 90 degrees. Este deton
2. The Right Square Prism (Fig. 90)
differs from the cube in having its four lat- Fig. 90.
eral planes c, C, C, c, rectangles, and the ter-
minal planes a a squares.
3. The Right Rectangular Prism (Fig.
90) differs from the former in having
terminal planes a, a, rectangular instead of
ET
square.
.
4. The Right Rhombic Fig. 91.
92.
Prism (Fig. 91) differs
from the two preceding
only in its terminal planes L.
a, b, being rhombs.id att
5. The Right Rhom-
boidal Prism (Fig. 92)
Biler
* The term right
è denotes that the lateral and terminal planes are
inclined to each other at a right angle. It is used in opposition to
C
Fig. 9
C

Crystalography
285
a
O
a
differs from the preceding form in the terminal planesco
being rhomboids.
6. The Regular Hexagonal Prism Fig. 93.
(Fig. 93) is bounded by six perpendicu-
lar or lateral planes, and two horizontal
or terminal planes, a, b, which are at right
angles to them.
o
(2.) Oblique Prisms.
7 The Rhombohedron
Fig. 94.
Fig. 95.
(Fig. 94) is bounded by
six rhombic faces, of the
same size and form.
8. The Oblique Rhombie
Prisms (Fig. 95) have the
terminal planes a,a, rhombs,
with the lateral planes forming oblique angles with them.
9. Oblique Rectangular Prism differs from the preceding
in having the terminal planes rectangles.
10. Oblique Rhomboidal Prism (Fig. Fig. 96.
96) differs from the two preceding forms
in the terminal planes a, a, being rhom-
boids.
II. The Octohedrons are also named from
their bases. The base of the octohedron
V
is a section passing through four angles.
11. Regular Octohe-
moto
dron (Fig. 97) has a Fig. 97.
Fig. 98.
square base, a a a a, and
B
b
is contained under eight
equilateral triangles —
hence all its plane an-
gles are equal to 60 de-
grees. This figure is a
regular solid of geom-
etry.
TOE STVO
12. Square Octohe-
3
titoso solo
dron (Fig. 93) has a
square base, a a a a, and is bounded by eight faces, which are
isosceles triangles. The base is always a square, the only
part of the figure which is constant.
oblique, which signifies that the sides are not perpendicular, but form
an oblique angle with the terminal planes. — T.
2
a
a
a
a
a

286
Crystalography.
Fig. 99.
13. Rectangular Octohedron (Fig.
99) has a rectangular base, a a a a, and
is bounded by eight isosceles triangles,
four of which are different from the other
four.
14. Rhombic Octohedron (Fig. 100)
has a rhombic base, a a a a, and is con-
tained under eight similar scalene trian-
gles, but all its dimensions are variable.
a
a
00
Б.
ايه
a
III. Dodecahedrons.
Fig. 100. Fig. 101.
15. There is but one pri-
mary dodecahedron, called
the rhombic dodecahedron,
(Fig. 101,) and is limited
by twelve similar rhombic
faces; the faces incline to do i//
each other at an angle of
6
120 degrees *
Petak odigravad
radiolo
Secondary Forms. sono
The secondary forms of crystals are very numerous,
amounting to millions. The forms of a single mineral calca-
reous spar have been found to be nearly a thousand; but each
of the secondary forms may be reduced to one or more of
the primary, by a process called cleavage. This process is
usually performed with a sharp instrument, by removing thin
laminæ from the faces, edges, or angles of the crystal. The
surfaces exposed by splitting or cleaving a crystal, are
termed the faces of cleavage, and the direction in which it
may be cleaved is called the direction of cleavage. Some
crystals are cleavable in one direction, and some in two, three,
four, or more directions.
Those which cleave in more than two directions may, by
the removal of layers parallel to the planes in their cleavage,
* The instrument used for measuring the angles, at which the planes
of crystals meet or incline to each other, are called goniometers. -
- See
Dana's Mineralogy, p. 32, New Haven. 1837.
Softshellders

Oxy-Salts.
287
be made to assume regular primary forms, whatever be their
figure previous to cleavage areas
pl. It was formerly supposed that each substance always had
the same primary form ; but the discovery was made by
Mitscherlich, in 1819, that identity of composition did not
always indicate identity of crystalline form.
To this new branch of science the term isomorphism
(from loos, equal, and pogon, form) is applied. *shion
The phenomena of crystallization are ascribed to cohesive
attraction, or, more properly, to crystalogenic attraction.
The crystallization of salts is most readily effected by dis-
solving them in water, and evaporating the solution.
Exp. Introduce into a large matrass a pound and a half of Glauber s
salts, (sulphate of soda,) with a pound of water, and boil the mixture
until all the salt is dissolved; cork it tight, as the heat is removed, and
let it cool. On taking out the stopper, the salt will suddenly crystal-
lize, and the whole will become nearly solid.
The water enters into the crystal in definite proportions,
and is called the water of crystallization. The quantity of
combined water is very variable in different crystals; such
salts, when heated, dissolve, if soluble, in their
own water
of crystallization, undergoing what is termed watery fusion :
some salts, when exposed to the air, lose their water of crys-
tallization, and crumble down into a fine powder; this is
termed efflorescence: others absorb water from the atmos-
phere, and are said to deliquesce.
Some salts enclose mechanically within their texture parti-
cles of water, by the expansion of which, when heated, they
burst with a crackling noise; this is called decrepitation.
The salts are divided into four orders: --
SA 19 Sisse
Wios sodio
SECTION 2.
ORDER I.-OXY-SALTS.
This order includes no compound the acid or base of
which does not contain oxygen. All the powerful alkaline
HELLO
candyby neando * See Turner, 5th ed. p. 429.
onda

288
Salts. - Sulphates.
bases, except ammonia, are protoxides of an electro-positive
metal. If M represent an equivalent of any metal, M+0
or MO is the strongest alkaline base, and generally the only
one which the metal is capable of forming; a single equiv.
of acid neutralizes MO, forming a neutral salt. Thus, if
an equiv. of sulphuric and nitric acids be represented by
SO3 and NO5, all the neutral sulphates and nitrates of the
protoxide will be indicated by MO+SO3 and MO+NO5;
hence it may be inferred, that, in each family of salts, there
is a constant ratio in the oxygen of the base and that of
the acid; that for sulphates is as 1 to 3, and the nitrates
as 1 to 5. If the base be a binoxide, the same relation
is preserved.
Salts sometimes combine with each other, forming double
salts; these are composed of two acids and one base, of two
bases and one acid, or of two different acids and two differ-
ent bases; these were formerly called triple salts:
Those salts which are formed by the same acid, combined
with different bases, have many properties in common, and
hence they are classed in the same family,
1. SULPHATES.
Many of the sulphates occur native; of which, those of
lime and baryta are the most abundant. They may all be
formed by the action of sulphuric acid on the metals, their
oxides, their carbonates, or by double decomposition. They
vary in solubility in water, and are all decomposed at a white
heat, and by carbonaceous matter with the aid of heat.
Sulphuric Acid, which is the acid of all the sulphates, is
readily detected by the chloride of barium — the acid having
a stronger affinity for baryta than for any other alkaline
base.
The sulphates are a very numerous family of salts. The
no
following are the most important:
Sulphate of Potassa, (KO+SO3. 87.25,) potassa sulphas,

Sulphates.
289
Potassa.
Soda.
was formerly called sal de duobus. It may be prepared by
neutralizing carbonate of potassa with sulphuric acid.
Properties. Taste saline and bitter. Its crystals belong
to the right prismatic system, and contain no water; soluble
in 16 times their weight of water at 60°, and in 5 of boiling
water.
Bisulphate of Potassa. KO + 2803. 127.35; with 1
equiv. of water, 136.35. This salt is prepared by heating
the sulphate, with half its weight of sulphuric acid, in a
platinum crucible.
Properties. It has a sour taste, and reddens litmus
paper; * is more soluble than the sulphates, and its crystals
belong to the same order. It is used for cleaning coin, and
other works in metal.
Sulphate of Soda (NaO + S03 71.4; in crystals, with 10
equiv. of water, 161.4) is well known as Glauber's salts.
It is found in the earth, and in the water of many springs.
It is easily formed by saturating SO3 with carbonate of
soda.
Properties. Taste bitter, cooling, and saline. Its crys-
tals belong to the right prismatic system; effloresces on
exposure to the air, and undergoes watery fusion when
heated. 12 parts of the salt require 100 of water at 32°
to dissolve them. Used in pharmacy, and in the manufac-
ture of glass.
Bisulphate of Soda. NaO + 2S03. 111.5; with 4 equin. of water,
147.5.
Sulphate of Litha (LO+S03. 58.1; in crystals, with 1 equiv. of
water, 67.1) has a saline taste, very soluble and fusible, and crystal-
lizes in flat prisms.
Sulphate of Ammonia (H’N+S03. 57.25; in crystals, with 1 equiv.
of water, 67.1) sometimes occurs native in volcanoes, and near cer-
tain small lakes in Tuscany. It may be prepared by neutralizing
sulphuric acid with carbonate of ammonia. It is contained in soot
from coal.
Properties. It crystallizes in long, flattened, six-sided
prisms, soluble in 2 parts of water at 60°, and in an equal
weight of boiling water; tffloresces in warm, dry air, losing
* Unglazed paper, moistened in an infusion of litmus, and dried. I
25

290
Sulphates.
Salts.
-
1 equiv. of water; yields its water of crystallization by
heat, fuses, and is decomposed, yielding nitrogen, water,
and sulphate of ammonia.
Uses. It is the source of the hydrochlorate of ammonia, which is
obtained by a mixture of common salt and sulphate of ammonia by
sublimation.
Bar
Sulphate of Baryta (BaO+SO3. 116.8. Sp. gr. 4.4)
occurs native in great abundance, and is known by the
name of heavy-spar.
Properties. Insoluble in water, and is precipitated by
adding sulphuric acid to any soluble salt of baryta. So
delicate is baryta as a test of SO3, that I part of sulphate
of soda in 400,000 of water is detected by it. It fuses at
a high temperature into an opaque, white enamel.
Uses. It is employed in the manufacture of jasper ware, and for a
paint under the name of permanent white.* (See Baryta, page 227.)
Sulphate of Strontia (Sr0+S03. 91.9) occurs native in
beautiful crystals in Sicily, and also on Strontian Island,
Lake Erie.
Properties. It has a blue tint, and is called celestine;
sometimes it is colorless and transparent; nearly insoluble,
requiring 4000 parts of cold, and 3840 of hot water to
dissolve it. Heated with charcoal, its acid is decomposed,
and sulphuret of strontium is formed.
Sulphate of Lime (CaO + SO3. 68.6; with 2 equiv. of
water, 86.6) occurs in nature in large quantities. Every
variety of gypsum is the sulphate combined with 2 equiv.
of water; such as plaster of Paris, selenite, — which is a
crystallized variety, - alabaster, a white, compact varie-
ty, used in statuary, --- and anhydrite, which contains no
water. The salt may be formed by mixing, in solution, a
salt of lime with any soluble sulphate.
Properties. Crystals of anhydrite belong to the right, and
of gypsum to the oblique prismatic systems. It is nearly
tasteless, soluble in 500 parts of cold, and 450 of boiling
* It is the best paint for marking phials and jars the laboratory
It may be prepared by mixing the powder with oil and lampblack.

Sulphates.
291
water; hence it is generally found in spring and river water,
and especially in those waters called hard. Baryta will de-
tect the sulphuric acid, and oxalic acid the lime. Heated to
212° in vacuo, it parts with 1 equiv. of water, and at 300°
the whole; in this state it is used as a cement. By mixing
it with a certain portion of water, it hardens rapidly, and be-
comes dry and solid; on this account it is much used for
taking impressions, for stereotype plates, and for casts, busts,
and a great variety of purposes in the arts. It is used in
agriculture as a mineral manure, and is highly useful to
most soils.
Sulphate of Magnesia (MgO + SOHO. 69.8; in crystals,
with 6 equiv. of water, = 123.8) was procured from the
springs of Epsom, England, and hence called Epsom salt.
It is found native, and constitutes the bitter salt and hair
salt of mineralogists. Sometimes it is found incrusting the
damp walls of cellars and new buildings. Many saline
springs contain it.
Process. But it is generally obtained from sea-water, and
exists in the bittern which is left after the crystallization of
common salt. It is obtained by decomposing the hydro-
chlorate of magnesia contained in it with SO3. It may also
be formed from the carbonate by adding sulphuric acid.
Properties. It has a saline, bitter, and nauseous taste.
Its crystals are small, quadrangular prisms,* slightly efflores-
cent in dry air, soluble in an equal weight of water at 60°,
and 3 of their weight of boiling water. They undergo watery
fusion when heated, and are partially decomposed at a white
heat.
Sulphate of Aluminu. 2A103 +503. 91.5; in crystals, with 9 equiv.
of water, 172.5
Tersulphate of Alumina. 2A103 + 3803. 171.7; in crystals, with 18
equiv. of water, 333.7.
The Hydrated Disulphate is called Aluminite.
Sulphate of Protoxide of Manganese. MnO+SO’HO. 84.8.
Sulphate of Protoxide of Iron. FeO +SOHO. 85.1; in
crystals, with 5 equiv. of water, eq. 130.1. This is known
* The larger crystals are generally right rhombic prisms.

292
Salts. - Sulphates.
by the name of green vitriol, or copperas. It is prepared on
a large scale for the arts, by exposing the native protosulphu-
ret of iron to air and moisture; the iron is converted into
an oxide, and the sulphur into SO3; they then combine and
form the sulphate. It may also be formed by the action of
SO3 on the iron.
Properties. Its taste is strongly styptic and inky. When
pure, it does not redden the vegetable blue colors. Its crys-
tals have a blue tint, and belong to the oblique prismatic
system ; soluble in 2 parts of cold, and in its weight of
boiling water. It is used in the manufacture of fuming sul-
phuric acid and in dyeing.
Tersulphate of the Sequioxide. Fe203 +3803. 200.3.
Disulphate of the Sequioxide. 2Fe203 + SO3. 200.1.
Sulphate of the Protoride of Zinc, (Zn0°+SOHO. 89.4;
with 6 equiv. of water=143.4, commonly called white vitriol,
is formed by the action of dilute sulphuric acid on zinc. It
is prepared in the arts by roasting the native sulphuret of
zinc.
Properties. It crystallizes, by spontaneous evaporation, in
transparent, flattened, four-sided prisms, referable to a right
rhombic prism, and isomorphous with Epsom salt. Taste
strongly styptic, and, although a neutral salt, reddens vegeta-
ble blue colors; soluble in 21 parts of cold, and a less quan-
tity of boiling water.
Use. A powerful emetic, and poisonous if given in large
doses.
Sulphate of Protoxide of Nickel (NiO+SOHO. 86.6)
crystallizes from its solution in pure water, in right rhombic
prisms, and, like most of the salts of nickel, is of a green
color.
Sulphate of Protoxide of Cobalt (CO + SOPHO. 86.6) is
formed by digesting dilute SO3 with oxide of cobalt. On
evaporation, it appears in the form of red crystals.
Tersulphate of the Sequioxide of Chromium. Cr2O3 +3
SO3. 200.3.

Sulphates.
293
Sulphates of the Oxide of Copper.
The Disulphate (2000+S03. 119.3) has not been ob-
tained in a separate state.
The Sulphate, or Blue Vitriol,* (CuO+SOHO. 88.7; in
crystals, with 4 equiv. of water, 124.7) is formed by roasting
the native sulphuret, or by dissolving the protoxide in dilute
sulphuric acid, and crystallizing by evaporation.
TE
Properties. The crystals are of a blue color, and yield 4
equiv. of water at 212°, and the whole at 430° Fahr., when
it becomes a white powder.
When ammonia is dropped into a solution of the sulphate,
it forms a dark blue solution, from which, when concentrated,
crystals are deposited by the addition of alcohol. This is the
ammoniaret of copper of the U. S. Phar. ad
Sulphate of the Oxides of Mercury.
22bog
The Sulphate of Protoxide (HgO + S03. 250.1) is formed
when 2 parts of mercury are heated with 3 of strong sul-
phuric acid, so as to produce effervescence. If a strong heat
is employed, the
Bisulphate (HgO2 + 2802. 298,2) results, both being an-
hydrous. When this bisulphate (the salt employed for
making corrosive sublimate) is thrown into hot water, a yel-
low salt, the
Subsulphate, (4HgO2 + 3803. 992.3,) called turpeth min-
eral, is generated.
Sulphate of Oxide of Silver (AgO+SO3. 156.1) is depos-
ated when sulphate of soda is mixed with nitrate of silver,
and also by boiling silver with its weight of sulphuric acid.
Properties. It is white, and easily fused; soluble in 80
times its weight of hot water, and deposits small, needle-
shaped crystals on cooling. It forms with ammonia a double
salt, consisting of 1 equiv. of oxide of silver, 1 of acid,
and 2 of ammonia. It crystallizes in rectangular prisms,
isomorphous with the double chromate and seleniate of oxide
of silver and ammonia.
* Great use is now made of this substance for exciting electricity in
galvanic batteries.
25 *

294
Salts. - Sulphates.
Nitrosulphuric Acid, consisting of 1 part of nitric dis-
solved in 10 of sulphuric acid, dissolves silver, but scarcely
acts upon copper, lead, or iron, unless diluted with water ;
hence its use in separating silver from old plated articles.
Double Sulphates.
Sulphate of Soda and Lime (NaOSO3 + CaOS03. 140) is the Glauber-
ite of mineralogists, and occurs in the salt-mines of New Castle.
Sulphate of Potassa and Magnesia (KOSO3 + MgOSO3) is formed
by mixing solutions of the two salts.
Sulphate of Potassa and Alumina. KOSO3 + A1203.3503
258.95, do. with 24 equiv. of water=474.95. This salt,
the common alum, is prepared by roasting and lixiviating cer-
tain clays, containing iron pyrites, and adding to the lyes a
quantity of sulphate of potassa. It is obtained in Italy from
alum-stone. Alum is also found in volcanic countries, pro-
duced by the action of sulphurous vapors on rocks containing
feldspar.
Properties. It has a sweetish, astringent taste; is soluble
in 5 parts of water at 60°, and crystallizes in octohedrons.
Ignited with charcoal, it forms Homberg's Pyrophorus.
Exp. Take 3 parts of lampblack, 4 of calcined alum, and 8 of pearl-
ashes; mix them thoroughly, and heat them in an iron tube to a bright
cherry-red, for one hour; on removal from the fire, the tube must be
carefully stopped. This substance, when exposed to the air and
breathed upon, ignites with slight explosions. The essential part is
probably sulphuret of potassium, in minute divisions.
lv in dve
Use. Alum is of great use in the arts, especially in dye-
ing and calico-printing, because of its attraction for coloring
matter.
Ammonia Alum has the same form, appearance, and taste.
Soda Alum is also similar, except that it contains 26 equiv.
of water.
dados
Iron Alum is formed by mixing sulphate of potassa with
tersulphate of sesquioxide of iron; it resembles common
alum in form, color, taste, and composition.
Chrome Alums. The tersulphate of sesquioxide of chro-
mium forms double salts, with the sulphate of potassa and
ammonia, very similar to the preceding.
idium
12

Sulphites - Nitrates.
295
Manganese Alum is formed by mixing a solution of ter-
sulphate of sesquioxide of manganese with sulphate of po-
tassa. These salts all crystallize in the octohedral system,
and are similar in composition, one oxide being substituted
for another, to form the different varieties
2. SULPHITES.
The salts of sulphurous acid have not hitherto been mi-
nutely examined; the sulphites of potassa, soda, and ammo-
nia, are made by neutralizing those alkalies with sulphurous
acid, and are soluble in water ; but most sulphites are spar-
ingly soluble, if at all; they are decomposed by the stronger
acids. — (See Turner, 5th edit. p. 443.)
3. NITRATES.
The nitrates may be prepared by the action of nitric acid
on metals, on the salifiable bases, or on carbonates. As
nitric acid forms soluble salts with all alkaline bases, the
acids of the nitrates cannot be precipitated by any re-
agent. — T.
Blog
The nitrates are all decomposed by a high temperature,
and by the agency of heat and combustible matter; hence
they are much employed as oxidizing agents. The process
of oxidation by nitre, is called deflagration, which is gener-
ally performed by mixing the inflammable body with an equal
weight of the nitrate, and projecting the mixture, in small
portions, into a red-hot crucible. All the neutral nitrates of
the fixed alkalies and alkaline earths, together with most of
the neutral nitrates of the common metals, are composed of
1 equiv. of nitric acid, and 1 of the protoxide; hence the
oxygen of the base is to that of the acid, as 1 to 5; the
general formula is MO+NO5.
Nitrate of Potassa (KO+ NO3. 101.3) is an abundant
natural product; it is obtained from the East Indies by
lixiviating certain soils; in Germany and in France, it is pro-
duced in what are termed nitre-beds.

296
-
Salts.
Nitrates.
The French process consists in lixiviating old plaster rub-
bish. Nitre also exudes from new walls. Some caverns in
Kentucky afford nitrate of lime, from which nitre is obtained
by adding carbonate of potassa ; it is also found under old
buildings, and is commonly called nitre and salt petre.
Properties. Colorless; has a saline and cooling taste;
soluble in its own weight of boiling water; crystallizes in
six-sided prisms without any water of crystallization; and
fuses at 616º.
Fulminating Powder is formed of 3 parts of nitre, 2 of dry
subcarbonate of potassa, and 1 of sulphur.
Exp: Heat a small quantity in the flame of a spirit lamp, and it will
explode with considerable violence.
Uses. Used in chemistry as an oxidizing agent, and in
the formation of nitric acid. In the East Indies, it is em-
ployed for cooling mixtures; one ounce of nitre to five of
water, reduces the temperature 15°. From its anti-septic
properties, it is employed for preserving animal substances.
1. In the arts, it is extensively employed in the manufacture
of gunpowder, which consists of nitre, sulphur, and charcoal.
In agriculture, it is used as a manure.
Nitrate of Soda, (NaO + NO5, 85.45,) called by the old
writers cubic nitre, occurs in the soils of India, and in
Peru; it is analogous, in chemical properties, to the prece-
ding; mixed with charcoal, it burns more slowly than nitre.
Nitrate of Ammonia (HPN + NO5. 71.3) is formed by
neutralizing dilute nitric acid by carbonate of ammonia, and
evaporating the solution. It is decomposed by heat, and
yields the exhilarating gas or protoxide of nitrogen.
Nitrate of Baryta (BaO + N05. 130.85) is easily pre-
pared by digesting the native carbonate in nitric acid,
diluted with 8 or 10 parts of water ; on evaporation, it
crystallizes in transparent, anhydrous octohedrons; soluble
in 12 parts of water at 60°, and 3 or 4 of boiling water.
This salt is used as a re-agent, for preparing pure baryta,
and in pyrotechny, to impart a green color to flame.*
* The green fire is composed of 13 parts sulphur, 77 nitrate of
baryta, 5 chlorate of potassa, 2 of arsenic, and 3 of charcoal.

Nitrates.
297
Nitrate of Strontia (Sro + NO5. 105.95; in prisms,
with 5 equiv. of water,= 150.95) is prepared from the carbo-
nate of strontia, in the same manner as the preceding, and
has similar properties; it is used for the red fire employed at
theatres. *
Nitrate of Lime (CaO +NO5, 82.65) is found in old
plaster and mortar; very soluble and deliquescent; crystal-
lizes in hydrated prisms.
The Nitrats of Magnesia (MgO+NO5. 74.85) has simi-
lar properties.
Nitrate of Protoxide of Copper (CuO + NO5. 93.75) is
formed by the action of nitric acid on copper ; its crystals
are prisms containing 7 equiv. of water, of a deep blue color,
soluble in water and alcohol, and deliquescent.
Exp. Spread a drachm of this salt on a piece of tin foil, moisten it
with water, fold it, and lay it on a plate; sufficient heat will often be
evolved to ignite the metal.
Nitrate of Protoxide of Lead (PbO+NO5. 165.75) may
be formed by digesting litharge in dilute nitric acid; it crys-
tallizes in anhydrous octohedrons, and has an acid re-action.
Dinitrate of Protoxide of Lead. 2PbO + NO5. 223.2+
54.15 = 277.35.
Nitrate of Protoxide of Mercury (AgO+N05. 264.15;
in crystals, with 2 equiv. water, = 282.15) is obtained by
digesting mercury in nitric acid, diluted with 3 or 4 parts of
water, until the acid is saturated, and then allowing the solu-
tion to evaporate spontaneously in an open vessel.
Nitrate of Peroxide of Mercury (HgO2 + NOS. 272.15)
is formed by heating mercury with strong nitric acid in
excess.
The solution, on cooling, deposits transparent, prismatic
crystals; when this salt is put into hot water, it is resolved
into a soluble salt, whose composition is unknown, and into
a yellow dinitrate of the peroxide. 2HgO2 + NO5. 490.15.
Nitrate of Oxide of Silver (AgO + NO5 170.15) may be
* Red fire consists of 40 parts of nitrate of strontia, 13 sulphur,
5 chlorate of potassa, and 4 sulphuret of antimony, with a little pow-
dered charcoal.

298
Salts. -- Nitrates.
formed by dissolving silver in nitric acid, diluted with 3
parts of water; if the silver contain copper, it will give a
greenish hue to the solution; if it contain gold, it will appear
in the form of a black powder. The solution should be per-
fectly clear and colorless.*
Properties. The solution by evaporation deposits trans-
parent, tabular crystals; it is caustic, and tinges animal sub-
stances of a deep yellow, which becomes, by exposure to
light, deep purple or black, and is indelible.
Heated in a silver crucible to 426°, it fuses, and when
cast into small cylinders, forms the lunar caustic of phar-
macy. This, when pure, is white and transparent; but the
common lunar caustic is dark and opaque, owing to the
decomposition of the nitrate, by raising the temperature too
high in its preparation, and also in consequence of copper
and gold, which are often contained in it; it is soluble in its
own weight of cold, and in half its weight of boiling water.
It is decomposed by light, leaving a black stain upon the
skin or on paper, (see p. 68;) hence it is a very delicate test
of animal matter, also of chlorine and hydrochloric acid,
which latter causes a white precipitate, the chloride of silver.
It is also decomposed by sulphur, phosphorus, charcoal,
hydrogen, and several of the metals.
Exp. Place a few grains of this salt, with a little sulphur, and also
with phosphorus, upon an anvil; when struck sharply with a hammer,
the former will detonate, and the latter explode violently.
Exp. Dip a piece of silk into a solution of this salt, and, while moist,
pass over it hydrogen gas; it will at first turn black, and then become
iridescent, from the reduction of the metal.
Exp. Immerse in a solution of this salt a stick of phosphorus; it will
soon become beautifully incrusted with the metal.
Exp. Immerse a slip of ivory in a dilute solution of the salt, till the
ivory has acquired a bright yellow stain; remove it to tumbler of dis-
tilled water, and expose it to the direct rays of the sun for two hours,
* One of the best solvents of silver may be formed by dissolving 1
part of nitre in 10 by weight of concentrated sulphuric acid. When
this compound is heated to between 1000 and 200° Fahr., it will dis-
solve about one sixth of its weight of silver without acting in the least
upon any copper, gold, lead, or iron, with which the silver may be
combined; hence it is very useful to detach silver from old plate. To
recover the silver from the solution, add common salt, and then de-
compose the chloride thus formed by carbonate of soda.

