V

I W

THE

CHEMISTRY OF CREATION:

Q £kdclj of % (tjjemkal

OF

THE EAKTH, THE AIR, THE OCEAN.
BY KOBEKT ELLIS, F.L.S.

M.R.C.S. ETC.

PUBLISHED UNDER THE DIRECTION OF

THE COMMITTEE OF GENERAL LITERATURE AND EDUCATION,

APPOINTED BY THE SOCIETY FOR PROMOTING

CHRISTIAN KNOWLEDGE.

THE EIGHTH THOUSAND.

LONDON

SOCIETY FOR PROMOTING CHRISTIAN KNOWLEDGE;

SOLD AT THE DEPOSITORIES,

GREAT QUEEN STREET, LINCOLN'S INN FIELDS;

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PREFACE.

NOTWITHSTANDING the exercise of much
labour and thought during the progress of
this volume through the press, in the en-
deavour to bring'it below its present limits,
the importance and variety of the subjects
on which it treats have precluded the
possibility of so doing. When the student
of nature investigates the connexions and
natural dependencies of those kingdoms
which together constitute the scheme of
creation, and even when only in one direc-
tion, as in the present case, the subject is
exhaustless. The Chemistry of Creation
is a theme not for one, but for many
volumes.

In the present Work the attempt has
been made to introduce all the recent dis-

2090817

vi PREFACE.

coveries in chemical science, related to
Nature's chemistry, and to apply them to
the explanation of the chemical phenomena
presented in the earth, the air, and the
ocean. That this attempt has been made
in the use of familiar language, and with
the desire to avoid the technicalities of
science, will not be allowed to detract from
the value and importance of the narrated
facts and discoveries of chemical philp-
sophy.

That this volume may be the companion
of the lover of nature, and that it may
assist him to trace in its varied and
beautiful chemical phenomena the work of
Him who is perfect in knowledge and
excellent in working, is the desire of the
writer, and the object of his book.

R. E.

CHELSEA, 1850.

CONTENTS.

INTRODUCTION.

Origin of Chemistry — Egypt — Arabia — China — Glass-
blowers in Egypt— Europe— Dreams of the Alchemists-
Transmutation of Metals— Juggling Tricks — Elixir of Life
— Universal Solvent- Birth-time of Scientific Chemistry —
Progress of the Science — Cavendish — Watt — Davy —
Dalton" — Faraday — Liebig— Prout— Present Importance
of the Science — Knowledge of the Chemistry of Nature
limited p. 1

PART I.-THE EARTH.

CHAPTER I.

THE IXOBGANIC CHEMISTBY OF NATURE.

Common and Philosophical Observation— The Scene— What
is an Element ? — Gases — Fluids — Solids — Remarkable
Arrangement in Nature — Laughing Gas — Economy of
Creation— Imperfection of our Knowledge — Oxygen- Hy-
drogen — Nitrogen — Carbon — Iron rusting — Why ? — Che-
mical Affinity — Composition of a Dew Drop — Chemical
Laws— The First— Oxygenated Water— The Second— The
Third — The Fourth — Importance and Influence of these
Laws — This is not all — LIGHT — Prismatic Spectrum — •
Composition of a Sunbeam — Influence of Sunlight — Light
and Colours— HEAT — Operation of, in Nature — Flowers —
ACTINISM— Chemistry of Sunlight — "Nature's sweet Re-
storer " — Daguerreotype — Talbotype — Magnetic Registers
— ELECTRICITY, necessary in Operations of Nature — Use
and Importance to Man — Electric Telegraph — Electric
Clock — Magnetism — Gravity — Whether Modifications of
one Principle ? p. 21

•VI CONTEXTS.

CHAPTER II.

CHEMISTBY OF THE LAND.

Apparent unchangeableness of the Aspects of Nature — Not
real — Secret Chemical Forces— Destruction slow, silent, but
Bure — Agencies — Water — Carbonic Acid — Oxygen — Nia-
gara Falls— Recession of— Salt-field of North wich— Crystal
Island— Powerful Effect of Carbonated Water— Professor
Rogers' Experiments — Effect of Oxygen — Disease of the
Granite — The Kettle and Pans — Porcelain Clay — Forma-
tion of, out of Granite — Silver Mines — California!! Gold —
Persistence of Egyptian Monuments— Its Cause— Debris —
Production of — Mont Blanc — Alps— Rhine— Valleys of the
Cordilleras — Alluvium — Composition and History of —
Rocks and Hills crumbling to Dust p. 65

CHAPTER III.

CHEM1STHY OF THE SOIL.

Composition of the Vegetable Soil — Mother-earth— Mould —
Chemical History of a Valley — A Delta — Clothing witli
Plants — Deatli of a Tree — Dispersion of its Elements —
Chemistry of its Death — The Farm-yard — The Dung-heap

— Ilniivis — Use' of Vegetable Soil — Carbon — Formation of
Coal — Mackenzie River — Chemistry of Coal — Peculiar
Character of its Decay — Arrangement of Coal-beds — The
Diamond— Chemical Origin of Amber p. 112

•

CHAPTER IV.

CHEMISTEY OF THE IKTEKIOH.

Disquiet within our Planet — Deep Chemistries of the Earth —
High Temperature of Interior— Proofs of — Artesian Wells
— Source of Telrestial Heat — The Sun — Chemical Decom-
position in Crust — Central Heat — Experiments of Mr.
Grove and Dr. Robinson— Curious Property of Intense
Heat — The Earthquake — Phenomena of — Causes of —
Electrical Origin of— Protection against -Earthquakes in
Britain — The Volcano — Chemistry of — Jorullo — The
Moffettes — Upas-tree and Valley — Choke-damp — Lake of
the Solfatara — Chemistry of Caves — Fire-damp — Niagara

— Salt-mine— Singular Evolution of Gas -^Safety-lamp —
" Blowers " in Coal-mines— Mud Volcano* Air Volcuuos-

OuXI'KNTS. Vll

Spriiigof Rock-oil — Boracic Lagoons — Remarkable Natural
Barometer — Metamorphism of Rocks — Experiments of
Mitscherlich — Chemical Phenomena of Iceland — Remark-
able -Aspect of the Country — Boiling Springs — Origin and
Explanation of — Palagonite Rock — Decomposition of by
Volcanic Emanations —Detection of Sulphuretted Hydrogen
Gas by a Cigar — Formation of the Geysers — Professor Bun-
sen's Discoveries — Great Geyser — Explanation of — Coun-
tries rising — Repose and Activity of the Interior of the
Planet, alternate . . . .~ p. 110

PART II.-THK AIR.

CHAPTER I.

ITS PHYSICAL CONSTITUTION.

The Air travels with the Earth — Limits of Air — A Journey
to the Moon — Finite Extent of the Atmosphpre — Extreme
Rarefaction— Gay Lussac's Balloon Ascent — Tides in the
Air — Cause — Solar and Lunar Influence — Atmospheric
Waves — Indian Summer — Weight of the Air — Barometer
—Weight of dry Air— Weight of Water in the Air— Effect
on Barometer — Effect of Pressure — Anecdote — Results of
Pressure — Limit to Aerial Navigation — Cold of Expansion
— Machines for Ice-making —Line of Perpetual Snow —
Snowy Mountain in Africa — Blueness of the Air — Remark-
able Instance of Polarised Light — The Polar Clock — Elec-
tricity of the Air p. 165

CHAPTER II.

CHEMICAL CONSTITUTION OF THE AIB.

Oxygen — The Fire Annihilator— Nitrogen — Rude Analysis
— Eudiometer — Accurate Analysis— Result— Exact Com-
position of Air — Air taken by a Balloon —Air not a Che-
mical Compound — Physical Constitution — Source of Oxy-
gen-i— Constancy of Composition — Carbonic Acid in Air-
Proportion — Properties — Power of Diffusion — Effects —
Coal Gas — Ammonia in Air — Variation of — Nitrogen in
Food — Source — Manures— Operation of — Effect of Char-
coal on a Rose-tret — Normal Composition of the Atmo-
sphere— Properties of Air p. 201

Vlll COXTKMTS.

CHAPTER III.

OCCASIONAL INGREDIENTS OF THE AIE.

Malaria— Epidemics— Origin— Propagation of— Air of Lou-
don — Air of Towns — Dew of Rooms — Organic Impurities
in Air — Asiatic Cholera — Deficient Electricity — M. Quete-
let's Results —Inorganic Impurities in Air — Dry Fog —
Saleniuretted Hydrogen — Black Rain— Ozone — Properties
of —Effects of— Test for— Sulphuretted Hydrogen— Decom-
positions in the Air — Chemistry of Putrefaction — Remark-
able Exceptions — Upper Egypt — The Atmosphere — Earth's
Treasury p. 233

CHAPTER IV.

THE WATERS OF THE AIB.

Water in a Gaseous Form — Philosophy of Dew — Darnell's
Hygrometer — Phenomena of Dew — Magical Properties of
— Hoar Frost —Office of Dew — Force of Evaporation — Fog
— Vesicular ? — Clouds — Forms of — Rain — Phenomena of
— Rain without Clouds — Chemical Functions of — Import-
ance of — Rain and Plants — Rain and Man — Progress of
Water into the Earth — Self-purification of the Soil— Hail
— Snow Crystals — Electrical Origin of Rain, &c. — Effects
of Fires— Artificial Rain p. 268

CHAPTER V.

MOVEMENTS OF THE AIE.

Cause of Motion in Air—Absorption of Solar Rays — Heat of
Sun — Land and Sea Breezes — Trade Winds — Philosophy
of — Discovery of Two Currents — Local Winds — Rotatory
Theory of Storms — Chemistry of Aerial Movements —
Insensible Movements - Cause of — Chemical Effects of
Wind — Benefits of a Fickle Climate — Effects of Irregular
Currents— Effects of Trade Winds p. 309

CHAPTER VI.

THE ATMOSPHERE AND ANIMALS.

Respiration— Chemistry of Breathing — The Lungs— The
Blood— Animal Heat — Combustion in the Body— The

CONTENTS. IX

Esquimaux and Hindoo — Cold and Appetite— Sources of
Animal Heat — The Breath of Life — Breathing in Insects
— Changes in the Animal Frame— Chemistry of Starvation
—Death p. 333

CHAPTER VII.

THE ATMOSPHERE AND VEGETATION.

Germination — Nutrition of Plants — The Orchids — Soil not
the chief Source of Carbon — Proofs — Experiment on a Vine
Branch — Carbonic Acid in the Air— Forests of New World
— Effect of Vegetation on Air — Sunlight and Plants — Ac-
tinism— Light — Heat — Relation of to Plants — Purification
of the Air — Trade Winds — The Air and the Soil — General
Constitution and Laws of the Atmosphere ... p. 353

PART III.-TBE OCEAN.

CHAPTER I.

IT8 PHYSICAL CONSTITUTION.

Depth — Deep Soundings — Pressure of the Waters — Elasticity
of Water — Light in the Ocean — Colour — Blue and Green
Grottos — Phosphorescent Seas — Luminosity of Marine
Beings — Temperature of the Ocean — Zones of Animal Life
— Stratum of uniform Temperature — Remarkable Law 01
Water — Ground Ice — Climate of the Channel Islands p. 383

CHAPTER II.

CHEMISTRY OF THE OCEAN.

Analysis of Sea-water — Saline Contents — Prof. Forchham-
mer's Results — Fresh- water overlying Salt — Constancy of
Composition — Origin of Saline Matter -Explanation —
Special Arrangement — The End in View — Organic Matter
in Sea-water— Chemistry of Phosphorescence — Discoveries
of Ehrenberg — Ozone and Phosphorescence — Fluorine in
Sea-water — Self-purifying Property of the Ocean . p. 407

X CONTKXTS.

CHAPTER III.

MOVEMENTS OF THE WATERS. '.

Effects of Heat and Cold— Waves — Analysis of a Wave-
Great Tidal Wave — Bore — Order among Waves— Mr.
Scott Russell's Discoveries — Speed and Height of Waves —
Capillary Waves — Oceanic Currents— Equatorial — Polar —
Effect of— Gulf- Stream — Submarine Currents— Chemistry
of the Tides — Effects of Air upon Mud — Decompositions
of Sea-weed— The Ebbing Tide— Mechanical Effect of
Waves — Remarkable Rocks — Grind of Navir — Disintegra-
tion of the Coast — Deposit of Sediment — Extraordinary
Accident — Chemical Results of Waves — Ocean Circu-
lation p. 435

CHAPTER IV. '

LIFE IK THE WATERS.

The Algse — Zones of Vegetation — Dredging Researches —
Antarctic Vegetations— Kelp — Analysis of Sea-weed —
Origin of its Constituents — Purifying Influence of Sea-
weed— Light, -and Sea-plants — Investigations on the Use of
Sea-weed — Animal Marine Life — Innumerable hosts of
Microscopic Beings— Zones of Animal Life — Researches
of Prof. Forbes — Chain of Animal Life — Respiration of Ma-
rine Animals — Products of — Molluscous Animals — Coral
Islands and Seas — Reefs — Conclusion p. 477

TOE ALCHEMIST.

INTRODUCTION.

WE must look through a long vista of ages
if we would discover, buried in the obscurity .of
time, the origin of what is now rightly called
the science of Chemistry. We know little about
the time when the few facts which formed its
first beginnings were gathered together, but it
appears probable that Egypt was the country
where this took place. Some one, it is pro-
bable, wiser than his fellows, first found out and
applied the chemistry of a few common bodies ;
he may have discovered the properties of a com-
mon acid, such as acetic acid ; or of a common

B

2 INTRODUCTION.

alkali, such as potash ; and combining or mix-
ing them together, he found a substance pro-
duced which was neither acid nor alkaline.
This would lead him to reflection, and reflection
to experiment, and experiment to a certain
acquaintance with the properties of a number
of substances around or familiar to him. Such
a man was the first chemist. Imparting his
knowledge to a few, of intellects as -keen as his
own, in the course of ,a little time chemistry was
acknowledged as a distinct occupation, although,
from its very nature, it was confined to a few
persons whose delight or whose interest it was
to make it as mysterious a subject as possible.
Those who have made the deepest research into
this subject inform us that there can be little
doubt that the philosopher we have thus alluded
to was Hermes Trismegistus, who, in their opi-
nion, is to be considered as the parent of the
science. But it is questionable even whether
such a man as he of this name ever existed ; and,
it must be confessed, it is in our day a matter of
but little moment whether he ever did or not ;
it being sufficient for us to remember that it
was in Egypt, and at a very remote and hidden
period, that chemistry probably took its origin.

From Egypt the knowledge of this new art
and mystery was carried into Arabia. Here, a
celebrated person of the name of Geber, a phy-
sician, paid great attention to it, and discovered
some most important facts, such as several salts,
acids, and metals, which appear to have been
either unknown to his predecessors, or to have
been concealed in their usual manner by de-
scribing them only in a language unknown to

EARLY CHINESE CHEMISTS. 3

the rest of the world. From this country the
science extended to surrounding nations by slow
degrees. Even in far- distant China it appears
certain that there was, at an early period, some
knowledge of chemistry; for we find that they
were well acquainted with many chemical dyes,
and with several metals, such as gold, silver,
mercury, lead, copper, iron, tin, and zinc, be-
sides several salts and chemicals, and also medi-
cinal preparations. In Egypt, also, the arts of
working in metals, of manufacturing soap, and
more singular still of manufacturing glass of the
most beautiful description, were practised, in all
probability, even before philosophers in that
ancient country caught a glimpse of the beau-
tiful science which was intimately connected
with these processes. Nevertheless, the mere
knowledge of the right employment of the dif-
ferent substances used in these arts was a kind
of chemistry, though not an enlightened one ;
it was the chemistry of experience. It is very
surprising to find how successful both the
Egyptians aijd the Chinese were in these arts,
notwithstanding their deep ignorance of the
laws of the science. Some of the colours em-
ployed by the Chinese for their porcelain, and
some of their dyes, cannot be equalled even in
our day, when so much is known about the
principles and practice of chemistry. The
Egyptians, before the Exodus of the chil-
dren of Israel, or about three thousand five
hundred years ago, were well acquainted with
the means of colouring glass in the most exqui-
site manner by some chemical substance, so that
they used to make artificial gems, such as the

4 INTRODUCTION.

amethyst, of glass, which could not be distin-
guished from the stone itself. The accompany-
ing hieroglyphics assure us also of the fact that
they knew how to blow glass in the same man-
ner as we do, and thus they may have formed
useful chemical vessels for the early professors
of this art. So far had the glass-workers of
Egypt advanced in their art that even coffins
were sometimes made of glass.

GLASS-BLOWING IS EGYPT.

The knowledge of chemistry came at length
into Europe. During the dominion of the
Moors in Spain, science of all kinds was much
encouraged, and the arts and learning flourished
luxuriantly. An immense library of books upon
every subject existed at Cordova, whither the
learned of Europe flocked, and where, in all
probability, they first became acquainted with

EARLY CHEMISTS. 5

the writings of the Arabian chemists ; the
knowledge they thus obtained being afterwards
communicated by them to others on their return
home. The crusaders also, on their return from
the Holy Land, are said to have brought the
knowledge of chemistry into Spain, and from
hence it spread into Germany, Italy, and France,
and eventually into England.

Up to this time, which reaches to the twelfth
century, very little progress was really made in
chemical knowledge, and we might in a few
lines sum up every simple or compound sub-
stance whose nature was accurately known to
the early chemists. Passing these purely his-
torical details, we may go on to mention some
of those curiosities in the history of chemistry
which are of a more extraordinary and interest-
ing character than are to be found in the records
of any other science whatever. Astrology forms
a very curious portion, it is true, of the history
of the noble science, Astronomy; but neither
it nor any other delusion is te be compared to
those which are unfolded to us as we look upon
the chemistry of the past.

We might say that chemists have had three
dreams. First was the dream that they could
turn the common metals into gold; next was
the dream that they could or might discover
the water of immortality; and, lastly, was the
singular dream that they could invent a liquid
which would dissolve every thing ! We can
ascribe it to no other cause than the deep-rooted
covetousness of the human heart, that, from
the very first, men regarded chemistry as a
means of making gold. It is a most remarkable

6 INTRODUCTION.

circumstance, that whether derived from ancient
Egypt or the remote empire of China, early
chemistry was chiefly occupied in the attempt to
turn the baser metals into gold. In short, for
ages chemistry was supposed to have no other
object in view, no other value than this ; and
the alchemists, its first professors, were men
who, from youth to age, toiled on in the arduous
and ruinous task of attempting this art, called the
transmutation of metals. Had they then no suc-
cess? Were we to credit their own accounts, we
must acknowledge that in a few instances their
success was remarkable. Thus, one of them tells
us, " I had long doubted whether gold could
be made from quicksilver. One who wished to
convince me of my error, sent me a drachm of
a certain powder of a red colour having a pecu-
liar odour, with which I was to make the expe-
riment. To avoid the possibility of fraud, I
purchased the requisite vessels and materials
from an ordinary warehouse : I put the mercury
into the vessel and cast the powder into it ; a
strong heat was then applied, and immediately
the whole mass was transmuted into ten drachms
of the finest gold!" We are even told in his-
tory that a celebrated philosopher, in the pre-
sence of King Edward VI., by means of a
certain powder, converted a mass of iron into
gold, which was afterwards coined into rose-
nobles. The powder of the true philosopher's
stone (if one could only procure some of it) was
so powerful, it was said, that a few grains of it
would turn twenty tons of lead into gold !