Nitrates
299
Chlorates.
when it will become black, but, on rubbing it, the surface will become
bright, resenibling pure silver.
Nitrate of Silver is the principal ingredient in indelible
ink, and in those compounds which are used for changing
the color of the hair.
In all these cases, the effect depends upon the reduction of
a part of the silver to the metallic state.
4. NITRITES.
According to Turner, very little is known of these salts.
5. CHLORATES.
The salts of chloric acid are very analogous to those of
nitric acid. They are all soluble in water, and are dis-
tinguished by the action of strong hydrochloric and sulphuric
acids, the former disengaging chlorine, and protoxide of chlo-
rine, and the latter chlorous acid.
The chlorates are mostly composed of 1 equiv. of protoxide
and 1 of acid; hence the oxygen of the base is to that of the
acid, as 1 to 5, or Mo + C105.
None of the chlorates are found native, and those of baryta
and potassa are the only ones which require particular notice.
Chlorate of Potassa (KO+C105. 122.57) may be formed
by transmitting chlorine gas through a concentrated solution
of
pure potassa, until the alkali is completely neutralized; the
results are chloride of potassium and chlorate of potassa.*
Properties. Chlorate of potassa generally occurs in four
and six-sided crystalline scales; colorless, and of a pearly
lustre; soluble in 16 times its weight of water at 60°, and in
24 of boiling water. It is anhydrous, and fuses at 400° or
500°; by increase of temperature, it yields pure oxygen gas.
It acts very energetically upon many imflammable bodies.
Exp. Put 2 grains of the salt into a mortar, with 1 grain of
sulphur. Mix them accurately, and then strike the collected mass
* For other processes, see Turner's Chemistry.

300
Salts. - Chlorates.
forcibly with the pestle; a loud detonation will ensue. Charcoal will
produce a similar effect; or,
Exp. Instead of the sulphur, add a grain of phosphorus, and the
detonation will be much louder.*
Many of the stronger acids decompose this salt.
Exp. Mix 2 parts of sugar with 1 of chlorate of potassa, and pour
upon it a few drops of sulphuric acid; the decomposition will be at-
tended by a sudden inflammation.
Exp. Put 2 parts of this salt with 1 of phosphorus into a wine-
glass filled with warm water, and then pour, by means of the dropping-
tube, strong sulphuric or nitric acids directly upon the salt; the phos-
phorus will ignite under the water, owing to the development of oxy-
gen from the decomposition of the salt.
Uses. It is employed in the preparation of percussion
powder, in which this salt is substituted for nitre.
Matches are also made by first dipping them in melted sul-
phur, and then in a composition of chlorate of potassa, sugar,
gum arabic, and vermilion.
Lucifer Matches have a similar composition.
An attempt was made in 1788 to substitute chlorate of
potassa for nitre, in the manufacture of gunpowder ; but,
as might have been expected, on triturating the mixture,
it exploded with violence, and destroyed several of the
operators.
A few grains of this salt, put into water with a few
drops of hydrochloric acid, form a convenient bleaching
liquor.
Chlorate of Baryta (BaO + C105. 152.12) is prepared by
digesting for a few minutes a concentrated solution of chlorate
of potassa, with a slight excess of silicated hydrofluoric acid ;
the alkali is precipitated in the form of an insoluble, double
hydrofluate of silica and potassa, while chloric acid remains
in the solution. The liquid, after filtration, is neutralized
by carbonate of baryta, which throws down the excess of
silicated hydrofluoric acid, and chlorate of baryta remains
in solution.
Properties. It yields, on evaporation, crystals in the form
of four-sided prisms, has a pungent taste, is soluble in 4 times
its weight of cold, and in a smaller quantity of warm water.
It is employed for forming chlorous acid.
* The hands should be covered with gloves, and the mortar turned
from the face.

Perchlorates
301
Iodates.
6. PERCHLORATES.
The neutral protosalts of perchloric acid consist of 1
equiv. of acid and base, as is expressed by the formula
MO+C107 Most of the salts are deliquescent, very solu-
ble in water, and soluble in alcohol. When heated to red-
ness, they yield oxygen gas and metallic chlorides; and they
are distinguished from the chlorates by not acquiring a yellow
tint, on the addition of hydrochloric acid. — T.
The salts are formed by neutralizing the base with per-
chloric acid, excepting perchlorate of potassa, which is
formed from the chlorate by heat and sulphuric acid.
burgo ligo 7. CHLORITES.
The alkaline chlorites are formed by transmitting a current
of chlorous acid gas into a solution of the pure alkalies ; they
are remarkable for their bleaching and oxidizing properties.
8. HYPOCHLORITES.
These salts may be formed by the action of chlorine gas on
the alkaline bases; the most important of these is the hypo-
chlorite of lime, which is well known as a bleaching powder.
9. IODATES.
The salts of iodic acid are very similar in character to
those of chloric acid ; in all the neutral protiodates, the oxy-
gen of the base and acid is in the ratio of 1 to 5; the
iodates are easily recognized by the action of de-oxidizing
agents. Thus the sulphurous, phosphorous, hydrochloric
and hydriodic acids deprive the iodic acid in the salt of
its oxygen, and set the iodine at liberty. None of the
iodates are found native; they are all insoluble, or sparingly
soluble in water, excepting the iodates of the alkalies.
Iodate of Potassa (KO+105. 213.45) may be obtained
26

302
Salts. - Phosphates.
by adding iodine to a concentrated, hot solution of pure
potassa, until the alkali is completely neutralized. All the
insoluble iodates may be procured from this salt; thus the
iodate of baryta may be formed by mixing chloride of
barium with a solution of iodate of potassa.
10. The Bromates are very similar to the chlorates and
iodates.
11. PHOSPHATES.
There are three acids of phosphorus which are isomeric —
the phosphoric, pyrophosphoric, and metaphosphoric; hence
it becomes necessary to have three corresponding families of
salts.
I. Phosphates. All the neutral protophosphates are solu-
ble in water, and redden litmus paper, on which account they
are called superphosphates.
RE
The Triphosphates, except those of the pure alkalies, are
sparingly soluble, or insoluble in water, but are all dissolved
by nitric or phosphoric acids. The phosphates and diphos-
phates are changed by heat into pyrophosphates 'and meta-
phosphates; the phosphates of the pure alkalies are but par-
tially decomposed by heat and combustible matter, and those
of baryta, strontia, and lime, undergo no change; but most of
the phosphates of the second class of metals are resolved into
hosphurets by those agents.
The insoluble phosphates are decomposed when boiled
with a strong solution of carbonate of potassa, or soda.
Triphosphate of Potassa (3KO +P205. 212.85) is formed
by adding caustic potassa in excess to a solution of phos-
phoric acid.
Diphosphate of Potassa (2KO.2H0+ P205. 165.7) is pre-
pared by neutralizing the superphosphate of lime obtained
from bones, with carbonate of potassa.
Phosphate of Potassa (KO.2HO+P205. 136.55) is formed
by adding phosphoric acid to carbonate of potassa, until the
liquid ceases to give a precipitate with chloride of barium,
and then setting aside to crystallize,

2 Phosphates.
303
Triphosphate of Soda. 3NaO + P205. 165.3; in crystals,
with 24 equiv. of water, =381.3. This salt is prepared by
adding pure soda to a solution of the succeeding compound,
until the liquid feels soapy to the fingers; the solution is then
evaporated until a pellicle forms; on cooling, the crystals
which are deposited, are quickly re-dissolved in water, and are
crystallized.
Properties. Triphosphate of soda crystallizes in colorless,
six-sided, slender prisms, which have an alkaline taste and re-
action; soluble in five times their weight of water at 60°, and
in still less of hot water; the crystals undergo watery fusion
at 170°, but are not decomposed at a red heat. The feeblest
acid deprives the salt of of its soda.
Triphosphate of Soda and Basic Water. 2NaO.HO +
P205. 143; in crystals, with 24 equiv. of water. = 359. This
salt is the most common of the phosphates, being manufac-
tured on a large scale, by neutralizing, with carbonate of
soda, the acid phosphate of lime, which is procured by the
action of sulphuric acid on burned bones.
Properties. It crystallizes in oblique rhombic prisms,
hence called rhombic phosphate; its crystals are always alka-
line to test paper; effloresce in the air ; soluble in four times
their weight of cold, and twice their weight of warm water.
Acid Triphosphate of Soda and Basic Water (NaO.2HO
+ P205, 120.7; in crystals, with 2 eq. water, = 138.7) is com-
monly called the biphosphate of soda, and may be formed by
adding phosphoric acid to a solution of carbonate of soda,
until it ceases to give a precipitate with chloride of barium.
When the solution is concentrated, it yields two different
kinds of crystals without varying its composition.
Phosphate of Soda and Ammonia (NaO.H3N+P205.
119.85, with 10 eq. water=209.85) is easily prepared by
mixing 1 equiv. of hydrochlorate of ammonia, and 2 equiv.
of the rhombic phosphate of soda ; each being previously
dissolved in a small quantity of boiling water.
It is known as microcosmic salt, and is much employed as
a flux in experiments with the blowpipe; when heated, it
parts with its water and ammonia.

304
Salts. - Phosphates.
Diphosphate of Ammonia (2H3N + P205. 105.7; in crys-
tals, with 3 equiv. water,= 132.7) is prepared by adding am-
monia to phosphoric acid until a precipitate is formed; the
primary form of the crystals is an oblique rhornbic prism.
Phosphate of Ammonia (HPN + P205, 88.55; in crystals,
with 3 equiv. water, 115.55) is formed in the same manner
as the phosphate of potassa, crystallizes in octohedrons with
a square base, and in right square prisms.
Bone Phosphate of Lime (8CaO + 3P205. 442.2) exists
in bones after calcination, and falls as a gelatinous precipitate,
on pouring chloride of calcium into a solution of rhombic
phosphate of soda.
Triphosphate of Lime (3CaO + P205. 156.9) occurs in the
mineral called apatite.
Diphosphate of Lime, (2CaO + P205 +1 eq. basic water,
=137.4,) commonly called neutral phosphate, falls as a granu-
lar precipitate, when the rhombic phosphate of soda is added,
drop by drop, to chloride of calcium in excess.
Phosphate of Lime (CaO + P205 + 2 eq. basic water, =
117.9) is commonly called the biphosphate, from its acid re-
action, and may be formed by dissolving either of the pre-
ceding salts in a slight excess of phosphoric acid; it exists in
urine.
Diphosphate of Magnesia. 2MgO + P205. 112.8.
Triphosphate of Magnesia. 3MgO + P205. 133.5.
Phosphate of Ammonia and Magnesia (2MgO + 2H3N+
10HO+P205, 237.1) subsides as a pulverulent, granular
precipitate from neutral alkaline solutions, containing phos-
phoric acid, ammonia, and magnesia; it constitutes a variety
of urinary concretions.
Triphosphate of Oride of Silver is formed when the
rhombic phosphate of soda is mixed in solution with nitrate
of silver, it is a yellow powder when dry; on exposure to
light, it is speedily blackened.
II. Pyrophosphates. The only salts of this family which
have been studied, are those of soda and oxide of silver.
They are thus constituted :

Arseniates.
305
Dipyrophosphate of Soda. 2NaO + P²O5. 62.6+71.4=134.
Dipyrophosphate in crystals, with 10 eq. water, 90=224.
Acid Dipyrophosphate of Soda and Basic Water. NaO.HO + P2O5 =
111 7.
Pyrophosphate of Soda. NaO.P2O5. 31.3+71.4=102.7.
Dipyrophosphate of Oxide of Silver. 2AgO + P20%. 232+71.4=
303.4.
III. Metaphosphates. The only salts of this family yet
examined are those of soda, baryta, and oxide of silver.
Metaphosphate of Soda. NaO.P2O5, 1 eq. Na, 31.5+ leq. P2O5, 71.4
= 102.7.
Metaphosphate of Baryta. BaO.P²O5, 1 eq. BaO, 767 +1 eq. P²05,
71.4=148.1.
Metaphosphate of Silver. AgO.P²O5, 1 eq. Ago, 116+1 eq. P²O5,
71.4=187.4.
Sub-metaphosphate of Silver. 3AgO+2P205, 3 eq. AgO, 348 +2 eq.
P2O5, 142.8=490.8.
12. ARSENIATES.
Arsenic acid resembles the phosphoric in composition,
and in many of its properties. The oxygen of the oxide and
acid in their salts is as 1 to 5; salts of 2 equiv. of basic
water are soluble in water, redden litmus paper, and are
usually considered bisalts; those with 1 equiv. of basic
water, in which the oxygen of the base and acid is as 2 to
5, are commonly called neutral arseniates; those without
water are described as subarseniates. This acid has a strong
tendency to form trisalts; some of the arseniates bear a red
heat without decomposition, but all are decomposed when
thus heated with charcoal, metallic arsenic being set at
liberty.com
The soluble arseniates are easily recognized by the tests
for arsenic. (See p. 256.)
The insoluble arseniates are tested by boiling them in a
strong solution of the fixed alkaline carbonates, by which
they are deprived of their acid; the acid may then be de-
tected in the usual way.
The following are the principal arseniates :-
Triarseniate of Soda. 3NaO + As?0, 3 eq. NaO, 93.7+1 eq.
As²O5, 115.4–209.3.
Do. in crystals with 1 eq. water 216=425.3.
26*

306
Salts. - Arsenites.
Diarseniate of Soda and Basic Water. 2NaO + HO + As’O”, eq. 187.
Acid Arseniate of Soda and Basic Water. NaO + 2H0 + As²Oaq. =
164.7.
Triarseniate of Potassa. 3K0 + As²O5, 3 eq. KO, 141.45+1 eq.
As²O6, 115.4=256.85.
Diarseniate of Potassa. 2K0 + As²O5, 2 eq. K0, 94.3+1 eq.
As’O, 115.4=209.7.
Arseniate of Potassa. KO. As?05, 1 éq. KO, 47.15+1 eq. As2O5,
115.4=162.55.
Diarseniate of Ammonia. 2H3N + As²O5, 2eq. NH3, 34.3+1 eq.
As’05, 115.4=149.7.
Arseniate of Ammonia. NH3, As²O5, 1 eq. NH3, 17.55 +1 eq.
As²O5, 115.4=132.55:
Triarseniate of Baryta. 3BaO + As²O5, 3 eq. BaO, 230.1 +1 eq.
As05, 115.4=345.5.
Diarseniate of Baryta. 2BaO + As’O”, 2 eq. BaO, 153.4+1 eq.
As²O3, 115.45=268.8.
Arseniate of Byrata. BaO + As’OS, 1 eq. BaO, 76.7+1 eq. As’05,
115.4=192.1.
Triarseniate of Lime. 3CaO + As’O, 3 eq. Cao, 85.5+1 eq.
As²O5, 115.4=200.9.
Diarseniate of Lime. 2CaO + As²O5, 2 eq. CaO,57 +1 eq. As²O5,
115.4=172.4.
Arseniate of Lime. CaO + As²O5, 1 eq. CaO, 28.5 +1 eq. As²O5,
115.4 = 143.9.
Triarseniate of Lead. 3PbO + As²O3, 3 eq. PbO, 334.8 +1 eq.
As²O5, 115.4=450.2.
Diarseniate of Lead. 2P60+ As?05. 2 eq. PbO, 223.2 +1 eq.
AsO6, 115.45338.6.
Triarseniate of O2-Silver. 2AgO + As²O, 3 eq. Ag0, 348 +1 cq.
As²O5, 115.45 463.4.
13.
RSENITES.
The arsenites of potassa, soda, and ammonia, may be
prepared by acting with those alkalies on arsenious acid.
They are very soluble in water, and have an acid re-action.
Most of the other arsenites are insoluble or sparingly solu-
ble in water, but are dissolved by an excess of arsenious,
nitric, and most other acids, with which their bases do not
form insoluble compounds.
They are all decomposed when heated in close vessels.
The soluble salts, if neutral, are characterized by forming
a yellow arseniate of oxide of silver, when mixed with nitrate
of silver, and a green arsenite of protoxide of copper -
Scheele's green - with sulphate of copper.
The arsenite of potassa is the active principle in Fowler's
arsenical solution.
Chromates
307
Borates.

14. CHROMATES.
The chromates may generally be known by their yellow
or red color. They may be known chemically by the green
solution of chloride of chromium, formed by boiling any
chromate with hydrochloric acid mixed with alcohol. They
are all decomposed by heat and combustible matter.
Chromate of Potassa (KO + CrO3. 99.15) is formed by
heating to redness the native oxide of chromium and iron
(chromate of iron) with nitrate of potassa, when chromic acid
is generated, and unites with the alkali of the nitre.
Properties. Taste cool, bitter, and disagreeable, soluble
in boiling water, and insoluble in alcohol.
Bichromate of Potassa (KO+2Cr03. 151.15) is of great
que
importance in dyeing. It is prepared by acidulating the
neutral chromate with sulphuric, or, still better, with acetic
acid, and allowing the solution to crystallize by spontaneous
evaporation.
Properties. When slowly formed, four-sided rhombic
prisms are deposited, which are anhydrous, and of a rich
red color; soluble in 10 times their weight of water at 60°
and the solution reddens litmus.
The insoluble chromates, such as those of baryta, zinc
lead, mercury, and silver, are prepared by mixing the soluble
salts of those bases with a solution of chromate of potassa.
Chromate of Lead. PbO + CrO3. 163.6. This is the
yellow chromate, and is extensively used as a pigment.
Chromate of oxide of zinc may be used for the same purpose.
15. BORATES.
The boracic is a feeble acid, and neutralizes imperfectly;
hence the borates, such as soda, potassa, and ammonia, have
an alkaline re-action; hence, also, the more powerful acids
separate the alkali from boracic acid, although, at a red heat,
boracic acid, owing to its fixed nature, decomposes every salt
whose acid is volatile. The borates of the alkalies are solu-

308
Carbonates.
Salts.
ble in water, but most of the other borates are sparingly
soluble; they are not decomposed by heat, though remark-
able for their fusibility. They are distinguished by the
following character :
By digesting any borate in an excess of strong sulphuric
acid, evaporating to dryness, and boiling the residue in
strong alcohol, the solution will burn with a green flame.
Biborate of Soda, (2B03 + NaO. 191.1; in crystals, with
10 equiv. of water, = 101.01, commonly called borar, oc-
curs native in certain lakes in Thibet. It is imported from
India under the name of tincal, which, after purification,
constitutes the refined borax of commerce.
Properties. It crystallizes in hexahedral prisms. The
crystals are efflorescent; when heated, they lose their water
of crystallization, fuse, and form, on cooling, a crystalline
mass, called glass of borax.
Borax is much used as a flux for welding iron and steel.
Boracite is a biborate of magnesia.
A new biborate of soda has been lately described; better
as a flux, for the use of jewellers, than the preceding.
16. CARBONATES.
The carbonates are distinguished from all other salts, by
being decomposed with effervescence, owing to the escape
of carbonic acid gas, by nearly all acids.
All the carbonates, except those of potassa, soda, and lithia,
are decomposed by heat; and all, except those of potassa,
soda, and ammonia, are of sparing solubility in pure water ;
but all are soluble in excess of carbonic acid. Several of
them occur native..
Carbonate of Potassa (KO+CO2 69.27) is procured by
lixiviating the ashes of land plants, and boiling the lye - a
process which is performed on a large scale in Russia, and
in this country. This is the impure carbonate of commerce,
known by the names potash and pearlash, and is of great utili-
ty in the arts, especially in the manufacture of soap and glass.
As thus prepared, it always contains other compounds, such

Carbonates.
309
as sulphate of potassa, and chloride of potassium.
For
chemical purposes, it is obtained by heating cream of tartar
to redness, when the acid is decomposed, and a pure car-
bonate of potassa mixed with charcoal remains. The char-
coal is removed by solution in water, and evaporation.
Properties. Taste strongly alkaline, and slightly caustic;
changes the vegetable purple colors to green; soluble in less
than an equal weight of water at 60°; deliquesces on ex-
posure to the air; is insoluble in pure alcohol, and fuses at
a full red heat, but undergoes no other change.
Bicarbonate of Potassa (KO+2C02. 91.39; in crystals,
with 1 equiv. water, = 100.39) is made by transmitting a
current of carbonic acid gas through a solution of the car-
bonate. This salt is milder than the carbonate, into which
it is converted by a low red heat. It does not deliquesce on
exposure, and requires four times its weight of water at 60°
for solution.
Carbonate of Soda (NaO+CO2. 53.42; in crystals, with
10 equiv. water,=143.42) is obtained from the ashes of sea-
weeds, in the same manner as carbonate of potassa. The
best variety of the impure salt is the barilla, which con-
sists of the semifused ashes of the salsola soda, a plant culti-
vated on the Mediterranean shores of Spain. Kelp is another
variety, and formed from the sea-weeds on the northern
shores of Scotland.
Properties. Crystallizes in rhombic prisms; effloresces,
and dissolves in its water of crystallization when heated, and
becomes anhydrous by continued heat ; soluble in about 2
parts of cold, and in less than its weight of boiling water.
Bicarbonate of Soda (NaO +2C02 75.54 ; in crystals,
with 1 equiv. water,=84.54) is formed by the same process
as the bicarbonate of potassa, and, like that salt, is much
milder than the carbonate. Slike that se
Sesquicarbonate of Soda (2NaO + 3C02. 4HO. 164.96)
is found native in Africa, on the banks of soda lakes, and is
called trona.
Carbonate of Ammonia (H3N+ CO2. 39.27) is obtained
by mixing dry carbonic acid over mercury, with twice its
volume of ammoniacal gas. It is a dry, white powder, and

310
Carbonates.
Salts.
has an alkaline re-action; its odor is pungent, resembling
ammonia.
Bicarbonate of Ammonia (H3N.2H0 + 2002. 79.39) is
obtained by transmitting a current of carbonic acid gas
through a solution of carbonate of ammonia, and evaporating
the solution by gentle heat. "It is deposited in right rhom-
bic prisms; inodorous, and nearly tasteless.
Sesquicarbonate of Ammonia (2H3N.2HOP + 3C02.
118.66) is prepared by heating 1 part of hydrochlorate of
ammonia, mixed with 14 of carbonate of lime, carefully
dried.
The chloride of calcium remains in the retort, and this
salt is sublimed; it is hard, compact, translucent, of a crys-
talline texture, and ammoniacal odor.
Carbonate of Baryta (BaO + CO2. 98.82) occurs native
in the mineral Witherite. It may be prepared by mixing a
soluble salt of baryta with any of the alkaline carbonates.
Properties. This salt is anhydrous, very insoluble, and
highly poisonous.
Carbonate of Strontia (Sro + CO2. 73.92) is known by
the name of strontianite; it may be prepared in the same
manner as carbonate of baryta ; it is soluble in excess of
carbonic acid.
Carbonate of Lime (Ca + CO2. 50.62) is a very abundant
natural production, occurring under a great variety of forms,
such as limestone, marble, chalk, Iceland spar, etc.; often
in regular crystals. Carbonic acid and lime have a strong
affinity for each other; and hence moist lime, or lime in so-
lution, when exposed to the air, absorbs the acid contained
in the atmosphere, and carbonate of lime is formed. It is
sparingly soluble in water, but soluble in excess of carbonic
acid; the crust formed on the top of lime water is car-
bonate of lime.
Carbonate of Magnesia (MgO + CO2. 42.82; in crystals,
with 3 equiv. of water,
69.82) is found native in the mine-
ral called magnesite, which is nearly pure anhydrous car-
bonate of magnesia. It is obtained in minute, transparent,

Carbonates.
311
hexagonal prisms, when a solution of the bicarbonate evapo-
rates slowly in an open vessel; the crystals lose their water,
and become opaque by a very gentle heat, and even in dry
air, at 60°. They are decomposed by water.
A Carbonate of Magnesia, consisting of 4 equiv. of water,
3 of acid, and 4 of magnesia, falls as a white powder when
carbonāte of potassa is added to a hot solution of sulphate
of magnesia; this salt is very insoluble, requiring 9000 parts
of hot water for solution.
Carbonate of Protocide of Iron (FeO + CO. 58.12) is a
very abundant natural production, occurring either in masses,
or in rhombohedrons. It exists also in most of the cha-
lybeate mineral waters. It may be formed by mixing an
alkaline carbonate with sulphate of protoxide of iron.
acts as a tonic upon the animal system.
Dicarbonate of Protoride of Copper (2CuO+Col. 101.32)
is found native as a hydrate, in the mineral called malachite,
of a beautiful green color.
It may be obtained by precipitation from a hot solution of
sulphate of protoxide of copper, by carbonate of soda or po-
tassa; this is the mineral green of painters.
When the hydrate is boiled for a long time in water, it
loses both carbonic acid and combined water, and the color
changes to a brown.
The blue copper ore, and the blue pigment called verditer, *
have a similar composition.
Carbonate of Protoxide of Lead (PbO+CO? 133.72) is
the white lead of painters. It occurs native in white pris-
matic crystals. As an article of commerce, it is prepared
from the subacetate by a
current of carbonic acid; also by
Teed to
* Refiners' Verditer, made by silver refiners, is composed of 3 equiv.
of oxide and 4 of carbonic acid.
A very good verditer is formed by adding a quantity of lime to ni
trate of copper sufficient to throw down the oxide. The green precip-
itate must be washed, and nearly dried upon a strainer. If it is then
mixed with 10 per cent. of fresh lime, the color will become blue. It
must now be dried, and is then fit for use.

312
--
Salts. -- Double Carbonates
- Silicates.
exposing metallic lead in minute division to air and moisture,
or by the action of the vapor of vinegar on thin sheets of
lead.
Dicarbonate of Peroxide of Mercury, 2HgO + CO
458.12. When a solution of the nitrate of peroxide
of
mercury is decomposed by carbonate of soda, this salt falls
as an ochre-yellow precipitate.
allo
17. DOUBLE CARBONATES.
The most remarkable of these salts is the double carbonate
of lime and magnesia, (MgO,CO2+CaO.CO2. 93.44,) form-
ing the minerals called dolomite, bitter spar, and pearl spar.
The rock called magnesian limestone is an impure variety
of dolomite.
Barytocalcite is a double carbonate of baryta and lime.
CaO.CO+BaO.CO. 149.44.
Carbonate of Soda, fused with the carbonate of baryta,
strontia, or lime, in the ratio of their equiv., yields crystal-
line, definite compounds. In the same manner, also, sulphate
of soda, heated with the above carbonates, yields double
salts, which are very similar.
18. SILICATES.
Silicic Acid is one of the most powerful acids. The salts
which it forms, although very numerous and important com-
pounds, have not hitherto been fully investigated. The sili-
cates are remarkable for their great variety of composition;
they are composed of from 1 equiv. of base and 6 of silicic
acid to 1 of acid and 3 of base. Those most frequently met
with are,
-
1. Simple Silicates, or those composed of 1 equiv, of base
and 1 of silicic acid. These are a very numerous class of
natural compounds, as, silicate of manganese, zinc, glucina,
cerium, zirconia, iron, &c.
2. Bisilicates, in which 2 equiv. of silicic acid are com-

Silicates.
313
bined with 1 of base. There are many native compounds
of this order : tabular spár is a bisilicate of lime; bottle
glass is another example. bebes
3. Trisilicates, in which 3 equiv. of silicic acid are united
to 1 of base. The most important of the bisilicates is plas-
tic clay, which is a trisilicate of alumina.
4. Quadrisilicates, which are principally artificial com-
pounds, among which are crown glass, French window glass,
flint glass, and enamel.
In addition, it should be remarked, that there are a very
great number of simple minerals, which are composed as
above, or by the union of silicic acid with other acids and
with bases. In fact, the greater portion of the crust of the
globe is composed of silicates. The soils, rocks, and
mountains, are but masses of silicates.
The silicates are all fusible before the compound blow-
pipe, and all, except those of magnesia and alumina, in a
forge fire. Those of 2 or more bases are most easily fused;
and those of fusible bases are more easily melted than those
whose bases are more refractory.
In the separation of the metals from their ores, such mat-
ters are added as will form with the earthy parts of the ores
fusible silicates. These float like glass on the surface of the
reduced metal, and are easily removed.
All kinds of glass are formed by heating siliceous sand
with alkaline carbonates. When heat is applied, the alkali
melts, and the sand (silicic acid) combines with the alkali,
while the carbonic acid escapes in the form of a gas, causing
the mass to swell to twice its former bulk. When the car-
bonic acid all escapes, the mass subsides, and is called frit.
This is then put into a refractory vessel, and placed in a
furnace, where it is heated until it is melted and becomes
glass. (See page 213.)
The silicates are all insoluble, excepting those of potassa
and soda. Those compounds formed by the union of 1 or
2 equiv. of silicic acid are more soluble than those of 3 or
4. The double silicates of these alkalies, that is, the union
24

314
Salts. - Hydro-Salts.
of another acid or base, renders the compounds still less
soluble.
The silicate of alumina and soda, which is combined with
sulphuret of sodium in lapis lazuli, is used by painters, under
the name of ultramarine, and is a very important compound
The silicates are the most important chemical com
pounds; forming, as they do, almost the entire mass of the
soil in every country, their influence upon vegetation is con-
stant and universal. To the agriculturist they are com-
pounds of great interest, and should be made the subjects
of intense study.
SECTION 3.
ORDER 11.- HYDRO-SALTS.
This order includes those salts the acid or base of which
contains hydrogen. The salts formerly called muriates or
hydrochlorates of metallic oxides, are now generally de-
scribed as chlorides of those metals, and also the salts of
hydriodic and most other hydracids. The only salts which
are included in this order are formed by the hydracids with
ammonia and phosphureted hydrogen.
Hydrochlorate of Ammonia. HÈN + HCL. 53.57. This
is the sal ammoniac of commerce, and was formerly imported
from Egypt, where it was prepared from the soot of camels'
dung by sublimation; but it is now formed by several pro-
The most usual is to decompose the sulphate of am-
monia* by the chloride of sodium or magnesium.
It occurs nativ?, in masses and in crystals, in the vicinity
of volcanoes.
Process. It may be produced directly, by introducing
liquid ammonia into one retort, (see Fig. 54, p. 113,) and
HCL into the other, and apply heat. As the two gases pass
cesses.
* This sulphate is obtained by digesting with gypsum the impure
carbonate of ammonia, procured from the destructive distillation of
bones and other animal substances, so as to form an insoluble carbonate
of lime and a soluble sulphate of ammonia,

Hydro-Salts
315
into the receiver, a white cloud appears, which is hydrochlo-
rate of ammonia in fine powder.
Properties. This salt has a pungent, saline taste, and is
insoluble in water and in alcohol; it sublimes at a tempera-
ture below that of ignition, without fusion or decomposi-
tion.
Uses. Used in the arts for a variety of purposes, in tin-
ning copper, to prevent oxidation, and by dyers.
When dissolved in nitric acid, it forms the aqua regia,
which is employed for dissolving gold, instead of nitro-
hydrochloric acid.
Hydriodate of Ammonia (HPN.HI. 144.45) is a white powder, very
soluble and deliquescent.
Hydrobromate of Ammonia (HPN.HBr. 96.55) is a white anhy-
drous salt.
Hydrofluate of Ammonia. H'N.HI. 36.83. See Turner, 5th edit.
P. 469.
Hydrosulphate of Ammonia (H3N+HS. 34.25) is
formed by heating a mixture of 1 part of sulphur, 2 of sal-
ammoniac, and 2 of unslacked lime. It is used as a re-
agent, and for this purpose it is formed by saturating a
solution of ammonia with hydrosulphuric acid.com
Hydrocyanate of Ammonia. H3N+HCPN. 44.54.
Hydrosulphocyanate of Ammonia. H3N+HCyS2 76.74.
Trifluoborate of Ammonia. 3H3N + BF3 118.39.
Difluoborate of Ammonia. 2H3N + BF3. 101.24.
Fluoborate of Ammonia. H3N+ BF3. 84.09.
Fluosilicate of Ammonia. H3N+SiF. 43.33.
Carbosulphate of Ammonia. H3N + CS2. 55.47.*
Salts of Phosphureted Hydrogen.
Phosphureted Hydrogen resembles ammonia in composi-
tion, and in some of its properties; it is a feeble alkaline
base, and combines with some of the hydracids. The salt
See Turner, 5th edit. p. 469.

316
Salts. -Sulphur-Salts.
best known is the hydriodate of phosphureted hydrogen,
which is composed of 127.3 parts or l eq. acid, and 34.4
parts or 1 eq. base, and crystallizes in cubes.
SECTION 4.
ORDER III.-SULPHUR-SALTS.
The sulphur-salts are double sulphurets, just as the oxy-
salts are double oxides.
The sulphur-salts, with two metals, are so constituted, that
if the sulphur in each were replaced by an equivalent quan-
tity of oxygen, it would form an oxy-salt.
The close analogy between the two orders of salts appears
also from the fact, that hydrosulphuric and hydrosulphocy-
anic acids unite both with ammonia and sulphur bases.
The principal sulphur bases are the protosulphurets of
potassium, sodium, lithium, barium, strontium, calcium,
magnesium, and the hydrosulphate of ammonia; and the
sulphur acids are the sulphurets of arsenic, antimony, tung-
sten, molybdenum, tellurium, tin, and gold, together with
hydrosulphuric acid, bisulphuret of carbon, and sulphuret of
selenium.
The sulphur-salts are divided into families which contain
the same sulphur acid; the generic name of each family is
formed from the sulphur acid terminated with sulphuret ;
thus the salts, which contain persulphuret of arsenic or
hydrosulphuric acid, as the sulphur acid, are termed arsenio-
sulphurets and hydrosulphurets, and a salt composed of those
sulphur acids, with sulphuret of potassium, is termed arsenio-
sulphuret, and hydrosulphuret of sulphuret of potassium, or
simply hydrosulphuret of potassium.*
* Dr. Hare has adopted a method of naming the sulphur-salts,
founded on the nomenclature of the oxy-salts. He calls the electro-
negative sulphuret an acid, and forms its name by changing the termi.
nation of the element with which the sulphur is combined into ic, and

Sulphurets.
317
1. HYDRO-SULPHURETS.
The salts of this family have hydrosulphuric acid for their
electro-negative ingredient; most of them are soluble in
water, are decomposed by exposure to the air and by acids.
Hydro-sulphuret of Potassium. KS+HS. 72.35.
The anhydrous salt may be obtained by heating to low
redness anhydrous carbonate of potassa in a tubulated retort,
through which a current of hydrosulphuric acid is transmit-
ted. It forms, when cold, a white, crystalline solid. The
hydrous salt has an acrid, alkaline, and bitter taste.
Hydro-sulphuret of Sodium. Nas +HS. 56.5.
Hydro-sulphuret of Lithium. LS+HS. 43.2.
Hydro-sulphuret of Barium (BaS + HS. 101.9) is formed
by the action of hydrosulphuric acid on a solution of baryta,
excluded from the air. It crystallizes in four-sided prisms,
and is very soluble.
Hydro-sulphuret of Strontium. Srs +HS. Eq. 77.
Hydro-sulphuret of Calcium. Cas+HS. Eq. 53.7.
Hydro-sulphuret of Magnesium. Mgs +HS. Eq. 45.9.
2. HYDRO-SULPHOCYANURETS.
The acid of these salts is the hydrosulphocyanuric acid.
Hydro-sulphocyanuret of Potassium (KS+HCys2. 114.84)
is a white, crystalline solid, soluble in water and in alcohol.
Hydro-sulphocyanuret of Hydrosulphate of Ammonia
(H3N+HS) + (HCyS2. 93.84) exists in long, brilliant crys-
tals, of a lemon-yellow color.
3. CARBO-SULPHURETS.
The acid of this family is the bisulphuret of carbon.
Carbo-sulphuret of Potassium (KS + CS?. 93.57) is pre-
pared by agitating bisulphuret of carbon with a strong alco-
holic solution of protosulphuret of potassium. The liquid,
when set at rest, separates into three layers, the lowest of
which is the carbo-sulphuret of potassium. On evaporation,
prefixing sulph or sulpho. Thus, persulphuret of arsenic he calls sulph-
arsenic acid, and its sulphur salts, sulpharseniates. Hydrosulphuric acid
he denominates sulphydric acid, and its salts sulphydrates ; so of the rest.
27 *

318
Salts. - Molybdo-sulphurets.
a deliquescent, yellow, crystalline salt is deposited, sparingly
soluble in alcohol.
The Carbo-sulphuret of Sodium (NaS + CS2. 77.72) and
the Carbo-sulphuret of Lithium (LS + CS. 64.42) are simi-
lar to the preceding.
Carbo-sulphuret of the Hydrosulphate of Ammonia (H3N.
HS + CS2. 72.57) is a very volatile salt, and must be kept
in bottles tightly corked. Exposed to the air, it absorbs
water and becomes red. *
4. ARSENIO-SULPHURETS.
Each of the three sulphurets of arsenic is capable of acting
as a sulphur acid; giving rise to three distinct families of
sulphur salts, arsenio-protosulphurets, arsenio-sesquisulphurets,
and arsenio-persulphurets. The persulphuret of arsenic is
the most powerful of these acids. The arsenio-persulphurets
of the alkalies and alkaline earths, are very soluble in water,
have a lemon-yellow color when anhydrous, but colorless
when combined with water of crystallization, or in solution;
but those of the second class of metals are generally in-
soluble.
5. MOLYBDO-SULPHURETS.
The acid in this family is the tersulphuret of molybdenum.
The most remarkable of these salts is
Molybdo-sulphuret of Potassium, (KS + MoS3. 151.25,)
which is formed by decomposing a solution of molybdate of
potassa with hydrosulphuric acid ; on evaporation, beautiful
crystals with four and eight sides are deposited. Berzelius de-
scribes this compound as the most beautiful which chemistry
can produce. The crystals, by transmitted light, are ruby-
red, and their surfaces, while moist, and also the solution
which yields them, shine like the wings of certain insects,
with a metallic lustre, of a rich green tint.
* The carbo-sulphuret of barium, (BaS + CS?. 123.12,) the carbo-sul-
phuret of strontium, (SrSCS?. 98.22,) and the carbo-sulphuret of calcium,
(CaS + CS. 74.92,) may be obtained by acting on bisulphuret of car-
bon with a solution of the protosulphurets of these metals. The solu-
tions are orange or brown, and the crystals, when dry, are of a citron-
yellow color. Carbo-sulphuret of magnesium. MgS+ CS2. 67.12.

Haloid Salts.
319
6. ANTIMONIO-SULPHURETS.
The acid of this family is the sesquisulphuret of antimony,
and the only salt examined is the antimonio-sulphuret of po-
tassium, which may be formed by mixing 2 parts of car-
bonate of potassa, 4 of sesquisulphuret ef antimony, and I of
sulphur, and fusing the mixture.
7. TUNGSTO-SULPHURETS.
The best known of this family is potassium. When a
solution of tungstate of potassa is decomposed by hydrosul-
phuric acid, and the solution evaporates, anhydrous, quadri-
lateral, flat prisms are deposited, of a pale-red color, which is
the tungstosulphuret of potassium. This salt unites with
tungstate of potassa as a double salt.
blo lo con
SECTION 5.
ORDER IV.-HALOID SALTS.
This order includes substances composed, like the pre-
ceding salts, of bi-elementary compounds, one or both of
which are analogous to sea-salt in composition. The haloid
acids belong generally to the electro-negative, and the haloid
bases to the electro-positive metals.
The following are the principal groups or families :-
1. Hydrargo-chlorides. The haloid acid is the bichloride
of mercury; they are obtained by mixing their ingredients in
the ratio of combination, and setting aside the solution to
crystallize.
2. Auro-chlorides. The acid in this family is the ter-
chloride of gold; they are prepared like the preceding; most
of them have an orange, or a yellow, color.
3. Platino-chlorides. The haloid acids in this family are
the protochloride and bichloride of platinum.
4. Palladio-chlorides are salts in which the chlorides of
palladium act as haloid acids, combining with many of the
metallic chlorides.

320
Haloid Salts.
Salts.
5. Rhodio-chlorides are formed by the action of sesqui-
chloride of rhodium on the chlorides of potassium and so-
dium.
6. The Chlorides of Iridium and Osmium are the haloid
acids of the iridio-chlorides and the osmio-chlorides.
7. Oxy-chlorides. This family embraces a large number
of compounds, in which a metallic oxide is united with a
chloride, generally of the same metal, but often of other
metals. These salts are commonly termed submuriates, on
the supposition that they consist of hydrochloric acid, com-
bined with two or more equivalents of an oxide.
Oxy-chlorides of Iron. When the crystallized protochloride of iron is
strongly heated in close vessels, a deep green oxy-chloride, in scaly
crystals, is formed.
Oxy-chloride of Copper constitutes the paint called Brunswick green,
and is prepared by exposing metallic copper to hydrochloric acid. This
is the compound formed by the action of sea-water on the copper of
vessels.
Oxy-chloride of Lead may be formed by adding pure ammonia to a
hot solution of chloride of lead; another oxy-chloride - the pigment
called patent yellow — is prepared by the action of moist sea-salt on
litharge.
8. Chlorides with Ammonia. The perchlorides of tin and
some other metals absorb ammonia at common temperatures,
and most of the other chlorides absorb it when gently heated;
but most of these compounds lose their ammonia, on exposure
to the air, and nearly all, by heat.
9. Chlorides with Phosphureted Hydrogen.
These are
very similar to those with ammonia, and are not of sufficient
importance to be inserted in this place.
10. Double Iodides. These compounds have not yet been
closely studied, but the iodides probably form with each other
an extensive family of salts.
The most important are the
Platino-biniodide of Potassium, prepared by digesting an excess of
biniodide of platinum in a concentrated solution of iodide of potassium,
and the Platino-biniodide of Hydrogen, which is prepared by acting on
biniodide of platinum with a cold dilute solution of hydriodic acid.
11. Oxy-iodides. The best known of this family are
those formed by the oxide and iodide of lead.
The double bromides have not yet been studied.

Organic Chemistry.
321
12. Double Fluorides. There are several extensive fami-
lies of these salts, in which the fluorides of boron, silicon,
titanium, and other electro-negative metals, are the acids,
and the fluorides of the electro-positive metals are the
bases.
13. Double Cyanurets and Ferro-cyanurets. The double
cyanurets constitute a large and important family of salts,
of which the principal are the ferro-cyanurets, ferro-sesqui-
cyanurets, zinco-cyanurets, cobalto-cyanurets, nicco-cyanu-
rets, and cupro-cyanurets, in which the proto-cyanuret of
iron, sesqui-cyanuret of iron, cyanuret of zinc, cobalt,
nickel, and copper, are the electro-negative cyanurets. (See
Turner's Elements, p. 487.)
CHAPTER IV.
NATURAL SUBSTANCES.
ORGANIC CHEMISTRY.
Organic chemistry treats of those substances which are
of animal or vegetable origin, and which are therefore called
organic. These substances differ from inorganic substances,
in being composed of the same elements, oxygen, carbon, and
hydrogen, often with the addition of nitrogen, which is most
abundant in fungous plants and animal substances. On the
other hand, inorganic compounds are composed of very dif-
ferent elements; a few other constituents, as, iron, silica,
potassa, sulphur, phosphorus, etc., are sometimes detected in
small quantity in organic substances, but can rarely be re-
garded as essential constituents. These compounds differ
chiefly in the proportions of their constituents; hence many
of them are easily convertible into each other.
A second characteristic of organic substances is the facility
with which they may be decomposed, and especially in being,

322
Vegetable Chemistry.
without exception, decomposed by a red heat, and often by a
Jower temperature; if heated in the open air, they are con-
verted chiefly into water and carbonic acid.
With a few exceptions, organic substances cannot be formed
artificially, by the direct union of their elements; they are
obtained only as already existing in organic bodies,* or by
the conversion of one into another, as of sugar into al
cohol.
Many organic acids and alkalies combine with inorganic
alkalies or acids, and form compounds, which, although not
entirely of animal or vegetable origin, are usually described
in connection with their organic constituents.
VEGETABLE CHEMISTRY.
Most vegetable substances consist of hydrogen and carbon,
usually with oxygen; in fungous plants, and in some others,
nitrogen is also present.
Proximate Principles. All compounds, which exist in
plants ready formed without artificial processes, as, gum,
sugar, starch, etc., are called proximate principles; the pro-
cesses by which they are separated, constitute proximate
analysis.
Ultimate Analysis consists in the reduction of organic
compounds into their elements. This was formerly done by
destructive distillation ; the substance was put into a close
vessel and decomposed by a high temperature; the products
were collected and examined. The process is now gener-
ally conducted by means of the oxide of copper, which easily
parts with its oxygen to the carbon and hydrogen of the
substance, forming carbonic acid with the former, and water
with the latter. These new compounds are collected, and
from their weight may be known the weight of the carbon
* The agent by which organic bodies are formed is life, whose na-
ture and mode of action we do not understand.

Vegetable Acids.
323
and of the hydrogen. The loss of oxygen in the oxide of
copper is also noted, and compared with the quantity in the
carbonic acid and water. The excess of the latter over the
former, is the amount derived from the substance under ex-
amination; and, if there be no such excess, it is inferred that
there was none in the substance.
Before entering upon a description of the various vegetable
principles, it will be proper to notice the results of the late
investigations of Wöhler, Liebig, Pelouse, and Dumas.
1. Amides, or Amidets. – Theory. Dumas discovered
that when crystallized oxalate of ammonia, represented by
the formula C203 + NH3 was distiiled, a white, tasteless
powder was obtained, which he called oxamide. On analyz-
ing this, he found it composed of C²02 + NH”; or it is oxalate
of ammonia deprived of one equivalent or atom of water.
On heating this with potassa, ammonia is disengaged, and
oxalate of potassa formed, by which treatment the atom of
water is restored.
The term amide has been generalized and applied to all
those anhydrous compounds of an acid and ammonia, which
by heat may be deprived of an atom of water; or to all those
compounds which, by adding an atom of water, can be con-
verted into a salt of amm
amonia; hence we have from benzoate
of ammonia (C14H503 +H3N) a substance called benzamide,
(C14H502 + H²N,) differing from the former by HO, or 1
equivalent of water less. Hence it is inferred that there must
be such a compound as HʼN, to which Liebig has given the
name amide, as potassamide, composed of K +H’N.
Dumas has given to these compounds the name of amidet.
Thus oxamide he calls amidet of oxide of carbon, (HPN
+ C202)
2. Benzoyl. — Theory. By the recent investigations of
Wöhler and Liebig, on the volatile oil of bitter almonds, they
have inferred that benzoic acid has a base, to which they give
the name of benzoyl, composed of C14H502. They also ob-

324
Vegetable Chemistry.
tained chloride, bromide, sulphuret, and cyanide of benzoyl,
from which it is inferred that benzoyl exists as a separate
compound, and that it is capable of combining with other
simple bodies.
3. Ethers. - Theory. Dumas considers the base of ether
to be C4H4. Liebig regards the base as thus constituted,
C4H5. Sulphuric ether, according to the latter, is an oxide
of C4H5, and is represented by C4H50. Alcohol is a hy-
drate of sulphuric ether, or C4H50 + HO. 10. kolo
The radical of ether (C4H5) is capable of combining with
chlorine, bromine, iodine, and forms chloric, bromic, and
iodic ethers.
4. Pyracids. — Theory. When several of the vegetable
acids are distilled, they undergo decomposition, and new acids
are generated, which are called by the term pyracids. Tar-
taric acid becomes pyrotartaric acid; gallic, pyrogallic; and
so of several others. The difference in composition seems to
be that a quantity of water is expelled by the heat.
5. Theory of Substitutions. When oxygen, chlorine,
bromine, and iodine, unite with various compounds, the latter
give out hydrogen, and the process is termed dehydrogenizing:
Thus, when dry chlorine gas is passed into pure oil of bitter
almonds, (C14H*O2 +H,) it loses its atom of hydrogen, and
an atom of chlorine is substituted, and the compound con-
sists of C14H502 + Cl, a chloride of benzoyl. This and
other analogous facts have been generalized by Dumas, and
the following general conclusions made: --
1. That when a body is subjected to the dehydrogenizing
action of O, CI, Br, and I, it gains one of the latter for each
atom it loses of hydrogen.
2: But if the body contain water, it loses its hydrogen
without any substitution. If, after this, hydrogen is extracted,
the substitution proceeds as before.
3. The fundamental radical and its derivatives will be
neutral or alkaline, whatever be the portion of oxygen, hy-
drogen, &c., entering into it. But when the oxygen,
bro-

Vegetable Acids.
325
mine, &c., enter into combination with this radical, they
render it acid, -T.
Secr. 1.
VEGETABLE Acids.
Vegetable acids are, for the most part, less liable to spon-
taneous decomposition than other organic substances, al
though none of them can exist at the temperature of a red
heat; they all contain carbon and oxygen, and most of them
hydrogen also; generally, they have more oxygen than would
be sufficient to form water by combination with the hydro-
gen; but a few have these elements in the same ratio as in
water, while in benzoic acid the hydrogen is in excess.
Oxalic Acid (C²03. 36, T. 200 +0. 36.24, L.) was dis-
covered by Scheele, in 1776, and is found in several plants,
among which is common sorrel, the sour taste of which is
caused by the presence of oxalic acid; it is obtained also by
the action of nitric acid on sugar. Many other organic sub-
stances, as starch, gum, most of the other vegetable acids
also, wool, silk, etc., are converted into oxalic acid by the
action of nitric acid; it contains more oxygen than any
other
organic substance.
Properties. Oxalic acid is sold in small, slender crystals,
and much resembles Epsom salts, for which it is sometimes
mistaken with fatal consequences. But, although a powerful
poison, it may be tasted without danger, when its strong
acidity will easily distinguish it; if taken by accident, pow-
dered chalk in water or magnesia should be administered.
Oxalates of Potassa. There are three of these compounds,
one of which, the binoxalate, (HO.C203, KO.C202 + 2A.
155.63,) is often sold under the name of essential salt of
lemons, for removing the stains of iron-rust from linen; a so-
lution of oxalic acid will answer the same purpose. Quad-
roxalate of potassa is sold for the preceding, and is formed
by dissolving the binoxalate in hydrochloric acid, and crystal-
lizing. In this way the salt is manufactured on a large scale
28

326
Vegetable Chemistry.
Oxalate of Lime (CaO.C203 + 2Aq. = 82.74) exists in
several species of lichen, and, when recently precipitated, is
a snow-white flocculent powder. This salt may be distin-
guished from most other precipitates by its being insoluble
in water, ammonia, and acetic acid, but soluble in nitric and
hydrochloric acids. On this account, lime may be detected
in solutions from which all other metallic oxides have been
separated : thus these oxalates are used to separate lime from
magnesia. Lime may also be used to detect oxalic acid.
Acetic Acid, C4H303. 51.48. This acid exists in the sap
of many plants, and is generated in large quantities, in the
destructive distillation of vegetable substances, and in the
acetous fermentation; it is the acid of common vinegar.
Distilled vinegar is transparent and colorless, of a strong
acid taste and an agreeable odor. To obtain acetic acid in
a purer state, saturate distilled vinegar with a metallic oxide,
as of copper or lead, and distil the compound. Pyroligne-
ous acid consists of acetic acid mixed with tar and a volatile
oil, and is made by the distillation of wood. The concen-
trated acid is very strong and volatile, with a refreshing
odor; its vapor is inflammable. Numerous salts are formed
by this acid.
Acetate of Lead. 1 eq. acid, 1 protoxide of lead, 3 water.
This substance, commonly known under the name of sugar
of lead, is prepared by dissolving either the carbonate of lead
(white lead) or litharge in distilled vinegar. Like most of
the compounds of lead, it is highly poisonous. It is one of
the most important of the acetates. It is used in pharmacy,
and by dyers and calico-printers for the preparation of
acetate of alumina and iron.
Acetates of Copper. Of these there are three or four.
Verdigris is a variable mixture of them, and is prepared in
France by covering copper with the refuse of grapes, after
the juice has been extracted. In England, a better article is
prepared by covering copper plates with cloth soaked in
pyroligneous acid.

Vegetable Acids.
327
Acetate of Alumina is extensively employed by calico-
printers as a mordant for fixing colors. Acetate of Iron is.
also used for the same purpose. Acetate of Ammonia has
long been used in medicine. Acetate of Zinc is sometimes
applied externally as a remedy, and Acetates of Tin have
been recommended as mordants for the use of dyers. Ace-
tate of Mercury was once used in medicine.
Malic Acid. C4H204. 60. This acid is contained in
grapes, currants, gooseberries, oranges, apples, and in most
of the acidulous fruits. It is also obtained by the action of
nitric acid on of its weight of sugar; it forms salts with
metallic oxides, called malates.
Citric Acid. C4H264, 60. This acid is also found in
many acidulous fruits, especially in limes and lemons, from
which it is usually obtained. It has an agreeable flavor, and
is an excellent substitute for lemons; it iš used in the prep-
aration of lemon sirup, in which, however, tartaric acid is
largely employed, being much less expensive, but of very
inferior flavor. Citric and malic acids are isomeric.
Tartaric Acid. C4H205. 66.24. This acid also exists in
acidulous fruits, usually in combination with lime or potassa.
Tartaric acid is used with the bicarbonate of soda for an
effervescing drink; it forms numerous salts, many of which
are double.
Bitartrate of Potassa. In an impure form, this is known
by the name of crude tartar, and is found incrusted on the
sides of wine casks, colored by the wine; when purified, it is
white, and is known by the name of cream of tartar. It is
used for the preparation of tartaric acid, and as a medicine.
Tartrate of Antimony and Potassa. This compound is
sold under the name of tartar emetic, and is prepared by boil-
ing sesquioxide of antimony with cream of tartar. It is neu-
tralized by vegetable astringents, as tea, or Peruvian bark,
which may therefore be used as an antidote, in case of taking
a too powerful dose. It is a white solid, slightly efflores-
cent, and is composed, according to Phillips, of 1 atom of

328
Vegetable Chemistry.
bitartrate of potassa, 3 sesquioxide of antimony, and 3 of
water.
Tartrate of Potassa and Soda is prepared by saturating
an excess of acid in tartar, with carbonate of soda. It has
long been used in pharmacy under the name of Rochelle Salt
and Sel de Seignette. It consists of I atom of tartrate of
potassa, 1 atom of tartrate of soda, and 10 atoms of water.
Tannic Acid, or Tannin. C'18H8O12. 212. This substance
exists in gall-nuts, (the excrescences of several species of the
oak,) in the bark of most trees, in tea, and in most vegetable
astringents, and is the cause of their astringency. With
gelatin or glue, it forms an insoluble compound, which is
the basis of leather. Hence leather is prepared by soaking
skins in water, which contains ground bark, the tannic acid
of which is taken in solution by the water.
Exp. To a strong solution of gelatin (common glue answers well
enough) add a strong infusion of gall-nuts; a white precipitate will be
formed, and may be collected upon a glass rod and pressed together,
fornring a strong extensible mass, resembling new leather. When ex-
posed to the oxygen of the air, it is gradually converted into gallic acid.
Gallic Acid. C'H'05. 85. This acid also exists in gall-
nuts and in the bark of trees, but is more abundantly ob-
tained by the oxidation of the tannic acid of gall-nuts.
Common ink owes its color to the compounds of tannic and
gallic acids with the sequioxide of iron, and may be extem-
poraneously prepared by adding to an infusion of gall-nuts
a solution of copperas, which has been exposed to the air.*
Some of the most important of the remaining vegetable
acids are the following: -
Mellitic Acid (C'03. 24.48 +24=48.48) is contained in
the rare substance called honey-stone. It exists as a white,
* A very good ink may be formed thus: Take 8 oz. of bruised galls,
4 oz. sulphate of iron, 3 oz. gum arabic, and 1 oz. of sugar candy. Boil
the galls in 6 qts. of water until but 3 qts. remain; strain, and add the
other ingredients, stirring the whole till dissolved.
Ink may be kept from moulding by keeping a few cloves in the bot-
tle. Common writing ink is much more permanent if Indian ink
which is lampblack made into a cake with isinglass — is dissolved in it,
1 oz. to 3 qts, of ink.