These statements are sufficient of themselves
to satisfy the modern reader of the painful

JUGGLIXGS OF THE ALCHEMISTS. 7

amount of falsehood and deception which cha-
racterises the records of the alchemists ; yet,
on a smaller scale, it -is undoubtedly true that
they appeared to possess the power of pro-
ducing gold at pleasure. It was effected by
clever juggling. Sometimes a piece of gold was
slipped into the crucible by sleight of hand,
— sometimes the instrument used to stir the
mixture contained it, — and sometimes the cru-
cible was artfully scooped out at the bottom, a
small mass of gold having been put in, and
covered over so as to be rendered invisible by
a little paste. When the heat of the furnace
had driven off the volatile substances forming
the pretended mixture, the glittering yellow
metal would then be discovered lying at the
bottom. A similar trick was to make a nail
half of gold, half of iron, which was painted over
so as to look like a rusty nail, and on being put
into a crucible would, of course, come out half —
as they said — turned into gold. Sometimes we
cannot doubt that the experimenters were sincere,
although they were the victims of deceit on
the part of others, or of self-deception in them-
selves.

Such was the first, and, strange to say, the
last also of the chemical dreams ; for while the
two others were of little influence and short
duration, this lived down even to the end of the
last century, one of its latest victims being a
Dr. Price, of Guildford, who destroyed himself
in disappointment at discovering the delusion
under which he had been labouring. We need
scarcely say the philosopher's stone, that won-
derful compound, which was to turn all metals

8 INTRODUCTION.

into virgin gold, was never discovered, and the
" art of making gold," as it was termed, visually
ended in reducing its professors to rags. Its
vanity and certain results are well told in the
following shrewd lines by the poet Spenser : —

" To lose good days, that might be better spent ;
To waste long nights in pensive discontent ;
To speed to-day, to be put back to-morrow ;
To feed on hope, to pine with fear and sorrow ;
To fret their souls with crosses and with cares ;
To eat their hearts, with comfortless despairs :
Unhappy wights ! born to disastrous end,
That do their lives in tedious tendance spend."

It was a striking example of that unquench-
able hope, which will hope against hope, that
the idea of an Elixir conferring immortality
could ever have long occupied the attention of
men styling themselves philosophers. The
origin of this remarkable error admits of being
traced, like that of so many errors, to an exag-
geration of original circumstances. A celebrated
physician of ancient time, by name Actuarius,
makes mention in his works of a certain famous
medicine which would preserve the body in
health to the end of life. Geber, the alchemist,
then asserted that he positively possessed a
medicine capable of curing every disease, how-
ever desperate, and of renewing " man's strength
like the eagles." Succeeding alchemists then
declared that they possessed the Elixir of Im-
mortal Life. It was a natural effect in some
respects, that the growing science of making gold
should have the consequence o£ extending the
desires of men to search for a draught which,
when their exhaustless riches were supplied,
would enable the possessor to satiate himself

THE UNIVERSAL SOLVENT, OR ALCAHEST. 9

therewith. Discovering also, in the worship of
their idol, the persistence and apparent immor-
tality of gold, a foolish and illogical train of
reasoning led them to believe that a solution of
this precious metal was the grand desideratum ;
and that in fact the elixir of immortality was a
preparation of fluid gold.

How lightly after all did they really estimate
the misery of immortal life to an individual in
the present world ! An immortality of the be-
holding of suffering, sorrow, and sin, of wither-
ing hopes, dying friends, unsatisfying occupations
— was this the object of their search ? Surely it
was the voice of mercy, not of wrath, which pro-
nounced, in solemn accents, death to be the wages
of sin, that it might add the glorious intelligence
that the gift of God is eternal life, through Jesus
Christ our Lord.

The alcahest, or universal solvent, was the
last of these three delusions. It may be con-
sidered also the most harmless. Properly
speaking, it was simply a foolish fantasy of
chemistry. The idea was, that some fluid might
be produced which would instantly dissolve all
substances exposed to its influence ; and it
seems to have had a long existence as a fanciful
speculation, rather than as a subject of arduous
experiment and tedious research. The expla-
nation of this is not difficult. The Universal
Solvent had little to offer which could excite
the hopes, and nothing which could inflame
the cupidity of mankind. Wealth was not in
its right hand, nor length of days in its left.
It was a reverie of the laboratory, without
interest, because it was without effect upon the

10 INTRODUCTION.

longings or passions of the great masses of the
human family. Yet there were a few chemists at
different times fully possessed with this folly also,
and ardently engaged in its pursuit. The whole
idea of the alcahest is overturned by a very
simple consideration which has been frequently
well put. If an universal solvent were possible,
what vessel could retain for an instant such a
fluid?

Nothing could have been more truly injurious
to the true advancement of the science of
chemistry than the prevalence of these three
dreams, and particularly of the first of them.
So long as the philosophers thought they had a
chance of opening, so to speak, a vein of gold in
their laboratories, so long they neglected the
truly useful and lucrative application of the
powers of chemistry to common manufactures,
and so long also they remained indifferent to the
discovery of any of the principles and laws of the
science. Thus while much was known about
chemical -substances, nothing was known about
what is termed chemical philosophy, that is, that
part of the science of chemistry which teaches
us the laws and governing principles of these
substances.

It was about the middle of the seventeenth
century, a period which was like the very birth-
time of all scientific knowledge, that, recognising
at length the absurdities of their predecessors,
philosophers began to lay the foundations of that
noble system of chemistry, which is now at once
the offspring, the pride, and the triumph of expe-
rimental philosophy. The principles laid down in
the celebrated work, called Novuni Organum, of

BIRTH-TIME OF SCIENTIFIC CHEMISTRY. 11

the illustrious Francis Bacon, proved most bene-
ficial to the development of true knowledge, and
assisted to destroy many of the foolish systems of
philosophy which had so long held it a captive.
As chemical philosophy was among the earliest to
benefit by these principles, so it soonest began to
expand and to gather continual strength. The
origin and further progress of the science has been
happily compared to Milton's fine description of
the erection of Pandemonium : —

" Soon had his crew

Opened into the hill a spacious wound

And digged out ribs of gold

Anon out of the earth, a fahric huge

Rose like an exhalation

Built like a temple."

About this period also the great scientific
societies first took origin : the Royal Society in
1662 ; the Academy of Sciences at Paris in
1666. Thus the progress of knowledge received
a most powerful impulse. The learned com-
municated periodically with each other, and
united in the prosecution of similar scientific
inquiries. Chemistry enjoyed much of their
attention ; and soon began to exhibit the hitherto
concealed energies of a most important depart-
ment of knowledge. Many of the elementary
bodies were now known ; and new ones were in
continual process of being added to the list.
Phosphorus, that most curious and peculiar
substance, at first the chemist's toy, and sold at
the rate of one hundred shillings the ounce, now,
in the form of the lucifer, our most common
domestic resource, with many salts, acids, and
chemical preparations, became common. The

12 INTRODUCTION.

advance, if not characterised by method, was rapid
and certain.

.It was now time that chemistry should
receive the requisite framework of a science.
A vast number of experiments, with their results,
were on record, and these were continually in-
creasing. Gleams of the laws of combination,
like scattered rays of light, darted upon the
minds of experimenters. The comprehensive
mind which should seize these indications, and
reduce them to form and order, was yet wanting.
•Nevertheless, chemistry was gradually assuming
the definite character of a science. The doctrine
of affinity, or of elective attractions, by which
it is taught that some bodies unite chemically
with others by preference, in the presence of
other substances for which they have a feeble
attraction, was promulgated by Bergman, and
became an important doctrine of chemistry.
That -a great and most salutary revolution had
been effected in the minds of the followers of
this science may be learned, when we read,
toward the close of this period, the good con-
fession of one who, scorning the pursuit of
science for the sake of gold, could write, " My
kingdom is not of this world. I trust that
I have got hold of my pitcher by the right
handle ; the true method of treating this study.
For the pseudo (or false) chemists seek gold ;
but the true philosopher, science, which is
more precious than any gold." It was in the
same spirit that a just reproof was given by
D'Alembert to an ambitious young man, and
as it deserves remembering, we venture to
record it. "Science," said he, "must be loved

CHEMISTRY A SCIENCE. 13

for its own sake ; and not for any advantage
to be derived from it: no other principle
will enable a man to make progress in the
sciences."

Remarkable discoveries upon the nature of
combustion succeeded, and were followed by
the labours of Hales, Black, and Cavendish,
in their important investigations upon the
chemistry of gases. The great discovery of
the gas, oxygen, and of a part of the chemistry
of vegetation, were next in order of progression.
Water was formed, by Cavendish, by the union
of its constituent gases, hydrogen and oxygen.
This discovery is justly considered as deserving
a special place in the history of chemistry.
Mr. Watt appears to have arrived at the right
conclusion as to the composition of this fluid,
even before Cavendish ; losing, however, as it is
said, the honour of his discovery from the delay
in the publication of his experiments. It would
be tedious to follow in consecutive order the
further progress of the science, and we shall,
therefore, hasten to a close. With each successive
year, it became richer in stores of facts, and more
extensively applicable to the arts, comforts,
and luxuries of mankind. The celebrated Dr.
Dalton, the propounder of the atomic theory —
one of the most beautiful of the science — pub-
lished his views in 1803 ; and shortly after
the immortal Davy rose to eminence by his
electrical investigations. Subsequently Dr.
Michael Faraday, by his splendid researches
upon the electric principle and its important
bearings upon Chemistry and chemical pheno-
mena in general, gave an impetus to the science

14 INTRODUCTION.

which will continue to be felt to the most distant
ages of the future. We are thus rapidly and
imperfectly brought to the state of the science
in our own day. The remarkable speculations
and discoveries of Dr. Prout on animal, and of
Baron Liebig on vegetable chemistry, and the
chemistry of agriculture, together with the won-
derful discoveries of the phenomena of the che-
mical rays of the sunbeam by Xiepce, Daguerre,
Herschel, R. Hunt, and others, may be fairly
taken as the most valuable additions made in
recent times to this department of knowledge.

In considering the present aspect and rela-
tions of chemistry, we are 'struck with the ex-
tent of its" influence, and with the importance
of the position it occupies. Advancing years
are continually extending the one, augmenting
the other. Every branch of the arts now ex-
periences its salutary reign. While it has con-
tributed much to the growth of other sciences,
by no means directly, or in the abstract, related
to it, it has also added a variety of substances
to our present list of domestic comforts and
conveniences. While it has tinged the purple
and bleached the fine linen of the great, it has
endowed with equal snowiness, and an equally
durable, though more homely lustre, the calico
and coarsest fabric of the poor. Nor has it
been less valuable in adding to our remedies
for the sick. For medicine, in fact, it will pro-
bably in future time do more, and this by reason
of its intimate connexion with that art, than
for any other department of science. In many
instances .chemistry detects the disease, and
points with much significance to the appropriate

PRESENT IMPORTANCE OF THE SCIENCE. 15

remedy. It analyses the processes constantly
in operation in the mysterious laboratory of

f r i • T • i • •

the human frame; and indicates with precision
many of the changes which matter undergoes
in the performance of the essential functions
of life. It teaches us the most appropriate
food for the strong and vigorous; and directs
us how to modify and re-arrange the diet of
the sick and feeble. Chemistry too bears more
directly than will be readily conjectured upon
the life and destinies of nations. It has engines
of tremendous power* for the annihilation of
fleets and armies ; yet, in its most peaceful
applications, to renew and invigorate the soil,
it gives promise to shed a full measure of
peace and prosperity upon ages to come. In
its products, while it has contributed much
to the adornment of our persons, it has also
warmed, lighted, and ventilated our dwellings,
purified our beverage, and supplied us with the
most exquisite utensils for our meals. While
we are enumerating the boons conferred upon
us by this science, the dim oriental outlines of
the fabled genii rise to recollection, by whose
supernatural agencies, held in control by the
magic lamp or ring, houses were built and
stocked, and many other wonderful works easily
performed. Such a heaven-born power is ours
in the science of chemistry — the plaything of
the child, the fascination of the student, the
servant of man, obedient to his bidding, who

* In all probability, Captain Warner's celebrated appa-
ratus for the destruction of vessels at a great distance is an
ingenious piece of mechanism charged with some explosive
chemical compound — perhaps the remarkable fluid, the
Chloride of Nitrogen.

16 INTRODUCTION.

has the true amulet of power — knowledge.
Surely the philosopher's stone, if it were a real
existence, would prove a poor possession con-
trasted with the riches placed at our command
by this science.

The instructive example has now been set
before us of a science almost fruitless, and
unproductive, when applied to base and un-
worthy ends, becoming, when directed to its
legitimate objects, an inexhaustible source of
blessing to mankind. It is an instance too
striking to be lightly passed by, of the really
withering consequences of a persistence in oppo-
sition to the wise and merciful ordinances of the
" Creator of the ends of the earth," and of the
truly valuable results which flow from using law-
fully the knowledge given to us by the Author
'and Giver of every good and perfect gift.

It has been thought useful to present this
short sketch of the origin and progress of
chemistry up to the present time, in order that
it may be seen what a tide of ignorance and
folly flowed over, and concealed that know-
ledge of the chemistry of natural things, which,
as gradually developed by modern experimen-
ters, we are now enjoying. The poor alchemist,
or he who ran after the phantom of an immor-
tal-life-bestowing liquid, while skilled in the
chemistry of the metals and in the preparation
of purely chemical substances, was absolutely
ignorant of the chemistry of nature. He could
not have told us why his fire burned, still less
could he have even guessed at the exquisite
chemistry of a blade of grass. He knew not
why the wind blew or the rain fell ; and was

IGNORANCE OF NATURE'S CHEMISTRY. 17

ignorant even of the composition or mode of
formation of a drop of dew. For a very long
time, even after chemistry was pursued scien-
tifically, the most fascinating of all its depart-
ments— the Chemistry of Nature — was totally
neglected. Dr. Priestley and Sir Humphry
Davy almost alone seem to have caught sight
of its interest and importance. And almost
all the knowledge we now possess of this
subject has been brought to light exclusively
during the last few years. As may therefore
be imagined, our information upon this point,
although of great extent, is still very imper-
fect ; and we require many experiments, and
much labour of investigation, to clear up our
present difficulties. If, then, instead of vainly
groping after gold, or gasping after an elixir
of life, or indulging in such-like dreams and
abstractions, the early chemists had but applied
themselves to the study of the chemistry of the
humblest objects in nature : if they had only
tried to solve the problem, How does a flower
spring up ? how far advanced might we not at
this time have been ! Instead of occupying a
place at the threshold, we might almost have
reached the goal. Let us be thankful, how-
ever, that a brighter time in the history of the
science has arrived; and let us look hopefully
forward for the day when the chemistry of
nature will be as well understood as that of the
ordinary substances which find a place in the
laboratory of the experimenter, or in the shop of
the chemist.

It is the intention of this work to explain
the leading chemical phenomena observed in

c

18 INTRODUCTION.

nature, and to do so, as far as possible, with-
out the unnecessary use and encumbennent of
scientific terms or expressions. In .carrying out
this design, the simplest plan appeared to be,
to treat successively the chemistry of the earth,
the air, and the ocean ; by which means, almost
all that is of importance to be learned of the
chemistry of nature, will come simply and
naturally under discussion. Such a notice of
the general principles of the science, as is re-
quisite to render the subsequent pages free from
difficulty, is added by way of a prefatory section
to the chemistry of the earth.

THE

CHEMISTRY OF CREATIOK

PART I.-THE EARTH.

'HIS HANDS PEEPAEED THE DBY LAND.

CHAPTER I.

THE INORGANIC CHEMISTRY OF NATURE.

WHEN an admirer of paintings walks through
a long gallery in which are displayed the most
famous works of a great artist, he stands per-
chance before one which more than all the rest
attracts his attention, and becomes lost in the
contemplation of its various excellences. The
rich hues of the foreground become contrasted
with the pale receding tones of colour on the
horizon, and with these the deep transparent
sky is exquisitely harmonized, the whole picture
producing an impression upon his mind highly
favourable to the skill of the painter. He goes

22 THE CHEMISTRY OF CREATION.

away, and the impression remains deeply en-
graved upon his memory ; yet if called upon to
account for this impression by separating the
individual peculiarities of the painting in the
form of an analysis, probably not one spectator
out of a thousand could execute the task. The
picture was agreeable to his rnind as a whole, and
not as a combination of various parts, of different
tints, and contrasted colours.

But if, on the contrary, a student stands
wrapped in thoughtful admiration before the
same painting, one whose own hand has laboured
at the brush and palette, and in whose 'breast
the aspiration after the highest honours of his
art is nursed in hope, how different the effect
upon his mind to that we have just been con-
sidering ! Having been carefully tutored in the
principles of the art, he is able to recognise
in the work before him, the various steps and
processes by which the unity and harmony of
the whole have been produced. He marks
with a scrutinizing and admiring eye the care-
ful manner in which the different portions of
the picture are worked out so as to be in keep-
ing with the tenor of the entire work ; and in
various ways he is enabled to detect the deve-
lopment of the peculiar principles upon which
the art of painting fundamentally rests. The
other gazed upon the picture and was pleased —

THE SCEXE. 23

he knew not why. This spectator also gazes
upon it with gratification ; but it is of a higher
and more refined nature, simply because he is
acquainted with the various rules and axioms
which guided the artist in its execution.

Such is, in a word, the difference between
" common " and " philosophical " observation,
or, to use a more homely phrase, between " eyes
and no eyes." The great majority of persons,
when beholding the majestic landscape which
the Divine hand has created, come under the
first of these designations, — they are common
observers. It is true they mark with real and
perhaps exalted pleasure the beauties of the
scene, but they do not attempt to define the
parts which in their union form the pleasing
*' whole." They see but they do not analyze ;
or in other words, they observe the scene as a
scene, but do not discover and separate from
one another the various parts which enter into
its composition. It is the privilege of him whose
mind has been opened to receive the truths of
science, when placed in a similar situation, t6
enjoy all the gratification produced by the
contemplation of the scene before him in its
entireness, and in addition, the pure and intel-
lectual pleasure of distinguishing the operation
of various laws by the means of which he is
aware that the harmony of the landscape has

24 THE CHEMISTRY OF CREATION.

arisen and is preserved. To the enjoyment of
this privilege, in so far as the knowledge of the
principal chemical phenomena of nature is con-
cerned, it is intended that the present work
shall Assist the reader.

Place we ourselves then in such a scene.* On
all sides but one, the rugged forms of ancient
rocks project into the sky, their summits capped
with meagre herbage, and their sides the
occasional resting places of some mountain-
flower. The roar of a cascade, formed by the
accumulated waters shed from the hills in the
distance, comes every now and then upon the
ear. ' Above is the blue stretch of an almost
unclouded sky. As the eye travels toward the
horizon through the opening already alluded to,
it sweeps over many miles of fertile land adorned
with trees or yellow with corn, and enlivened
by an occasional traveller, or by herds of cattle,
until it rests upon the blue line of the ocean in
the extreme distance. Here let us take our
stand, and in the spirit of observation of which
we have spoken, let us bring under review the
interesting matters for chemical discourse pre-
sented to us by such a spot.

In so doing it is our intention to take up in
succession the chemistry of the inorganic, the
animal, and the vegetable kingdoms of nature, so
* Vide the Frontispiece to this Part.

WHAT IS AN ELEMENT? 25

far as it can be conveniently considered under
the three great divisions of our work, the earth,
the air, and ocean. An outline of many of
the truths of chemistry will thus be brought
under notice : but for purposes of scientific
information of a more profound kind, and for
the more abstruse doctrines of the science, the
reader will naturally seek elsewhere. The
object in view is more humble ; yet this work
may fulfil a legitimate calling in provoking the
desires of some minds to deeper investigation,
and in other instances, in giving that peculiar
interest in the objects of nature which arises
from a perception of some of the intricate and
beautiful machinery which directs and controls
their movements.