Vegetable Acids.
329
-
slightly-crystalline powder, soluble in alcohol; and, by boil-
ing the solution, there seems to be formed an acid mellitate
of ether. It forms salts called mellitates.
Croconic Acid (C504 30.6 +.32= 62.6) is a yellow, ea-
sily-crystallized solid, soluble in water and in alcohol. All
its salts are yellow.
Lactic Acid, (C6H505. 36.72 +5+40 = 81.72,) so
called from being first noticed in sour milk, was discovered by
Scheele, in 1780. It has since been found in several vegeta-
ble bodies when left to spontaneous fermentation. It is col-
orless, without smell, but excessively sour. Its salts are
termed lactates.
Kinic Acid (C15H10010. 91.8+10+80 = 181.8) exists
in cinchona bark, in combination with lime, quinia, and
cinchonia.
Pyrocitric Acid. C10H203. 61.2 +2 +24=87.2.
Racemic Acid (C4H²O5. 24.48 +2 +40=66.48) is as-
sociated with tartaric acid in the juice of the grape.
Benzoic Acid (C14H503. 85.68 +5+24=114.68) ex-
ists in gum benzoin, from which it is commonly extracted, in
the balsams of Peru, and in several other vegetable sub-
stances, in the-urine of the cow and other herbaceous ani-
mals. This acid crystallizes in soft, white scales, flexible,
transparent, and of a pearly lustre; or in hexagonal needles ;
is slightly biting, but of a sweetish taste, producing sensation
in the throat; fuses at 250°, and sublimes at 300°.
Exp. Suspend a small branch of a shrub in a tall glass, without a
bottom: place a small quantity of the acid upon a plate of metal;
place the jar over the plate, at the same time applying the heat of a
lamp to evaporate the acid; the branch will be covered with delicate
white crystals.
Meconic Acid (C²H20". 42.84 +2 +56=100.84) is
found in the poppy, in combination with morphia, and crys-
tallizes in white, transparent scales.
Pyromeconic Acid, C10H304.
Metameconic Acid (C12H4010 73.44 +4+80= 157.44)
is obtained from the meconic by boiling its aqueous solution.
28 *

330
Vegetable Chemistry.
Pyrogallic Acid (C6H3O3. 36.72 +3 +24= 63.72) is
obtained by heating gallic acid to 419º.
Metagallic Acid (C12H303. 73.44 +3 + 24 = 100.44) is
formed by heating gallic acid to 480°.
Ellagic Acid (C?H?04. 42.84 +2+32= 76.84) is very
similar to the preceding.
Succinic Acid (C4H²03. 24.48 +2+ 24 = 50.48) exists
in amber, and is obtained by the aid of heat. It is obtained
in three states: -- 1. Combined with an atom of water, which,
when pure, is the crystallized acid of the shops. 2. With }
an atom of water, produced by keeping the crystallized acid
for a long time between the temperatures of 260° and 284°.
3. Anhydrous. The compounds which this acid forms with
bases are termed succinates.
Mucic Acid. C6H508. 36.72 +5+64 = 105.72.
Camphoric Acid (C20H1605. 122.4 +16+40=178.4)
is obtained from camphor by nitric acid.
Valerianic Acid (C10H’O3. 61.2 +9 + 24 = 94.2) ex-
ists in the root valerian, and is obtained by distillation.
Rocellic Acid. C16H1604. 97.92 +16 + 32=145.92.
Moroxylic Acid is found, in combination with lime, on the
bark of the white mulberry.
Oily Acids, so called because they are obtained from oils
or fat, and enter into the composition of soaps.
Stearic Acid (C70H605. 527) is obtained from soap, and
is a white, tasteless, inodorous substance, insoluble in water,
and burning like wax. Its salts are termed stearates.
Margaric Acid (C70H7009. 562) is distinguished from the
preceding by fusing at 140°. When distilled with lime, a
white substance is obtained, called margarone.
Oleic Acid (C70H6207 538) is obtained from the soap
made from linseed oil and potassa. It burns like the fixed
oils, and forms salts, or soaps, called oleates. When olive oil
is mixed with half its weight of concentrated sulphuric acid,
three acids are formed, one of which has been called sulpho-
oleic; and this, when decomposed, affords hydro-oleic acid.

Vegetable Acids.
331
From this last compound two liquids have been obtained, of
the same composition with olefiant gas. The one has been
called olein, the other elain.
Olein (C6H6) is a white liquid, lighter than water, strong
odor, very combustible, burning with a greenish flame, and
yielding a poisonous vapor.
Elain is composed of C9 + Hº, and burns with a fine white
flame.
The Azulmic Acid, (C8H4N404,) the Indigotic, (C23H71
N1J015,) which is obtained by boiling indigo in rather dilute
nitric acid, and the Carbazotic acids, (C15N3015. 252,) also,
are obtained from indigo containing nitrogen.
Pectic Acid (C11H*010. 153) has been imperfectly ex-
amined.
Crenic Acid (108) was discovered by Berzelius, in 1832,
in the water of Porla well, in Sweden. It is inodorous, a
sharp, followed by an astringent taste, yellow and trans-
parent; very soluble in water and in alcohol. When the
solution is exposed to the air, apocrenic acid is formed.
Its salts are termed crenates, and resemble extracts in ap-
pearance, but are incapable of crystallizing.
Apocrenic Acid (132) was obtained by digesting the ochre
of Porla well with potassa, and precipitating the acid by
means of acetate of
copper.
The apocrenate of copper falls,
from which the acid is separated by the action of hydrosul-
phuric acid, absolute alcohol, and potassa. It is a brown
substance, resembling a vegetable extract. Crenic and apo-
crenic acids have been detected in many waters, and in the
vegetable mould of soils.
There are also a numerous class of compound acids. For
a complete description of the vegetable acids, the student is
referred to Thompson's Chem., Organ. Bodies.
Cyanogen and its Compounds. A numerous class of
bodies are formed by the combination of cyanogen' with other
substances which exist in the vegetable and mineral king-
doms; for a description of which, see Webster's Chem., and
also Thompson's Chem., Organ. Bodies.

332
Vegetable Chemistry.
Sect. 2. VEGETABLE ALKALIES.
The existence of vegetable alkalies was not known until
the present century, and very little attention was given to
them until 1816. They are eighteen or twenty in number.
Their constitution is remarkable, as they each contain 1
equiv. of nitrogen in each equiv. of the alkali. The equiva-
lents of oxygen vary from one to six, of hydrogen from
twelve to twenty-two, and of carbon from twenty to thirty-
four; all, which have been analyzed, consists of these four
elements. In vegetable bodies they usually exist in combi-
nation with acids, forming salts.
The method of preparation is nearly the same for all of
these alkalies; the substance which contains one of them is
steeped in a large quantity of water, which dissolves the salt
that contains it; the solution is boiled for a short time with
lime or magnesia, and the vegetable alkali is set free in an
insoluble state, and may be collected on a filter with the lime;
if then boiled in alcohol with powdered charcoal, it is dis-
solved by the former, and purified by the latter; then, by
filtering while hot, it is separated from the charcoal, and the
lime with which it was mixed; it is deposited from the alco-
hol on cooling, by evaporation.
Morphia. C34H18N106 = 284. This alkali is the narcotic
principle of opium, in which it is combined with sulphuric
and meconic acids, and is associated with several other vege-
table alkalies, and with gummy, resinous, and coloring mat-
ters. Opium contains about nine and a half per cent. of mor-
phia; when pure, it is very insoluble in water, and conse-
quently but little poisonous; but when in the state of a salt,
as in opium, it is a very powerful poison; one half a grain in
solution will produce alarming effects on the animal system.
When opium has been administered as a poison, the presence
of its morphia may be detected by a process too elaborate to
be inserted here. A skilful chemist will detect a single grain
of morphia in 700 grains of water. Some of the salts of mor-

Vegetable Alkalies.
22
DOO
phia are useful as medicines, of which the hydrochlorate and
acetate are the principal.
Narcotina (C40H20N012 = 370.24) was discovered by Des-
rone, in 1803, and is obtained from opium ; it is a white sub-
stance, and may be taken into the human stomach without
sensible effects, but it is speedily fatal to dogs.
Cinchonia (C20H12N011 =158) and Quinia, (C20H12NO2
= 162.) These two alkalies were detected by Pelletier and
Caventou, in 1820, in Peruvian bark, and impart to it its
value as a medicine. Cinchonia is found in the pale bark ;
quinia, with a little cinchonia, in the yellow bark; and both in
the red bark. Cinchonia is insoluble in cold water, and
nearly so in hot water ; in boiling alcohol it is freely dissolved,
and the solution has an intensely bitter taste; some of its salts
are soluble in water.
Quinia, or Quinine, is also almost insoluble in water, but
with alcohol forms an intensely bitter solution.
Quinia forms several salts, one of which, the sulphate, is
manufactured in large quantity for medical purposes, and is
commonly sold by the name of quinine. It is soluble in al-
cohol, or slightly in pure water, and freely if the water is
slightly acidulated by sulphuric acid; the solution, although
containing but a minute portion of quinia, is intensely bitter.
On account of its high value, sulphate of quinia is often
adulterated with gum, starch, sugar, magnesia, and various
other substances; gum and starch are insoluble in alcohol,
and may be detected by dissolving the suspected quinia in
boiling alcohol. Sugar may be detected by adding pearlash
to the solution in water, when the quinia will be thrown
down, and the sweet taste may be perceived; magnesia will
be left after burning a portion of the adulterated article.
Strychnia (C30H16NO3=237.75) was discovered in 1818,
by Pelletier and Caventou. This remarkable alkali is found in
the nux vomica and in the upas-tree. It is freely soluble in
alcohol, and but slightly so in water; although nearly insoluble
in the latter, the minute portion which is taken up, commu-
nicates to the water the most intense bitterness; a single

334
Vegetable Chemistry..
grain of strychnia will render eight gallons of water bitter.
It is one of the most virulent poisons yet discovered ; half a
grain in the throat of a rabbit occasioned death in five
minutes. Its action is always accompanied by symptoms of
locked-jaw.
Emetia. This alkali constitutes 16 per cent. of ipecacu-
anha, and appears to be the sole cause of its emetic
proper-
ties.
Sanguinaria is a peculiar alkali, discovered, by Mr. Dana,
in the blood root, (sanguinaria Canadensis.) Its salts have a
red color.
Nicotina is the peculiar principle of tobacco; it is a viru-
lent poison.
Codeia ; discovered in 1832, by Robiquet, in the hydrochlo-
rate of morphia. When taken into the stomach in doses of
from 4 to 6 grains, it produces an excitement similar to in-
toxication, followed by depression, nausea, and vomiting.
Brucia, or Brucina, resembles strychnia, and may be pro-
cured from the nux vomica. It is intensely bitter, less poison-
ous than strychnia, but similar in its effects.
Conia is the active principle of conium-maculatum, or hem-
lock, and is the most virulent poison known, with the excep-
tion of hydrocyanic acid.
Parillia, or Parillina, exists in the common sarsaparilla of
commerce. Its color is white, taste, sharp and bitter, and,
when swallowed to the extent of 13 grains, produces nausea,
vomiting, diminishes the rapidity of the circulation, and acts
as a sudorific.
SECT. 3. Neutral SUBSTANCES.
Sugar. C12H10010 = 162.24. Sugar is found in most ripe
fruits, but more abundantly in the sap of the maple-tree, in
the sugar-beet, and in the sugar-cane; from the latter it is
obtained by evaporating the juice by a moderate ebullition,
until the sirup is sufficiently thick to crystallize on cooling.
During this operation, lime water is added to neutralize the

Neutral Substances.
335
acid present, and to remove impurities which rise with the
lime in a scum to the surface; it is next drawn off into shal-
low coolers, in which it becomes a soft solid. Lastly, it is
put into barrels with holes in the bottom, through which the
molasses gradually runs out, leaving raw or brown sugar.
Raw sugar is purified by boiling it with the white of eggs or
bullock's blood and lime water; it is then received into con-
ical vessels, and in cooling assumes the form of loaf sugar.
When two pieces of loaf sugar are rubbed together in the
dark, phosphorescence is observed; it is obtained in large
crystals by fixing threads in a sirup, which evaporates grad-
ually in a warm room; in this state it is called rock-candy.
Sugar does not deliquesce when exposed to the air, except
when impure, as raw sugar. It is soluble in an equal weight
of cold water, and is much more soluble in warm water; it is
soluble in four times its weight of boiling alcohol, from
which solution fine crystals are obtained. The vegetable
acids diminish the tendency of sugar to crystallize, as in
molasses.
By the action of sulphuric acid, starch, and common
wood, may be converted into sugar.
Sugar of Grapes (C12H12012) contains rather less carbon
than common sugar, and is rather less sweet.
Honey consists of two kinds of sugar, one of which, when
separated, crystallizes, and the other is uncrystallizable. Be-
sides sugar, it contains gum, and probably an acid; when di-
luted with water, honey undergoes the vinous fermentation.
Common sugar requires the addition of yeast for this change.
Manna is the concrete juice of several species of ash, and
owes its sweetness, not to sugar, but to a distinct principle
called mannite.
Liquorice owes its sweetness to a saccharine principle
which is quite distinct from sugar.
Starch. Starch exists abundantly in the vegetable king-
dom. It is the principal constituent of most kinds of grain,
potatoes, and other farinaceous substances. It is obtained

336
Vegetable Chemistry.
from potatoes by washing them in cold water, when the glu-
ten, which is the other principal constituent, remains in the
hand, and the starch is mechanically diffused through the
water. The water is then allowed to stand, and the starch
subsides, while the saccharine and mucilaginous matters
remain in solution. When made from the dough of wheat
flour, the water containing the soluble and insoluble parts of
the flour is allowed to ferment; acetic acid is thus formed,
which dissolves the gluten, and facilitates the separation of
the starch.
Starch is easily converted into sugar. In the germination
of seeds, and in the malting of barley or other grain, this
change takes place. If starch is boiled for a considerable
time in water, which contains 15 its weight of sulphuric acid,
it is converted into a kind of sugar like that obtained from
grapes.
Arrow-root, prepared from the root of a plant, is a very
pure starch. Sago, prepared from the pith of an East India
palm-tree, and tapioca and cassava from the root of a plant,
are essentially the same.
Gluten. Gluten exists with starch in most kinds of grain,
which are chiefly composed of two principles. It is obtained
from wheat flour by washing out the starch and soluble mat-
ter, and boiling the remainder in alcohol. On adding water
and distilling off the spirit, it is deposited. It is without
taste, very tenacious, elastic, and insoluble in water. When
kept warm and moist, it ferments. The tenacity of common
paste is owing to the gluten which it contains. The rising
of bread is caused by the fermentation of gluten, the tenacity
of which retains the bubbles of carbonic acid gas formed in
fermentation. Gluten has been resolved into four distinct
principles, viz., vegetable albumen, emulsin, mucin, and
glutin. These substances are obtained by the action of
alcohol upon the gluten of wheat.
Gum. Under this name are included all those vegetable
principles which form, when dissolved in water, an adhesive,

Oils.
337
viscid liquid, called mucilage, and which yield an acid, called
mucic acid, when boiled with four times their weight of
nitric acid. Gum is insoluble in ether and alcohol, and is
precipitated by them from its aqueous solution, as an opaque,
white substance; but, with acids and alkalies, it is more
soluble than in pure water.
er.
Gum Arabic is the most common variety of gum; it is
obtained from several species of acacia or mimosa in
Africa and Arabia. Gum Senegal differs in no important
respect from gum arabic. The gum of the peach, plum, ,
and cherry-tree, although identical in composition with gum
arabic, differs in being insoluble in cold water; after being
boiled, however, it assumes the characters of that gum.
Gum Tragacanth differs from gum arabic in containing a
large portion of bassoric, starch, and water; it is tougher
than common gum, which is quite brittle. Gum tragacanth
is therefore a very useful ingredient in paste. The jelly of
fruits is distinct from gum in some properties, but is nearly
allied. 602
Lignin. Lignin, or the woody fibre, constitutes the
fibrous structure of plants, and is the most abundant prin-
ciple in them. The common kinds of wood contain about
96 per cent. of lignin. It is insoluble in alcohol or water.
With strong alkalies or acids, it is changed. With sulphuric
acid, it is changed into gum, and, on boiling, is further
changed into a sugar like sugar of grapes. Straw, bark,
and linen, in the same way, may be converted into sugar.
Sect. 4. Oils. leginy art
pate with more
These substances are divided into fixed and volatile oils.
The former are not much affected by a heat which does not
decompose them, while the latter rapidly pass away in vapor.
The greasy stain of the former on paper, or any other sur-
face, is permanent; that of the latter soon disappears.
1. Fixed Oils. The vegetable fixed oils are usually oko
29

338
Vegetable Chemistry.
tained from seeds; as the almond. linseed, and poppy-seed.
Olive oil, however, is extracted from the pulp around the
stone. The density of these oils is less than water, varying
from .9 to .96. They are solid at a low temperature. They
burn with a clear, white light. By exposure to the air, they
become rancid, and at length viscid. In this change, oxygen
is absorbed; and the oil itself probably undergoes some
change, although it has been supposed that rancidity was
caused by the acidification of some mucilage present. By
heating the oil in open vessels, it acquires the property of
drying rapidly; in which process much oxygen is absorbed,
and carbonic acid and hydrogen given off. Drying oils are
used for paint, and, when mixed with lampblack, constitute
printers' ink. Drying oils sometimes absorb oxygen so
rapidly as to set fire to combustibles. Spontaneous com-
bustion often occurs where cotton has been moistened with
them.
By means of mucilage or sugar, the fixed oils may be
permanently suspended in water. Such a mixture is called
an emulsion. With ammonia, they form a soapy liquid called
volatile liniment, which is a direct compound of oil and the
alkali. The fixed alkalies have a similar action in the cold,
but, when heated, soap is generated. A further notice of
soaps will be found under Animal Chemistry.
The fixed oils consist of two proximate principles, one of
which, called margarine, is solid at common temperatures,
while the other is fluid, and is called oleine.*
These oils consist of carbon, hydrogen, and oxygen.
The principal fixed oils are the following: -
Olive Oil, which is expressed from the pericarpum of the
fruit of the common olive, (olea Europea.) By the action
of hyponitrous acid, the solid substance called elaidin is
formed. It contains an acid called elaidic, which combines
with alkalies and forms soaps. It is used as an article of
luxury
* From £lalov, oil.

Oils.
339
Croton Oil is obtained from the croton tiglium of the
East Indies, and possesses powerful purgative properties.
Palm Oil has the consistency of lard, and is used in the
manufacture of yellow soap.
Cocoa-nut Oil is a white, hard substance, used as a sub-
stitute for tallow.*
2. Volatile or Essential Oils. The flavor of aromatic
plants is owing to the presence of volatile oils, which are
obtained by distillation. Water must be added to the plants
to keep them from burning. Some, however, are obtained
by expressing the rinds of certain fruits, such as the orange,
lemon, bergamot. Although usually of an agreeable odor,
those oils have an unpleasant, acrid taste; but, when diluted,
some of them have an agreeable taste. They are but slight-
ly soluble in water, and are freely dissolved in alcohol.
Such solutions are commonly sold under the name of
essences. Like the fixed oils, they burn with a clear, white
light. They have the property of dissolving sulphur, and
the solution is called balsam of sulphur.
A few of these oils -- as the oil of turpentine, of lemons,
and of copaiva - contain only carbon and hydrogen; others
contain oxygen also. A few contain one or more additional
elements, as sulphur and nitrogen.
The principal volatile oils are
are, oil of turpentine, lemons, anise,
juniper, camomile, caraway, lavender, peppermint, rosemary, cam-
phor, cinnamon, cloves, sassafras, mustard, and bitter almonds.
Common Spirits of Turpentine consists of resin dissolved
in the oil of turpentine — which last may be obtained by
distillation. To Set
Camphor is a volatile oil, solid at common temperatures.
On account of its toughness, it is pulverized with difficulty,
unless a few drops of alcohol be added. It is insoluble in
water, but is freely soluble in alcohol. Artificial camphor
* The various kinds of wax — such as beeswax, myrtle wax, and
cow-tree wax -- are regarded as similar in composition with the fixed
oils, and are classed by some chemists with them.

340
Vegetable Chemistry.
may be formed by passing a current of hydrochloric acid gas
through oil of turpentine or oil of lemons. Camphor is very
offensive to insects, which are prevented from devouring cab-
inets of natural history, collections of birds, insects, etc., by
placing pieces of camphor in the cases.
Resins. Resins are the concrete juices of plants, solid,
brittle, and without taste; they are good non-conductors
of electricity, and, by friction, become negatively electrified;
they are easily melted, and burn with a yellow flame and
dense smoke. They are soluble in alcohol, ether, and the
essential oils, but are quite insoluble in water.
The different kinds of resin are numerous.
Common Resin is procured by heating turpentine; the
volatile oil is expelled, and resin remains.
Turpentine is the juice of several species of pine-trees.
Other resins are copal, lac, mastic, and dragon's blood.
Copal is the most important, and is used for varnish. In-
dian ink is a solution of borax, lac, and lampblack.
The uses of resin are various. Dissolved in oil or alco-
hol, and diluted with spirits of turpentine, they form various
kinds of varnish. Sealing-wax is made of lac, turpentine,
and common resin. It is colored red with cinnabar or red
lead, or black with lampblack.be bolezni
The soot, which is procured from the combustion of res-
inous wood, turpentine, or resin, is lampblack. When tur-
pentine is extracted by heat, it is partially changed, and be-
comes tar. When tar is thickened by boiling, it becomes
pitch. oder sonstiges
Amber is a fossil substance, consisting of a peculiar bitumi-
nous matter and resin; it often contains insects.
Balsams are the juices of some kinds of trees. Some are
solid, others are liquid. They are composed of resin and
benzoic acid.nl
Gum Resins are the hardened juices of certain plants, con-
sisting of resin, gum, and volatile oil. Their proper solvent,
therefore, is a mixture of alcohol and water, or common

Oils. — Alcohol.
341
spirits. They are numerous, and many of them are valuable
medicines; among them are aloes, asafoetida, galbanum,
gamboge, myrrh, and guaiacum.
Caoutchouc, or India rubber, is obtained from four species
of trees, two of which grow in South America, and two in
the East Indies. It is usually black, but when not darkened
by smoke, is of a whitish color. It burns with a bright flame;
is insoluble in water or alcohol. It is soluble in ether, the
essential oils, etc. If a bag of it be soaked in ether, it will
become soft and gelatinous before dissolving, and in that
state may be blown out into a very large and thin bag. The
most useful solvent of caoutchouc is a dark, volatile liquid,
obtained by the careful distillation of caoutchouc itself;
about four fifths of the solid pass over in this liquid form.
Wax Wax is found in the pollen or dust of flowers, on
some leaves as a kind of varnish, and especially on the berries
of the wax-plant, (myrica cerifera.) As bees deposit wax,
when fed only on sugar, beeswax is an animal product. Wax
is insoluble in water, and is sparingly dissolved by alcohol
and ether. It is composed of two principles, cerin and
myricin.
Creosote. This substance exists in tar, and in pyroligne-
ous acid. It is a colorless, oily liquid, with an odor like
smoked meat. It has burning taste, followed by sweetness.
Its most remarkable property is that of preserving meat. The
antiseptic properties of smoke, and crude pyroligneous acid,
appear to be owing to this substance. It is soluble in 80
parts of water, and freely in alcohol. Insects and fish are
killed by the aqueous solution. It is said to be useful as a
cure for toothache, ulcers, etc.
Sect. 5. SPIRITUOUS AND ETHEREAL SUBSTANCES.
Alcohol. C4H50+HO. 46. This substance is the prod-
uct only of fermentation, and is never found ready formed in
any vegetable substance. It is obtained by the distillation
of ardent spirits, of which it constitutes 50 per cent.
After
29 *

342
Vegetable Chemistry.
a second distillation, it still contains some water, most of
which may be removed by carbonate of potassa added in a
dry state. Common alcohol has a specific gravity of about
.86, but when freed from water, of .82. The purest alcohol
boils at a temperature of 176° Fahr., is highly inflammable,
burning with a very pale blue, but hot flame. No smoke is
produced in its combustion, and hence it is of great utility
for lamps in a laboratory, various kinds of apparatus being
thus conveniently heated, and not soiled with smoke. Al-
though exposed to a temperature of -176° Fahr., pure alco-
hol has never been frozen.
Alcohol combines with water in every proportion; with
an equal quantity of water, it constitutes spirit of the first
proof. The density of this is about .92. The density will
be in proportion to the weakness of the spirit. Proof spirit
is very useful, in cabinets of natural history, for the preser-
vation of specimens of fishes, reptiles, etc. Its effects upon
the animal system, as a poison, are well known: it has the
power of passing into the circulation undigested, and ir-
ritates all the organs with which it comes in contact. The
stronger wines contain 18 to 25 per cent., and the weaker
from 12 to 17 per cent. In wines it appears to have less in-
toxicating power than in ardent spirits, which may be owing
to its chemical combination with mucilaginous and saccha-
rine matters.
As a solvent, alcohol is useful. Many vegetable princi-
ples, not soluble in water, are freely so in alcohol. Both
mineral and vegetable alkalies are soluble, but it does not
dissolve the earths, or other metallic oxides.
Ethers. Most of the stronger acids, when heated with
alcohol, yield a very volatile, inflammable liquid, called ether.
Different kinds are formed from different acids.
Sulphuric Ether (C4H50) is the most common.
pared by boiling equal weights of alcohol and sulphuric acid;
the vapor of ether passes over, and is condensed in a vessel
surrounded by ice-cold water.
It is pre-

Ether. - Coloring Matters.
343
The specific gravity of pure ether is . 7; as commonly sold,
.74. It boils at the temperature of blood heat; in a vacuum,
it boils at -40° Fahr. It congeals at -46° Fahr. It is
slightly soluble in water, but combines with alcohol in all
proportions.
Hydrochloric Ether (C4H5Cl) is formed by the action of
hydrochloric acid on alcohol. It burns with an emerald-
green flame, without smoke.
Nitrous Ether (C4H50+NO3) is produced by the action
of equal quantities of nitric acid and alcohol, and resembles
sulphuric ether, but is more volatile.
Oxalic Ether (C4H*0+ C203) is formed by mixing 1 part
of alcohol, 1 binoxolate of potassa, and 2 of SO3.
Enanthic Ether (C4H0+C14H1302) gives to wines their
peculiar odor, and is obtained in the distillation of wine, as
an oily liquid, which is a mixture of enanthic ether with ex-
cess of ænanthic acid. The ether is separated by distillation.
It produces intoxication when inspired.
Pyroxylic Spirit (C2H30 + HO. 32) is a kind of ether
formed by heating wood, and comes over with the aqueous
liquid. It has an alcoholic and aromatic odor, and is em-
ployed by hat-makers, for the purpose of dissolving shellac
and mastic, to stiffen and render hats water-proof.*
វិបសនា
SECT. 6. COLORING MATTERS.
The most common colors in the vegetable kingdom are
green, yellow, blue, and red. The greater part of the infinite
diversity of colors consists of different shades or mixtures of
these. The coloring matter of plants is usually diffused
through other proximate principles. All vegetable colors
are destroyed by chlorine, and usually changed by acids or
alkalies.
Lakes are insoluble compounds of coloring matter with
alumina, or oxide of iron or of tin.
* For a complete description of ethers, see Thompson, Org. Bodies.