Attractive as the possession of this knowledge
appears, it is not to be acquired nor retained
without a general acquaintance with some of
the fundamental principles of the science ; and
as this is by no means a difficult task, we pro-
pose, as briefly as may be, to acquaint the reader
with a few of their leading features.

Here our first attempt must be to reduce all
material substances to their elementary or simple
condition ; our next to discover the laws by
which the elements are governed in their be-
haviour one toward another. The ancient idea
of the Elements was, as is well known, that there

26 THE CHEMISTRY OF CREATION.

were but four — fire, air, earth, and water. But
in truth none of these were elements ; three are
compounds ; that is, each consists of two or more
substances, and the fourth (fire) is only a con-
dition of substances undergoing rapid chemical
union. What then is an element? It may be
described as a simple substance, which cannot be
analyzed, or, in more popular terms, subdivided
into two or more different substances. As an
example we may select the element iron. All
experiments upon this substance lead to the con-
clusion that it cannot be decomposed or sub-
divided into anything else than this simple ele-
ment— iron. Let the chemist try his powers on
the other hand upon water; very different is
the result; the fluid disappears, and two gases
arise, thus informing us of the fact that water is
a compound, while iron is a simple substance.
Such then, is the difference between an element
and a compound. To lay down the constitu-
tion of an element in precise terms, we should
say it is a simple substance, separate and dis-
tinct from all other substances, and incapable
of being resolved into any further constituents.
Yet it is to be remembered that an element
is proved to be so only negatively ; that is to
say, we cannot discover it to be anything else
by our present apparatus and means of analysis.
It may, or may not, remain for the chemists of

GASES — FLUIDS — SOLIDS. 27

future years to develop the truth or falsity of
a view which has been entertained by the minds
of some of the profoundest philosophers, as well
as by those of the wildest of the alchemists, —
that all matter has a common origin; that in
fact, there is but one element, of which all the
others are but modified forms.

Modern chemists have laboured to reduce,
as far as possible, all substances within their
reach to their ultimate constituents ; to separate
them, that is to say, until it was impossible to
separate them any further. In so doing it has
been discovered that a number of bodies once
conceived to be elementary, have no real claim
to that character. Such bodies have been
found to be in fact composed of two or more
elements. The number of chemical elements
at present recognised as such is sixty-two.*
But several of these are doubtful ; and as
science proceeds, it will probably remove many
from the list. The phenomena exhibited by
some of the so-called elements, in different ex-
periments of the laboratory, are so suspicious
as to perplex the mind of the chemist as to
their real constitution, leading him to suppose
that they are anything but simple bodies, and
many are looking forward to a period when it
will be found that the number of true elements

is small indeed.

* Dr. Fownes.

28 THE CHEMISTRY OF CREATION.

It is convenient to arrange them under the
following heads : 1, gases ; 2, fluids ; 3, solids.
Or they may be also described as 1, metallic;
2, non-metallic : 3, gaseous. But in these
conditions bodies shade as it were into each
other, the same body being under some circum-
stances solid, and under others fluid, such as
water or mercury when frozen, and at the com-
mon temperature.

Out of the number above mentioned, forty-
seven are tolerably well-marked metallic sub-
stances, about which little doubt now prevails ;
thus the majority of the elements belong to this
division. There are but four gases ; that is,
of course, elementary or primary gases ; these
are oxygen, hydrogen, nitrogen, and chlorine.
The remaining eleven are the non-metallic ele-
ments, or elements of intermediate characters.

When we come to consider the amount of
relative importance which is borne by each of
these elements to the rest of creation, we arrive
at an interesting and somewhat startling result.
It would have been more in accordance with the
ideas and expectations of the human mind to
anticipate that a number of elements compara-
tively so small as that specified (sixty-two), was
inadequate to form such singularly contrasted
objects as surround us in creation, and to produce
such varied results as are presented to us in the

REMARKABLE SIMPLICITY IN NATURE. 29

kingdom of nature. Or, if we allowed that
number to be sufficient, man would anticipate
the entire exhaustion of its powers, and would
suppose that the whole number of elements had
been employed and put together in various ways,
in the work of constructing a universe full of the
most varied and opposite substances. Chemistry
teaches us that such is far from being the case-
Do we look to the framework of the solid globe,
triumphantly expecting to discover in its count-
less constituents the exhaustion of the whole
range of elementary bodies ? Our investigations
supply a very different answer, and we may
almost without an hyperbole say that so far as the
crust of the globe is accessible to our experiments
and analysis, and our researches penetrate deep
therein, chemistry declares in round terms that
the earth en masse is composed of but seven ele-
ments ! These are silicium, calcium, aluminum,
magnesium, potassium, and sodium, united with
the gas oxygen. Do we turn to the zoological
and vegetable worlds, point to the countless
myriads of species, and to the innumerable
products of these kingdoms? How strange to
discover that these are after all chiefly carbon,
nitrogen, hydrogen, and oxygen ! Lastly, do
our eyes rest upon the broad ocean, consti-
tuting as it does three-fourths of the area of
our planet? This vast accumulation of fluid

30 THE CHEMISTRY OF CREATION.

may have its principal components expressed in
two words, — oxygen and hydrogen. The num-
ber of the metals employed in the work and
service of man is equally small in comparison
with the number known to chemistry. Gold,
silver, iron, copper, zinc, lead, and tin being in
commonest use ; the larger number of metallic
substances being obtainable with so much diffi-
culty as to render them of little comparative
utility; and the metals on the whole, properly
so called, form but a very small part of the
crust of the globe.

Thus while the forms in which material sub-
stances and organizations present themselves to
our notice, are of the most pleasing aspect and
unbounded variety, and though the bodies them-
selves possess the most opposite and dissimilar
properties, all are reducible to a comparatively
very small number of elements, or in other
words, ultimate constituents. The results of
this arrangement are very striking, How sur-
prising to find that a gas (carbonic acid), dif-
fused in fractional quantities even in the purest
air, in one of its principal constituents (carbon)
is one and the same with the solid material
composing the dense forests ! How wonderful
to learn that the millions of tons of wood con-
tained in some of the primeval forests of the
earth were actually in a great measure directly

LAUGHING GAS. 31

derived from this gas dissolved in water, carried
up by the roots, and metamorphosed in the
leaves !

This variety of result may be illustrated in
another manner. The acrid, dangerous, and
highly corrosive liquid well known to every
person as aquafortis, or impure nitric acid, — in
its pure condition one of the most powerful
re-agents of the laboratory, is composed of ni-
trogen and oxygen. These are also the consti-
tuents of the summer breeze ! Whence then
this notable change? The answer is, 1st, the
relative proportions or quantities of the two
elements are not the same — in the one the pro-
portion of oxygen to that of nitrogen is much
greater than in the other ; and 2nd, in the case
of the nitric acid the elements are in chemical
union, in the air they are only in a state of
mixture. Thus an apparently trivial alteration
in chemical conditions and proportional num-
bers effects a change of the most unexpected
and startling order ! Another alteration again
in our atmosphere would produce "laughing
gas," a substance whose stimulating properties
have supplied its title. Not to proceed further,
here are three- products, of the most entirely
opposite and unlike character, namely, nitric
acid, atmospheric air, and laughing gas, com-
posed of precisely the same elements. Why then

32 THE CHEMISTRY OF CREATION.

do they differ so strikingly from one another?
Because air is only a mixture of the two ele-
ments, laughing gas is a true chemical compound
of the same, and nitric acid is also a chemical
compound, but has five times the quantity of
oxygen possessed by the laughing gas. But
these are familiar examples. A more surprising
vein of thought is opened when it is stated that
chemistry is acquainted with substances which
are absolutely identical, in the number and
relative proportions or quantities of their ele-
ments, yet are as totally unlike one another in
their sensible properties, such as colour, odour,
and taste, as might be conceived of substances
in noways related to them.

Such then is that peculiar and most wonder-
ful feature in the constitution of creation, — the
accomplishment of astonishing variety out of
the fewest materials, which at the very onset
chemistry presents to our admiration. And
such in fact is the universal language of science ;
it may be called the economy of the creation.
The Creator has taken, as it were, a mere handful
of elements, and has formed out of them not only
the gorgeous structure on which we dwell, but
also ourselves, that is our material bodies, and
our fellow-occupants of the earth, and the inha-
bitants of the air and the sea. Chemistry alone
can disclose this fact, because it has found it out

"WE KNOW IN PAKT." 33

by searching and experiment. Yet while it
catches a sure glimpse of this and other general
laws, it also beholds phenomena of which it may
take a dim cognizance, but as yet cannot com-
prehend. Do we ask why? The solemn voice
of revelation answers, " Now we know only
in part." The foreground mists of ignorance
disappear indeed before the light of science ;
eternity and space, in their unfathomed realities,
lie beyond.

If, then, it has pleased Grod to rear this
beautiful creation upon so small a comparative
number of predominant elements; if it has
pleased Him to show his glorious attributes of
power and wisdom in the formation of such
multifarious products out of, in the main, but a
few materials ; what powers of developing new
and exquisite harmonies, fresh and yet more
lovely combinations of matter than earth has
ever beheld, does chemistry suggest to us,
should it be consistent with his will, in the form-
ation of a new heaven and earth, to call into
more extensive use the elements which in the
present plan take so comparatively an insig-
nificant part in the work of creation! If, as
we may be permitted to conjecture, out of such
limited resources such an astonishing variety
has been produced, what may not the beauty
of creation be, should all the resources we know

D

34 THE CHEMISTRY OF CREATION.

to 'exist be brought prominently into operation !
If, to illustrate more clearly this idea, a great
musician can produce charming music out of
an instrument of but a few notes' compass, what
soul-stirring melodies may we not expect when
he is seated at a musical instrument better
suited to display his powers ! These and other
considerations which we might adduce, show us
how partial and imperfect is our highest know-
ledge. We only see, we only hear in part.
Creation is but a partial display of the power
and wisdom of its Author.

It has been well said not to be a scheme of
optimism. Beautiful as creation, so far as our
world is concerned, appears, nature as yet only
wears what we might call her working dress.
When the sabbath of the world dawns, then will
she appear all glorious in apparel, all beautiful in
form. And if so fair and lovely now, what will
she not then be !

The thoughts we have here attempted to
throw out, not to pursue, are intended to quicken
our aspirations after that long-desired and yet
future time, for which all creation waits and
groans, when in more of their fulness the attri-
butes of the Creator will be displayed before our
wondering eyes.

We must consider the almost universally dif-
fused element Oxygen, as occupying important

OXYGEN — HYDROGEN — NITROGEN. 35

perhaps the most important, offices in the che-
mistry, of nature. It is therefore by far the
most abundant of the elementary bodies. It
is the largest constituent by weight of the
ocean, forming eight-ninths by weight of pure
water. It forms a fifth part, by bulk, of the
atmosphere : and it enters into a large number
of combinations with the solid ingredients of
the globe. It is possessed of the most exten-
sive range of chemical affinities; that is, it is
capable of entering into chemical union with
by far the greatest number of the other ele-
mentary or simple substances. Its connexion
with, and its relation to, the vital functions of
the animal frame, the necessities of mankind,
the purity of the atmosphere, and the renovation
of the face of the earth, will come into considera-
tion in different portions of this work. When it-
combines with another body, the chemical name
of that process of union is " oxidation," and
when it is completed the resulting substance is
an " oxide."

Hydrogen is also an important element. It
forms about one-ninth of the weight of water,
which is, in fact, an oxide of hydrogen; it also
enters largely into the composition of animal and
vegetable structures.

Nitrogen forms one of the chief constituents
of the atmosphere. It is remarkable chiefly for

36 THE CHEMISTRY OF CREATION.

its indifference to the other elements, not rea-
dily uniting with the majority of them. But
when under proper management it is made to
combine with oxygen, the resulting substances
are possessed of the most intense energies.
United with the gas, hydrogen, it forms the
important substance ammonia, upon which the
life of vegetation, and, indirectly, of man
himself and the animal world, appears to be
dependent.

Finally, the element, Carbon, must also be
considered important. It exists in minute
proportions in union with oxygen in the at-
mosphere, as a gas, and in the solid form it
composes, together with the elements of water
and nitrogen, the chief part of the woods and
vegetable clothing of the present, and of the coal
formations belonging to a former period in the
history of the earth.

Such is a short and simple outline of the
characters of the most active and abundant
elementary substances entering into the com-
position of the animal and vegetable worlds.
In the mineral world we find a greater number
of substances taking a prominent part in the
chemistry of nature. The most important of
these are silicon, calcium, magnesium, potas-
sium, sodium, aluminum, iron, phosphorus, and
sulphur. As we proceed we shall have sue-

CHEMICAL AFFINITY. 37

cessively to consider the innumerable links of
union which connect these together, and which,
as a whole, constitute the beautiful scheme of the
chemistry of creation.

If a piece of polished iron is left in the open
air, and is slightly moistened, we all know that
it will very shortly rust, turning quite brown.
Why does the iron rust? It is, because it,
as an element, has a certain attraction for an-
other element which is oxygen; so much so,
that when they are placed together in favour-
ing circumstances they will unite, or join to-
gether, so as to form a new substance — the
rust. A certain unseen power draws the two
elements together, and retains them by the
closest bond in a new condition of union.
This power or attraction is called Chemical
Affinity. Each of the elements is under the
influence of this power ; that is, every element
has a tendency to unite with one or more of
the other elements ; some with a greater, some
with a smaller number. The iron unites with
the oxygen because it is thus influenced. It
is now found to be a general rule, that the
more unlike to each other in their chemical
properties bodies are, the stronger is their
tendency to unite with one another. The
tendency to unite between oxygen and iron is
very powerful indeed; for these two elements

38 THE CHEMISTRY OF CEEATION.

are strongly opposed to each other in their
chemical properties. Hydrogen and iron, on
the contrary, have little or no disposition to
unite, for they exhibit many chemical properties
in common.

Bearing in mind this tendency of every
element to unite or combine with its dissimi-
lars, we may readily imagine what sad confu-
sion would take place in nature if the power
which they are thus endowed with were not
itself subject to certain fixed rules beyond
which it could not operate. To-day, for ex-
ample, iron might unite with one element,
to-morrow with another; to-day it might be
found in one condition, to-morrow in another ;
water might be to-day the fluid known to us
as such, to-morrow it might be converted into
one of another composition, and the third day
might be resolved into its constituent gases —
oxygen and hydrogen, the great ocean, and
the seas and rivers disappearing into the air,
to the destruction of the animal and vegetable
worlds. In a word, it is not too much to say
that the entire system of our globe would be
speedily broken up, and the elements would
return to their original state of confusion or
chaos. To obviate such a result, that Almighty
Creator, who is not the Author of confusion
but of order, has appointed certain fixed laws

COMPOSITION OF A DROP OF DEW. 39

which limit this tendency to unite among the
elements in a very simple and remarkable
manner. A drop of dew supplies us with an
excellent illustration of the operation of these
controlling laws, by which we may hope to
render their action readily intelligible. This
drop of dew consists of two gases, oxygen and
hydrogen, which are chemically united into
one substance — the water. Having obtained
the same gases by chemical means, let us mix
them together ; if we then set fire to the mix-
ture there follows a great explosion, and we
find the jar in which the gases were contained
no longer filled with air, while drops of water
bedew its sides.* Let the reader now ask
himself, Why is this? Why are we quite sure
that on mixing these gases thus together, and
firing them, we shall produce water? Why
not something else ? The reason is, that although
these gases have a powerful tendency to unite
together, there are certain laws which compel
them to unite in a certain manner, and to
produce, so long as they do so, a certain
result. If these laws did not exist, it would
be impossible for us to tell what would be
produced when we mixed and lighted the

* This experiment should only be performed with small
quantities of the gases, and the jar should be thick and
strong, and covered, all but the mouth, with a coarse cloth. .

40 THE CHEMISTRY OF CREATION.

two gases. These laws are the laws of chemical .
combination.

Having thus alluded to the elements, to
their tendencies to combine together, and to
the results that would without doubt follow
were no controlling principles in existence to
direct, harmonize, or neutralize the contend-
ing powers, we may briefly mention the laws
which effect these objects, and by their simple
but beautiful adjustments, produce much of
that harmony which we behold in nature. Other
laws may be broken or rendered inoperative
by the force of circumstances ; but these laws
are fixed and unalterable. They are four in
number.

1st. The same chemical compound (say water)
must always possess a definite and unalterable
constancy of composition.

For example : — If we took a glass-full of
water from a way-side brook in England, and
another from the bosom of the Ganges deep in
Hindostan, or a third from some mountain-
torrent of the Alps, and examined them each
chemically, of course taking care to distil
them separately so as to obtain the water free
from all earthy or other impurities, we should
find that the water in these three instances
had precisely the same composition; that is,
by weight, eight parts oxygen, and one hydro-

OXYGENATED WATER. 41

gen. If, again, we wished to form water by
uniting its constituent gases, we should find
that we must take eight parts by weight of
oxygen gas, and one of hydrogen, and that
no other proportion would succeed. From
these two experiments it would be manifest
that water, wherever or however formed, is
always the same substance, and is made up of
the same component gases in the same relative
proportions. If, again, we found a clear fluid,
having all the appearance and character of
water, and discovered, on analyzing it, that it
contained sixteen parts of oxygen by weight to
one of hydrogen, we should be immediately
justified in declaring, on this account alone,
that this was not water. Such a compound of
oxygen and hydrogen actually exists, and has
been called peroxide of hydrogen, or oxyge-
nated water. From the circumstance of its
possessing a different composition to that of
water, however like that fluid it may appear,
it is nevertheless a different substance. And
this would be, because the first law of chemical
combination declares that "the same chemical
compound must always possess a definite and
unalterable constancy of composition for the
same substance."

" The converse of this rule, however, is not
so universally true; the same elements com-

42 THE CHEMISTRY OF CREATION.

bining in the same proportions, do not of
necessity generate the same substance. Or-
ganic chemistry furnishes numerous instances
of this very remarkable fact, in which the
greatest diversity of properties is associated with
identity of chemical composition."* Thus,
while the same substance is always made up of
the same elements in the same proportion, the
same elements, in the same proportion, do not
always form the same substance. This may
appear paradoxical, but it is strictly true,
although at present we are not quite able to
explain or understand the cause.

2nd. Every chemical body, in uniting with
other bodies, does so in a certain definite quan-
tity or proportion, or in multiples of that quan-
tity, and this is called the "equivalent," or
combining proportion of the body.

For example : — When oxygen unites with
hydrogen to form water, it does so in this
proportion, — eight parts oxygen to one hydro-
gen. Four parts oxygen would not unite with
one of hydrogen, nor any other number but
eight, or a multiple of eight, such as sixteen.
Again, nitrogen unites with oxygen in the pro-
portion of fourteen parts by weight to eight of
this gas. Every other element has what is
called its combining proportion, or equivalent,
* Fownes : Chemistry, p. 174.

COMBINING QUALITIES. 43

by which is to be understood, in the words
of the law, that " certain definite quantity " in
which, and in none other, will it unite with
other elements. These proportions or equiva-
lents are all different from each other, though
some approach remarkably close to a common
number ; thus, the " equivalent " of carbon is 6 ;
that of lithium 6'43.

3rd. When a chemical body, say oxygen,
unites with another in several quantities or
proportions, or " equivalents," these propor-
tions bear a simple relation to each other.