344
Vegetable Chemistry.
Process. Dissolve alum in a colored solution, and, on add-
ing an alkali, (as potassa,) alumina will be precipitated, and,
at the moment of separation from the alum, will combine
with the coloring matter.
In dyeing, some colors have a sufficient affinity for the
fibre of the cloth to remain fast on a mere immersion of it.
In many cases, however, this is not sufficient, and the color
would be removed by washing. A third substance is intro-
duced, which, having an affinity both for the coloring matter
and the cloth, fixes the former permanently to the latter.
This third substance is called the mordant or basis : those
which are in common use are, alumina in alum, oxide of
iron in copperas, and chloride of tin, which is converted into
the oxide. All the colors of dyed stuffs are produced from
the four – blue, red, yellow, and black.
Blue Dyes. Indigo is the most important of these, and is
obtained from several species of a genus of plants which are
cultivated in America and Asia. The plants are fermented
and beaten in water, at the bottom of which the indigo sub-
sides. Common indigo contains, in addition to its peculiar
blue, a red and a brown coloring matter, with some gluten.
Pure indigo sublimes at 550° Fahr., and condenses in acic-
ular crystals. It is insoluble in water, and but slightly
soluble in boiling alcohol; it is soluble in sulphuric acid. If
indigo be put into a tube with three times its weight of green
vitriol, and an equal quantity of slacked lime, with water, the
protoxide of iron will be precipitated by the lime from the
green vitriol, and the indigo will be de-oxidized by it, and
become yellow. Dyers dip their cotton cloth into it in this
condition, and by exposure to air the cloth becomes perma-
nently blue.
Red Dyes. The most common substances for red dyes
are cochineal, lac, archil, madder, Brazil wood, and logwood.
Cochineal is obtained from an insect which feeds
the
leaves of several species of the cactus, and which is supposed
to derive this coloring matter from its food. It is very solu-
ble in water, and is fixed on cloth by means of alumina or
upon

Fermentation.
345
oxide of tin. Its natural color is crimson, but when bitar-
trate of potassa is added to the solution, it yields a rich,
scarlet dye. The beautiful pigment called carmine, is a lake
made of cochineal and alumina or oxide of tin. — T. Archil
is obtained from a lichen which grows in the Canary Islands.
Litmus, which consists of red coloring matter and alkali, is
prepared from it. Madder is the root of the rubia tendorum,
and employed for dyeing the Turkey red.
Yellow Dyes. The principal are quercitron bark, turmeric,
saffron, and fustic.obra oss
Black Dyes. These are prepared from the same ingre-
dients as writing ink. The addition of logwood and acetate
of copper gives a blue-black.
Secr. 7. FERMENTATION.
SIGHT
Many vegetable substances, when exposed to warmth and
moisture, undergo spontaneous changes, and the process is
called fermentation. It is most commonly observed in sub-
stances containing gluten, starch, gum, or sugar. In different
stages of the process, sugar, alcohol, and acetic acid are
formed, and finally, there is a total dissolution of the sub-
stance. These stages of the process are called the sac- .
charine, vinous, acetous, and putrefactive fermentations.
Saccharine Fermentation. Starch only is subject to this
kind of fermentation. The quantity of sugar produced equals
in weight half of the starch employed. The ripening of fruits
has been regarded as kind of saccharine fermentation, in
which the acid of the green fruit is converted into sugar;
this change is caused by heat, not by the vitality of the plant.
Vinous Fermentation. When sugar with water, and yeast
or some other ferment, is exposed to a warm temperature, the
sugar is converted into carbonic acid gas and alcohol, in
nearly equal weights of each. As starch is convertible into
sugar by fermentation, if the process be continued under the
above conditions, it will be converted into alcohol and car-
bonic acid. All vegetable bodies contain some substances

346
Vegetable Chemistry.
which act as a ferment, and therefore, by the addition of
moisture and regulation of the temperature, various kinds of
grain containing starch, and of ripe fruits containing sugar,
will undergo the vinous fermentation. Thus cider is formed
from apples, and beer from grain. To obtain ardent spirits,
the fermented liquor is heated, and the alcohol passes over by
distillation.
In the fermentation of bread, the saccharine matter of the
flour is resolved into alcohol and carbonic acid gas. The
latter causes the dough to rise, and the former is entirely ex-
pelled by the heat of baking. A company in London was
formed for collecting the spirit emitted by the baking of
bread; if the fermentation of dough be continued, it under-
goes the change next described, and becomes sour.
Acetous Fermentation. Any liquid which has undergone
the vinous fermentation, or pure alcohol with water and yeast,
exposed to the air in a warm place, undergoes a change, in
which oxygen is taken from the air, and carbonic acid thrown
off. In place of alcohol, acetic acid is found in the liquor.
Thus cider becomes sour by age, if exposed to the air, and
at length is converted into vinegar. In France, wine is con-
verted into vinegar, and in England, an infusion of malt.
Acetic acid is often formed in the spontaneous decomposi-
tion of vegetable substances without sugar. In these cases,
the process is quite different from the acetous fermentation,
properly so called.
Putrefactive Fermentation. Many vegetable principles, as
the acids, oils, resins, and alcohol, are not subject to putrefac-
tion; those which contain oxygen and hydrogen in the pro-
portion to form water, and especially those in which nitrogen
exists, are subject to this change; moisture, and a moderately
warm temperature, are essential to the process, which is also
promoted by air; water serves to loosen the particles of the
substance, and enables them to act freely upon each other.
The products of vegetable putrefaction are carbonic acid
gas, and light carbureted hydrogen. In stagnant waters,
which contain decaying plants, these gases often rise in bub-

Germination.
347
bles, especially if the bottom be stirred. Usually, light car-
bureted hydrogen is the most abundant gaseous product.
In plants, which contain nitrogen, ammonia is generated;
water is the principal liquid product, and vegetable mould,
consisting of charcoal, a little oxygen and hydrogen, the
solid product.
Secr. 8. GERMINATION.
Germination refers to the process by which a new plant
originates from the seed. The seed consists of two parts.
The germ, which is endowed with the vital principle, and the
cotyledons, or seed-lobes, which furnish nourishment to the
plant before it can derive it from the earth. The germ is
composed of the radicle, or that part which descends into
the ground, and forms the root, and the plumula, which rises
into the air, and forms the stem of the plant.
The three conditions necessary to the germination of the
plant, are moisture, a certain temperature, and oxygen gas.
Dry seeds will not germinate, or, if moist, germination will
not take place at 32°, nor at the temperature of boiling water,
which deprives the germ of its vitality. The most favorable
temperature is froin 60° to 80°, varying with the nature of
the plant. Air is also necessary to germination ; for if seeds
are buried deep, excluded from the air, they will never pass
through this process.
In the malting of barley, the process of germination may
be accurately studied. The malting is done by exposing the
grain to moisture, warmth, and air, until it begins to germinate,
and then drying it in a kiln, where the temperature ranges
from 100° to 160°, or more. The chemical changes which
take place in this process, are the following: The hordein,
an insoluble substance, is converted into starch, gum, and
sugar, which are soluble and very nutritive substances,
easily absorbed by the radicle of the plant; at the same
time, oxygen gas is consumed, and carbonic acid gas is
given off

348
Vegetable Chemistry.
Growth of Plants. There are many points of resemblance
between the growth of plants and of animals; and also many
points in which they differ. The chemical changes which
the sap undergoes, by what is called the respiration of plants,
is probably very analogous to what takes place in the blood
of animals; with this difference, however, that animals con-
sume oxygen, and throw off carbonic acid, while vegetables
absorb carbonic acid and yield oxygen gas, provided, in the
latter case, they are exposed to sunshine. In the night, the
reverse often takes place; light seems necessary to the color-
ing of plants, and to their health and perfection.
Food of Plants. Plants derive their food, for the most
part, from the earth. The soil generally consists of siliceous
earth, clay, lime, and sometimes magnesia, mixed with the
remains of animal and vegetable substances. The water
passes through it, and dissolves the salts contained in it, and
absorbs the gaseous, extractive, and other matters, which the
process of decomposing animal and vegetable remains pro-
duces. It is then absorbed by the roots of the plant, and is
conveyed to the leaves, where it is fitted to nourish the plant.
There are some plants, however, which do not derive their
nutrition from this source, as they are found to vegetate in
distilled water, and to grow for some time when merely sus-
pended in the air. This is accounted for on the supposition
that carbonic acid is the proper food for plants. This sub-
stance is obtained from the atmosphere, absorbed by the
leaves of the plant, and appropriated to its nourishment.
When plants are burned, their ashes contain various salts
which must have been derived from the earth.
The peculiar vegetable substances which are formed from
sap, appear to be under the control of the vital principle,
over which the ordinary agents of chemical changes have but
ittle power.
tot

Animal Chemistry.
349
CHAPTER V.
ANIMAL CHEMISTRY.
With the exception of the oils, animal substances usually
contain a large portion of nitrogen, and have a strong ten-
dency to putrefaction. Their proximate principles are much
less numerous than those of vegetables. In addition to car-
bon, hydrogen, oxygen, and nitrogen, sulphur, phosphorus,
iron, earthy and saline matters are usually present in animal
bodies.
SECT. 1.
PROXIMATE PRINCIPLES NEITHER ACID NOR
OLEAGINOUS.
Fibrin. This principle is the basis of the muscles, and is
found abundantly in the blood. It is a white, insipid solid
when pure, and easily putrefies. When subjected to the
action of nitric acid, it throws off a large quantity of nitrogen,
and with acetic acid forms a jelly.
Albumen. Albumen exists in a solid state in the skin,
glands, and vessels, and in a liquid state in the serum of
blood, the fluid of dropsy, and the white of eggs. The latter
substance consists almost solely of it. When liquid, it is
coagulated by heat, as in the boiling of an egg, or by alco-
hol and the stronger acids. Corrosive sublimate is a very
delicate test, producing a milkiness in water, which contains
2000 albumen.
Gelatin. This substance is abundant in the solid parts of
animals, in the skin, cartilages, membranes, and bones. It is
easily soluble in boiling water, and forms a bulky jelly on
cooling. One part in 100 of water, will render the whole
solid when cool. The jelly is a hydrate of gelatin; and, if
the water be expelled by a gentle heat, it may be preserved
for any length of time. This is glue, which is prepared
from the ears, skins, and hoofs of animals. Isinglass is the
purest yariety, prepared from the sounds of fish.
30

350
Animal Chemistry.
Osmazome exists in the muscular fibres. It is very insolu-
ble, and is supposed to give to broth its peculiar flavor.
SECT. 2.
ANIMAL ACIDS.
Many acids are found in animals, which are found also in
the mineral and vegetable kingdoms; such are the sulphuric,
hydrochloric, phosphoric, and acetic acids. Those which
are peculiar to animals, are very few, and are derived chiefly
from urine, or from oils and fats; of the latter are stearic,
oleic, and margaric acids. Formic acid is a remarkable acid,
found in ants, and is ejected by them when they are irritated.
SECT. 3.
ANIMAL OILS AND FATS.
These substances are very similar to the vegetable oils,
and may be used either in the manufacture of soap, or for
giving light.
Train Oil is obtained from the blubber of the right whale,
and is much inferior for lights to spermaceti.
Spermaceti Oil is obtained from the blubber of the sperm
whale, and from a large cavity in the head, from which
twelve or fifteen barrels of liquid oil are sometimes dipped
out. This substance is strained through stout bags, which
are subjected to a strong pressure. The solid which remains
is spermaceti, of which candles are manufactured, and the
liquid is the spermaceti oil. As the oil is more liquid in hot
weather, summer-strained oil contains more spermaceti, and
a given quantity will'therefore produce more light, and burn
less freely than winter-strained oil; the latter is usually pre-
ferred, as giving a clearer light, and as being less affected by
cold, but it is much less economical.
Hog's Lard and Suet are well-known substances, differing
much in respect to their point of fusion.
Animal oils and fats are not proximate principles, but con-

Complex Animal Substances.
351
sist chiefly of stearine and margarine, which are solid at
common temperatures, and oleine, which is liquid.
Soaps. When any of the animal or vegetable oils or fats
are boiled with a solution of potassa or soda, the former are
converted into margaric, oleic, or stearic acids, and another
principle called glycerine. The acids combine with the
alkali, and form soap. The compounds which they form
are soluble in pure water, but in solutions containing salts of
lime, oxide of lead, and many other metallic compounds,
they combine in preference with these oxides, and form in-
soluble compounds. Hence hard water, containing salts of
lime, curdles soap.
Ambergris, found floating on the ocean, is supposed to be
a concretion formed in the stomach of the sperm whale.
SECT. 4.
COMPLEX ANIMAL SUBSTANCES.
Blood.
Blood consists of a liquid, through which are diffused red
globular particles. The liquid portion consists of water,
holding in solution fibrin, with albumen, and saline and oily
matters. When set at rest, it coagulates, forming a jelly.
The red globules are also compound, containing fibrin and
the coloring matter. In mammiferous animals, these globules
are spherical; but in birds, reptiles, and fishes, they are
ellipsoidal.de
When blood is set at rest, it does not separate into the two
parts above mentioned, but into a red coagulum called the
clot and the serum, which is a yellowish liquid.
The saline substances contained in the blood are carbon-
ates, phosphates, and sulphates of potassa and soda. It con-
tains also chloride of sodium, (common salt,) chloride of
potassium, and sesquioxide of iron. More than of the
blood is water; the coloring matter is in the ratio of 125
parts in 1000, and albumen, about 67 in 1000. The propor-

352
Animal Chemistry.
tions vary somewhat, even in the same person, at different
times.
The following table, by M. Le Canu, represents the com-
position of the blood as derived from two careful analyses : --
Water,
780.145 785.590
Fibrin,
2.100 3.565
Coloring matter,
133.000 119.626
Albumen,
65.090 69.415
Crystalline fatty matter,
2.43 4.300
Oily matter,
1.310 2.270
Extractive matter soluble in water and alcohol, .790 1.920
Albumen combined with soda,
1.265 2.010
Chloride of sodium,
of potassium,
Carbonates
8.370 7.304
Phosphates of soda and potassa,
Sulphates
Carbonates of lime and magnesia,
Phosphates of lime, magnesia, and iron,
2.100 1.414
Peroxide of iron,
Loss,
2.400 2.586
1000.000 1000.000
66
The changes which are effected on the blood by respira-
tion, are due to the oxygen of the atmosphere. The dark
blood of the veins enters the lungs, and, being there exposed
to the action of the air through a thin membrane, absorbs
oxygen, throws off or forms carbonic acid gas, and passes
into the arteries with a bright red color.. A large quantity
of carbonic acid is emitted by the lungs, and hence the ne-
cessity of a free circulation of air in small or crowded rooms.
Animal Heat. There is a striking analogy between the
process of combustion and respiration. In both cases, oxy-
gen is consumed, and carbonic acid produced. This fact led
Dr. Black to infer that the heat generated in the animal sys-
tem was derived from the change which takes place in the
lungs. That the development of animal heat is dependent
upon respiration, is a matter of easy demonstration; but how
the effect takes place, has not been satisfactorily explained.
In those animals which consume a small quantity of oxygen,
the temperature of their bodies varies with the surrounding
medium, and are called cold-blooded; but in those that con-

Complex Animal Substances.
353
sume a larger quantity of oxygen, the temperature is nearly
uniform, whatever be the temperature of the medium. They
are hence called warm-blooded. The temperature of the
same animal varies often, according as the respiration is slug-
gish or rapid. Det kan bestillin
To account for animal heat, Dr. Crawford proposed the
first consistent theory, which is founded on the supposition
that the blood, when purified by the oxygen of the air, has
its capacity increased for caloric; and hence the heat pro-
duced in the lungs by the consumption of the oxygen, enters
into an insensible state in the arterial blood. As this blood
circulates through the system and enters the veins, it loses its
capacity, and gives out its caloric. But Dr. Davy denies that
there is any difference between the capacity of venous and
arterial blood. If, however, we suppose that the oxygen does
not combine with the carbon in the lungs, but in the course
of circulation, there would be heat developed in all parts of
the system; and this view would account for the facts, irre-
spective of the different capacities of the two kinds of blood.
The influence of the vital principle, doubtless, has much to
do, both in the development and preservation of animal heat.
The nerves have been supposed also to possess a specific
power of generating heat; but, whatever be the cause, it is
evident that the arterialization of the blood does not account
for all the heat of the animal system, from the fact that a
healthy animal imparts more heat to surrounding bodies,
than could be produced frożn this source alone.
Saliva. This liquid contains only seven parts of solid
matter in a thousand. It contains chloride of potassium,
sulphate, phosphate, acetate and carbonate of potassa, with
some other salts. It forms a soft, pulpy mass with the food
in mastication, preparing it for more easy digestion.
Gastric Juice. This fluid taken from an empty stomach
has a saline taste, and is neutral. But when any substance
enters the stomach, acid is secreted. Both hydrochloric and
acetic acids are formed. All nutritious substances are dis-
solved by this juice, and converted into a pulpy mass called
30 *

354
Animal Chemistry.
chyle. It does not act on living substances, or the stomach
itself would be dissolved, as sometimes is the fact after death.
Its solvent power is due to the acids, which are greatly aided
by the temperature of the stomach. By taking magnesia, the
acids are neutralized, and the digestive power suspended for
the time.
Bile. The bile is a yellow or greenish, nauseous liquid,
of which z are water, and the remainder a peculiar bitter
principle, called picromal, with resin, and several salts. The
bile stirnulates the intestinal canal, and assists in converting
the chyme into chyle.net
Chyle. This is a white fluid resembling milk. It contains
about 90 per cent. of water; of the other constituents, albu-
men is most abundant.
Milk. This liquid is well known to consist of cream,
curd, and whey. 100 parts of cream, of specific gravity
1.0244, contain only 4.5 parts of butter; of the remainder,
92 are whey, and 3.5 curd. The coagulation in sour milk is
produced by the generation of acetic acid, which, in com-
mon with acids generally, separates the curd from the whey.
The same effect is caused by rennet prepared from a calf's
stomach, which is impregnated with the gastric juice, and
therefore contains acid Milk is of course curdled when
taken into the stomach.
Lymph is a peculiar, limpid, transparent liquid, which
moistens the cellular membrane, and collects abundantly in
some dropsical affections. It consists chiefly of water, with
hydrochlorate of soda and albumen.
The humors of the eye contain more than 80 per cent. of
water ; the other ingredients are albumen, muriate and acetate
of soda, pure soda, and an animal matter like curd, which
gives it a milky appearance.
The tears contain pure soda, chloride of sodium, and phos-
phate of soda, with water, and an animal matter analogous
to albumen.
Mucus is a fluids ecreted by the mucous surfaces, as the
nose.

355
Pus is a liquid matter secreteď by an inflamed and ulcera-
ted surface. Its characteristic ingredient resembles albumen.
Sweat is the vapor which constantly passes off from the
skin, and consists mostly of water, mixed with a little muriate
of soda, and free acetic acid.com
Urine differs from most animal fluids in serving no ulterior
purpose in the animal economy. It is an excretion consisting
of substances which would prove injurious to life and health.
The urine is separated by the kidneys from the blood, and
consists of a great variety of substances, such as water and
urea, which are the principal, uric acid, lactic acid, lactate of
ammonia, mucus, sulphates of potassa and of soda, phos-
phates of soda and of ammonia, muriates of soda and of am-
monia, earthy matters with a trace of fluate of lime, and sili-
ceous earth.
Eggs. The shell of an egg is about to, the white jo,
and the yolk 1% of the whole. The shell consists chiefly of
carbonate of lime; and the white, of albumen, with a little
sulphur. The yolk contains phosphorus, which supplies
phosphoric acid for forming the bones of the chicken.
Bones. Bones contain about f of animal matter, 1 of
phosphate of lime, io of carbonate of lime, with a little fluoride
of calcium, and some other salts. Teeth have the same con-
position, but the enamel contains 78 per cent. of phosphate
of lime. The shells of crustaceous animals, as lobsters and
crabs, consist of carbonate and phosphate of lime, with ani-
mal matter ; but the shells of molluscous animals, or true
shells, as of the oyster, snail, etc., consist almost entirely of
carbonate of lime and animal matter.
Horn differs from bone in containing only a trace of earth.
The composition of the nails, hoofs, and cuticle of animals is
similar to horn.
Tendons are composed almost wholly of gelatin.
The true skin has nearly the same composition. Membranes
and ligaments contain in addition some substance which is
insoluble in water, and is similar to coagulated albumen.
Hair contains a peculiar animal substance, insoluble in
water at 212°, but soluble in a solution of potassa. It also

356
Analytical Chemistry.
contains an oil, which gives the peculiar color of the hair,
sulphur, upon which the nitrate of oxide of silver acts in stain-
ing it, together with silica, iron, manganese, and carbonate
and phosphate of lime.
.
Wool and feathers are similar in composition to hair.
Silk is covered with a peculiar varnish, which amounts to
about 23 per cent.
Muscle. The lean flesh of animals consists essentially of
fibrin, with numerous other ingredients, such as albumen,
gelatin, a peculiar extractive matter called osmazome, fat, and
salts.
CHAPTER VI.
ANALYTICAL CHEMISTRY.
It is the object of analytical chemistry to point out the
method of separating compound bodies into their simple
elements. As the subject is extensive, a few things only
will be inserted here, in order to give the student an idea of
the nature of the process.
SECT. 1.
ANALYSIS OF MIXED GASES.
6
* 1. Gaseous Mixtures containing Oxygen.
Fig. 102.
The best process by which oxygen gas may
be withdrawn from gaseous mixtures, is by
6
6
means of hydrogen gas. In case of the air,
a given portion is taken, and rather more
hydrogen added than is sufficient to com-
bine with the oxygen. The mixture is then
introduced into a strong glass tube, or eudi-
ometer, (Fig. 102,) over water or mercury,
ca
and exploded by the electric spark. The
total diminution in volume, divided by three,
will give the quantity of oxygen present.
Instead of exploding the gases, they may be
made to combine slowly, by introducing into the mixture
platinum sponge.
חדוהדומה

Analysis of Minerals.
357
2. Gascous Mixtures containing Nitrogen. As the air
contains only oxygen and nitrogen, when other substances
are withdrawn, if its oxygen is determined, the quantity of
its nitrogen may be easily known. The only mode of ascer-
taining the quantity of nitrogen in any mixture, is to with-
draw the other gases from it.
3. Gaseous Mixtures containing Carbonic Acid. When
carbonic is the only acid gas present, as is the case with air
and organic compounds, the process consists merely in ab-
sorbing this
gas by lime water, or a solution of caustic potassa.
4. Gaseous Mistures containing Hydrogen and other In-
flammable Bodies. The quantity of hydrogen, when mixed
with nitrogen, oxygen, or atmospheric air, is ascertained by
adding a portion of oxygen, and exploding the mixture. The
quantity of other inflammable bodies, such as carbonic oxide,
light carbureted hydrogen, or olefiant gas mixed with nitro-
gen, is determined by adding a sufficient quantity of oxygen,
and detonating the mixture. The diminution of volume in-
dicates the quantity of hydrogen contained in the mixture,
and by withdrawing the carbonic acid, the quantity of car-
bon may be known.
SECT. 2. ANALYSIS OF MINERALS.
In order to analyze any mineral compound, the first object
is to bring the body into a state of solution. This is effected,
generally, by water or acids; but in cases where the sub-
stance is not dissolved by these, it is made into a paste, with
three or four times its weight of fused borax, potassa, soda,
baryta, or their carbonates, and subjected to a strong heat,
in a platinum or silver crucible. By this means, the alkali
combines with one or more of the constituents of the min-
eral, and then it is in a state to be acted upon by acids.
1. Analysis of Minerals soluble in Acids with Effervescence.
Reduce the mineral to a fine powder, and boil it for two hours in
the acid which holds it in solution, diluted with five or six times its
bulk of water. This solution may contain lime, baryta, magnesia,
strontia, alumina, and oxides of inetals.
1. Add to a small portion of the liquor, diluted with 20 parts of water,

358
Analytical Chemistry.
sulphate of soda, and if a precipitate appear, baryta, or strontia, or
both, are present. Nitric acid, diluted with an equal weight of water,
will dissolve the strontia, if present, in the separated precipitate, but
will not act upon the baryta.
2. Add to a portion of the liquid, ferrocyanate of potassa, and if
metallic oxides are present, a precipitate will be thrown down, the
color of which will probably show the kind of metal.
3. Carbonate of potassa will precipitate the lime, magnesia, and
alumina, froin which the alumina may be dissolved by a solution of
potassa, and precipitated again by dilute hydrochloric acid.
Having precipitated the alumina, dilute hydrochloric acid will re-
dissolve what remains, from which oxalate of ammonia will precipitate
the lime.
Add to the remaining liquid, in successive portions, carbonate of
ammonia and phosphate of soda, and magnesia, if present, will be pre-
cipitated.
II. Analysis of Minerals which are insoluble in Acids.
Heat a mixture of 1 part of the mineral to 3 of fused borax, for three
hours, in a platinum crucible; dissolve the contents by digesting the
whole in hydrochloric acid, for several hours; add carbonate of am-
monia, and the whole will be precipitated; filter and wash the precipi-
tate, to separate the borax, and re-dissolve in hydrochloric acid. If any
matter remain, it is silica. The solution may then be tested as in the
former case.
III. Analysis of Minerals containing Carbonate of Lime, Silica,
Oxide of Iron, and Magnesia.
1. Reduce the mineral to a fine powder, and weigh out a given por-
tion, as 1000 grs.; dry the powder just up to browning paper; the loss
of weight is water.
2. Having put the powder into a flask,
Fig. 103.
to which a cork with a bent tube is at-
tached, (Fig. 103,) pour upon it water, and
then hydrochloric acid, quickly inserting
the stopper, and placing the tube in a ves-
Б
sel of baryta water; carbonic acid will
escape through the tube into the solution
of baryta, and form carbonate of baryta,
which will be in fine powder. Filter and
dry the residue; the weight will give the
quantity of carbonic acid, 22 parts of acid
NI
being combined with 78 of baryta.
3. Dilute the liquor in the flask with
water, throw it upon a filter, and wash;
the insoluble matter is silica.
4. The washings of the filter contain a solution of the oxide and lime.
Precipitate the oxide with excess of ammonia; filter, wash, dry, and
weigh; from this the iron may be estimated, as the oxide will contain
12 parts of oxygen, 9 of water, and 28 of iron. Oxalate of ammonia will
precipitate the lime from the remaining liquor, which being filtered,
washed, and burned in a crucible, lime only will remain. The magnesia,
which is still in solution, may be precipitated by carbonate of ammonia
in excess, and by adding phosphate of soda; filter, dry, and weigh; 100
parts will contain 40 of pure magnesia.
The Compounds of Silica, Alumina, and Iron, are decomposed by al-
a

Analysis of Metallic Ores.
359
kaline carbonates, at a red heat. For further processes, see Turner's
Chemistry, or Rose's Analytical Chemistry.
IV. Tests of Metallic Ores.
1. Ores of Antimony are first dissolved in nitrohydrochloric acid, which
takes up all the sulphur. The oxide of antimony is then precipitated
by simply adding water.
2. Ores of Lead are dissolved in nitric acid, with the exception of
the sulphur, which may be separated by a filter; add to the solution
carbonate of soda, and carbonate of lead will be thrown down. The
silver, if present, will also be precipitated, and may be separated from
the carbonate of lead by liquid ammonia, which holus it in solution.
3. Ores of Mercury are mixed with iron-filings or lime, and exposed,
in an iron retort, to a strong heat; when the mercury will distil over.
4. Ores of Zinc may be boiled in nitric acid to dryness, and the pro-
cess repeated. If iron is present, it will be peroxidated, and dilute
nitric acid will dissolve out the zinc; filter the solution, and add liquid
ammonia in excess; the lead, if present, will be precipitated, and the
zinc will remain in solution. The oxide of zinc is obtained by boiling
this solution to dryness.
5. Ores of Tin. As these ores usually contain silica, they must be
first treated like an earthy mineral not soluble in acids. The tin will
be detected by forming a purple solution with the chloride of gold.
6. Ores of Iron. The peroxide of iron is first rendered soluble by
heating it for an hour with one eighth of its weight of powdered char-
coal. The black oxide is soluble in dilute hydrochloric acid. If phos-
phate of iron is present, it may be detected by adding to the hydrochloric
solution 10 parts of water, (which has been boiled, to separate the air,)
placing it in a bottle corked tight, and set aside for 6 or 8 days, when
the phosphate of iron will be precipitated. The filtered solution may
contain oxides of iron, manganese, and zinc, all of which are thrown
down by carbonate of soda. The oxide of zinc may then be separated
by ammonia, and the oxide of manganese by acetic acid. The oxide
of iron will then remain, and, after being ignited, will contain 72 per
cent. of the pure metal.
7. Ores of Copper are boiled dry with five times their weight of sul-
phuric acid. The sulphate of copper which is formed is dissolved by
water, and the metallic copper precipitated by a plate of clean iron.
8. Ores of Silver are dissolved by nitric acid. Immerse in the solu-
tion a plate of polished copper, and the silver will be precipitated upon
it, if no lead is present. Common salt will throw down the chloride
of silver.
9. Ores of Gold and Platinum are dissolved in nitrohydrochloric
acid ; the solution is then evaporated until nitrous acid fumes cease to
appear, and the odor of chlorine is perceptible; the product is dissolved
in water, and a solution of hydrochlorate of tin added, when a purple
precipitate will be thrown down, if gold is present. If platinum is in
the mixture, it may be precipitated by hydrochlorate of ammonia.
When the solution contains gold with other metals, the sulphate of
the protoxide of iron precipitates the gold with the palladium, mercury,
and silver, if present. As silver is most frequently present, common
salt should be added previous to the sulphate of iron, to precipitate it.
Earthy Sulphates. The sulphate of lime is easily analyzed by boil-
ing it for fifteen or twenty minutes in a solution of twice its weight of
carbonate of soda. The carbonate of lime and sulphate of soda are

360
Analytical Chemistry.
formed by double decomposition. The sulphate of soda is then de
composed by chloride of barium, and the carbonate of lime analyzed in
the usual way.*
SECT. 3. ANALYSIS OF MINERAL WATERS.
The purest water is obtained by distillation. Rain water,
or that from fresh fallen snow, is next in purity.
Well and spring water contain some salts, which are de-
rived from the soil through which the rain water passes :
hence the purity of water will depend upon the nature of the
soils. If it is filtered through primitive strata, such as gran-
ite, it will contain few salts, but if through secondary soils,
such as limestone and gypsum, it becomes impregnated with
various other substances, and is mineralized. Lime renders
it hard.
The different kinds of mineral water are acidulous, alka-
line, chalybeate, sulphureted, saline, and siliceous springs.
1. In acidulous springs, of which those of Saratoga and
Seltzer are examples, the acidity is due to the carbonic acid
with which their waters are impregnated; they frequently
contain protoxide of iron, carbonates of lime, magnesia, and
other saline compounds. The carbonic acid is easily expelled
by heat, and may be collected over mercury.
2. Alkaline springs are very rare; they generally contain
a free or carbonated alkali.
3. Chalybeate springs. These waters are characterized by
styptic, inky taste, and by striking a black color with infu-
sion of gall-nuts. The iron is either combined with hydro-
chloric and sulphuric acids, or exists in the form of proto-
carbonate, held in solution by free carbonic acid.
On
exposure to the air, the protoxide is oxidized, and the hy-
drated peroxide subsides as an ochreous deposit
, which is
commonly found in the vicinity of chalybeate springs. — T.
4. Saline springs owe their properties to saline compounds,
such as sulphates and carbonates of lime, magnesia, and so-
da, and the chlorides of calcium, magnesium, and sodium.
In the analysis of saline springs, the first object is to ascer-
tain the nature of the ingredients. Hydrochloric acid is
detected by nitrate of oxide of silver, sulphuric acid by chlo-
ride of barium; and if an alkaline carbonate be present, the
precipitates will contain a carbonate of oxide of silver, or of
baryta. Lime and magnesia may be detected, the former by
* For other sulphates, see Turner, p. 241.