For example : — Oxygen unites with nitro-
gen in five different quantities, or proportions,
thus :

Nitrogen 14 unites with 1 oxygen or 8 parts by weight.
„ „ „ 2 oxygen or 16 „

„ „ „ 3 oxygen or 24 „

„ „ „ 4 oxygen or 32 „

„ „ „ 5 oxygen or 40 „

In this table, while the proportion of nitrogen
remains constant, that of oxygen increases in
the simple ratio of 8, 1.6, 24, 32, 40.

4th. The combining quantity, or " equiva-
lent" of a compound substance, is the sum of
the combining quantities of its component ele-
ments.

For example : — is itric acid, without any water
in its composition, is composed of fourteen

44 THE CHEMISTRY OF CREATION.

parts of nitrogen, and forty parts of oxygen ;
that is, one equivalent of nitrogen, or 14+5
equivalents of oxygen or 40. Add these to-
gether, and we have 54 as the equivalent or
combining quantity of this acid. Of how great
importance the knowledge of this, and indeed
of all the laws of chemical philosophy, is in the
Arts, need scarcely to be told. As an illustra-
tion,— if it were requisite to make pure nitrate
of soda, and nitric acid and the alkali, soda,
were put into our hands to form it with, this
last rule teaches us exactly how much nitric
acid and how much soda we ought to use, so
that the one shall be in exact combining pro-
portion to the other, and so prevent our wasting
either of these substances.

Thus, Soda is . Sodium 23 -27
Oxygen 8- 0

31-27

We already know the combining quantity of
nitric, acid to be 54 ; therefore, in order to
produce nitrate of soda, we must weigh out
31*27 grains or pounds of soda, and 54 grains
or pounds of nitric acid. On mixing them
we should exactly form nitrate of soda with
neither acid nor alkali in excess. The im-
mense works now in full operation as chemical

INFLUENCE OF CHEMICAL LAWS. 45

factories, where many hundred weights of mate-
rials are used at one operation, would succeed
very indifferently, if at all, were not this last
law taken as the guide of all their proceedings.
Soda, glass, soap, paint, and a number of other
substances, are now prepared in these works on
purely scientific principles ; and were it otherwise
— as, indeed, it used once to be when the laws
of chemistry were not known — vast losses would
in many instances take place from one or other
of the materials employed in excess or the con-
trary.

The harmonious regularity and order of the
world around us are dependent upon these
laws. There is no confusion of substances and
elements without a definite purpose, and with-
out stability, in nature. Every particle of
which this great earth is formed is held bound
by the chain of these laws ; they direct its
behaviour towards other particles, and the
result is that the chemistry of nature, instead
of presenting us with a scene of disorder and
destruction, appears before us like some beau-
tiful structure, every part of which has its
appointed place, every stone its niche, every
bolt its proper resting-place, while the whole
is of exquisite beauty and design.

When we have enumerated the elements, of
many of which every object we behold, as we

46 THE CHEMISTRY OF CREATION.

stand on this fair spot, and of the whole, the
round world and all that therein is, are com-
posed,— we have indeed learned much of the
chemistry of nature. We can take up a stone
and say. Such and such substances form it; or
we can point to the tumbling waters of that
cascade, and say, It is after all chiefly oxygen
and hydrogen. We can say more — we can
declare that the elements which go to form all
this lovely creation are under certain laws
which we can lay down with the utmost pre-
cision. This is to know much more still of
this interesting subject. But this is not all.
Had these blades of grass a voice, they would
echo back, This is not all. Had the sunbeam
a tongue, it would cry, This is not all. Had
those fleecy clouds which have crept up from
the horizon, and are now gently sailing above
us, had these the power of speech, they too
would cry, This is not all. Nay, could these
very rocks cry out, they must tell the same
truth, and say, This is not all. We should be
very ignorant of what is going on all around us
if we alone were to answer back, This is all.
No ! there are wonderful forces in active ope-
ration on every side, so delicate in their mode
of action, and so subtle in their nature, that
until we are informed of their existence, it
were scarcely to be wondered at if we were

THREE PRINCIPLES OF LIGHT. 47

to exclaim, — Surely the knowledge of the ele-
ments, and of the laws which they observe, must
comprise all that can be learned of the funda-
mental chemistry of creation.

If we were to ask, Why is this grass so
green, that flower so fair in its coloured rai-
ment, this gentle air so warm and balmy, and
every object around us, glittering with light?
we must apply to the sunbeam for an answer,
and in the answer we shall find that pervading
all nature, and performing the most important
part in its operations, there are three distinct
principles — all united in the sun-ray — heat,
light, and chemical power, or actinism. Could
we break up these bright streams of light which
are now pouring down on hill and dale, giving
joy, gladness, and life to the scene, into in-
dividual rays, and by some process separate one
from all the rest, we should find all three in
it — that is, we should find it to consist of a ray
of heat, a ray of light, and a ray of chemical
force or actinism, each of these rays being
itself made up of several others. A simple ex-
periment will prove that these three different
classes of rays co-exist in a ray of sunlight. If
on a bright summer's day we allow the rays of
the sun to pass through a hole into a dark
room, and then through a glass prism, we shall
find, on holding up a white card a certain dis-

48 THE CHEMISTRY OF CREATION'.

tance off the prism, that the ray of light is
broken up into a strip of various colours, which
is called the prismatic spectrum. (See cut.)

PRISMATIC SPECTBUM.

This shows us that the ray of light is made up
of several rays — three, as it is commonly now
believed, the others being made up by the
mingling of these in various ways together.
This streak of beautiful colours exhibits to us,
then, the Light of the solar ray ; how are we
to detect its Heat and Actinic force? If we
take a very delicate thermometer, and put it
first in the violet part of the streak, then bring
it gradually downwards to the red, it would
be found that the mercury rose very little in
the violet part, and very much in the red part,
and, strange to say, even a little beyond it,
where we can see no colour at all, it would be
highest of all ! This shows us not only the
heat of the sunbeam, but also the curious fact,

COMPOSITION OF A SUNBEAM. 49

that it exists chiefly in part of the prismatic
spectrum where the red rays lie, and even
where there is no light visible. It is supposed
that this is accounted for by the rays of heat
being less bent out of their direction by the
prism than are the rays of light. We have
still got to show the existence of that curious
and interesting class of rays — the Actinic.
This also may be readily done. A piece of
paper on which some solution of nitrate of
silver, or lunar caustic, as it is commonly called,
has been brushed, after it has been dried,
must be placed in the streak of coloured
light. After a little time it will be found
that the paper is blackened where the violet
and indigo colours shone, and even beyond
them, but less quickly, or to a very trifling
degree, where the other colours are placed.
The truth has been, that the nitrate of silver
lias been decomposed by the actinic, or chemical
rays which exist chiefly in the upper part of
this prismatic streak It is supposed that the
actinic rays are most bent out of their direction
by the prism, so that they appear at the highest
point of the spectrum.

Thus we see that every ray pouring down
from the sun consists of light rays, of heat
rays, and of chemical or actinic rays. Need
it be said these have each a vastly important

E

50 THE CHEMISTRY OF CREATION.

influence upon the many chemical processes of
nature? We may spend profitably a few mo-
ments in glancing at these three principles, upon
which so much depends in the beautiful world
around us.

It is very remarkable that in the sublime,
Divinely-inspired account which Moses has
been authorized to give us of the Creation, }t
is related that the first step was the creation of
Light. " And God said, Let there be light :
and there was light." Thus showing us the
infinite importance that this principle bears to
all .created things. Light is even now abso-
lutely necessary to life, not less so than then,
when its first beams darted upon a yet un-
fashioned world "without form and void."
To every animal and plant, and equally to man,
the monarch of creation himself, light is indis-
pensable, and is^ inseparably connected with
health, motion, and activity. What a gloomy
world were ours if a deep canopy of black over-
hung the sky, leaving its inhabitants in dark-
ness and the shadow of death ! Unhappy
persons, for offences of a political ' kind, have
been long immured in prisons where no ray of
light ever stole to enliven the solitude and horror
of their dungeon, and the result has been in-
variably that such persons become of a death-like
paleness, and lose every power both of mind

SUNLIGHT AND COLOURS. 51

and body, being ultimately reduced to a pitiable
wretchedness of condition. These effects are
doubtless chiefly to be attributed to the absence
of light. Little though it may be generally
known, the flowers of various hues, the feathered
tribes of glorious plumage, and the bright and
beautiful among the insect tribes, and of those
which inhabit the great deep — all owe their
many-coloured aspect to the influence of . light.
Is it not in the glowing atmosphere of the
Tropics that we find the most splendid flowers
and birds and insects ? There, where the
shadow of a cloud seldom flies over the bright
and burning plains, where no fogs and vapours
like those of our " distempered climate " interfere
with the power and brilliancy of the solar rays,
every object is in holiday attire, and gleams
with colours such as we should seek in vain in
our more temperate, but after all, more highly-
favoured region. Some remarks by Professor
Edward Forbes, in his Report on the Mollus-
cous and Radiate animals of the ^Egean Sea,
exhibit this very clearly : — " The animals of
Testacea and the Radiata of the higher zones
are much more brilliantly coloured than those
of the lower, where they are usually white,
whatever the hue of the shell may be. Thus
the genus Trochus is an example of a group
of forms, mostly presenting the most brilliant

52 THE CHEMISTRY OF CREATION.

hues, both of shell and animal; but whilst the
animals of such species as inhabit the littoral
(or sea-shore) zone are gaily chequered with
many vivid hues, those of the greater depth,
though their shells are almost as highly coloured
as the coverings of their allies nearer the sur-
face, have their animals, for the most part, of a
uniform yellow, or reddish hue, or else entirely
white. The chief cause of this increase of in-
tensity of colour as we ascend, is doubtless
the increased amount of light above a certain
depth." The sea-weeds and fish which have
their abode near the surface of the water are
far more beautiful than those which are found
deeper down ; and where the finny tribe live at
the bottom, or at depths where a mere glimmer of
light is all that distinguishes day from night, they
become nearly colourless. On a future page, it
will become necessary for us to enter more fully
into the chemical influence of light upon the
vegetable world, where it will be found that the
wood and green parts of plants are principally
formed by its agency.

Not less important is the principle of Heat
in the phenomena of nature. It is this which
assists to call into activity the germ of life
lying dormant in the seed; this bids the in-
sect's egg awake and live ; this breaks up the
hard and stony surface of the ice-bound field,

INFLUENCE OF HEAT IN NATURE. 53

and lets a thousand cold-imprisoned plants go
free ; this clothes the forest with its leafy
honours, ripens the green untempting burden
of the orchard, and makes all creation to re-
joice. All the day long the sun pours down
upon the earth unfailing streams of this life-
giving principle, which then become diffused
into the surrounding air; so making the breeze
soft and warm, or penetrate a little distance
into the soil, whence they again in part disperse
into the air at night, when the sun has left us.
Every object we behold is influenced to a
greater or less degree by this principle. This
nettle and that blade of grass; the one all
covered with hairs, the other polished and
glistening, are both affected by the warm sum-
mer rays, but not both alike. The nettle,
being rough, is a good radiator, and therefore
loses heat faster than the grass which is smooth
and a bad radiator ; but then the nettle is also
a good absorber of heat, whereas the grass
absorbs it slowly. Undoubtedly this difference
of properties as respects heat was not appointed
in vain. We do not know why, but it is cer-
tainly necessary for the well-being of both
plants, that they should be as they are. Per-
haps the nettle may require to absorb much
heat, and very quickly, in order to perfect some
of the chemical phenomena of its growth ;

54 THE CHEMISTRY OF CREATION.

and the contrary with respect to the blade of
grass.

But more than this : while every flower that
blows is dependent upon heat for its expansion,
and the perfection of its various functions,
flowers differ from one another in what we may
call the amount of their debt. Some absorb
much heat, and with great rapidity ; others
absorb less, and that slowly. Strange to say,
this is connected with their various colours,
for it has been proved by philosophical experi-
ments that bodies variously coloured have dif-
ferent absorbing and radiating powers with
respect to heat.- Dr. Franklin placed pieces of
cloth of different colours in the sunshine on the
surface of snow in winter, and found that in
proportion to the depth of the colour, the snow
melted most rapidly, in consequence of the deep-
coloured pieces having absorbed heat much
faster than the rest. When we look therefore
at the flower-garden all begemmed with brilliant
colours, how interesting is it to remember these
colours were not given in vain. The streaked
tulip and the spotless garden lily do not absorb
or radiate heat alike. The deep blush of the
rose, the pale azure of the blue-bell, the glow-
ing gold of the meadow butter-cup, are not
therefore merely ornaments, or intended only
to give variety to the scene, though doubtless

CHEMISTRY OF SUNLIGHT. 55

that may be another object accomplished, by
their different hues, but were all admirably
adapted in order to enable the flowers to drink in
that portion of the quickening influences, of the
sun's rays, which is most expedient for their
peculiar wants.

The heat of the sun's rays performs other
duties of a more momentous kind than any
hitherto indicated. It is the grand agent by
which currents are produced in the air. Yet,
little do we think that the summer breeze that
fans our cheek, little does the sailor think that
the steady wind which impels his vessel, or the
storm which threatens him and his ship with
destruction, are alike put into movement by
the subtile beams of the sun ! Thus the cir-
culation necessary for the preservation of the
purity of the atmosphere is sustained, — thus
the clouds are wafted to drop their burden on
our thirsty fields, — thus man can spread his
canvas wings, and fly to the ends of the earth
— all as a consequence of this warm flood of
sunshine in which the insects bask, and the
landscape lies bathed and asleep. The heat of
the sun is the great cause of the evaporation of
water, and thus it lifts into the air the vapour,
which, when condensed, comes down as the
grateful shower to fertilize our land. Also,
since chemical changes of all kinds go on -much

56 THE CHEMISTRY OF CREATION.

more rapidly at high than at low temperatures,
the heat of the sun is largely concerned in each
of the chemical phenomena, which are constantly
taking place throughout nature.

The most remarkable of the three principles
hitherto found in the sunbeam is the Actinic
ray. The discovery of this most remarkable
principle — if that is a correct term for it — is
quite recent, comparatively with that of the
two others. Yet its effects have been known
for ages. From time immemorial chemists have
known that on exposing preparations of silver
to the sun they become decomposed, and en-
tirely altered in character. -The researches of
many philosophers in modern times have now,
as we have already shown, proved the existence
of these rays of actinism, in the most unques-
tionable manner. It is at present impossible
to explain the real nature of the actinic force.
We must rest satisfied by describing it as that
power in the sun's ray which produces the
chemical changes taking place in bodies exposed
to the light.

These delicate yet potent rays fall, like the
sunlight in which they are found, upon every
portion of the surface of the landscape, and
together with those of heat and light, they
then produce effects of a most important kind.
The towering trees of yonder forest, as well as

"NATURE'S SWEET RESTORER." 57

the humble moss which clusters on their bark,
owe their health and vigour, nay, their very
existence to the actinic rays. Take away these
from them, and they become sickly and feeble,
and die. To this subject, however, we shall
have occasion to return by and by. It is
almost more surprising to discover that these
rays exert a most powerful influence upon in-
animate bodies. It is found that it is impossible
to expose any solid substance, whatsoever its
nature, to the sun's rays without its undergoing
some change in consequence of the operation of
these rays on its surface. Wonderful thought 1
the sunbeam cannot even impinge upon a plate
of the hardest steel without leaving a trace of its
passage behind. Every object in this scene is
affected by this agency ; those rugged cliffs, and
those tall and frowning mountains, are for every
hour that the sunlight strikes them undergoing
a destructive change, and the most extensive
effects would soon be produced, were it not
that a beautiful remedy has been provided, by
which the injurious results that would otherwise
follow are entirely obviated. If the world had
not, like man, its stated time of rest, it would
soon undergo the most serious changes, the end
of which would be undoubtedly an entire alter-
ation of every object on its surface. During
the silent hours of night, however, it has been

58 THE CHEMISTRY OF CREATION.

found that all these effects of the solar ray
pass off, and all bodies restore themselves again
to their original condition. It is not, therefore,
to man and the animate world in general, and
to vegetation, alone, that night and gentle
sleep conie " as Nature's sweet restorers ;" the
great earth must rest likewise. These fields and
yonder, hills sleep, and become restored and
refreshed equally with the. living and moving
beings on their surface. Night is precious
alike to all ; in truth, it is indispensable.

The beautiful contrivance now so largely
employed for the purpose of portrait taking,
the Daguerreotype, exhibits in a singularly
striking manner to us the potency and rapidity
of action of the actinic rays of the sunbeam.
In a darkened chamber, generally in a little
box appropriately fitted, the rays of light pro-
ceeding from the sitter's figure are collected
by means of a lens, and are caused to fall upon
a silvered plate, which has been prepared by
exposing it to the vapour of iodine and bro-
mine. In a second of time the most faithful
picture of the person is fixed upon the metal
surface, in lines which years cannot efface. By
means of a camera obscura, and paper • pre-
pared in a peculiar manner, Mr. Fox Talbot
has succeeded in producing the most exquisite
sun-pictures, in which all the varying tones of

PICTURES DRAWN BY THE SUN. 50

light and shade, and every line of the scene, is
exhibited with an accuracy to which no painter
has, nor can attain. This invention is called
the Talbotype. Thus the researches of modern
science have enabled us to press the sunbeam
into our service as an artist more speedy in
execution, and more admirably accurate in its
productions than the most skilful of men.
Nature's own pencil is now employed to depict
itself — the fairest landscape imprints its own
image upon the enduring surfaces of metal or
paper ; the most minute points of detail are
thus indelibly preserved to us, and the wanderer
in foreign climes needs little exertion of his own
to store his portfolio with pictures drawn by
the sun, which on his return may often serve to
bring to his recollection scenes and objects far
distant then. An important improvement has
recently taken place in the photographic art, in
the substitution of plates of glass for sheets of
paper. The pictures thus obtained are ex-
tremely beautiful. At Greenwich a great num-
ber of the various observations are self-regis-
tered by employing the actinic power of light.
The details are too complicated to be easily
unde«tood ; this application, however, is chiefly
made in the case of the magnetical observations
by little mirrors placed upon the needles, which
reflect the light of a lamp on to a sheet of pre-

60 THE CHEMISTRY OF CREATION.

pared paper. Thus, when the needles move,
they cause the reflected light also to move
a certain distance on the paper, and wherever
this light falls it leaves its mark in the dis-
coloration that instantly takes place. It has
also been proposed to copy objects in the
microscope by casting the image on prepared
paper. This would be highly useful. This de-
lightful art is called Photography, that is,
light-drawing, but it would be preferable to
style it Heliography or sun-drawing, since it is
the actinic rays, not the strictly light — or lumi-
nous rays of the sunbeam which produce them.
Hitherto we can only be said to have perfectly
succeeded in producing pictures of one tint
alone; but some singular experiments have
been made, and are still in the course of pro-
secution, which seem to indicate that in time
it will be even possible to produce perfect pic-
tures, each object being represented in its natural
colours.* This would indeed be a triumph in
the science of light.

The warm and pleasant sunshine then, gently
though it flies from hill to hill, and lies on
the valley and distant waters, is an agent of
astonishing power, and of the most vita] im-

* Recent announcements have shown the possibility of
this. It is said that pictures have actually been taken im-
pressed with the natural colours of the objects.

ELECTRICITY. 61

portance to all things around us. Though we
cannot quite say, with the poet, that the glorious
sun

" plays the alchemist,

Turning with splendour of his precious eye
The meagre cloddy earth to glitt'ring gold ;"

yet when we look at all the exquisite colours
and forms which owe their existence to its
beams, we can say that a ray of light fulfils a
wonderful part in the chemistry of creation.
We shall have occasion, as we proceed, to refer
to its varied influences in the different kingdoms
whose chemistry we propose to consider.

Yet the sunshine after all only forms one of
several agencies which combine together to give
life to, and to preserve the many beauties of
our landscape. The earth, the grass, the trees,
yon shining river, and those sailing clouds, could
they be again interrogated, would disclose to
us yet another agent, which influences them all,
and is for ever darting from and to them, silently
and unseen, assisting in all the phenomena they
exhibit, and consequently intimately concerned
in the various processes of the chemistry of
creation. This agent is electricity. This quick
and wonderful principle passes incessantly
through the soil on which we tread, influencing
in various ways the chemical ingredients it
<x)ntains. Every blade of grass is sensible of

62 THE CHEMISTRY OF CREATION.

its passage through its juicy cells into the air,
and every leaf, and every tree, is constantly
either parting with it, or receiving it, and con-
ducting it to the soil. Even the animal frame
is pervaded by it. The wide atmosphere is a
grand receptacle in which immense quantities of
it are stored. No chemical change can take place
in nature without the development of this agent,
or, at any rate, without its becoming implicated
in the process.

More wonderful even than the application of
the actinic power of light to the wants and
purposes of man, is that of Electricity. By its
aid, with the assistance of the ingenious con-
trivance of the Electric telegraph, we can
communicate in a second of time our wishes or
commands to immense distances. Recent im-
provements have enabled us even to print by
electricity, and this at any interval of space, so
that the Eoyal speech may be printed and
distributed at the very ends of our island on
the afternoon of its delivery. By it also, even
portraits can be painted; so that if a criminal
were on his flight, not only would electricity
immeasurably outstrip him and carry the news
to the terminus, but it might also be made to
depict his correct likeness, and so .infallibly
secure his detection and arrest. Electric mes-
sages are now also sent beneath the waters of

ELECTRIC CLOCK. 63

the Channel, forming a chord of communication
between England and France. The electricity
of low intensity produced by means of the gal-
vanic battery is now largely employed in mul-
tiplying casts of medallions and in overlaying
articles of various kinds with silver and gold.
A beautiful application of the same power, and
one which affords us a pleasing evidence of the
fact that electrical currents are constantly flying
through the solid crust beneath our feet, is
the Electrical clock. Mr. Bain has, by arrang-
ing plates in the earth, with connecting wires
attached to them, conveyed away sufficient
electricity from these currents to keep in
constant and regular motion a clock of peculiar
construction ; and he proposes to regulate all
the clocks in a large city by this means, so that
all should exhibit precisely the same time ! In
addition to the forces already enumerated, the
powers of Magnetism and of Gravity bear in a
particular manner importantly upon a variety
of the chemical phenomena of nature. Into
the consideration of these, however, we shall not
enter.

Thus, standing on this point which commands
a view of the whole of the scene* before us,
we have found that a number of subtle princi-
ples or forces have been exhibited to us as con-
* See p. 24.

64 THE CHEMISTRY OF CREATION.

cerned in the countless chemical phenomena
which are taking place so silently and imper-
ceptibly around, above, and beneath us. All
nature owns the sway of light, heat, actinism,
electricity, magnetism, and gravity. Yet the
real constitution of every one of these powers is
hidden from us. Philosophy is completely at a
loss, when she is asked what are light, or heat,
or any of the other active agencies enumerated.
We can estimate and correctly describe their
effects ; but there we must stop. Many men of
science in the present day appear to think they
are all modifications of one principle ; we have,
however, much to learn before this can be
rendered a probable, or at least, a satisfactory
view of the subject. It is a reflection full of con-
solation to the Christian mind to remember that
all these agencies, so active in themselves, and
so powerful, are only subordinate instruments
in the hands of an ever-superintending God, the
Creator, and can only do that which He pleases
— fulfil that which He has first commanded.
Other thoughts, however, and a new range of
inquiry, await us.

CHAPTEE II.

CHEMISTRY OF THE LAND.

STANDING on this elevated spot we may take a
survey of the scene before us. All is still ;
the breeze has died away, the air is now clear,
and without a cloud, and the ear listens in
vain to catch a sound, beyond the low and
fitful rushing of those foaming waters, which,
as they leave their rocky channel and flow
through the fields beneath, again become silent,
and roll noiselessly into the sea. The shepherd's
flock lies under the shadow of the overarching
elm-tree, the cattle are standing in the shady
hollow by the river-side, and the cowherd
himself stretches his lazy length upon the soft
grass on the bank. These green meadows, so
fresh and luxuriant in their appearance, seem
also asleep. The humble and soberly-arrayed
flowers which bedeck the soil, lift up th.eir gaze
to the light, and seem athirst for a refreshing
shower. . Although it is midday, and every
object is bathed in sunshine, all is so quiet and
so motionless, that the repose is like that of the
night.

F

66 THE CHEMISTRY OF CREATION.

We may return home, and on another oppor-
tunity revisit the spot. If we go in Autumn,
we shall find that it has shed its golden tones of
colour over hill and valley, the earth has yielded
its increase, and the fields, bared of their waving
burden, look empty and naked. If in Winter,
the waterfall is hung round with pendants of
ice, the surface of the river is hard and solid,
and a white canopy of snow envelopes the
whole face of the landscape. With these na-
tural changes we are made familiar by the con-
tinual round of the seasons; but beyond these,
to the unscientific observer it would appeal-
that all tilings continue as they were. From
year to year the hard lineaments of the rocks,
and the rounder figure of the hills, are as fami-
liar to our eyes as are the well-known faces at
the fireside, and the elastic sod seems in all
respects the same as that on which we danced
in childhood.

Is it, however, so in reality? Are there no
changes taking place around us of a different
kind to those of the seasons? In truth there
are, and those of a most important kind. Che-
mical forces are in ceaseless operation, the ten-
dency of which is to bring down to the dust of
the earth the hardest of those proud cliffs, now
looking so strong and enduring. The substance
of these rocks is gently crumbling away and

CHEMICAL CHANGES INCESSANT. 67

falling in fine particles to become united with
that of the plains at their feet. The green
sward, though apparently the same, is in reality
not so even from year to year ; its materials are
being constantly removed, altered, and re-depo-
sited. The air we breathe is incessantly altered
in composition, and restored again, and its par-
ticles are in constant commotion and change
of place and condition. The ocean is the scene
of similar events.

The face of the earth is for ever renewed,
altered, and re-formed. Generations of men,
animals, and plants, perish and pass away, and
with the fall of each, the constituents and cha-
racter of the surface perpetually vary. All is
in process of change ; yet all presents the
appearance of a profound repose. All things
are working together and without cessation,
even in the natural kingdom, and for good.
The chemical energies know no such condition
as quiescence in nature. They take no rest;
the cessation of one process is only the com-
mencement of another ; there is no absolute
rest. They could cease from action only when
they had reduced the whole earth to a smooth,
level ball; and all that it contains to a certain
fixity of composition. But there are wise
counteracting causes which forbid such a result,
and these very laws of change often also react

68 THE CHEMISTRY OF CREATION.

upon themselves, so that the real condition of
nature is an equilibrium — an equilibrium, how-
ever, which is preserved by continual efforts on
each side to upset the balance.

This is a strong expression of the facts
silently presented to us even in such a quiet
scene as we have been contemplating. And it
is necessary to offer them with one qualifica-
tion. Many of the changes thus ceaselessly
occurring are absolutely inappreciable by the
ordinary tokens : thus, chemistry alone can
tell us that the atmosphere is constantly un-
dergoing changes of addition, subtraction, and
restitution, to the most enormous amount; but
the senses cannot discover it. And with regard
to the surface-changes, the amount of alteration
at any one time is minute, and the extent can
only be measured by a long lapse of years. It
is important therefore to remember that these
changes are in constant progress under our eyes,
however silent and imperceptible may be their
occurrence. By little and little the beautiful
fabric of our globe gets out of repair, and is
repaired again; its features the meanwhile not
sensibly altered, although continually altering.
The rocks which shut in the valley in which
we have placed ourselves are dropping to pieces.
Could years be compressed into hours, we should
see their rugged sides crumbling down in great

WATER — CARBONIC ACID — OXYGEN. 69

heaps ; and could a thousand years be as one day,
we should probably see many of them swept away
and levelled to the ground before our feet.

It will now be interesting to inquire by what
processes these destructive, wearing-down opera-
tions are accomplished. The apparently feeble
and contemptible powers are Water, Carbonic
Acid, and Oxygen. Water acts in two ways,
first simply as a mechanical agent, or as a solvent
of various matters; and secondly as a medium
by which carbonic acid and oxygen in a dis-
solved state are applied to the substances under-
going the change. The sacred philosopher long
since wrote : — " The dropping of water weareth
away the stones," and undoubtedly in moun-
tainous regions where the force of running
water is very great, or in any other place
where a large mass of water sweeps along the
earth, the mechanically-destructive powers of
water are very great. At the Falls of Niagara,
for example, geologists are considered to have
proved that in the course of time the river
has cut its way back through several miles
of rock, and is still gradually receding, though
with extreme slowness, at the rate, it is said, of
a foot a year.* In so doing it is difficult even

* It will be understood that while admitting this fact, no
assent is thereby given to the argument as to the assumed age
of the earth, which is conceived to be supported by this phe-

70

THE CHEMISTRY OF CREATION.

to calculate how many millions of tons of solid
rock the water must have worn away in the
time occupied in the removal of the Falls from
their previous to their present position. The
manner in which this process of disintegration is

BIBD'S-EYE VIEW OF XIAGAKA FALLS AND COUNTRY AKOVJTD.

effected is described by Sir C. Lyell in the fol-
lowing terms : — " The waters, after cutting
through strata of limestone, about fifty feet
thick in the Eapids, descend perpendicularly at
the Falls over another mass of limestone, about
ninety feet thick, beneath which lie soft shoals of
equal thickness, continually undermined by the

NIAGARA FALLS; RECESSION OF. 71'

action of the spray driven violently by gusts of
wind against the base of the precipice. In
consequence of this disintegration portions of
the incumbent rock are left unsupported, and
tumble down from time to time, so that the
cataract is made to recede southwards. The
descent of huge rocky fragments of the under-
mined limestone at the Horse-shoe Fall in 1828,
and another at the American Fall, in 1818, are
said to have shaken the adjacent country like an
earthquake."

In particular districts the simple dissolving
power of water produces alterations of the most
serious kind. One of the most interesting
examples of this kind fell under the observation
of the writer in the salt districts of Cheshire,
and it is probably unique of its kind. The
reader is, doubtless, aware that at a certain
depth beneath the soil in these districts, exist
vast beds of common salt. Some of these are
worked in the usual manner by mining, shafts
being bored down to them, and the salt being
then dug and blasted out. By this means, the
hard, impure substance, called " Eock Salt," is
procured. But ordinary table salt is obtained
in a different manner. In various parts of the
districts, what are called brine springs have
been found; these are simply springs of water
charged with a large quantity of salt, and are

72 THE CHEMISTRY OF CREATION.

naturally formed by water percolating through
the soil to the salt-beds, there dissolving a
portion of the salt, and then being pumped up
by machinery. From this brine table-salt is
procured by boiling down in large flat iron
pans, in which it crystallizes, and from which
it is ladled out, poured into wooden moulds, and
dried.

There are a large number of salt-works con-
stantly in operation, which by means of power-
ful steam-engines are continually pumping up
immense quantities of brine, and so remov-
ing constantly large portions of the salt-beds
beneath, which disappear under the dissolving
influence of water. At a very large salt-work
the annual quantity of salt thus dissolved out
is considerably upwards of 52,000 tons ! In
other words, we may say that water in the im-
mediate neighbourhood of this factory carries
away every year upwards of 52,000 tons
of solid material from the ground beneath.
Conceive the effect of this in twenty or thirty
years ! Above all, conceive the effect of many
large works, each draining away many thousands
of tons even in a single year! Multitudes
of railway excavators could not make such a
cavity in the earth in the same space of time
as does the water acting simply as a solvent.
As may be imagined, all this does not go on

NORTH VVICH SALT-FIELD. 73

without sensibly affecting matters on the sur-
face; in fact, the effects are most extensive,
and even disastrous. Every year the land in
the vicinity of Northwich, near the banks of
the river Weaver, subsides to a greater or less
degree, and as it subsides the river encroaches
upon it, converting what was formerly meadow-
land into a lake of many acres in extent.
Those works which are placed near the stream
are every year compelled to be raised to a
higher and higher level to avoid the encroach-
ing waters. What was once a pleasant walk
is now a pleasant sail, for it is covered with
deep water! Cottages, landmarks, footpaths,
are all gently, but surely, becoming submerged
by the sinking of the land. Buildings in these
spots are rendered most insecure by the gradual
failure of the foundation. Some are bound
together with iron girders to keep them from
falling. Tall chimneys present a most ludicrous
appearance ; many of them lean as much as the
leaning tower of Pisa, and are only kept from
tumbling down by strong iron rods which are
attached to them to hold them up. In short,
the whole district around the brine springs is
settling down, at a rate which is proportionate
to the amount of solid salt dissolved by the
water, so as to fill up the vacuity left. Water
has performed a curious office also for the rocks

74 THE CHEMISTRY OF CREATION.

of one of the islands of the Pacific. These rocks
are composed of crystallized carbonate of lime,
perhaps originally coral, but by exposure to the
air, and by the percolation of water, the loose
particles of calcareous matter have been washed
away, and the whole mass presents in conse-
quence a very brilliant crystalline appearance.

The island is represented in the cut. Other
instances* of the extensive influence of the dis-

* The baths of San Philippe, in Tuscany, arc mentioned by
Sir Charles Lyell as yielding waters which contain so much
lime in solution as to yield a stratum a foot thick in four

POWEEFUL EFFECT OF CARBONATED WATER. 75

solving power of water might be mentioned,
but none so strikingly illustrate the fact as those
here detailed. The mechanical influence of
water upon our sea-coasts will receive notice in
another part of this work. We must pass by,
however, the simply mechanical and solvent
powers of water as concerned in the phenomena
of nature, to the far more important considera-
tion of its chemical effects.

In this respect — that is, as a chemical agent —
water acts chiefly as a vehicle for the applica-
tion of another chemical body — Carbonic acid.
This gas is capable of being largely dissolved
by water, and so becomes peculiarly applicable
to fulfil the duties of a chemical agent, since
such bodies always act most readily in solution.
It has been found that felspar, which forms a
great part of the hard' rocks, granite and por-
phyry, will withstand, almost without injury,
for some time, the action of cold muriatic acid,
which is a powerfully corrosive, fuming liquid.
But water, charged with carbonic acid gas,
affects it rapidly, causes it to decompose, and

months. In a pond into which they are conducted, they have
deposited a solid mass, thirty feet thick, in the period of
twenty years. The mineral contents 'of the water are turned
to profitable account by the establishment of a manufactory
for medallions in basso-relievo. Moulds are exposed to the
spray of falling waters, and in a short time are coated over
with a beautifully white crust, as hard as marble.

76 THE CHEMISTRY OF CREATION.

breaks up the obdurate mass into particles.
Tims granite, one of the most dense and endur-
ing rocks entering into the construction of our
planet, of all others perhaps the least generally
affected by chemical re-agents, yields to the
gentle influence of a chemical power so appa-
rently feeble as that of carbonated water. We
shall immediately have to notice how great are
the effects produced in nature by this means;
but it may be stated, in the meanwhile, that
the manner in which carbonated water pro-
duces these wonderful and important effects,
appears to be as follows : — Granite being largely
composed of felspar, contains a considerable
quantity of alkali in its composition, for which
the carbonated water has an affinity — that is, it
has a tendency to unite with and to dissolve out
the alkali. The consequence is, that the alkali
being dissolved out of the mass, it crumbles in
pieces, and in course of time becomes, as we
shall see, quite a different substance.

The Professors Rogers, of America, have
recently instituted an elaborate series of experi-
ments upon the actual dissolving and decom-
posing power of water, pure, and charged with
carbonic acid gas. They find that the influence
here attributed to these simple chemical agents
has not been over-rated; and that rocks of all
kinds, those without an alkali in their com-

INFLUENCE OF OXYGEN. 77

position, as well as those which possess one,
are decomposed or dissolved by this means, with
comparative rapidity.

Oxygen gas, forming a part of the air, also
acts in a powerful manner upon rocks of various
kinds. It does so chiefly when they contain
iron in their composition. Many times must
the reddish brown stains on the exposed surface
of various rocks have attracted notice. Such
stains generally indicate that the rocks contain
some compound of iron in their substance, and
show the influence of the air and water in de-
composing it, and so causing it to be removed
and washed away. This gas, uniting with the
iron, causes the particles of the rock to lose
their mutual cohesion, and consequently the
hard mass becomes cracked and softened, and
ultimately, after a sufficient lapse of time, is
actually reduced to a powdery condition. This
gas is, like carbonic acid, soluble in water,
although only to a very slight extent. We may
conceive, therefore, that in a dissolved state, as,
for example, in rain-water, it may have some
decomposing power over the rocks washed by the
winter shower, which, though trifling at a time,
may become important in its accumulated effects.

Having thus alluded to the influence of the
most important agents employed in the che-
mistry of nature for the purpose of wearing down

78 THE CHEMISTRY OF CREATION.

the hard rocks and minerals exposed to their
action, we may proceed to select a few in-
stances which will exhibit the importance of
their operations on the large scale. D'Aubuisson
relates that the granite -country of Auvergne
and the Eastern Pyrenees is often so much
decomposed, that the traveller may imagine
himself upon large tracts of gravel. And to
show that this process, under favouring circum-
stances, may be of sufficient rapidity to be
observable in a few years, the same author
mentions, that in a hollow way which had been
only six years blasted through granite, it was
found on examination that its walls were so
much decomposed by the influence of carbonic
acid, that the solid rock, to the depth of three
inches, was in a crumbling condition. Dolo-
mieu calls the peculiar effect produced by this
gas a " disease of the granite," la maladie du
granite. In such districts, masses of granite
are found, which look quite solid, yet when
touched by the hand, or trodden by the foot
of the traveller, fall to powder. Such is the
influence of this decomposition in granite, that
it is found in the quarries at Dartmoor, to the
depth of fifty or sixty feet, to be more or less
decomposed. Consequently, this granite, which
is called surface granite, is less durable than
that obtained beyond the influence of decom-

THE KETTLE AND PANS.

79

position. The prison at Dartmoor is formed of
this surface granite, and the result is, that each
block has become a spongy mass, absorbing
moisture continually, rusting the iron bars, and
rendering the cells so damp that they can only
be used by covering the walls within and
without with Roman cement or tiles. The
granite used for the Kelson Monument in

London is obtained from beyond the influence of
atmospheric decomposition. The most curious
and grotesque results often arise from this
cause. Many of the strangely-fashioned stones

80 THE CHEMISTEY OF CREATION.

which antiquaries take pleasure in considering to
be the work of Druid hands, have been chiselled
by these decomposing powers alone. Sir H. de
la Beche mentions a singular specimen of such
natural sculpture, as occurring at a point on
the Isle of St. Mary, Scilly Islands, called the
"Kettle and Pans." This curiosity consists of
several basins, apparently hewn out of the rock,
some of which are eighteen feet in circumference,
and six in depth. It is believed they are
entirely attributable to the operation of the causes
in question.

It is a singular fact that we are indebted
for all our porcelain to the results of the
decomposing agents just described ! All our
earthenware, from the commonest jug to the
house-tile and flower-pot, is in like manner
produced from a material which is formed by
the influence of water, air, and carbonic acid,
upon rocks of various kinds, but all more or
less agreeing in composition as to their chief
ingredients. In certain districts in Devonshire
and Cornwall, there exist rocks of a fine white
granite, which exhibit the decomposing effect
of these agents in a remarkable manner.*

* At Shaw, a few miles from Plymouth, the surface for
hundreds of acres consists of decomposed felspar, in a state
resemhling flour. When purified and baked it forms a fine
porcelain.