Test Tubes.
361
sions.
oxalate of ammonia, and the latter by phosphate of ammonia.
Potassa is known by the action of chloride of platinum. Το
detect soda, the water should be evaporated to dryness, the
deliquescent salts removed by alcohol, and the matter insolu-
ble in that menstruum taken up by a small quantity of water,
and allowed to crystallize by spontaneous evaporation. The
salt of soda may then be recognized by the rich yellow color
which it communicates to flame. If the presence of hydri-
odic acid be suspected, the solution is brought to dryness, the
soluble parts dissolved in two or three drachms of a cold so-
lution of starch, and strong sulphuric acid slowly added. — T.
Sulphureted springs are characterized by their odor, and
by the brown precipitate, which a salt of lead or silver occa-
This is owing to the hydrosulphuric acid gas which
they contain. - The quantity of gas is ascertained by boiling
the water, which expels it.
To detect Hydrosu'phuric Acid. Take a flask, Fig. 104.
with a tube bent twice at right angles, one end
of which dips into a solution of acetate of lead.
(Fig. 104.) Introduce the water into the flask,
and apply heat until it boils. The gas will be
driven off, and decompose the acetate, forming a
sulphuret of lead; filter, dry, and weigh. 16.1
parts will be sulphur, and 103.6 parts lead. It
part of the weight of the sulphur, added to its
weight, will give the weight of the hydrosulphu-
ric acid
If the water, after being boiled, yields a black the
precipitate, with acetate of lead, acetic acid must be added, and the
liquor boiled, and the gas passed through the acetate, as before.
The mode of estimating the solid inatter held in solution in mineral
waters is simply to boil the whole to dryness, and weigh the residue.
The different kinds of matter are then detected in the usual way for
analyzing other solid bodies.
Test Tubes. For
Fig. 105.
the purpose of test-
ing substances in
solution, test tubes
(Fig. 105) are very
convenient. They
are glass tubes, from
3 to 12 inches in
length, and from
to 1 inch in diame-
ter, open at one end,
while the closed end
is so made that the
liquid may be heata
SE
TAH
TE

362
Analytical Chemistry.
ed as in a retort. A small quantity of any solution may be
examined in them with great facility, and they are especially
convenient to form precipitates. These tubes may be placed
upon a frame, as in the figure, and answer often the threefold
purpose of retort, receiver, and test tube.
As this opera-
Filtration. When a solution has been prepared for exam-
ination, it ought to be perfectly clear. If it appears muddy,
it must be subjected to filtration ; that is, it must be passed
through a paper filter, by which means it is separated from
solid matters, which make it appear opaque.
tion frequently occurs in chemical analysis, and in various
manipulations, it is important to understand the mode of
per-
forming it.
The filtering paper should contain no glazing or sizing,
and should be folded in the following form:
1. Take a square piece of paper, and fold it like a sheet of
paper, that is, so as to bring two corners together; then fold
it so as to bring four corners together; cut off the corners,
and by opening the folds it will have the form of an inverted
cone, and may be placed in a funnel.
Fig. 106.
2. But for filtering rapidly,
4.
the filter may be folded in the
following form: - Fold the pa-
per in two, as before; then (Fig.
106) fold 10 upon 2, then 10
upon 6, then 1 10 upon 1 8,
then 2 upon 8; then 2 upon 6,
2 upon 4, and 10 upon 4: this will produce Fig. 107.
7 folds, all on one side of the paper. Make,
now, folds between each of these, so as to
raise ribs on the opposite side of the paper.
Cut out the projecting corners, to give the
whole a circularshape; open it, and form it into
a cup. (Fig. 107.)
6
7
3
9
12
11
10
2
15
or

Filtration.
363
The filter may then be placed
Fig. 108.
in the funnel c, (Fig. 108,) and
supported by a lamp-stand or a
wood-stand, made for the pur-
pose; or it may be placed in the
top of a tall jar. The liquid to
be filtered is then put into it, and
a vessel placed beneath to con-
tain the liquid as it slowly passes
7
through the paper. By this pro-
cess, the solid and liquid parts
are separated, and either may
be examined in their separate
state.
If it is desired to estimate the quantity of solid matter, the
filter must be weighed previous to placing it in the funnel ;
and the solid matter, after being washed, by directing a fine
stream of water upon it, until the water comes through taste-
less, is dried and weighed: the difference of weight shows
the quantity of solid matter.
Supports of filters and vessels may be Fig. 109.
of iron wire, made into the form of a
tri-
angle. (Fig. 109.) Take three pieces of
iron or copper wire, and twist the ends as
A
in the figure, leaving a triangular aperture :
this may be placed upon the tops of jars
and other vessels, or upon the rings of the
lamp-stand, to support crucibles, evapo-
rating dishes, retorts, filters, &c.
* For chemical manipulation, and bloupipe analysis, the student is
referred to Griffin's Chemical Recreations.

APPENDIX.
DA
Wollaston's Synoptic Scale of Chemical Equivalents.* -
The scale consists of a movable slider, with a series of
numbers upon it, from 10 to 320, on each side of which, and
on the fixed part of the scale, are set down the names of va-
rious chemical substances.
The scale is founded on the constancy of composition in
chemical compounds, the equivalent power of the quantities
that enter into combinations, and the properties of a logo-
metric scale of numbers.
The numbers are so arranged, that at equal intervals they
bear the same proportion to each other. The student will
easily observe and understand this, by measuring a few dis-
tances upon the scale, with a pair of compasses, or even a
piece of paper. If his paper extend from 10 to 20, it will
also extend from 20 to 40, or from 55 to 110, or from 160 to
320. Whatever number is at the upper edge of the paper
will be double at the lower. If any other distance be taken,
the same effect will be observed. If, for instance, the paper
extends from 10 to 14, then any other two numbers found at
its upper and lower edge will be in the same proportion as
these two numbers 10 and 14. Thus, make the upper num-
ber 100, and the lower number will be 140.
Now, supposing that the paper were cut of such a width
that, one of its edges being applied upon the scale to the num-
ber representing the equivalent of one body, the other should
coincide with the number of the equivalent of a second body;
then, upon moving the paper, wherever it was placed over the
numbers, those at its upper and lower edges would still rep-
resent the corresponding proportional quantities of the two
bodies as accurately as at first, because the numbers at equal
* The paper, by its author, describing the scale, is inserted in the
Philosophical Transactions for 1814.

Appendix.
365
up
distances on the scale are proportional to each other. Thus,
suppose the upper edge were made to coincide with 40 and
the lower with 78, then the upper edge might be called sul-
phuric acid, and the lower baryta; and this width once as-
certained, the paper, wherever applied upon the scale, would
show at its lower edge the quantity of baryta necessary to
combine with the quantity of sulphuric acid indicated by its
upper edge.
It is evidently of no consequence whether the paper be
moved and down over the scale, or the line of numbers
be moved higher and lower, to bring its different parts to the
edges of the paper. And supposing the piece of paper just
described to be pasted upon the side of the scale, then, by
moving the latter, any of the numbers might be made to coin-
cide with the upper or lower edge at pleasure, and conse-
quently the quantity of sulphuric acid necessary to combine
with any quantity of baryta, and vice versa, ascertained by
mere adjustment and inspection of the scale. Or if, instead
of referring to the separate piece of paper, marks were to be
made on the side of the scale at 40 and 78, and named sul-
phuric acid and baryta, the same object would be attained,
and the same method of inquiry rendered available.
Other substances are to be put down upon the scale ex-
actly in the same manner. Thus, the scale being adjusted
until the number 40 coincides with the sulphuric acid already
marked, then sulphate of baryta is to be written at 118, and
thus its place is ascertained; nitrate of baryta at 132 ; soda
at 32 ; sulphate of soda at 72; and a similar process is to be
adopted with every substance, the number of which has been
ascertained by experiment. The instrument, which in this
state merely represents the actual numbers supplied by exper-
iment, will faithfully preserve the proportions thus set down,
whatever the variation of the position of the slider may be.
It is therefore competent to change all the numerical expres-
sions to any degree required, the knowledge of one only being
sufficient, first by adjustment, and then by inspection, to lead
to the rest.
A few illustrations of the powers and uses of this scale
will be sufficient to make the student perfect master of its
nature and applications. Suppose that, in analyzing a mineral
water, the sulphates in a pint of it have been decomposed by
the addition of muriate of baryta, and the resulting sulphate
of baryta washed, dried, and weighed; from its quantity may
31 *

366
Appendix.
be deduced the exact quantity of sulphuric acid previously
existing in the mineral water. Thus, if the sulphate of baryta
amount to 43.4 grains, the slider is to be moved until that
number is opposite to the sulphate of baryta, and then at sul-
phuric acid will be found the quantity required, namely, 14.7
grains.. In the same manner the scale will give information
of the quantity of any substance contained in a given weight of
any of its compounds; these having previously been deduced
from experiment, and accurately set down on the table in the
manner just explained.
If it be desired to know how much of one substance must
be used in an experiment to act upon the other, it is evident
that the equivalent must be taken, and this may be learned
from the scale. Suppose that a pound of sulphate of baryta
has been mixed with charcoal, and well heated, to convert it
into a sulphuret, and that by the addition of nitric acid it is
to be converted into nitrate of baryta. The quantity of acid
which will probably be required may be learned by bringing
100 to sulphate of baryta, and then by looking for the num-
ber opposite nitric acid; it will be found to be 46. But this
represents the quantity of dry acid; casting the eye therefore
lower down, upon liquid nitric acid of a specific gravity of
1.50, it will be found that 61 lbs., or a little more, is the
equivalent for 100 lbs., and consequently that 61 hundredth
parts, or somewhat above of a pound of such acid, will
be sufficient for the pound of sulphate of baryta operated
with.
If a certain weight of carbonate of baryta be required in
that moist and finely-divided state in which it is obtained by
precipitation, and in which it cannot be weighed, the accu-
racy of the quantity may be insured by taking the equivalent
of dry muriate, or nitrate of baryta, precipitating it by an ex-
cess of carbonate of potassa, and then washing off the salts
which remain in solution. Suppose 100 grains of the car-
bonate were required; by bringing that number to carbonate
of baryta, it will be found that the quantity of dry muriate
necessary will be 105.8 parts, and the quantity of nitrate
133.4; and if the quantity of carbonate of potassa necessary
for this purpose be also required, it will be found, opposite
the name of that substance on the scale, to be a little less
than 70 parts, so that 5 or 10 parts more will insure a satis-
factory excess.
The second paragraph of Wollaston's description of this

Appendix.
367
scale may be transcribed, as a further illustration of the
powers of the instrument. “If, for instance, the salt under
examination be the common blue vitriol, or crystallized sul-
phate of copper, the first obvious questions are — (1) How
much sulphuric acid does it contain? (2) How much oxide
of copper? (3) How much water? He [the analytic chemist]
may not be satisfied with these first steps in the analysis, but
may desire to know further the quantities (4) of sulphur, (5)
of copper, (6) of oxygen, (7) of hydrogen. As means of
gaining this information, he naturally considers the quantity
of various re-agents that may be employed for discovering the
quantity of sulphuric acid, (8) how much baryta, (9) carbon-
ate of baryta, or (10) nitraté of baryta, would be requisite
for this purpose. (11) How much lead is to be used in the
form of (12) nitrate of lead; and when the precipitate of
(13) sulphate of baryta, or (14) sulphate of lead, are obtained,
it will be necessary that he should also know the proportion
which either of them contains of dry sulphuric acid. He
may also endeavor to ascertain the same point by means of
(15) the quantity of pure potassa, or (16) of carbonate of
potassa, requisite for the precipitation of the copper. He
might also use (17) zinc, or (18) iron, for the same purpose;
and he may wish to know the quantities of (19) sulphate of
zinc, or (20) sulphate of iron, that will then remain in the
solution."
All these questions and points are answered by moving the
slider until the number expressing the quantity operated with,
coincides with sulphate of copper crystallized. 5, Water.
Let it, for instance, be 100; this being brought opposite crys-
tallized sulphate of copper, the information relative to all the
above points, except the sixth and seventh, is supplied by
mere inspection. The sixth may be supplied by substracting
(5) the quantity of copper from (2) the quantity of oxide of
copper, or by halving the quantity at 2 oxygen, or taking the
third of that at 3 oxygen. The seventh relates to the quan-
tity of hydrogen in the 5 water present in the salt; this quan-
tity of hydrogen does not come within the line of numbers,
but may easily be obtained by doubling the quantity of water,
or doubling the quantity of the salt used, which will then
bring 10 hydrogen into the scale, and the half of this is to be
taken as the quantity in 5 water, or in 100 grains of the salt.
Putting, therefore, 200 to sulphate of copper, 10 hydrogen, is
indicated as 17 parts nearly, when of course the half of this,

368
Appendix.
or 8.5 parts, is the quantity in 100 grains of the crystallized
salt of copper.
Whenever it thus happens that the number known or the
number sought for is out of the scale, then some convenient
multiplier of the numbers may be used. The most conve-
nient method is to use the tens or the hundreds as units, or,
what is the same thing, to consider for the time that decimal
points are inserted between the units and the tens, or between
the tens and the hundreds of all the numbers on the scale.
Thus, if it were required to ascertain how much magnesia and
sulphuric acid were contained in a pound of crystallized sul-
phate of magnesia, no 1 exists upon the scale, and of course
no fractions or small parts of 1; but imagine decimal points
between the tens and the hundreds, then 10 upon the scale
becomes one tenth, 22 twenty-two hundredths, 100 one, 220
two and two tenths, and so on. Bringing, therefore, 100 to
crystallized sulphate of magnesia, it represents the 1 pound,
and by inspection it will be found that it contains 16 hun-
dredths of a pound of magnesia, and 32 hundreds of a pound
of sulphuric acid.
As another illustration, suppose that the quantity of mag-
nesia in 50 lbs. of crystallized Epsom salt were required;
upon bringing 50 opposite the name of the salt, the quantity
of magnesia will be found smaller than any quantity expressed
upon the scale; but all that is necessary to obtain the answer
is, to double the quantity of the salt, and then to halve the
quantity of magnesia indicated; in which way it will be found
that the 50 lbs. contain about 8 lbs. of the oxide.
These Synoptic Scales are generally constructed of paper
or wood. It is almost impossible that they should be accu-
rate, because of the extension and contraction of the paper,
and the facility with which it yields to mechanical impressions,
and may be stretched when in a moistened state. These scales
should never be considered as accurate when they first come
from the instrument-maker. They may be examined by a
pair of compasses or a piece of paper, to ascertain how nearly
equal intervals on the scale of numbers accord with equal
proportions between the aumbers at the extremities of those
intervals, and thus the degree of error in them, and the part
where it exists to the greatest extent, may be observed; but it
will be useless to do so with the view of finding one so accu-
rate as to dispense with calculation in exact analytical exper-
iment.

Appendix.
369
Those scales which are laid down directly upon wood,
though not liable to the same sources of error as the paper
scales, are still seldom, if ever, so accurate as to compete
with calculation. — W.
Cementing. 1. When vapors of watery liquors, and such
others as are not corrosive, are to be confined, it is sufficient
to surround the joining of the receiver to the retort with
slips of wet bladder, or of linen, or paper, covered with flour
paste, or mucilage of gum arabic.
2. Soft cement is made of yellow wax melted with half its
weight of turpentine and a little Venetian red to give it color.
It can be easily moulded by the fingers, and sticks well to
dry substances.
3. For containing the vapors of acid, or highly-corrosive
substances, fat lute is made use of. This is formed by beat-
ing perfectly dry and finely-sifted tobacco-pipe clay, with
painters' drying oil, in a mortar, to such a consistence that it
may be moulded by the hand. To use it, it is rolled into
cylinders of a convenient size, which are applied, by flatten-
ing them, to the joinings of the vessels, which must be quite
dry, as the least moisture prevents the lute from adhering.
The lute, when applied, is to be covered with slips of linen
spread with the lime lute; which slips are to be fastened
with pack-thread.
Job
4. When penetrating and dissolving vapors are to be con-
fined, the lute to be employed is of quick lime slacked in the
air, and beaten into a liquid paste with white of eggs. This
must be applied on strips of linen ; it is very convenient, as
it easily dries, and becomes firm. This lute is very useful
for joining broken china ware.
DIE
5. For cementing stone ware to metals and wood, litharge
and red lead mixed and worked up with spirit of turpentine,
makes a good cement. It takes several days to give off the
turpentine and become dry and hard.
6. Cement for fastening brass necks upon glass jars, etc. :
4 parts of rosin, 1 of wax, and 1 of finely-powdered brick
are melted and well mixed together. It is to be put on warm,
but care is to be taken not to apply it so hot as to split the
glass. It holds very hard.
7. Mix linseed meal with water, and knead it into a stiff
paste. It soon hardens, and withstands the fumes of acids
and ammonia. It is better if made with lime water, or thin
glue. It is charred by a strong heat.

370
Appendix
8. Thick gum water, with pipe clay and iron-filings. Mix
well. It becomes very hard and firm, and is fit to be used
where it is required to hold good a considerable time.
9. Plaster of Paris, stirred up with milk, starch water, or
thin glue. It hardens immediately, and is very good for
securing tubes in flasks, when the corks do not fit well, and
gases are to be prepared in them.
10. Dissolve melted India rubber in boiling linseed oil,
and afterwards thicken the latter with pipe clay till it forms
a stiff mass. The thorough incorporation of the pipe clay
demands a great deal of labor. This is a capital cement to
be used when acids are to be prepared.
11. Cement for fastening Labels upon Bottles. Soften and
subsequently boil glue in strong vinegar. During the boil-
ing, thicken it with flour. This mixture can be preserved in
a soft state without becoming mouldy. It should be put into
a glass bottle, with a wide neck and a ground stopper. When
it is to be used, it is taken out of the bottle on the point of a
spatula, warmed over the lamp, if too thick for use, and then
spread upon the paper.
12. Universal Cement. Curdle skim milk, press out the
whey, break the curd in small pieces, dry it, and grind it in a
coffee mill. Take ten ounces of dry curd, one ounce of fresh
burnt quick lime, and two scruples of camphor. Mix the
whole intimately, and preserve it in small, wide-mouthed
bottles, closely corked. When it is to be used, mix it with
a little water, and apply it immediately.
13. Diamond Cement for Glass or Porcelain. Dissolve
five or six pieces of gum mastic, as large as peas, in the
smallest possible quantity of alcohol. Mix this liquid with
two ounces of a strong solution of isinglass, (made by soften-
ing and dissolving isinglass in boiling brandy or rum to
saturation,) having previously incorporated the two ounces
of isinglass solution with two or three small pieces of galba-
num or gum ammoniac, by trituration. The mixture is to be
preserved in a well-closed bottle, and is to be gently heated
by holding the bottle in hot water at the moment when you
are going to use it. — Griffin's Chem. Recreations.
Elastic Tube Making. Take a piece of the sheet rubber, 1 or 15
inches long, and a little more than three times as wide as you intend
the tube to be. Take a glass rod rather smaller than the intended

Appendix.
371
caoutchouc tube, fold a slip of paper round the glass rod, and over it
the piece of caoutchouc, previously softened by warming before the
fire. Fold the two edges together, and cut off the double projecting
edges by a pair of scissors, so as to produce two parallel straight edges.
Put the two clean surfaces thus produced face to face, being careful not
to let the fingers, or any thing else, touch them. Press the two faces
together by the thumb nails, and finally press the seam from end to
end with the flat part of the thumb nail. The junction is then effected
and the tube complete. But if the fingers or any dirt is allowed to
touch the clean cut surfaces of the rubber, they cannot be made to
unite by pressure. After you have withdrawn the glass rod and the
slip of paper from the rubber tube, you are to smear its inner surface
with flour or fine ashes, to prevent the subsequent sticking together of
its sides, which is otherwise liable to take place. — Ib.
Cutting Glass. Dissolve in spirits of turpentine as much camphor
gum as the liquid will hold in solution by the aid of moderate heat -a
common file dipped into the solution and applied to glass, will cut it
with nearly the same facility as iron.
66
66
C6
66
Specific Gravity of Essential and other Oils.
Oil of Anise-seed,
" Bergamot,
16 Cajeput,
u Caraway,
66 Cassia,
" Cinnamon,
66 Cloves,
66 Fennel,
6 Juniper,
" Lavender,
664 Lemons,
6 Nutmegs,
** Peppermint,
66 Roses, (Ottar of Roses,)
Rosemary,
66
0.9958
0.885
0.948
0.975
1.071
1.035
1.061
0.997
0.911
0.898
0.8517
0.948
0.899
0.832
0.85
66
(
66
66
Oils of Fermented Liquors.
Oil of Grain Spirits,
66 66 Potato Spirits,
0.835
0.821

372
Appendix.
lo
TABLE.
TO
The following are the results obtained by a commission ap-
pointed by the Parisian Academy of Sciences to examine
the elastic force of vapor. * They were obtained by
experiment up to a pressure of 25 atmospheres, and at
higher pressures by calculation.
Temperature ac-
cording to Fahr.
Temperature ac-
cording to Fahr.
Elasticity of the vap.
taking atmospheric
press. as unity.
1
11
Elasticity of the vap.
taking atmospheric
press. as unity.
13
14
15
16
tule2
23
17
3
3.1
4
41
5
51
6
61
7
73
8
9
10
11
12
212°
233.96
250.52
263.84
275.18
285.08
293.72
300.28
307.5
314:24
320.36
326.26
331.70
336.86
341.78
350.78
358.88
366.85
374.00
18
19
20
21
22
23
24
25
30
35
40
45
50
380.66°
386.94
392.86
398.48
403.82
408.92
413.78
418.46
422.96
427.28
431.42
435.56
439.34
457.16
472.73
486.59
491.14
510.60
* Brande's Jour. N. S. viii. 191.
Tiga

GLOSSA RY.
A.
ABSORPTION, from absorbeo, to suck up; the power or act of imbibing
a fluid.
ACETIC ACID, from acetum, vinegar; the acidifying principle of com-
mon vinegar.
Acicular, from ucus, a needle; having sharp points like needles.
Action, from dyw, to move; the effort by which one body produces,
or endeavors to produce, motion in another.
ADHESION, -IVE, from ad, to, and hæreo, to stick; the tendency which
dissimilar bodies have to adhere or stick together.
AERATION, from àic, the air; the saturation of a liquid with air.
AERIFORM, from aer, the air, and forma, a form; having the forn)
of air.
AEROSTATIon, from ởie, the air, and lotnu, to weigh; primarily, it'
denotes the science of weights suspended in the air; but, in the
modern application of the term, it signifies the art of navigating
the air.
AFFINITY, from ad, to, and finis, a boundary; relationship; the force
which causes dissimilar particles of matter to combine together,
so as to form new matter.
ALBUMEN, -INOUS, from albumen, the white of an egg; an important
animal principle. The white of an egg is albumen mixed with
water.
ALKALI, a soluble body, with a hot, caustic taste, which possesses the
power of destroying acidity; the term is derived from kali, the
Arabic name of a plant, from the ashes of which one species is
obtained, and the article al.
AMALGAM, from qua, together, and youéw, to marry; a chemical term,
signifying the union of any metal with mercury, which is a sol-
vent of various metals.
AMORPHOUS, from ở, not, and uogi, a form; not possessing regular forin.
ANALYSIS, from dvd, thoroughly, and auw, to loosen; the separation of
a whole into parts.
ANGLE, from angulus, a corner; the inclination of two straight lines
to each other, which meet together, but are not in the same
straight line.
ANHYDROUS, from ở, not, and vdwo, water; containing no water.
Anion, from èvè, up, and ein, to go; that which goes up; a substance
which in electrolysis passes to the anode.
ANODE, from åve, up, and odos, a way; the way which the sun rises ;
the surface at which the electricity passes into a body, supposing
the currents to move in the apparent direction of the sun.
ANTISEPTIC, from årti, against, and ortow, to make rotten; possessing
the power of preventing putrefaction
32

374
Glossary.
APPROXIMATE, -IVELY, from ad, to, and proximus, nearest ; having
affinity with; bordering upon.
AQUA REGIA, i. e., REGAL WATER, a mixture of nitric and muriatic
acids; so called from its property of dissolving gold, held by the
alchemists to be the king of the metals.
AQUEO, from aqua, water; when prefixed to a word, denotes that.
water enters into the composition of the substance which it
signifies.
Arc, from arcus, a bow; a part of a curved line, as of a circle,
ellipse, &c.
ARMATURE, from armo, to arm; a piece of soft iron applied to a load-
stone, or connecting the poles of a horseshoe magnet.
ASTATIC NEEDLE, from Zoratos, balanced; a double magnetic needle,
not affected by the earth's magnetism.
ASTRONOMY, from äotoov, a star, and vómos, a law or rule; the science
which treats of the heavenly bodies, their motions, periods, &c.,
and the causes on which they depend.
ATHERMANOUS, from ó, not, and 9 tonos, heat; that through which
heat will not pass is said to be athermanous.
ATMOSPHERE, -IC, from atmòs, vapor, and opałod, a sphere; the sphere
of air which surrounds the globe.
ATOM, -1c, from ở, not, and térvo, to cut; a minute particle, not sus-
ceptible of further division.
ATTRACTION, -IVE, from ad, to, and traho, to draw; the tendency which
bodies have to approach each other.
AUSTRAL, from auster, the south; southern.
Axis, in geometry; the straight line in a plane figure, about which it
revolves to produce or generate a solid; more generally, the right
line conceived to be drawn from the vertex of a figure to the
middle of the base.
B.
BAROMETER, -RICAL, from Búpos, weight, and uétqov, a measure; an
instrument for measuring the varying weight of the atmosphere.
BIBULOUS, from bibo, to drink; that which has the quality of drinking
in moisture.
Binary, from bis, twice; containing two units.
BOREAL, from boreas, the north ; northern.
C.
CALORIMETER, from calor, heat, and metrum, a measure; an instrument
for measuring caloric.
CAPILLARY, from capillus, a hair; resembling or having the form
of hairs.
CAPSULE, from capsula, a little chest; a small, shallow cup.
CARBON, from carbo, a coal; the chemical name for charcoal.
CATALYSIS, frem zdte, thoroughly, and auw, to loosen; an imaginary
force, which is supposed to assist the decomposition of some bodies,
and the composition of others.
CATHODE, from zatè, downward, and ósos, a way; the way which the
sun sets; the surface at which electricity passes out of a body,
supposing the current to move in the apparent direction of the sun.
Cation, from nate, down, and elut, to go; that which goes down; &
substance which in electrolysis passes to the cathode.
Caustic, from xaiw, to burn; possessing the power of burning.