NATURAL SOURCE OF PORCELAIN CLAY. 81

On the surface, and for a considerable depth
into their substance, the rock is altered to a
soft matter resembling mortar. This is col-
lected and washed ; the water which comes from
the washing of it being of the colour of milk,
in consequence of its containing a quantity of
white earthy substance suspended in it, is con-
ducted into tanks, and in its passage through
several reservoirs, deposits this white earthy
matter at the bottom. The tanks are then
emptied of water, and the white deposit being
removed and dried in the open air, and subse-
quently more completely by a drying -stove,
constitutes the beautifully fine white clay em-
ployed in the manufacture of porcelain. Not less
than 10,000 tons of this white clay, thus derived
from the decomposed material of the granite
rock, is exported annually for the use of the
potteries. Its chemical composition — the com-
position in great part of our china cups and
ornamental ware — is alumina (the basis of com-
mon alum), silicic acid, a little alkali and lime,
and in the unburnt state, a large proportion of
water, together with a variable amount of sand.
The Chinese, as well as ourselves, employ the
same material for the manufacture of their ex-
quisite porcelain.

The composition of granite, unchanged as
contrasted with that which has been thus de-

G

82 THE CHEMISTRY OF CREATION.

composed, shows us which of its ingredients
goes to form the white clay spoken of. Un-
altered granite, upon analysis, is found to con-
sist of quartz, mica, and felspar. It is the latter
ingredient, as we have already noticed, which
undergoes decomposition by the influence of
water, carbonic acid, and air. Consequently,
the two others, quartz and mica, are left behind,
and form the heavy particles of the decomposing
rocks which remain after the white clay has been
washed away.

Clay of every description is produced in the
same manner; yet, as is familiarly known, it
is only the best china which is of a pure white
colour. Common earthenware is more or less
yellowish, or brown, or even red. This does
not essentially depend upon any difference in
the mode of formation of the clay from which
it is made; it is all equally derived from the
decomposition of felspar, but arises simply from
the fact, that some rocks containing felspar
contain also iron, or other colouring matter,
which of course communicates its stain to the
clay obtained from it.

Surprise has often been expressed how mines
of silver have been discovered in such extra-
ordinary situations as some of those on the
bleak summits of the Cordilleras of South
America. But a little consideration of the

SILVER MINES — CALIFORNIAN GOLD. 83

effects of the agents we are speaking of would,
in a simple manner, have removed the difficulty.
Silver, it is well known, resists the action of the
air and weather, while the rocks in which the
veins of the metal lie, are readily decomposed,
and worn away. The natural result is, that in
process of time the veins of silver are left
standing out from the surface of the cliff, which
has been worn away all around them, and so the
first wanderer that passes by finds a mass of the
precious metal sticking out of the rock. We
are told by Mr. Darwin that the celebrated and
rich mine of Chanuncillo, from which silver,
to the value of many hundred thousand pounds,
has been raised in the course of a few years,
was discovered by a man who threw a stone at
his loaded donkey, and thinking that it was
very heavy, he picked it up, and found it full
of pure silver. The vein occurred at no great
distance, standing up like a wedge of metal.

That vast supply of gold which has been re-
cently discovered in the sands of rivers, and in
the valleys of Australia and California, is another
indirect result of the disintegrating influences of
air, carbonic acid, and water. This noble metal
being scattered in small particles through the
substance of various ancient rocks, is at length,
by the constant wearing down of the latter, set
loose, and is then washed down and borne by

84 THE CHEMISTRY OF CREATION.

mountain-torrents to a distance from its original
position. Its great weight and density render it
easily separable, simply by washing, which carries
away the lighter particles of sand and mud, leav-
ing the heavy metal behind.

In Egypt, the student of the chemistry of
nature is presented with a highly remarkable
illustration of the operation of these causes of
waste and decay. In countries where the atmo-
sphere is charged with moisture, and rain is
frequent, or wind prevalent, the destructive
effects of these agents upon the strongest build-
ings soon become evident. This is strikingly
exemplified in the Delta and the rest of Lower
Egypt, which are affected by the exhalations
arising from the neighbouring sea. The conse-
quence is, that Memphis, which was formerly
the celebrated capital of the whole kingdom,
Heliopolis, Sais, and other important cities, are
now mere heaps of ruins. The granite obelisks
at Alexandria are partly illegible through the
corroding influence of the atmosphere. On the
contrary, in Upper Egypt, the monuments, un-
affected by the inundations of the Nile, and
the tombs, exhibit no signs of decay after the
lapse of many centuries. The black bricks
made out of the mud of the Nile, and dried in
the sun, some of which have been exposed to
the open air for thousands of years, as is proved

CURIOUS OBSERVATIONS ON EGYPT. 85

by their bearing the name of Eamses Miamun,
who is supposed to have reigned in the fourteenth
century before the birth of our Lord, still
retain their original hardness and firm position in
the temples, pyramids, and tombs for which they
have been used, together with all their architec-
tural ornaments.

Materials thus worn down by the chemical
agency spoken of is called debris, a word which
signifies a wreck, or waste of anything, and is
therefore very appropriately employed to de-
signate the wreck or waste of the cliffs under
the slow but certain powers of the chemistry of
nature. Debris generally collects at the base of
the cliffs, by the decomposition of which it has
been formed, and does so generally in the form
of conical heaps, the upper point of the cone
resting against the side of the rock. Some-
times, and particularly in the stupendous moun-
tains of South America, great masses of this
" waste " slide down into the valleys like huge
avalanches, overwhelming every object in their
course. It is at the base of these mighty
mountains, that the " waste " rises sometimes
to the enormous height of two thousand feet
— the accumulated result of the action of
water, gas, and air, for innumerable centuries.
But these heaps, vast as they are, are only
the visible monuments of the power and ex-

86

THE CHEMISTRY OF CREATION.

tent of these destroying agents, and as such
only represent a very small amount of the
debris actually produced. The greater part

DKBBIS AT THE BASE OF CLIFFS.

of it is swept down by rain and borne away
to be deposited in the last resting-place of
the rivers, whether that be lake or ocean into
which it ultimately falls. The granitic summits
of Mont Blanc, and of the adjoining range, ex-
posing a vast surface to the atmosphere, are of

MONT BLANC — THE ALPS AND RHONE. 87

course peculiarly exposed to the destroying
powers in question. Glaciers and avalanches
sweep down from their sides the crumbling
particles, in the form of mud, pebbles, and
detritus, or crushed rubbish, and thus supply
the impetuous river A*rne, which descends from
these lofty regions. " Scarcely," says Sir C.
Lyell, " has the Rhone passed out of the Lake
of Geneva before its pure waters are filled with
sand and sediment by the Arne. The Rhone
afterwards receives vast contributions of trans-
ported matter from the Alps of Dauphigny,
and the volcanic mountains of central France ;
and when at length it enters the Mediterranean,
it discolours the blue waters of that sea with a
whitish sediment for the distance of between six
and seven miles." The Red River of Louisiana
is so full of the disintegrated particles derived
from a region of red porphyry rocks through
which it flows, as to have received its name
from the fact ; the river deposits its sediment
on its banks in regular layers of red. Many
other rivers are coloured blue, black, yellow, and
brown from similar causes. The very names of
the Ganges and Nile are so associated with the
fertilizing influence of the mud they convey, as
scarcely to make it necessary to allude to them
in illustration of this subject. But it may be
mentioned as affording us somewhat of an illus-

88 THE CHEMISTRY OF CREATION.

tration of the amount of effect possible to be
thus produced, that it has been calculated that
the former of these rivers, in the course of a
single year, carries down many millions of tons
of mud — that is, of disintegrated rock. The
sediment thus carried down is spread out upon
the bottom of the seas, into which it is dis-
charged, there forming a layer of yearly increas-
ing thickness.

The more wild and rugged the scenery of
nature, the more certainly and rapidly do
these agents, first the chemical forces, and next
the mechanical, combine to carry on the work
of disintegration, and, if we may so call it,
decay. In the gorgeous scenery of the Andes,
where rise bare and precipitous hills of por-
phyry, pinnacles, and fortresses of rock, more
wild and grand than painter yet conceived, and
where violent conflicts of the elements are not
unfrequent, it may be imagined that this process
goes on with unusual rapidity. The following
passage from the journal of Mr. Darwin conveys
the impression with peculiar force : —

"The rivers which flow in these valleys (of
the Cordilleras) ought rather to be called moun-
tain torrents. Their inclination is very great,
and their water the colour of mud. The roar
which the Maypu made, as it rushed over the
great rounded fragments, was like that of the

VALLEYS OF THE COKDILLERAS. 89

sea. Amidst the din of rushing waters, the
noise from the stones, as they rattled one over
another, was most distinctly audible even from
a distance. This rattling noise, night and day,
may be heard along the whole course of the
torrent. The sound spoke eloquently to the
geologist; the thousands and thousands of
stones, which, striking against each other, made
the one dull uniform sound, were all hurrying in
one direction. It was like thinking on time,
where the minute that now glides past is irre-
coverable. So was it with these stones ; the
ocean is their eternity, and each note of that
wild music told of one more step towards their
destiny.

"It is not possible for the mind to compre-
hend, except by a slow process, any effect
which is produced by a cause repeated so often
that the multiplier itself conveys an idea not
more definite than the savage implies when he
points to the hairs of his head. As often as I
have seen beds of mud, sand, and shingle, ac-
cumulated to the thickness of many thousand
feet, I have felt inclined to exclaim, that causes,
such as the present rivers and the present
beaches, could never have ground down and
produced such masses. But, on the other hand,
when listening to the rattling noise of these
torrents, and calling to mind that whole races

90 THE CHEMISTRY OF CREATION.

of animals have passed away from the face of
the earth, and that, during this whole period,
night and day, these stones have gone rattling
onwards in their course, I have thought to
myself, Can any mountains, any continent, with-
stand such waste ?"

The material washed down by rivers after it
has been disintegrated by chemical forces, and
deposited under water either in the sea or in a
lake, is called alluvium, when in the course of
natural events it is at length raised above the
surface of the water, as when, by some circum-
stance, the course of the river becomes altered,
and the matter it formerly carried towards the
sea becomes exposed. It constitutes, in fact,
what may be called the mineral soil of many
valleys, such as that we are contemplating,
lying just underneath the vegetable soil formed
chiefly by the decay of vegetable matters. It
consists of sand, gravel, stones, and fine sedi-
ment or mud, most of which may be often
traced back -to their source in the mountains or
hills in which the rivers took origin, simply by
analyzing them, and finding out their respec-
tive composition. We may thus, frequently,
with some certainty, on taking up a stone from
the bed of the torrent, and examining it at
home, were we to find it composed of lime,
declare that it was broken off and carried from

KOCKS AND HILLS CRUMBLING DOWN. 91

some rock of the same substance, perhaps many
miles from the spot where we obtained the
specimen.

Enough has now been said to exhibit the
powerful, although silent influences which, un-
der the direction and constant control of the
Allwise Creator, are incessantly at work in
altering and destroying some of the most ap-
parently unchanged and unchangeable objects
which surround us. It has been seen that the
rocks and hills are slowly crumbling away, and
the forces which perform this duty have been
shown to consist only of water, air, and carbonic
acid. While mountain, rock, and valley, lose
by the touch of water and gas, can the softer
soil resist their influence ? or are these alone
affected by the powers of chemistry and the
movements of time ?

CHAPTER III.

CHEMISTRY OF THE SOIL.

THE law of change, illustrated in the last
chapter exclusively by its influences upon the
sterner features of our landscape, the rocks and
mountains, prevails even in the soft and tender
layer of brown earth, which we find on the sur-
face of the field. Here, it is true, are less ob-
vious processes of chemical change, even than
in the instances we have been considering ; but
they nevertheless exist, for the whole mass of
vegetable mould is a body of substances con-
tinually decomposing and altering in nature.
This, therefore, also becomes an interesting sub-
ject of inquiry to the student of the chemistry
of creation.

The soil which covers so extensive a por-
tion of the earth's surface consists of materials
which differ essentially in different localities,
but which may be described in general terms,
as comprising the following constituents — the
disintegrated particles of rocks, sand, clay, and
calcareous matters, and the decomposing remains

VEGETABLE SOIL. 93

of animal and vegetable bodies. The soil is
that reservoir from whence men and animals
indirectly, and vegetables more directly, derive
their sustenance. From hence proceed, by
virtue of the beautiful laws of vital chemis-
try, the pleasant fruit for man's refreshment,
the valuable grain for his support, the medicinal
herb for the relief of his sufferings, the root for
the colouring of his garments, and that large
list of useful products, which manifest by their
very number and variety, the benevolence and
wisdom of God. While the depths of the earth
supply man with materials for his utensils, for
his luxury, or for his bodily comfort, the soil
yields to all the animate creation, as well to
the meanest animal as to man, as well to the
humble violet as to the lofty tree, almost all
that they require for the support of life. The
phrase, then, " Mother-earth," is, even in a
literal sense, correct.

We have in the last chapter drawn the very
necessary distinction between the " mineral "
and the " vegetable " soil. The chemical
processes concerned in the formation of these
two important layers of material are very
different. The mineral soil consists of the
waste of rocks, &c. ; the " vegetable" of the
debris, or waste of plants, with organic remains
superadded. And though in nature the one

94 THE CHEMISTKY OF CREATION.

cannot be distinctly separated from the other,
because both are mixed in a great measure to-
gether, it should not be lost sight of that the
natural processes which produce the alluvium,
and those which form vegetable soil or " mould,"
are quite different, and must not be confounded
together. The subject, therefore, of the present
chapter, is the chemistry of vegetable soil, or
mould, and the method of its formation.

Let us travel back in thought to the time when
the scenery we are now beholding exhibited a
very different aspect. Yonder river now rolling
down a channel, some twenty miles long, and
emptying itself into the sea, was then an impe-
tuous torrent, not a third of its present length.
Those green and fertile plains which ibrm the
smooth bottom of the valley, were then sub-
merged beneath the waters ; and from the spot
on which we now stand, the eye, as it looked
across to the rocks and hills on the other side,
would have seen only tossing waves, in the place
of waving corn. In a word, this valley did not
then exist, it was a beautiful bay, the waters of
the sea washing the foot of the hills and rocks,
which now hem it in ; and at its upper end the
torrent, formed by the water-shed of the distant
mountains inland, and of the hills around, poured
into the sea, bringing down mud, gravel, and
stones incessantly.

CHEMICAL HISTORY OF A VALLEY. 95

Time went on; the waters of the sea gra-
dually went back, leaving more and more of the
bottom of the bay exposed, and the river had,
of course, now to flow through a longer channel
in order to reach the sea. As the waters re-
tired, they left a large part of the upper end of
the bay, where the river had emptied itself at
first, uncovered ; and here the river had left its
alluvium or sediment, spread out in a triangular
form, or like the Greek letter A, the point
representing the mouth of the river, and the broad
part or base, the spreading out of the sediment,
at first under the waters.

At this time nearly all the soil contained with-
in this triangular piece, or, as it is called by
geologists, Delta, was " mineral soil ;" and was
obtained by the river, from the " waste " of the
hills and rocks. The sea appeared to retire,
leaving the bottom of the valley, for such it now
became, covered with the mineral soil, brought
down by the river. At first, this soil presented
the appearance of dried mud; and we should
have looked in vain for the soft brown layer,
which now covers the whole valley, from one
end to the other. This brown layer consists of
vegetable soil, and the vegetable soil had not then
been formed, for the waters had only recently
departed, leaving the ground dry.

The seeds of plants carried by the wind, or

96 THE CHEMISTRY OF CREATION.

dropped by birds, fell upon the alluvium ; soon
they put forth roots and leaves and flourished in
great luxuriance, for this soil is very rich in the
mineral ingredients and metallic oxides which
plants require for their nutrition. More and
more plants tenanted the once bare and naked
surface, and it soon looked green and flourish-
ing. Grasses and herbs crowded upon it ;
and where but a short time before the turbid
waters of the river rolled down, now, in green
glory waved a number of humble plants, whose
vigour of growth sufficiently indicated how ac-
ceptable the situation they occupied was to
them. So it went on for a Spring, Summer,
and Autumn. But Winter came, and slew all
these, for they fell withered and dead, beneath
his icy touch, and showers of dead leaves, from
the forest on the hills hard by, covered them
over as in a tomb. As soon as they were dead,
the powers of chemistry began to act upon them.
Water and oxygen caused their dead parts to
rot or decompose, to become softened, reduced to
powder, and at length to become altered into that
very brown mould, which we now find on digging
into the surface.

The layer thus formed was, of course, very
thin at first. But year after year, as it saw
fresh plants spring up, flourish, die, and decay,
added to its thickness ; and so in course of time

DEATH OF A FOREST-TREE. 97

a considerable layer was formed, several inches in
depth, mainly consisting of the material formed
by the decay of successive generations of plants.
Such is briefly the history of the vegetable soil of
this valley.

In examining the chemical history of this
substance, it may be profitable to select an
anecdote of forest life, in regions where sun, and
air, and rain, together with other co-operating
causes, act more powerfully than in our temperate
climate.

The inhabitants of the vast primeval forests
of the New World are frequently startled by
the crash of falling timber, shaking even the
solid ground under foot. Proceeding in the
direction of the noise, it is found to have arisen
from the downfall of some vast vegetable mo-
narch, which, after centuries of increasing
strength and grandeur, has at length fallen a
victim to the exhaustive influences of time
and old age, and lies on a heap of humbler
forest-trees, which it has dashed to the ground
in its descent. No sooner has it fallen than
a number of agents set to work to effect
its complete destruction. The rain-drops
from heaven saturate it, the burning solar
ray darts down upon and heats it, and fa-
voured by the temperature, the air begins
to act chemically upon the prostrate trunk.

H

98 THE CHEMISTRY OF CREATION.

Insects come, and bore long galleries through
its sides; ants and beetles also drill their holes
through and through, and others eat away its
bark. Thus rain and air get access to the
very heart of the tree. By-and-bye, all the
insects have taken their departure. The sun,
wind, and rain, have been, nevertheless, inces-
santly acting upon it ; and now a tribe of
painted fungi, of the most curious forms and
splendid colours, sit upon the crumbling mass.
Another portion of time glides away. Where
is the prostrate tree?

The smiling sward, the up-springing flower,
the unruffled aspect of surrounding vegetation,
answer, " Not here — not here." Even so. The
place which for centuries it covered with the
grateful shadow of its broad branches, which
it protected from the fierce pelting of the
tropical storm, and fiercer rays of a tropic's
sun, has forgotten even its existence. " The
place thereof knows it no more."

Is it so ? Is the tree not there ? Surely it is ;
but its elements have all long since passed into
another form, and some may at this moment
actually form a portion of the ungrateful vege-
tation, which by its thick and clustering growth,
and undisturbed appearance, seemed to have
denied even its existence. The tree has crum-
bled into dust ; and the dust has blended with

CHEMISTRY OF ITS DEATH. 99

the earth, and can no longer be distinguished
therefrom. How has this great change been
effected ? By what means has the hard and un-
yielding woody fibre of this giant tree been
broken up, and left a mass of powder? Che-
mistry gives the reply, and informs us, that it is
by successive chemical decompositions, that the
loftiest inhabitant of the woods has fallen, and
entered the common home of all living things,
where the great and the small, even among
plants, rest together.

When woody fibre is moistened, and freely
exposed to the action of the atmosphere, it im-
mediately begins to undergo chemical decompo-
sition. There is an interchange of ingredients
between it and the air. There is also a certain
amount of heat evolved. The fibre alters its
external characters, changes colour, and loses
tenacity : in common language, it is said to be
"rotting." The process goes ,on, the colour
deepens, until at length it becomes brown, and
the mass is so friable as to crumble to pieces in
the hand.

The chemistry of this change is not difficult.
The organic compounds of the tree decompose,
and their elements, carbon, oxygen, hydrogen,
and nitrogen, become re-arranged in a more
simple form. The hydrogen of the wood com-
bines with oxygen, and is gradually given off

100 THE CHEMISTKY OF CREATION.

as water. The nitrogen and hydrogen combine
to form ammonia in small quantities. The
carbon unites with oxygen and forms carbonic
acid, which is slowly given off. These processes
continue, until the form and substance of the
wood are no longer recognisable ; and the re-
mainder is now called humus. Its chemical
composition, although very variable, consists, in
general terms, of carbon, with a little oxygen
and hydrogen, and some insoluble earthy mat-
ters, formerly entering into the composition of
vegetable tissue. The carbonic acid given off
in this process of decay, either escapes into the
air, or, dissolved by water, it supplies the roots of
plants with a small portion of their food. Some-
times, when air is excluded, or partly so, as in
the centre of a hay-stack, chemical changes go
on so rapidly as to produce sufficient heat to set
fire to the stack, if the hay has been stacked in
too moist a state. Hence means are employed
to ventilate the interior of ricks by boring
large holes into them. Heaps of tow, hemp,
cotton, &c., take fire spontaneously in a similar
manner.

The most familiar example we could select
of a decay of woody fibre, is the rotting of straw,
and the formation of vegetable manure. Those
to whom the busy farm-yard has at any time
been an interesting scene, will readily be able

CHEMISTRY OF THE FARM- YARD. 101

to follow the changes which the fibre undergoes,
after having left the stable, and being cast upon
the dung-heap.* The decomposition goes on
at so rapid a rate, that the temperature of the
mass rises very considerably ; and we know
familiarly, that the heat thus produced, is
turned to good account by horticulturists, for
the formation of their hot-beds. As a tolerably
equable source of moist heat, it is almost un-
equalled for such purposes. The long and
glittering stems of the straw break up, lose their
golden lustre, and are gradually reduced to an
earthy, brown mass. The change is now com-
plete, and in the crumbling condition in which
it is now found, it is transferred again to the
fields, the scenes of its bygone youth, vigour, and
ripe age.

Thus is vegetable mould, strictly so called,
chemically produced. It must, therefore, be
regarded as a layer of material, in which, as we
have said, continual processes of decomposition
are going forward. A large amount of oxygen
is absorbed from the air, and a continual return
is made by the disengagement of carbonic acid
gas. Vegetable mould in this condition is, we

* In consequence of the volatile nature of the carbonate
of ammonia, formed in the decay of manure, this proceeding
is a very wasteful one, since this substance is found to con-
stitute a great part of the efficacy of such manure.

102 THE CHEMISTRY OF CREATION.

may repeat, called humus. When decay has
proceeded to a certain length, the constituents
have become so entirely altered and recon-
structed, that this decomposition no longer
takes place. No more oxygen is absorbed, and
no more carbonic acid is discharged. In this
condition mould is analogous to peat, which
may be defined to be vegetable fibre which has
undergone comparatively complete decay, only
the decay proceeds on somewhat different prin-
ciples to that of ordinary vegetable mould, or
humus.

This ultimate cessation of changes, however,
never in reality takes place in nature, because
every Autumn witnesses a fresh accession of
decomposing material to the soil, in the shape
of withered roots, stems, and leaves. The
mould of our gardens, fields, and woods, is con-
sequently always in process of change; absorb-
ing oxygen, emitting carbonic acid, restoring
the carbon of pknts to the soil, and fulfilling its
most important office, in causing the separation
of the mineral ingredients, previously contained
in the decaying plants, by the thorough disor-
ganization of structure and tissue which takes
place.

An important question here arises — Of what
use is the decaying woody fibre to vegetation?
Is the fibre thus comminuted, and reduced to

USES OF VEGETABLE MOULD. 103

powder, that it may again enter into the or-
ganism of plants ? The gardener who prizes his
well-rotted leaf soil for his floral nurslings, the
agriculturist who spreads his fields with steaming
loads of his farm-yard produce, and the majority
of persons unacquainted with the chemistry of
agriculture, will perhaps smile at our even ven-
turing to question the exceeding great value of
vegetable mould. When they behold the rich
blossoms and luxuriant stems of the conservatory,
and the soil groaning under a heavy harvest,
and all this fertility following the application
of vegetable manure, they appear to have a
natural and unquestionable argument in its
favour. Nor is its utility to be denied. The
question is — On what does the fertilising property
depend ?

One of the principal ingredients of plants is
the element carbon. Carbon is also the principal
ingredient of vegetable mould. Is the mould
then the true source of the carbon, or solid part
of vegetables? It was long thought to be so.
Liebig, with his usual happy method of demon-
stration, has now clearly proved that this long-
received opinion is an error. While we shall
return to this subject on a future occasion, when
it will be more appropriately introduced, we may
here mention that the fact is now well ascer-
tained, that pure vegetable mould is, when em-

104 THE CHEMISTRY OF CREATION".

ployed alone, almost useless for the purposes of
vegetation. The principal uses of vegetable
mould are to supply a small portion of carbonic
acid to the delicate rootlets of young plants, and
to restore the different salts and mineral ingre-
dients of plants back again to the soil. The
inorganic matters necessary to the life of plants
are thus given back to the surface ; they consist
chiefly of the alkalis, phosphates, silica, sulphur,
iron, lime, magnesia, &c. Peat is a soil full of
carbon ; and yet, because of the absence of the
latter ingredients, peat is the most barren of soils
for all ordinary purposes ; in fact, plants potted
in pure peat, from which all soluble and in-
soluble salts, and other matter, are washed away,
will languish and die. The different data upon
which this interesting and important conclusion
rests, will be found under the chemistry of the
atmosphere.

While such is the process of decay adapted
to the production of the vegetable soil, there is
a remarkable variety of the same process, which
has a most momentous bearing upon the welfare
of mankind. This is the decay preceding the
formation of coal. In the Mackenzie Eiver we
may be said to be permitted to see a modern
type of the process, by which, in former times,
the formation of this invaluable material was
accomplished. Vast quantities of timber are

FORMATION .OF COAL. 105

brought down annually by this stream into the
Slave Lake. The trees which have been torn
down by the impetuous current, generally
retain a considerable mass of earth and stones
entangled in their roots ; they, therefore, readily
sink, and by so doing form considerable shoals,
which time converts into wooden islands.
" Then," says Dr. Eichardson, " a thicket of
small willows covers the newly-formed island, as
soon as it appears above water, and their fibrous
roots serve to bind the whole together firmly.
The trunks of the trees gradually decay, until
they are converted into a blackish brown sub-
stance, resembling peat, but which still retains
more or less of the fibrous structure of wood."
If we now suppose this island sunk to the bot-
tom of the river, covered over with many beds
of mud, and then left for a long period to per-
fect the chemical changes already begun, we
have a complete idea of this interesting process.

The chemistry of it is as follows. In contact
with but little air, and a large mass of water,
the changes which take place are necessarily
somewhat different from those occurring in
woody fibre exposed to the air. Under these
circumstances, a decomposition somewhat ana-
logous to putrefaction or fermentation takes
place in the wood. Its elements undergo re-
arrangement, the ultimate effect of which, com-

106 THE CHEMISTRY OF CREATION.

bined with pressure, is to reduce it to a black
substance, possessed of almost mineral charac-
ters. The decomposed mass becomes gradually
covered with a deposit of sediment : the great
pressure of which, when accumulated into beds
of clay, or sand of some thickness, gives the
hardness and density of a true mineral to this
substance. It thus becomes stored up, it may
be, for future employment in the service of
man.*

It is interesting to remark the manner by
which it has pleased the Great Architect of the
world to order matters so, that out of the same
material, two products so totally different in
uses and structure as vegetable soil and coal,
should be formed. Woody fibre is the material
in both cases ; the result how different ! Thus,
the decay of plants and leaves on the surface,
in the course of a single year, restores to the
soil all the materials it had been deprived of in
their production ; and this is effected by one
sort of chemical decay. But the decomposition
by which coal has been produced, the object in

* The leaves of ferns, reeds, and other plants, are fre-
quently found between layers of shale or slaty clay, beauti-
fully perfect, but quite converted into coal ! And in many
kinds of coal by means of very thin sections, and by the em-
ployment of the microscope, the cells of a vegetable structure
become visible ; thus affording us a distinct proof that coal is
really a vegetable substance, and produced by vegetable decay.

REMARKABLE ARRANGEMENT OF COAL BEDS. 107

view being different, is so ordered as to result
in the formation of an admirable fuel, for the
convenience of man. Decay in this case cer-
tainly takes place, but in so peculiar a manner,
as to effect an alteration in the wood, which
almost preventing further change, yet sup-
plies an inestimable economical product, the
very source of greatness and power to nations,
of comfort, and even of existence, to large
masses of mankind.

This peculiar decomposition in the production
of coal is a beautiful example of the chemistry
of creation. And in connexion with the sub-
ject, it is interesting to notice the wonderful
manner in which the masses of coal have been
arranged, in the great storehouse of the earth,
for the use and convenience of man. " What,"
says Dr. Fownes, " can be more striking than
the aspect of an English coal-field, where iron-
ore of excellent kind lies interstratified with the
fuel necessary to reduce it? Where the lime-
stone used as a flux, and even the very grit and
fire-clay to build the furnace, are all to be found
in one and the same series, often within a few
yards of each other ?" If, in fact, the ore and
the fuel were not thus nearly placed together,
this invaluable metal, iron, would become of so
high a price, as to render it comparatively
unavailable for the general purposes of man.

108 THE CHEMISTRY OF CREATION.

Surely here is wisdom in design, here is fore-
thought, and pre-arrangement of events ; and this
is the work of God.

Before passing from this subject, we may
mention that the origin of a jewel, the most
precious in the eyes of the wealthy, and the
most valuable in some of the arts, is probably
ascribable to a process somewhat similar to that
of the decay first mentioned. The diamond is,
as is very generally known, crystalline carbon.
It may be, therefore, burned, like charcoal, in
oxygen gas. Diamonds are frequently found,
whose lustre is greatly dimmed by some im-
purities within. When such " flawed " brilliants
are burned, there generally remains a little
heap of ashes behind. Under the microscope
these ashes are found to possess traces of
organized tissues, like the celled tissue of
leaves or wood, in a skeleton state. It has
been supposed, therefore, that the diamond has
been produced under peculiar circumstances
by the decay of woody fibre proceeding to its
extreme limit, when crystallized carbon became
at length separated.

This would seem the most probable explana-
tion to which science can at present point for
a solution of the difficulty in which chemists
find themselves when called upon to account
for its origin. Diamonds cannot be artificially

ORIGIN OF AMBER. 109

produced at a high temperature, or by any
form or variety of chemical experiment. It
would appear probable they were first liquid,
and crystallized from that condition. Amber,
also, has been considered by some to be a pro-
duct of decaying vegetable matter; it is found
in abundance on the coast of Prussia, partly in
beds of fossil coal, partly on the shore, and at
the bottom of the sea, Others suppose it to be
simply a fossil resin.

CHAPTER IV.

CHEMISTRY OF THE INTERIOR.

WE have seen that on the surface the powers
of the chemistry of creation are never at rest ;
that the repose which, prevails is apparent, not
real, and that there is a ceaseless law of change
influencing all the objects which have been
presented to our notice. Must we suppose
that the earth's chemistries are only on the
surface, and that all within is quiescent ? Could
by some power a chasm be rent through the
crust on which we stand, and we look down
into the fearful gulf below, we should doubt-
less find that there was no scene of quiet, no
symptom of repose. It might be thought that,
without such a means of ascertaining what was
going on in the interior of the earth, there was
little for the student of nature's chemistry to
investigate upon this subject. But we shall
proceed to show that in various ways a very
large and very interesting amount of informa-
tion is afforded us, as to the chemical processes

DEEP CHEMISTRY OF THE EARTH. Ill

in operation in regions to which no mortal eye
can penetrate. And evidence will be adduced to
show, that in all probability the interior of this
great planet resembles rather some immense
laboratory, where enormous chemical decom-
positions are continually carried on, amid the
fury of intense fires, than the silent and dark
abyss we are commonly disposed to regard it.

What matter of thought is here"? Deep
under those smiling fields, beneath that peaceful
hamlet, lie stores of raging elements, fiercely
contending together. All around us here ex-
hibits to us the forces of chemistry only in their
gentler operations. The chemical phenomena
of the landscape takes place without tumult, and
altogether imperceptibly to the senses. But there
we may conceive the wild artillery of nature
constantly roaring, while masses of matter of
enormous magnitude are now resolved into this,
now into that chemical compound, the changes
being accompanied with proportionate evolu-
tions of light, heat, and electricity. How solemn
these reflections ! How solemn the remembrance
of the predicted end of the present heavens and
earth — they are " reserved unto fire !" How
easily might God cause the great earth to open,
and let loose upon the fair creation outside
all the terrible powers which, at his command,
lie bound within ! All that can be learned of

112 THE CHEMISTRY OF CREATION.

the state of matters within our globe, goes to assure
us that the deep chemistry of the earth is on a
scale of grandeur to which we are entire strangers
on the surface of the planet, and seems • to bid us
remember upon how frail and uncertain a tenure
our lease of this position is held.

Yet its workings are, and must remain, in a
great measure concealed from our eyes. The
fairy tales of the East represent the world be-
low as a scene of enchanting beauty, a palace
adorned with bright and glittering jewels, and
with minerals of wondrous structure, and
dazzling lustre. If so, such beauties are unr-
known to us. All the idea we are able to
form of its contents must be drawn from the
emitted products with which we are familiar;
and these, singular as some of them are, do not
justify the conceptions that might be formed of
any romantic regions of beauty below the earth's
surface. That it is a region of disquiet, a scene
of tumultuous agitations, of mighty conflicts
between opposed powers of a material kind,
we have sufficient evidence to show. For the
interior of the planet is for ever reacting upon
its exterior, as we have evidence in the earth-
quake, the volcano, &c., and by the magnitude
and extent of these phenomena we may form
some conception of the force of the powers
within. But these terrible manifestations of

HIGH TEMPERATURE OF THE INTERIOR. 113

chemical force lend no countenance to the
fanciful creations of fable.*

Let us now set before the reader some of those
natural phenomena which seem to help us to
some sort of acquaintance with the chemistry of
the interior. And we may first allude to the
remarkable facts which have been discovered
relative to the temperature of the crust of the
earth. If a thermometer is taken with us as
we descend into a mine, and carefully examined,
it will indicate a gradual rise of temperature
proportionate to the depth of the descent.
If we were to make the descent in winter, the
increase would be very sensible even to the
surface of the body. The actual increase has
been ascertained by a number of experiments
made in different countries, and amounts pretty
constantly to one degree of Fahrenheit's scale,
for every fifty or sixty feet in depth. A
thermometer placed in a hole cut in the solid
rock, at the vast depth of 1,380 feet, was
observed to register on the average 68°, while at
the same time the mean temperature of the
surface was only 50°. It is a familiar fact also

* Fable has peopled the deep abyss with men, animals,
and plants, and has conjectured even the existence of two
planets, which have been called Pluto and Proserpine, to
give light to this charming world within the world ! Leslie
and Halley affirmed that it was a hollow sphere, made up of
stories like a house.

I

114 THE CHEMISTRY OF CREATION.

that miners working at great depths in the
earth, enjoy a kind of perpetual summer, which
is almost entirely unaffected by the condition of
the surface, even though the earth be clad in
the cold but glittering raiment of the sharpest
winter. There is a mine in Cornwall, one of
the levels of which is so hot, that although a
stream of cold water is purposely allowed to
flow through it, in order to reduce the temper-
ature, the miners are compelled to work nearly
naked, and will bathe in water at 80° to cool
themselves ! In another mine in the same
county, which has been carried to the immense
depth of 320 fathoms, the temperature is hotter
than on the surface in the warmest summer day ;
for while a very hot day in July will raise the
thermometer to 82°, this instrument in the
mine rises to nearly 100°. The Artesian wells
illustrate the same fact. These wells are formed
by boring to the depth of many hundred feet
in the earth. It has been found by experience,
that the waters of such wells are hotter than
ordinary well water, and exhibit a regular
increase of heat in proportion to the increased
depth of the borings. It has been a speculation
whether, in fact, water could not be thus ob-
tained sufficiently hot for economical purposes.
The celebrated Artesian well at Crenelle, near
Paris, has been sunk, after a labour of seven

HIGH TEMPERATURE OF THE INTERIOR. 115

years and two months, to the depth of nearly
1,800 feet. The temperature of this beautifully
pure and abundant spring is 82°, being about
30° higher than the average temperature of the
surface. The same fact was noticed in sink-
ing the Artesian well at Southampton. At the
depth of 520 feet the water which flowed into
it was from 61° to 62°. The atmosphere of the
well at 50 feet was 54°; at 160 feet, 60°; and
at 543 feet, 65°; showing a rise of temperature
with the descent. The phenomena of hot-springs,
volcanic eruptions, and earthquakes, all seem to
indicate a high temperature in the world within.
The heat of substances ejected from volcanoes
cannot be less than 1000° Fahr.

Now, if the same increase of temperature
continued as we descended, supposing we could
bore to the depth of rather less than two miles,
water would rise up through the tube at the
boiling point, or 212° of Fahrenheit. Upon a
similar calculation, the increase of 1° for about
every fifty feet of depth, we should arrive at
the point of red heat on penetrating to the
depth of nine miles : at about forty miles' depth
all substances with which we are acquainted
would melt, and presuming that the same law of
increase prevailed, it is not difficult to reach a
point in the imagination when the temperature
would be great beyond all powers of expression

116 THE CHEMISTRY OF CREATION.

by figures or language. There are three
methods of explaining this curious fact. Very
probably all three together are actually necessary
in order to explain the whole phenomena of the
temperature of the crust of the earth. The first
supposes it to be chiefly due to the absorption
of heat from the sun. The second supposes
that it is due to great chemical changes taking
place in the substances forming the crust of the
earth. And the third conceives the existence
of a vast central body of fire in the interior of the
earth. It is certain that from each of these causes
separately heat may be communicated to the crust
of our globe.

The heat-rays of the sun accompany the
beams of light, and striking upon the surface
of the earth, become absorbed by it. A large
portion of them are radiated back again into
the air, but another portion become conducted
from particle to particle of the rocks and other
materials of the earth's crust, and thus pene-
trate some distance into it. Of course the parts
of the earth nearest the equator, where most of
the solar influence is felt, receive most heat,
and there it penetrates farthest into the crust
of the earth. The regions near the poles receive
least, and there of course the heat of the sun
penetrates but a very short distance into the
crust. Although much heat is lost by radiation

EXPLANATION. 117

at night, yet the whole is not thus dissipated,
for when once the ground is heated, it parts
with its heat very slowly, in consequence of its
bad conducting powers. Hence the earth retains
permanently a certain amount of heat in its
crust, which was originally derived from the
sun. At a depth varying from 40 to 100 feet
below the surface there is a stratum at which the
temperature appears to be invariable, and corre-
sponding with the mean annual temperature of
the surface. The diurnal variations of tem-
perature are not perceived below two or three
feet. At Paris the stratum of invariable tem-
perature is ninety feet below the surface; in the
tropics three or four feet ; in temperate regions
generally fifty to sixty feet. This constant
temperature is highly advantageous to both the
animal and vegetable creation. If the earth
were a metal ball, it would be so hot during the
day in summer, as to scorch all substances on
its surface, while during the night it would cool
down so rapidly as to freeze everything with the
severest cold. In a word, it would have no con-
stant temperature of its own, like that which it
now possesses.