Glossary.
375
CHEMISTRY, -ICAL, from an Arabic word, signifying the knowledge of
the substance or constitution of bodies; the science whose object
it is to examine the constitution of bodies.
CIRCUMFERENCE, -TIAL, from circum, around, and fero, to bear, the
line which is the boundary of a circle.
CLEAVAGE, PLANE OF; the plane in which crystals have a tendency to
separate.
COHESION, -IVE, from con, together, and hæreo, to stick; the relation
among the component parts of a body, by which they cling
together.
COMBUSTION, from comburo, to burn; the disengagement of light and
heat which accompanies chemical combination.
CONCAVE, from concavus, hollow; curved inwardly, or hollow.
CONDUCTION, from con, together, and duco, to lead. The power of
transmitting caloric, without change in the relative position of the
particles of the conducting body.
CONE, -ICAL, and -1c; a solid figure, having a circular base, and its
other extremity or vertex terminated by a point.
CONGELATION, from con, together, and gelo, to freeze; the process of
freezing
CONGERIES, from congeries, a heap; a mass of bodies heaped up
together.
CONSTITUENT, from constituo, to put together; that of which any thing
consists or is made up.
Contact, from con, together, and tango, to touch; the relative state
of two things which touch one another, but do not cut.
CONTRACTION, from con, together, and traho, to draw; the state of
being drawn into a narrow compass.
CONVERGENT, from con, together, and vergo, to bend; tending to one
point from various parts.
Convection, from con, together, and veho, to carry; the power in fluids
of transmitting heat or electricity by currents.
Convex, from con, together, and veho, to carry; curved outwardly, or
protuberant.
CORPUSCULAR, from corpus, a body; composed of or relating to ators.
CORUSCATION, from corusco, to flash or shine; a flash, or quick vibra-
tion of light.
CRUCIBLE, from cruz, crucis, a cross; a little pot, such as goldsmiths
melt their gold in; so called from having a cross impressed upon it.
CRYOPHORUS, from noros, cold, and géou, to produce; an instrument
for showing the relation between evaporation at low temperatures
and the production of cold.
CRYSTALOGRAPHY, from zouotahos, a crystal, and yo&epo, to describe;
the science which treats of crystals.
CRYSTAL, -LINE, from zouotaikos, ice; a substance having a regular
form, as rock-crystal, which resembles ice.
CRYSTALLIZATION; the formation of crystals during the passage of
certain bodies from a fluid to a solid form.
CUBE, -IC; a solid figure, contained by six equal squares.
D.
DECOMPOSITION; the resolution of a compound body into its compo-
nent parts.
DECREMENT, from decresco, to grow less; the quantity by which any
thing decreases or becomes less.

376
Glossary.
DEFLAGRATION, from deflagro, to burn; burning.
DEFLECTION, from de, from, and flecto, to bend; a turning aside out
of the straight way.
DEGREE, from de, down, and gradus, a step; a quantity in measure-
ment — as, in geometry, the 360th part of the circumference of a
circle.
DELIQUESCENCE, from deliqueo, to melt; a gradual melting, caused by
the absorption of water from the atmosphere.
DENSITY, from densus, thick ; vicinity or closeness of particles.
DEPHLOGISTICATED; deprived of phlogiston, the supposed principle
of inflammability.
Detonation, from detono, to thunder; explosion, accompanied with
noise.
DIAMETER, from ded, through, and péroov, a measure; the line which
passes through the centre of a circle, or of any other curvilinear
figure.
DIAPHANOUS, from dia, through, and gaivo, to shine; that which allows
a passage to the rays of light.
DIATHERMANOUS, from sid, through, and I lovos, heat; that throuyh
which heat will pass is said to be diathermanous.
DILATATION, from differo, to bear apart; the act of extending into
greater space.
DIMORPHOUS, from dis, twice, and yog', a form; having two forms.
Disc, from discus, a quoit; the apparent surface of a heavenly body.
DISINTEGRATION, from dis, meaning separation, and integer, whole;
an utter separation of particles.
DISPERSION, -IVE, from di, in different directions, and spargo, to scat-
ter; the act of scattering:
DISRUPTION, from dis, in different directions, and rumpo, to break;
the act of tearing asunder.
DISSECTION, from disseco, to cut to pieces; the act of separating into
pieces.
DISTILLATION; separation drop by drop; the process by which a fluid
is separated from another substance, by first being converted into
vapor, and afterward condensed drop by drop.
DIVELLENT, from divello, to tear asunder; that which causes sepa-
ration.
DIVERGENT, from di, in different directions, and vergo, to bend; tend-
ing to various parts from one point.
DODECAHEDRON, from dódexa, twelve, and adod, a base or side; a solid
figure contained by twelve equal sides.
DYNAMICS, -ICAL, from durapus, power; that branch of mechanical sci-
ence which treats of moving powers, and of the action of forces
on solid bodies, when the result of that action is motion.
E.
EBULLITION, from ebullio, to boil; the act of boiling.
EFFLORESCENCE, from effloresco, to blow, as a flower; the formation
of small crystals on the surfaces of bodies, in consequence of the
abstraction of moisture from them by the atmosphere.
ELASTICITY, -ic, from xhauvo), to push or thrust; the property bodies
possess of resuming their original form when pressure is re-
moved.
ELECTRODE, from inextpov, electricity, and ódos, a way; the point at
which an electric current enters or quits the body through which
it passes.

Glossary.
377
ELECTROGRAPHY, from Hertqov and ypágpos; a method of copying
medals, copperplate, &c., by galvanism.
ELECTROLYSIS, -LYTE, &c., from extoov, electricity, and Ivw, to
loosen; the act of decomposing bodies by electricity.
ELECTRO-MAGNETISM; magnetism produced by electricity.
ELECTROMETER; an instrument for ascertaining the quality and quan-
tity of electricity in electrified bodies.
ELECTROPHORUS; an instrument for producing electricity.
ELECTROSCOPE ; an instrument for exhibiting the attractive and re-
pulsive agencies of electricity.
ELEMENT, -ary, from elementum, an element; that which cannot be
resolved into two or more parts, and contains but one kind of
ponderable matter.
ELLIPSE, from èz, deficiently, and leinw, to leave; one of the conic
sections, formed by the intersection of a plane and a cone, when
the plane makes a less angle with the base than that formed by
the base and the side of the cone.
EMPIRICAL, from èv, in, and terpúou or, to make trial; that which is
made or is done as an experiment, independently of hypothesis or
theory.
EMPYREUMATIC, from év, in, and trūg, fire; having the taste or smell
of burned animal or vegetable substances.
ENDOSMOSE, from érdov, within, and womos, the act of pushing; a flow-
ing from the outside to the inside.
EPIDERMIS, from ērti, upon, and Siqua, the skin; the exterior layer of
the skin.
EQUILIBRIUM, from æquus, equal, and libra, a balance; the state of rest
produced by forces equally balancing one another.
EQUIVALENT, from æquus, equal, and valeo, to be worth ; equal in
value.
ETIOLATION; the blanching of vegetables by exclusion from light.
EVAPORATION, from è, out, and vapor, vapor; the conversion of a
liquid into vapor.
Exosmos r., from w, without, and wouós, the act of pushing; a flow-
ing from the inside to the outside.
EXPANSION, from expando, to open out; the enlargement or increase
in the bulk of bodies, which is produced by heat.
EXPERIENCE, from experior, to attempt, to try; knowledge gained by
observation
EXPERIMENT; something done in order to discover an uncertain or
unknown effect.
Explosion, from ex, out, and plaudo, to utter a sound; a sudden ex-
pansion of an elastic fluid, with force and a loud report.
F.
FERRUGINOUS, from ferrum, iron; of iron.
FILTER; a strainer.
FILTRATION; the process whereby liquids are strained.
FLEXURE, from flecto, to bend ; the act of bending; also, the bend or
curve of a line or figure.
Focus, -CAL, from focus, a fireplace; a point in which a number of rays
of light or heat meet, after being refracted or reflected.
FORMULA ; a general theorem; it is called algebraic, logarithmic, &c.,
according to the branch of mathematics to which it relates.
Friction, from frico, to rub; the rubbing or grating of the surfaces of
32 *

378
Glossary
bodies upon one another; also, the retarding forcé caused by this
rubbing of surfaces together.
G.
GALVANISM, from Professor GALVANI; current electricity is sometimes
so called.
GALVANOMETER; an instrument for measuring galvanism.
GAS, -EOUS; a term first introduced by Van HELMONT ; a permanent,
aeri form fluid.
GELATINOUS, from gelo, to freeze ; resembling jelly.
GONIOMETER, from ywvíc, an angle, and Métpov, a measure; an instru-
ment for measuring angles.
GRAVITATION, from gravis, heavy; the abstract power which draws
bodies towards each other's centres.
Grávity, from gravis, heavy; the natural tendency of bodies to fall
towards a centre.
GRAVITY, SPECIFIC; the relative gravity of a body considered with
regard to some other body, which is assumed as a standard of
comparison.
H.
Halo, from Aws, a crown; a luminous circle, appearing occasionally
around the heavenly bodies, but more especially about the sun
and moon.
HELIOGRAPHIC, from 32105, the sun, and ygúgw, to write; delineated
by the sun.
Helix, from sioow, to twist round; a screw or spiral.
HEMISPHERE, from flous, half, and opaipa, a sphere; the half of a
sphere, formed by a plane passing through the centre.
HERMETIC SEAL; when the neck of a glass vessel or tube is heated
to the melting point, and then twisted with pincers until it be
air-tight, the vessel or tube is said to be hermetically sealed, or to
have received the seal of Hermes, the reputed inventor of chem-
istry.
HETEROGENEOUS, from ÉTEQOS, different, and yévos, kind; different in
nature and properties.
HOMOGENEOUS, from ómós, alike, and yévos, kind; alike in nature and
properties.
Horizontal, from ópítw, to bound or terminate; parallel to the hori-
HYDRATE, from üdwo, water; any uncrystallized substance which con-
tains water in a fixed, definite proportion.
Hydro, when prefixed to the name of a chemical substance, denotes
that hydrogen enters into the composition of the substance which
it signifies.
HYDROMETER, from üdwe, water, and uétqov, a measure; an instru-
ment for comparing the density and gravity of liquids with water.
HYDROSTATICS, from vdwe, water, and otatós, standing ; that branch
of natural philosophy which treats of the pressure and equilibrium
of non-elastic fluids, and also of the weight, pressure, &c., of
solids immersed in them.
HYGROMETER, from vygos, moist, and uétqov, a measure; an instru-
ment for ascertaining accurately the quantity of moisture in the
atinosphere.
HYGROSCOPE, from vypos, moist, and oxuntén, to consider; an instru-
ment for exhibiting approximatively the moisture of the atmos-
phere.
zon.

Glossary.
379
Hypo, from úró, under; when prefixed to a word, denotes an inferior
quantity of some ingredient which enters into the composition of
the substance which it signifies.
HYPOTHESIS, -TICAL, from vrò, under, and thenui, to place; a princi-
ple supposed or taken for granted in order to prove a point in
question
I.
IMPINGING, from impingo, to strike against; dashing against.
INCANDESCENT, from incandesco, to grow white; white or glowing
with heat.
INCIDENCE, from in, upon, and cado, to fall; the direction in which
one body falls on or strikes another; the angle which the moving
body makes with the plane of the body struck, is called the “angle
of incidence."
INCREMENT, from incrésco, to increase; the quantity by which any
thing increases or becomes greater.
INDUCTION, -IVE, from in, to, and duco, to lead; the process of reason-
ing, by which we are led from general to particular truths.
INDUCTION, ELECTRICAL ; the effect produced by the tendency of an
insulated electrified body to excite an opposite electric state in
neighboring bodies.
INDUCTOMETER; an instrument for measuring electrical induction.
INERTIA, from inertia, inactivity; the disposition of matter to remain in
its state of rest or motion
INFLAMMABLE, from in, and flamma, a flame; capable of burning with
a flame.
INFLECTION, from in, to, and flecto, to bend.
INSULATION, from insula, an island; when a body, containing a quan-
tity of free heat, or of electricity, is surrounded by non-conductors,
it is said to be insulated.
INTEGRANT, from integer, whole, entire; those parts of a body which
are of the same nature with the whole, are called integrant.
INTERSTICES, from interstitium, a break or interval; the unoccupied
spaces between the molecules of bodies.
IRIDESCENT, from iris, the rainbow; marked with the colors of the
rainbow.
ISOMERIC, from loos, equal, and uipos, a part; substances which con-
sist of the same ingredients, in the same proportion, and yet differ
essentially in their properties, are called isomeric.
ISOMERISM; that portion of chemical science which treats of isomerie
substances.
J.
JUXTAPOSITION, from juxta, near, and pono, to place; the placing of one
thing close to another.
L.
LAMINÆ, from lamina, a thin plate; extremely thin plates, of which
some solid bodies are composed.
LENS, from lens, a bean; properly a small glass in the form of a bean ;
but more generally it means a piece of glass, or other transparent
substance, having its two surfaces so formed that the rays of light,
in passing through it, have their direction changed, and are made
to diverge or converge, or to become parallel after diverging or
converging:
LEVIGATION, from lævis, smooth; the art of reducing to a light powder.

380
Glossary.
LIQUEFACTION, from liquefacio, to make liquid ; the process of convert-
ing into a liquid state.
LITMUS; a blue pigment obtained from the lichen rocella; it is a most
delicate test of acids, which turn it red.
LOADSTONE, i.e., LEADSTONE ; an ore of iron having magnetic properties.
M.
MAGNET, from Magnesia, a town in Asia Minor ; artificial magnets are
sınall bars of steel or iron, which, when placed at liberty, turn one
end to the north.
MAGNETISM; the peculiar property possessed by certain ferruginous
bodies, whereby, under certain circumstances, they attract and re-
pel one another according to certain laws.
MAGNETO-ELECTRICITY; electricity produced by magnetism.
MALLEABLE, from malleus, a hammer; that which is capable of being
spread by beating.
Maximum, from maximus, greatest; the greatest value of a variable
quantity.
MECHÀNICS, from pingavi, a machine; the science which treats of the
laws of the rest and motion of bodies.
METALLURGY, from métodov, a metal, and oyov, a work; the art of
working metals, and separating them from their ores.
MINERALOGY ; the science which treats of bodies not being vegetable
or animal.
MOIRÉE METALLIQUE, from moirée, a watered silk ; when tin plates are
washed over with a weak acid, the crystalline texture of the tin
becomes apparent, forming a crystalline appearance, which has been
called Moirée Métallique.
MOLECULES, -AR, a diminutive from moles, a mass; the infinitely small
material particles of which bodies are conceived to be aggregations.
MOMENTUM, from moveo, to move ; the product of the numbers which
represent the quantity of matter and the velocity of a body, is
called its momentum or quantity of motion.
MUCILAGINOUS ; resembling mucilage or gum.
MULTIPLE, from multiplico, to render manifold; a quantity is said to be
a multiple of another when it contains that other quantity a certain
number of times without a remainder.
N.
NASCENT, from nascor, to be born; in the moment of formation.
NEGATIVE, from nego, to deny ; quantities to which the sign of subtrac-
tion, or negative sign, is prefixed, are called negative quantities;
this sign is also used to denote operations which are the reverse
of those denoted by the positive sign.
NODES, -AL, from nodus, a knot; in the doctrine of curves, a node is a
small oval figure made by the intersection of one branch of a curve
with another.
NORMAL, from norma, a rule; according to rule.
NUCLEUS, from nucleus, a kernel ; the central parts of a body, which are
supposed to be firmer, and separated from the other parts, as the
kernel of a nut is from the shell; also, the point about which mat-
ter is collected.
0.
OBLATE, from ob, in front of, and latus, broad; flattened or short-
ened.

Glossary.
381
OBLONG, from ob, in front of, and longus, long; greater in length than
in breadth.
OCTOHETRON, -AL, from óxto, eight, and doc, a side; a solid figure con-
tained by eight equal and equilateral triangles.
OLEFIANT Gas, from oleum, oil, and fio, to become; a colorless, taste-
less gas, which derives its name from its property of forming an
oil-like liquid with chlorine.
Optics, from öronlar, to see; that branch of natural philosophy which
treats of vision, and of the nature and properties of light, and of the
various changes it undergoes.
Organic MATTER, from őgyaror, an organ; when matter possesses or-
gans, or organized parts for sustaining living action, as animals and
plants, it is called organic.
ORGANIZATION; construction in which the parts are so disposed as to
be subservient to each other.
OSCILLATION, from oscillor, to swing; the vibration or reciprocal ascer i
and descent of a pendulum.
Oxide; a combination with oxygen, not being acid.
OXIDIZABLE; capable of being converted into an oxide.
OXYGEN, from ošús, acid, and yevvưw, to produce; a colorless, aeriform
fluid, which was formerly supposed to be the universal acidifying
principle.
P.
PARABOLA, from apů, parallel to, and Búraw, to place; one of the conic
sections, formed by the intersection of a plane and a cone, when the
plane passes parallel to the side of the cone.
PARALLEL; a term applied in geometry to lines and planes, which are
every where equidistant from one another; straight lines, which, if
infinitely produced, never meet, are called parallel straight lines.
PARALLELOGRAM; a four-sided figure, of which the opposite sides are
parallel and equal.
PARALLELOPIPEDON; a solid figure contained by six parallelograms,
the opposite sides of which are equal and parallel.
PELLICLE, a diminutive from pellis, a skin or crust; a thin crust formed
on the surface of a solution by evaporization.
PENDULUM, from pendeo, to hang; a heavy body so suspended that it
máy vibrate, or swing backward and forward about some fixed
point, by the action of gravity.
PERCOLATE, from per, through, and colo, to strain ; to strain through.
PERMEATE, from permeo, to pass through; to penetrate.
PERPENDICULAR; the straight line which, standing upon another
straight line, makes the adjacent angles equal, and consequently
right angles, is said to be perpendicular to the line upon which it
stands.
PHENOMENON, from qalvoudt, to appear; an appearance.
PHILOSOPHY, -ICAL, from puzéo, to love, and copia, wisdom; the study
or knowledge of nature or morality, founded on reason and expe-
rience, the word originally implying a love of wisdom.”
PHLOGISTON, from gåéyo), to burn ; a name given by the older chemists
to an imaginary substance, which was considered as the principle
of inflammability.
PHOSENE, from spôs, light, and yɛvview, to produce; produced by light.
PHOSPHORUS, from põs, light, and géour, to produce; a highly inflam-
mable substance, obtained from calcined bones, which emits light
when placed in the dark.

382
Glossary.
PHOTOMETER, from pôs, light, and pérgov, a measure; an instrument
for measuring the different intensities of light.
PHYSIOLOGY, -ICAL, from qúous, nature, and hóyos, an account; the
science which treats of the structure of living beings.
PNEUMATICS, from a veðud, air; that branch of natural philosophy
which treats of the weight, pressure, and elasticity of aeriform fluids.
POLARITY; the opposition of two equal forces in bodies, similar to that
which confers the tendency of magnetized bodies to point to the
magnetic poles.
POLARIZATION; the communication of the above opposition of forces.
POLARIZED Light; light which, by reflection or refraction at a certain
boc angle, or by refraction in certain crystals, has acquired the prop-
erty of exhibiting opposite effects in planes at right angles to each
other, is said to be polarized.
POLES OF A MAGNET; points in a magnet where the intensity of the
magnetic force is a maximum; one of these attracts, and another
repels, the same pole of another magnet.
Pores, from nópos, a passage ; the small interstices between the solid
particles of bodies.
PRECIPITATION, from præcipito, to fall suddenly; the separation of a
solid from a liquid; a triangular glass solid used for the separation
of rays of light by refraction.
PROJECTILE, from pro, forward, and jacio, to throw; a heavy body pro-
jected, or cast forward into space, by any external force.
PROPORTION; the relation of equality subsisting between two ratios.
PYROMETER, from no, fire, and péroov, a measure; an instrument for
measuring higher degrees of temperature than can be ascertained
by a thermometer.
PYROXYLIC SPIRIT, from nữo, fire, and oğüs, acid; a colorless, transpa-
rent spirit, obtained by the destructive distillation of wood.
PYRO; when prefixed to a word, denctes that the substance which it
signifies has been formed at a high temperature.
PHOTOGRAPHY, from pws, light, and yeaww, to write ; writing with the
sun's rays.
Q.
QUADRANT ; the fourth part of the circumference of a circle.
R.
RADIATION, from radius, a ray; the shooting forth in all directions
from a centre.
RADICAL, from radix, a root; the original principle of a compound.
RADIUS ; the straight line drawn from the centre to the circumference
of a circle.
RAREFACTION, from rarus, rare, and facio, to make; the act of causing
a substance to become less dense; it also denominates the state of
this lessened density.
RATIO ; the relation which subsists between two quantities of the same
kind, the comparison being made by considering what multiple
part or parts one of them is of the other.
Ray; a beam of light propagated from a radiant point.
REACTION; the reciprocation of any impulse, or force impressed, made
by the body on which such impression is made. Reaction is always
equal to action.
RECTANGLE, from rectus, right, and angulus, an angle ; a four-sided plane

Glossary
383
figure, in which all the angles are right angles, and its opposite
sides equal and parallel.
RECTIFICATION; the process of drawing any thing off by distillation, in
order to make it more pure and refined.
RectiLINEAR ; consisting of, or bounded by, straight lines.
REFLECTION, from re, back, and flecto, to bend; the act of bending back;
when rays of light fall on the surfaces of bodies, part of them are
thrown back or reflected.
REFRACTION, from re, back, and frango, to break; the deviation of rays
of light from their direct course, when passing through media of
different densities.
REFRANGIBLE; susceptible of refraction.
REFRIGERATION, from re, again, and frigo, to cool; the act of cooling.
REPULSION, from re, back, and pello, to drive; that property in certain
bodies whereby they mutually tend to recede and fly off from each
other.
RETORT, from re, back, and torqueo, to twist; a vessel with a bent neck,
which is made use of in chemical operations.
RHOMBUS; a figure which has all its sides equal, but its angles are not
right angles.
RHOMBOHEDRON; a solid figure, whose sides are composed of rhombs.
RHOMBOID; a figure which has its opposite sides equal, but all its angles
are not equal, neither are all its angles right angles.
S.
SALIFIABLE Bases, from sal, salt, and fio, to become; bodies capable
of combining with acids to form salts.
SATURATION, -ATED, from satur, full; the solution of one body in an-
other until the receiving body can contain no more.
SCALE, from scala, a ladder; an instrument in which a line is divided
into small and equal parts, and which is applied for the purpose of
ascertaining the relative dimensions of other lengths not so divided.
Section, from seco, to cut; a cutting, or part separated from the whole.
SEGMENT OF A CIRCLE ; any portion cut off by a straight line.
SINE; the straight line drawn from one extremity of an arc, perpen-
dicular to the radius which passes through the other extremity.
Solution, from solvo, to loosen ; in chemical language, any fluid that con-
tains another substance dissolved in and intimately mixed with it.
SOLVENT; any substance which will dissolve another.
Specific, from species, a particular sort or kind; that which denomi-
nates any property which is not general, but is confined to an in-
dividual or species.
SPECTRUM; the colored image formed on a white surface by rays of
light passing through a hole, and being refracted by a glass prism.
SPHERE; the solid figure formed by the rotation of a semicircle about
its diameter.
SPHEROID, -AL; a solid figure, formed by the revolution of an ellipse
about one of its axes; hence it is sometimes called an ellipsoid;
the spheroid will be oblate or prolate, according as the revolution
is performed about the minor or major axis of the ellipse.
Statics, -ICAL, from otatoş, standing ; that branch of mechanical
science which treats of the equilibrium, pressure, weight, &c., of
solid bodies when at rest.
STRATUM, from sterno, to strew; a layer.
SYMMETRY, -ICAL, from oudy, together, and uétqov, a measure ; confor
mity of measure.

384
Glossary.
SYNTHESIS, from ovv, together, and tignu, to place; the composition
of a whole from its parts; in mathematics, the process of reasoning
out new principles from those already established.
SUBLIMATION, from sublimis, high; the act of raising into vapor by
means of heat, and condensing in the upper part of a vessel.
SYNCHRONOUS, from our, together, and xpóvos, time; performed in the
same time.
T.
TACTILE, from tango, to touch; of or relating to touch.
TANGENT, IAL; the line which touches a circle or any other curve, but
does not cut it.
TERNARY, from ter, thrice; containing three units.
TETRAHEDRON, from Tiogaqes, four, and ¢dod, a base or side ; a solid
figure contained by four equal and equilateral triangles.
THEORY, -ETICAL, from gewpic, a view; a collected view of all that
is known on any subject into one.
TAERMO-ELECTRICITY ; electricity produced by heat.
THERMOMETER, from liquos, heat, and kétpov, a measure; an instru-
ment for measuring the degrees of heat.
THERMOSCOPE, from Jiquos, heat, and ozonéw, to view; an instrument
for exhibiting the powers of heat.
Tire; a hoop of iron used to bend and receive the felly of a wheel.
TORSION, FORCE OF, from torqueo, to twist; a terni applied by Cou-
lomb to denote the effort made by a thread which has been twisted
to untwist itself.
TRANSPARENT; a term to denote the quality of a substance which not
only admits the passage of light, but also of the vision of external
objects.
TRITURATED, from trituro, to thrash ; reduced to powder.
TRUNCATION, from truncus, cut short; the cutting off a portion of a
solid, as of the solid angle of a crystal.
U.
UNDULATION, from unda, a wave; a formation of waves.
UNIAXAL, from unus, one, and axis, an axis; having but one axis.
V.
VACUUM, Latin; a space empty and devoid of all matter.
VENTILATION, from ventus, wind; the supply of fresh air.
VERNIER ; an instrument invented by Vernier; it consists of a small,
movable scale, running parallel to the fixed scale of a quadrant or
other instrument, and having the effect of subdividing the divisions
of the instrument into more minute parts.
VIBRATION, from vibro, to brandish; the regular reciprocating motion
of a body, as of a pendulum, &c.; a motion to and fro.
VOLUME, from volumen, a roll; the apparent space occupied by a body.
W.
Weight; the pressure which a body exerts vertically downward in
consequence of the action of gravity.
Z.
ZERO; the numeral 0, which fills the blank between the ascending
and descending numbers in a series.

INDEX.
copper
ALE Page. Acid, hydrosulphocyanic.... 200
Acetate of alumina..
327 hydrosulphuric..
197
ammonia
327 hydrosulphurous
199
326
hydrotelluric..
263
iron.
327
hydrothionic.
197
lead
326 hypochlorous
138
mercury, tin, zinc.
327 hyponitrous..
165
Acetous fermentation. 346 hypophosphorous
202
Acid, acetic..
326 hyposulphuric.
194
antimonic
264 hyposulphurous
192
antimonious
264 indigotic
331
apocrenic.
331 iodic
143
arsenic.
257 iodous
112
arsenious.
255 kinic.
329
azulmis
331 lactic
329
benzoic.
329 malic
327
boracic
208 margaric
330
bromic
145 manganic.
240
camphoric
330 meconic.
329
carbazotic
331 115 mellitic.
329
carbonic.
176 metagallic
330
chloric
139
metameconic
329
chlorous
139 molybdic
262
chloriodic
143
moroxylic
330
chlorocarbonic
181 mucic.
330
chromic.
259 muriatic.
154
citric...
327 nitric ...
166
columbic
263
nitrohydrochloric. 168
crenic.
331 nitrohydrofluoric
169
croconic.
329 nitrous
165
cyanic
188 nitromuriatic.
169
cyanohydrosulphuric. 200 oxalic
325
cyanuric
188 oleic .
330
elaidic
338
paracyanuric.
189
ellagic
330
paraphosphoric..
204
fluosilicic
213
pectic...
331
fluoboric
209 perchloric
140
fulminic.
188
permanganic.
240
gallic
328 periodic.
143
hydriodic.
155 phosphoric.
203
hydrobromic
157 | Acidulous springs.
360
hydrochlorie.
154 Acid, phosphorous.
203
hydrofluoric
157 prussic ..
189
hydroselenic
211 pyrocitric..
329
..
..
33

386
Index
mixed gases
Acid, pyrogallic
330 | Analysis of carbonate of lime 358
pyroligneous.
326 Analysis of minerals... 357
pyrophosphoric.
204
356
racemic
329 Angles of crystals.
284
rocellic.
330 plane
284
selenic
211 solid
284
selenious
210 Analysis of mineral waters.. 360
silicic ...
212 Anhydrite
290
silicohydrofluoric 213 Anthracite.
173
stearic
330 | Animal acids.
350
succinic.
330 chemistry
349
sulphuric.
194 heat
353
sulphurous
192 oils and fats.
350
tannic...
328 Antimonio-sulphurets. 319
tartaric.
327 | Antimony
263
telluric..
268 Appendix
364
tellurous
268 Aqua fortis.
168
titanic
267 potassa.
220
tungstic
262 Archil
345
valerianic
330 Aerostation.
149
vanadic
261 Arrow-root
336
Affinity, chemical.
105 Arseniates.
305
disposing
147 table of compounds. 306
double
106 Arsenic
254
effects of
112 Arsenites.
306
elective
106 Arsenio-sulphurets
318
measure of.
111 | Arseniureted hydrogen 258
simple
106 Atomic theory...
118
Air..
160 Auro-chlorides
319
Alabaster.
290
Albumen
349
B
Alcohol ..
... 341 Balloons..
149
Alkalies, metallic bases of... 218 Balsam of sulphur.
339
Alkaline earths
227 Balsam
340
Alloys of antimony.
265 Barilla
308
copper
227
270 Barium
gold
280 Barometer
53
lead
272 Baryta
227
manganese
241 Barytes
290
silver
277 Bell-metal
276
sodium and potassium. 225 Biborate of soda.
308
Alum...
294 Bicarbonate of ammonia. 310
ammonia
294
potassa.
310
Alum stone.
294 soda
310
iron..
294 Bicarburet of nitrogen...... 188
294 Bichromate of potassa.
manganese
Alkaline springs.
360 Bichloride of cyanogen...... 189
Alumina
234 mercury.
274
Aluminium
234 platinum
234
Aluminous earth.
tin....
250
Amalgams.
275 titanium.
268
Amber.
340
tungsten
262
Ambergris.
275
351 Bicyanuret of mercury
Ammonia
354
170 | Bile
...
....
307
....
281

Inder.
387
189
145
272
...
....
. . . . .
233
225
197
205
221
211
213
247
C. 247
230
32
26
36
29
31
Bichloride of molybdenum... 262 Bromide of cyanogen.
Bipiodide of platinum.
282
iodine..
tin....
250 lead
Binoxide of barium
228 magnesium
columbium
263 sodium.
copper
270 sulphur
gold ..
279 phosphorus
hydrogen.
153 potassium
mercury.
274 selenium
molybdenum.
261
silicon
nitrogen.
164 zinc
platinum
281
tungsten
262
С
tin...
250 Cadmium
vanadium
261 Calcium..
Biphosphuret of cobalt. 253 Caloric.
Bisilicates
312 absorption of
Bismuth..
266 conduction of
Bisulphuret of carbon. 199 effects of.
calcium
232 radiation of
cobalt.
253 reflection of
iron
244 theories
mercury
275 Calomel..
platinum
282 Camphene
tin...
251 Camphor..
selenium
211 Canton's phosphorus
titanium
268 Calorimotor
Bisulphate of the peroxide of Caoutchouc.
mercury
293 Carbon
potassa.
.2289 five-fourths chloride
soda
289 Carbonates
Bitartrate of potassa
327 ammonia
Bituminous coal.
173 baryta.
Black dyes
345 lead
lead
173
lime
oxide of copper
270 magnesia.
oxide of iron.
243 potassa.
Bleaching
137
protoxide of iron.
powder.
232
soda
Blue vitriol
293 strontia
Block tin..
249 Carbonic oxide.
Blood
351 Carbosulphate of ammonia..
Bone phosphate of lime 304 Carbosulphurets..
Bones.
355 ammonia
Borates
307
barium
Borax.
308 calcium
Boron
207
sulphuret of lithium
Brass
270 magnesium
Bromine
143
potassium
Bromates.
302 sodium
Bromide of carbon.
181
Carburet of manganese.
bismuth.
267
iron..
calcium
231 Carmine
barium
228 | Cast iron.
274
184
339
231
80
341
172
181
308
309
310
311
310
311
348
310
309
310
176
315
317
318
318
318
318
318
317
318
241
245
345
245

388
Index.
254
245 | Cocoanut oil.....
339
336 Cohesion
107
369 | Coloring matters
343
341 | Columbium..
263
266 Combustion
133
266 Complex animal substances.. 351
173 Composition of blood.
351
181 Compound blow pipe
152
299 Copal...
340
300 Copperas.
294
299 Copper
269
228 Copper pyrites.
269
267 Corrosive sublimate
274
145 Cream of tartar
327
248 Creosote
341
231 Croton oil...
339
181 Crucibles.
191
252 Crude tartar
327
270 Crystal
283
188 | Crystallization
283
272 Crystallogenic attraction 287
232 Crystalography
283
226 Cyanogen
188
233 Cyanuret of lead
272
254
barium ..
229
221
manganese
241
211 nickel
213 silver
277
277 sodium.
225
225 zinc
247
224
potassium
223
229 Cube
284
268 Cubic nitre
296
247 Cuticle..
355
360
179
D
133 Daguerreotype
68
301 Decrepitation.
284
307 Definite proportions
115
307 | Deflagration.
295
307 Deflagrator.
82
307 Deliquesce
287
258 Destructive distillation. 322
354 Dichloride of sulphur.
197
333 Difluoborate of ammonia 315
273 Dipyrophosphate of soda 305
184 oxide of silver.
305
soda and basic water
305
286 Diamond
172
286 Dicarbonate protoxide of cop-
286
311
per
185 Dichloride of copper.
270
251
Dicarbonate of mercury
311
344 | Dicarburet of hydrogen
...
217
182
Cast steel.
Cassava
Cementing
Cerin
Cerite.
Cerium
Charcoal
Chloral
Chlorates.
baryta
potassa.
Chloride of barium.
bismuth
Abromine
cadmium
calcium
carbon
cobalt...
copper
cyanogen
lead
lime
lithium.
magnesium
nickel.
potassium
selenium
silicon
silver
soda
sodium
strontium.
tellurium
zinc
Chalybeate springs.
Choke-damp...
Chlorine
Chlorites
Chromates
lead
potassa.
oxide of zinc.
Chromium
Chyle..
Cinchonia
Cinnabar
Citrine..
Classification of metals.
Cleavage
faces of..
direction of
Coal gas
Cobalt .
Cochineal

Index.
389
........ 59
Digester, Marcet's.........
55 | Evaporation
Diphosphate of potassa...... 302
Diphosphate of ammonia.... 304
F
lime
304 Febrifuge salt of Silvius...... 221
magnesia
304 | Feathers
356
Diphosphuret of iron.
245 Fermentation
345
Dinitrate of protoxide of lead 297 Fibrin...
349
mercury....
297 Filtration
362
Diniodide of copper.
270 Fire-damp
186
Dioxide of copper
... 260 Fixed oils
337
Disulphate of alumina 291
Flowers of zinc
247
protoxide of copper. 293 Fluoborate of ammonia. 315
Disulphuret of iron.. 244 | Fluoride of barium.
228
nickel.
254 calcium
231
Dodecahedron
286 lead...
271
Dolomite ,
290 lithium.
226
Double bromides..
320
magnesium
233
carbonates
312
potassium
221
cyanurets.
321 sodium.
225
fluorides
321
strontium.
230
iodides
320 zinc
247
Drying oils
338 Fluorine
145
Ductility
215 Fluosilicate of ammonia.. 315
Food of plants..
348
E
Fowler's arsenical solution 306
Ebullition
52 Freezing mixtures.
50
EMoresce
287 Fulminating gold.
279
Eggs
355 platinum
282
Elaidin.
338
silver.
277
Elasticity
109 Fuming liquid of Libavius... 250
Electricity
72 Fusion ..
109
Electrical machine
74 Fusion, watery.
287
Electro-chemical decomposi- Fusibility
215
tion...
90
Electrodes..
88
G
Electrography
104 Galena..
271
Electrometer, gold leaf. 74 | Galvanism
78
balance
77 theories
82
Electro-magnetism
91 effects of
84
theory
100 Gasometers.
129
Electro-magnetic multiplier.. 93 Gas lights.
184
Electrophorus.
77 Gastric juice.
353
Electrotype.
104 Gaseous mixtures
356
Emetia..
334
containing carbonic acid 357
Emulsion.
338
hydrogen....
357
Essences
339
nitrogen..
357
Etching
158
356
oxygen.
Etherine, four-four carburet Gelatin
349
of hydrogen.
184 Germ...
347
Ethers
342 Germination.
347
Ethiop's mineral
275 Glass
213
Eudiometer
152
213
Eudiometry.
163
213
crown.
Eupione..
1841 plate
213
green bottle
33*

390
Index.
355
243 Kelp
Glass, flint.
213 | Iodide of cadmium
248
Glauber's salts.
289 lead
272
Glucina
236 magnesium
233
Glucinium
236 silver
277
Glue.
349
sodium.
225
Gluten.
336 phosphorus
205
Gold...
278 sulphur
197
powder.
280
potassium
221
Green vitriol.
291 strontium.
230
Graphite
245 zinc
247
Gum
336 Iodine
140
arabic
337 Iron
241
senegal.
337 Iron pyrites.
244
tragacanth.
337 Iridium
282
resins
340 Iridochlorides
320
Gypsum
276 Isomorphism..
287
Ivory-black.
173
H
Hair ..
K
Hartshorn
170 Kalium
218
Hemetite, red
243 Kermes mineral.
265
brown.
309
Hexahedron
284
Homberg's pyrophorus 294
L
Hog's lard.
350
Honey
335
Lakes..
343
Hoofs.
355 Lamp-black.
173
Horn
355 Lapis causticus
220
Hordein.
347
Latanium
283
Horn silver.
277
Lead
271
'Hydrates.
152 Leyden jar
76
Hydriodate of ammonia. 315 Light...
66
Hydro-salts
314
reflection of
66
Hydrochlorate of ammonia.. 314
refraction of
66
Hydrobromate of ammonia.. 315 decomposition of
67
315
Hydrofluate of ammonia
69
absorption of....
Hydrocyanate of ammonia... 315 Light carbureted hydrogen.. 182
Hydrogen
49
146 Liquefaction..
Hyduret of potassium.
222 Lignin.
337
230
Hygrometers
Lime-water.
230
I
Liquorice
335
271
Idrialine
184 Litharge
Lithia
226
Ignition
70
Lithium.
226
Induction
75
Litmus
Indefinite proportions.
114
Lucifer matches.
300
Indelible ink.
298
Lunar caustic..
298
India rubber ..
341
Ink
328
Insolubility
108
M
Iodates..
301 Madder
345
Iodate of potassa
301 Magnesium
232
lodide of barium
228 Magistery of bismuth
267
calcium
231 | Magnesia
233
62 | Lime
345

Index.
391
...158
311 | Oils
335 Oily acids
318 Oil gas.
Magnetic iron pyrites..
244 Nitrogen
Magic circle
96 Nitrous ether
343
Malleability
214 Notation
126
Magneto-electric induction.. 99 Nomenclature
122
Magneto-electric machine
99 Nux vomica..
334
Manganese
238
Manna..
335
0
Margarine
351 Oblique prisms
285
Massicot
271 rhombic prisms.
285
Matches
300
OS rectangular
285
Membranes
355
rhomboidal
285
Metals
214 Octohedron
285
Metallic lustre
214 Octohedron, regular
286
Metaphosphates
305
square
285
Mercury.
273
rectangular
286
Milk
354
rhombic
286
Microcosmic salt
303 | Enanthic ether
342.
Mineral green.
337
Molasses
330
Molybdesulphurets
183
Molybdosulphuret of potassa. 318 Oleine
331
Molybdenum.
261
Olefiant gas.
182
Morphia.
332 Orpiment..
258
Mosaic gold.
251 Osmium.
282
Mucus
354 Osmazome.
350
Muscle
356 Osmio-chlorides
320
Myricine
341 Oxalate of potassa
325
of lime..
326
N
Oxalic ether
343
Nails..
355 Oxigenation
133
Naphtha
184 Oxidation.
133
Naphthaline
210
184 Oxide of selenium
Narcotina
333 cadmium
248
Natron
223 carbon
196
Natural substances.
321 phosphorus
202
Neutral substances.
267
334 titanium.
Nickel
277
253 silver
Nicotina.
334 strontium.
230
Nitre.
320
295 Oxychlorides.
Nitric oxide.
164 chromium
260
128
Nitrous oxide
163 Oxygen
Nituret of potassium.
222 Oxysalts
287
Nitrates ....
295 Oxysulphuret of antimony.. 265
Nitrate of ammonia.
296
baryta
296
Р
lime
....
...
....
. . . .
282
297 Palladium
magnesia
319
297 Palladio-chlorides.
potassa..
339
295 Palm-oil...
soda
296 Paracyanuric acid..
189
strontia...
184
297 Paranaphthaline.
184
protoxide of copper
297 Parraffine
lead..
173
297 Peat ..
mercury
308
297 Pearlash
oxide silver.
297 Perbromide of phosphorus... 205
183
Nitrites
299 Percarbureted hydrogen.
.....

392
Index.
Percussion powder..
300 | Potassium
218
Perchlorates
301 Potash and pearlash.
308
Perchloride of iron.
243 Primary forms.
284
manganese.
240 Printer's types
265
phosphorus
205 Protobromide of iron
244
Periodide of arsenic.
258 potassium..
221
iron...
244 Protochloride of iron.
243
carbon
· 181 tin....
250
Perfluoride of iron
244 carbon
181
manganese.
240
manganese.
238
Perphosphuret of hydrogen.. 206 Protochloride of arsenic 257
Peroxide of strontium
229 cerium
266
calcium ..
231 mercury
274
manganese.
239
gold
280
iron..
243 platinum
281
cobalt
252 uranium..
266
four-three oxcobalt. 252 Protocyanuret of iron. 245
titanium..
267 Protiodide of iron.
243
tellurium
268 cadmium
248
lead.
271 carbon
181
Permuriate of tin
250 tin....
250
Persulphuret of arsenic. 258 platinum
282
tellurium ..
268 Protohyduret of arsenic 258
Perphosphuret of iron 245 Protosulphuret of arsenic 258
Pewter...
265 platinum
282
Phosphureted hydrogen 206 mercury
275
Phosphorus
200
cerium
266
Phosphorescence
70 cobalt
253
Phosphates
302 nickel.
254
Phosphate of potassa.
302 manganese
241
soda and ammonia. 303 tin.
251
ammonia ......... 304 iron.
244
lime
304 strontium..
230
magnesia and ammonia.. 304 calcium
231
Phosphuret of potassium 222 Protosulphocyanuret of iron.. 245
cadmium
249 Protoxide of strontium
229
calcium
232 cerium
266
manganese
241
hydrogen
150
hydrogen
205
bismuth
267
barium
229 nitrogen.
163
Pitch
potassium.
220
Pinchbeck.
270 gold.
279
Photometers
sodium
224
Photographic drawing.
68
copper.
270
Platinum
281 lithium
226
spongy
251 barium
227
Platinochlorides
319 lead..
271
biniodide of potassium. 320 calcium
230
Plumbago
173 magnesium
233
Pneumatic cistern
129
mercury
273
Pot-metal
271 thorium
237
185
manganese
238
Potassa
221 iron..
242
hydrate of.
221 platinum
281
Potassa-fusa.
221 zinci.
247
.
.
340
Portable gas

Index,
393
..
Protoxide of tin
cobalt
nickel.
vanadium.
molybdenum.
uranium
Proximate principles.
Prussian blue
Pus.
Plumula.
Putrefactive fermentation.
Pyrometers ...
of Wedgwood
of Daniell
of Brequet.
Pyrotechny
Pyrophosphates
of soda
Pyroxylic.spirit..
um
Q
Quadrisilicates
Quadrochloride of nitrogen
Quartation..
Quinia.
249 Saliva....
353
252 Salifiable base.
283
253 Saline springs.
360
261 Saltpetre ..
296
261 Salts or secondary compounds 283
265 double
288
322 triple
288
243 Sandarac
254
355 Scheele's green
306
347 Sealing-wax
340
346 Seleniuret of aluminium. 235
37 Seleniuret of potassium.. 222
46 Selenium ....
209
- 46 Sesquiphosphuret of alumini-
46
235
296 cobalt.
253
304 Sesquibromide of arsenic
258
305 carbonate of ammonia. 310
343 carbonate of soda. 309
Sesquichloride of aluminium. 235
antimony
264
313 arsenic
257
169 cerium
266
278 chromium
260
333 uranium..
266 -
Sesquifluoride of chromium.. 20
Sesquioxide of aluminium. 234
347 antimony
264
258 bismuth
267
344 cerium
266
239 chromium
259
272 glucinium
236
274
manganese
239
180 nickel.
254
platinum
281
348 sodium
224
94
tin....
250
284 uranium.
266
284 zirconium
237
284 Sesquisulphuret of aluminium 235
284 antimony
265
284 arsenic
258
282 chromium
260
320 tin.
251
285 cobalt.
253
328 Sesquisulphocyanuret of iron. 245
335 Sulphọcyanuret of barium...
229
iron..
245
potassium
223
Shells.
355
345 Silver..
276
187 Silver glance
277
336 Silex..
212
314 Silicon
212
. . 60
R
Radicle
Realgar
Red dyes.
Red oxide of manganese.
lead.
Red precipitate.
Respiration
Resins
Respiration of plants.
Revolving rectangle..
Right prisms
Right square 'prisms
rectangular
rhombic.
rhomboidal
Rhodium....
Rhodio-chlorides
Rhombohedron
Rochelle salt.
Rock candy
340
..
224
salt..
s
Saccharine fermentation.
Safety lamp
Sago
Sal-ammoniac

394
Index.
OL engine
of grapes.
Silicium.
212 | Sulphate of nickel
292
Silica.
212 silver
293
Silk..
356 zinc.
292
Solution..
108 Sulphureted springs
361
Spirituous and ethereal sub- Sulphuret of barium
228
stances
341
boron
209
Spirits of turpentine
339
bismuth
267
Soaps
351 cadmium
248
Sodium.
223 cobalt.
253
Soda..
224
copper
270
Solder
272 Sulphuret of cyanogen.
200
Specific gravity
121 lead..
272
of essential and other oils 371 potassium
222
Spermaceti oil.
350 silicon
213
Starch
335 sodium
225
Steam
56 silver
277
artillery
59 uranium.
266
58 zinc..
247
generator.
58 Sulphur-salts
316
Steel...
245 Sulphuric ether.
342
Stream tin.
249 1 Sweat.
355
Strontia
229 Sympathetic ink
252
Strontium
229
Strychnia
333
T
Sugar..
334 Table of discovery of metals.. 217
335 Tannin.
328
of lead.
326 Tapioca
336
Subphosphuret of cobalt.. 253 | Tar..
nickel....
254 Tartar emetic.
327
Subsulphate of protoxide of Tartrate of antimony
327
mercury
293 potassa..
327
Subsesquiphosphuret of cop-
soda
328
per
270 Tears
354
Sublimation
190 Teeth.
Suet
350 Tellurium
268
Sulphur ...
190 Tendons...
355
flowers of.
190 | Terchloride of boron.
209
rool-brimstone.
190 molybdenum.
262
Sulphates....
288 gold
280
Sulphate of ammonia. 289 chromium
260
alumina
291 Terfluoride of chromium. 260
baryta.
290 Teroxide of potassium 221
lime
290 Teriodide of nitrogen
169
lithia.
289 | Terphosphuret of tin. 251
potassa
-288 Tersulphate of alumina..
291
soda.
289
sesquioxide of chromium 292
strontia ...
290 Tests of metallic ores.
359
potassa and alumina
294 Teroxide of gold.
279
potassa and magnesia.. 294
potassium
221
protoxide of copper . 293 Tersulphuret of tin.
251
cobalt
292 Tertrasulphuret of iron. 244
iron
291 Theory of animal heat
353
manganese
291 Thermo-electricity.
mercury
293 | Thermometers
340
355
102
42

Index.
395
249
..
Thermometers, aiy.
42 Vegetable acids..
325
differential.
43 alkalies...
332
mercurial..
44 Verdigris.
326
graduating of
44 Verditer..
311
register..
45 Vermilion
275
Thorina
237 | Vinegar, distilled...
326
Thorium.
237 Vinous fermentation.
345
Tin
249 Voltaic electricity.
78
Tin foil.
circles
79
Tincal
308
pile.
81
Titanium
267 | Volta-electric induction 97
Torpedoes
277 | Volatile
52
Train oil
350 oils
339
Trifluoborate of ammonia.. 315 liniment.
338
Triphosphate of potassa. 302 Volatility
215
soda
303
soda and basic water. 303
W
acid triphosphate.. 303 Water
150
lime
304 of crystallization
287
magnesia
304 of nitre..
167
ox. silver.
304 Water gilding.
280
Tripliosphuret of copper.
270 Wax...
341
Trisilicates
313 White oxide of arsenic. 255
Trona...
309 | White vitriol...
292
Tungsten
262) Wollaston's scale of chemical
Tungstosulphurets.
319
equivalents
364
Turkey red..
345 | Wool
356
Turpentine
340 Woulfe's apparatus.
155
Turpeth mineral.
293
Y
U
Yellow dyes
345
Ultimate analysis.
322 Yttria...
236
Universal cement
370 | Yttrium
236
Uranium
265
Urine
355
Z
Zaffre..
252
V
Zinc...
246
Vanadium
260 | Zinc blende
247
Vaporization.
52 Zinetum
246
Variegated copper pyrites... 244 Zirconia.
237
Varvicite
240 | Zirconium
237
.....
....m
.......
..
...
...
ooh
AS
2009

INDEX OF FIGURES.
... 131
66
66
CG
....
Fig.
Page. Fig.
Page.
1. Conductometer
27 59. Retorts
130
2. Apparatus for heating liquids... 28 60. Lead tubes for connection..
3, 4. for conduc'n of liquids 29 61, 62, 63. Apparatus for oxygen.. 132
5.
for radiation of cal... 30 64. Apparatus for collection of gases
6.
for reflection of caloric 31
heavier than the air
139
7. Concave mirrors...
31 65. App. for decomposition of water 146
8. Pyrometers
37 66. Gas bag and bubble pipe....... 147
9, 10. App. for expansion of liquids 38 67. Method of filling gas bags. 148
11. App. for expansion of air... 38 68. Balloons...
149
12. Air thermometer.
42 69. App. for musical sounds.. 149
13. Differential thermometer.
43 70. Hydrogen pistol..
149
14. Common and laboratory do.. 44 71. Eudiometer..
152
15. Blowpipes...
44
72. Compound blowpipe
153
16. Different scales of thermometers 45 73. Woulfe's apparatus.
155
17. Register thermometer.
74. App. for obtaining nitrogen... 159
18. Metallic thermometer..
46 75.
for analyzing the air.. 162
19. Influence of pressure on the boil-
76.
for obtaining nitric acid.. 167
ing point..
53 77. 6 showing the properties of
20. Pulse glass....
53
nitric acid.
168
21. App. culinary paradox..
54 78. " for collecting gases lighter
22. Marcet's digester
55
than the air.
170
23. Spirit lamp..
55 79. 16 for carbonic acid.
178
24. Steam engine illustrated... 58 80. Effect of gauze wire upon flame 187
25, 26. Distillation. Cryophorus..59, 60. 81. Safety lamp.....
187
27. Apparatus for refraction of light. 67 82. Platinum wire for wicks. 187
28. Prism
67 83. Crystallization of sulphur..... 191
29. Gold leaf electrometer.
74 84. Crucibles.
192
30. Electrical machine..
75 85. Production of sulphur in volca-
31. Apparatus for induction.
76
noes
199
32. Electrophorus
77 86. App,for combustion of phospho-
33. Balance electrometer.
77
rus in oxygen.
202
34. Simple voltaic circles
79 87. App. for phosphureted hydrogen 206
35. Calo
otor
80 88. Evaporating dishes..
208
36. Voltaic pile..
81 89. Hexahedron
284
37. Deflagrator
81 90. Right square prism..
284
38. App. for decomposition of water 86 91. Right rectangular prism.. 284
39. Transfer of chemical substances 87 92. Right rhomboidal prism.
284
40. App. for change of colors.
87 93. Regular hexagonal prism..
285
41. Galvanometer
92 94. Rhombohedron
285
42. Revolving rectangle..
93 95. Oblique rhombic prism.. 285
43. Helix and stand..
95
rhomboidal prism..
285
44. Magnet with three poles..
95 97. Regular octohedron..
43. Electro magnet..
95
98. Square
46. Magic circle..
99. Rectangular "
286
47. Vibrating magic circle.
100. Rhombic
286
48, 49. Separable helices. .97, 98 101. Dodecahedron
286
50. Magneto-electric machine
102. App. analysis of gases.
356
51. Theory of electro-magnetism ... 101 103. App. analysis of minerals.. 358
52. Electrotype.
104 104. App. to detect hydrosulphuric
53. Dropping tube...
112
acid...
361
54. App. for change of form..
113 105. Test tubes.
361
55. Ills. of atomic theory
118 106. Mode of folding filters.
365
56. Specific gravity..
121 107. Filters
365
57. Aërometer.
122 108. App. for filtration.
363
58. Pneumatic cistern
363
129
109. Supports
96.
66
285
285
66
66
. .




.
ous And
rina
и natio

1842
Gray, Alonzo
7350
Gr