What we have to consider is, whether the
increasing heat felt in descending into the earth
is due to this cause alone ? Down to a certain
depth, which varies according to climate, the

118 THE CHEMISTRY OF CREATION.

rise of temperature is undoubtedly principally
ascribable to this cause. But when we reflect
how bad a conductor is rock or earth, and how
very steadily on the average the temperature is
found to rise as we descend, instead of diminish-
ing, as it should do the farther we get from the
supposed source of the heat, and also how little
the influence of climate seems to affect it, we
must probably come to the conclusion that the
heat of which we speak cannot be by any means
altogether explained by referring its source to
the sun.

Sir Charles Lyell, the eminent geologist,
and others, appear disposed to believe that this
heat is due to great chemical decompositions
taking place constantly in the crust of our
planet. This forms the second theory in our
list. School-boys are in the habit of perform-
ing a little chemical experiment, which will
illustrate this idea very well. They take certain
chemical ingredients, among which are sulphur
and iron, and bury them a little way in the
earth. The substances act on each other, and
become heated, so as even to take fire and burn.
We can conceive, then, that chemical decom-
positions on a larger scale may produce im-
mense supplies of heat in the earth's crust,
which may be conducted by it throughout its
substance.

SINGULAR NATUKAL PHENOMENON. 119

Without doubt such decompositions are con-
tinually taking place in the earth's crust. The
mineral called iron pyrites, which is a sulphuret
of iron, on exposure to moisture decomposes with
rapidity, and eliminates a large amount of heat.
It is well known that immense masses of this ore
exist in the earth ; and if we can imagine that a
current of water flowed upon or through them,
we may easily recognise a source of much heat
in the changes which would succeed. A French
chemist, M. F. Leblanc, examined the air of the
galleries of a mine of iron pyrites in a district
in Brittany, and found, strange to say, that
the air only contained from 17 to 18 per cent,
oxygen, and in some parts only 10 per cent.,
without the deficiency being replaced by car-
bonic acid. This singular effect is attributable
to the pyrites walls of the mine absorbing this
gas from the air. This constant chemical pro-
cess could not go on without the evolution of a
large amount of heat. We may conceive, there-
fore, that a part of the earth's heat is derived
from this source also. Yet it seems impossible
to suppose that it is entirely due to this cause.

Upon the third view, the earth's heat is due
to a great central body of fire. Probable
though this may be, when we remember the
phenomena of volcanoes emitting burning lava,
of hotsprings and earthquakes, it is only as yet

120 THE CHEMISTRY OF CREATION.

to be considered in the light of a theory, the
proof of which has not been placed within the
reach of man.

Some remarkable experiments have been re-
cently made by Mr. Grove, and also by' Dr.
Eobinson of Armagh, which throw light upon
what we may conjecture to be the state of
matters in those intensely-heated regions which
appear to exist in the interior of the earth.
Mr. Grove has succeeded in decomposing water
into its constituent gases, oxygen and hydrogen,
merely by dropping upon it fused globules of
melted platinum, heated to great intensity, in the
flame of the oxy-hydrogen lamp. Dr. Robinson
has also shown, that as the temperature of water
is increased up to 212°, the chemical affinity of
its elements is lessened, and eventually destroyed.
Applying these highly important experiments
to the matter before us, we may gather from
them the startling fact, that a greatly increased
temperature, such as that we may conceive to
exist in the deep region beneath us, might not
only prevent the chemical union of different bodies,
but actually destroy it, if it existed in such bodies
as might be exposed to its influence. Hence the
elements may be conceived to intermingle one
with another in the interior of the earth, where
this inconceivably great heat reigns, without any
tendency to unite ! Oxygen and hydrogen, car-

CURIOUS PROPERTY OF INTENSE HEAT. 121

bon, iron, phosphorus, and the metals generally,
may move their particles in indifference to each
other, being separated by the intense force of
heat which overcomes their tendency to unite.

Should, however, any portion of them by any
cause become cooled, to a certain extent, then
instantly the powers of chemical affinity reassert
their dominion, and violent chemical combina-
tions immediately take place, which may develop
themselves on the surface either in the upheaving
might of an earthquake, or the red torrent of the
volcano. It is apparently a certain fact that the
internal temperature of the earth does not affect
the temperature of the earth's surface, nor of the
ocean, overlying earth's deep cavities.

That tremendous natural phenomenon, the
Earthquake, has been mentioned as apparently
giving countenance to the idea, that the interior
of the earth resembles a great chemical labo-
ratory. Let us now advert to some particulars
concerning it, and in so doing briefly mention
the external phenomena which accompany these
appalling catastrophes. A violent explosion is
often heard, such as is produced by the firing of
a mine, althoiigh the occurrence of this is un-
certain ; then follow a series of concussions and
vibrations, the bosom of the earth heaves up like
a sleep-disturbed giant, thunderings like legions
of artillery roll beneath the feet, and deep chasms

122 THE CHEMISTRY OF CREATION.

open up, ejecting torrents of mud or sulphu-
reous winds. Clouds of black smoke, fountains
of boiling liquids, gusts of deadly gases, jets of
steam, and up-springing flames, form its dreadful
accompaniments, and spread desolation and de-
spair around, while thousands of overwhelmed
men and animals rend the air with their cries.
Shoals of poisoned fish are cast upon the uneasy
shore, and myriads of reptiles and vermin die
suffocated by the streams of carbonic acid and
other gases which issue from the earth.

These terrible phenomena plainly indicate
the violence of the strugglings of the chemistry
of the interior. Hence the up-heaving move-
ments of the solid earth, reeling, we might sup-
pose, under the accumulated pressure of elastic
vapours, originating from sudden or it may be
more gradual chemical decompositions within.
The clouds of steam, the emissions of different
gases, the concussions, and the out-bursting
flames, — these are all indicative of the existence
of chemical phenomena, probably not materially
different from the experiments of the laboratory,
except in quantity, duration, and force. It
would be vain to attempt to define the nature
or mode of origin of the elastic vapour, or
vapours, the enormous pressure of which is
supposed to be equal to the production of
such tremendous physical phenomena. In the

CAUSES OF EARTHQUAKES. 123

absence of all positive knowledge on the sub-
ject, and comparing them with the lesser phe-
nomena, we are ourselves able to produce by
various combinations of different substances,
that view of their nature seems most probable
which regards them as of a purely chemical
origin and character.

Eecently a theory has been put forth, which
advocates the idea that earthquakes are of an
electrical origin, being the result of electric dis-
charges in the earth, passing violently through
beds of non-conducting substances. It has
hence been thought quite possible to prevent
them, if a metallic or other good conduct-
ing communication could be effected through
the temporary or permanent non-conducting
strata, so that the electric currents might find
a ready passage. It is singular that this idea
has already been carried into execution. The
Chevalier Vivenzio, at the latter end of the last
century, being self-convinced that earthquakes
were the result of electric currents, the free
passage of which was thus impeded, proposed
to fix metallic rods, terminating in a number of
points, like a brush, in the ground, to as great a
depth as possible. But a better method was sub-
sequently devised. In Naples there is a pyramid
erected before a church, under which is a deep
well, with several mouths opening about the

124 THE CHEMISTRY OF CREATION.

base. This was made that the water, being a
good conductor, might form a free electric
communication between the strata through
which the well is sunk, and thus acting on the
principle of a lightning conductor, draw off the
fluid. In the city of Udine, wells and other
excavations have been made for the same pur-
pose, and also great numbers in Nola in the
kingdom of Naples. The success of these ex-
periments at Naples and Udine does not appear,
but at Nola it seems that since they have been
undertaken the city has not been damaged by
earthquakes. Whether we are to attribute it
to this or other causes, appears more than ques-
tionable ; the experiment, however, deserves
repetition.

The idea is very prevalent that we know
nothing of the effects of earthquakes in Eng-
land; and that while other countries are
shaken to their foundation, our land, excepting
on rare occasions, is altogether unmoved by
the great powers lying below. But this idea is
erroneous. Scientific observers have been sta-
tioned at a particular place in Perthshire, and
have obtained evidence that in every year a
greater or less number of shocks of earthquakes
have been felt even in Great Britain. By
means of ingenious instruments of various
kinds, sixty distinct shocks were observed be-

CHEMISTRY OF A VOLCANO. 125

tween July 1841 and June 1842. Twelve of
these occurred in one day in July. The shocks are
found to be most frequent in autumn and winter ;
and it has been noticed that very wet weather
not unfrequently precedes their occurrence.

It is a very singular fact, that the instruments
called magnetometers employed in studying the
phenomena of terrestrial magnetism, indicate
with great delicacy also the occurrence of earth-
quakes. Those employed at Dublin indicated
from ten to twenty shocks in one year.

Another evidence of subterranean movements
is the Volcano. Every stage of volcanic vio-
lence is attended with peculiar chemical phe-
nomena. At first, when the vast artillery of
nature opens fire, glowing ashes shoot up into
the heavens, then a molten flood of lava is
pressed up into the crater, and rolls down in
devastating terrors upon the smiling country
below. These are accompanied with the pouring
forth of clouds of steam, and occasionally electric
flashes dart across the lurid flames. At a
later period, steam, sulphuretted hydrogen and
carbonic acid gases, are the only symptoms of
chemical activity, and lastly, when the fire is
almost- extinct, carbonic acid gas alone rises
from the once fire-glowing crater. Vapours of
hydrochloric and sulphurous acids, together with
pure nitrogen gas and ammonia, have also been

126

THE CHEMISTRY OF CREATIOX.

detected among the gaseous exhalations of these
fountains of fire. The celebrated volcano of
Jorullo rises out of a plain, the remarkable
aspect of which communicates a vivid idea of
the activity of chemical forces going on beneath
the surface. This scene is represented in the
accompanying engraving.

VOLCANO OP JORULLO.

Philosophy fails to inform us as to the real
causes of the volcano. But upon chemically
analysing the lava, and on a consideration of
the nature of the gases discharged, conjee-

STREAMS OF GAS CALLED THE MOFFETTES. 127

tures of various kinds have been made. Into
these we shall not enter. Dr. Daubeny says
the lava itself and the gases, together with the
intense heat of the substances discharged from
the crater, leave little doubt that the phenomena
of the volcano are only an external indication
of the contests of the powers of chemistry, in
which oxygen plays an important part, deep
in the earth. There can be little question that
the eruption of a volcano acts like the opening
of a safety-valve, and relieves the accumulating
pressure of contending elements within, which,
if the volcano-vent were closed, would result
in the production of dreadful earthquakes, more
destructive and desolating probably than any
volcanic eruption.

In addition to these violent indications of
chemical activity, we are presented with some
which are not less interesting in their nature,
although less tumultuous in operation. One of
the most common is the effusion of carbonic
acid gas, in very large quantities, from cracks
and fissures in the ground. In many vol-
canic districts this phenomenon exists in a
remarkable degree. Frequently, also, it rises,
largely dissolved by the waters of springs in
suck localities. The gas being invisible, and,
excepting when undiluted, destitute of odour,
its presence is not so easily detected as that of

128 THE CHEMISTRY OF CREATION.

other gases. When volcanic fires are dying out,
large emissions of it take place. When Vesu-
vius has ceased to emit lava, there escape im-
mense volumes of carbonic acid from the crater,
and these entering the atmosphere are well
known by the Italian people under the title of
the Moffettes. These streams of gas are some-
times dangerous to life, if a person is exposed
to their full influence. So largely does carbonic
acid escape from the ground in the far-famed
Grotto del Cane, near Naples, as to cause it to
be fatal to animals which, by accident or design,
axe exposed sufficiently long to its effects. All
the dogs for miles around dread the spot, for it is
a common experiment to put them into the cave
until they are insensible, and then to bring them
to life again by throwing them into a pool of
water. The celebrated Upas valleys owe their
deadly reputation to a similar cause. These val-
leys are described as about half a mile in circum-
ference, full of the skeletons of men and animals,
and teeming with sources of carbonic acid. They
are narrow, flat, and desolate — the very valleys
of the shadow of death ; for there universal
death holds its reign. Heaps of dead insects
and ^ birds lie around, — sad proofs of the deadly
nature of the gas.* The fatal air rises to the

* Although there has been much fable about the Upas Valleys,
the deadly effects of which were attributed to the poisonous

MINERS "CHOKE-DAMP. 129

height of about eighteen feet from the ground.
The only plant which flourishes there is the
tall and fearfully-poisonous Pohon Upas-tree,
which grows luxuriantly amid a scene of the
gloomiest description. This gas is in other'
districts so abundantly evolved from the earth
as to be heard issuing with a hissing noise
from cracks in the limestone ; and it often proves
fatal to birds which unconsciously come within
its influence.

Carbonic acid appears, however, under circum-
stances where volcanic agency plays no part.
Effusions of this gas take place in the vicinity
of extensive layers of wood-coal, principally,
however, in the form of an aqueous solution ;
in other words, as carbonated springs. The
gas may often be seen bubbling around the
edges ; and the pleasant waters of some of these
springs make them a valuable possession to the
inhabitants.

From these considerations we learn, that the
effusion of this gas is an indication of two classes
of chemical activities — first, of volcanic decom-
positions ; and, secondly, of those more gradual
changes which time produces in the constituents
of the coal-layers or measures. Both these

nature of the trees, it must not, therefore, be supposed that
the whole matter is fabulous. The statement above given
has been abimdantly confirmed by modern travellers.

K

130 THE CHEMISTRY OF CREATION.

decompositions possess interest. It appears more
than probable that the true source of this gas,
in the first case, in volcanic districts, is that
simple decomposition which heat effects upon
limestone, whereby a portion of its carbonic
acid is discharged, — a decomposition precisely
similar to that we effect in burning limestone,
the gas of which has so often proved fatal to
the incautious traveller. The intense heat of an
eruption must affect all adjoining rocks ; and it
is presumed that the calcareous or limestone
rocks, heated by this means, expel their carbonic
acid, and produce the phenomenon in question.
We have the authority of Dr. Daubeny for this
supposition. There is less difficulty in disco-
vering the source and mode of production of
the gas in the latter case. In the chemical de-
compositions which accompany the formation
of brown coal, carbonic acid is extracted from
the substance of the wood. The same process
appears to be continually taking place at great
depths in all the layers of wood coal, sometimes
rendering mines unavailable from its abundance
in the form of what miners call "choke-damp."
Water percolating through the soil to these
strata, and meeting with the gas, dissolves it,
and rises to the surface as an acidulous carbon-
ated spring.

But, from whatsoever source proceeding, this

CHEMICAL ORIGIN OF CAVERNS. 131

gas — itself in all cases an undoubted evidence of
chemical decompositions at a depth below the
surface — is the cause of important chemical
changes in the crust of the earth. Feeble as the
agency may appear, the gas, being a weak acid,
exerts in reality a most powerfully decomposing
and disintegrating effect upon the different strata
through which it is compelled to permeate in
its passage to the surface. Strata, which would
otherwise remain solid and intact for centuries,
are ready to crumble to pieces in consequence.
Dissolving out, by its solution in water, many
of the elements of the rocks, it eventually occa-
sions them to become quite soft, or even (as in
the case of limestone rocks) it may produce those
great caverns and long galleries, of which dif-
ferent countries present us with such curious and
magnificent specimens.* When the solution
thus obtained reaches the surface, it there loses
its carbonic acid, and deposits its calcareous
matter (carbonate of lime) in the form of a white,
solid, stony mass, called " travertin." A remark-
able example of water fully charged with carbonic

* At Fredericshall, in Norway, is a cavern 11,000 feet deep.
The most celebrated cave is at the village of Adelsberg, hi
Austria. The mere vestibule, called the Dome, to this mag-
nificent cavern, is upwards of 100 feet high, and more than
300 feet deep. The entire extent of the cavern cannot be
ascertained ; it is known to be very great. Yet all appears
to be due to the action of water and carbonic acid !

132

THE CHEMISTRY OF CREATION.

acid, and holding a large quantity of calcareous
matter thus obtained, occurs in a lake existing
in the Campagna of Borne, called the Lacus
Albula, or the Lake of the Solfatara. The water
is so impregnated as to assume a bluish, milky
aspect. The ancient Romans erected their baths

PETRIFYING SPRINGS.

here, which were celebrated for the cure of dis-
orders of the skin. The temperature of the
water is about twenty degrees higher than the
average or mean temperature of the air. " Reeds,
lichens, confervae, and a vast mass of aquatic

A CITY LIGHTED WITH NATURAL GAS. 133

vegetation," says Sir H. Davy, "here find a rich
repast, and grow in the utmost luxuriance,
forming a number of floating islands on its
surface." In certain districts of Asia Minor, the
springs are so charged with calcareous matter
as to deposit it in extraordinary quantities.
It is said by a traveller into those regions, that,
in order to make stone fences round the gardens
and vineyards of Hierapolis, it was only neces-
sary to conduct the water of such springs into
narrow channels, and they soon became filled up
with stone ! Even high roads are thus easily
laid down by other than human skill. When
such springs run over an eminence, they present
the curious appearance of a frozen cascade.

An equally singular exhalation, also indicative
of decompositions deep in the earth, is that
of light carburetted hydrogen, or " coal-gas,"
called by miners the " fire-damp." Being in-
visible, like carbonic acid, it is only to be
detected by its peculiar odour, and its inflam-
mability. When once a light is applied to these
streams of gas, they instantly inflame, and often
continue burning for years, until the supply
ceases. In the village of Fredonia, in the State
of New York, gas thus naturally produced is
collected and used to light the streets with !
and also for heating and culinary purposes. At
the edge of the river above the rapids, at the

134 THE CHEMISTKY OF CREATION.

Falls of Niagara, a burning spring exists. The
gas makes its way in countless bubbles through
the clear transparent waters of the Niagara.
On the application of a candle it takes fire and
plays about with a lambent flickering flame,
which seldom touches the water, the gas being
at first too pure to be inflammable, and only
obtaining sufficient oxygen after mingling with
the atmosphere at the height of several inches
above the surface of the stream. This gas rises
out of a bed of limestone rock, probably from the
decomposition of some bituminous matter below
it. The Chinese collect it in such quantities, by
means of bamboo tubes, from wells, where it is
produced naturally, as to apply it on the large
scale for heating evaporating pans. One such
well is said to heat more than 300 pans. The
production of the gas in this, as in some other
instances, appears connected with saline springs.
It is related that, while boring for salt near Lake
Erie, the borer suddenly fell, after penetrating to
the depth of 197 feet. Salt-water sprang up for
several hours ; after which, a considerable quan-
tity of inflammable gas burst forth from the
same aperture, and, being ignited by a fire in
the vicinity, consumed all within its reach. A
similar eruption of this gas was related to the
writer, as having occurred in a magnificent salt-
mine near Northwich, in Cheshire. On a hole

COTTAGE LIGHTED WITH GAS. iSo

being made into the floor of the mine, suddenly
up burst a jet of gas, which caught fire, and
streamed fourteen feet high, until it was put
out by the terrified miners. The hollow sound
of the floor of the mine had led them to suspect
some cavity beneath ; and on their boring into
it, the escape of gas was the unlooked-for re-
sult.

In many of the coal districts of the north, this
gas is frequently found issuing in jets from the
ground ; and it is almost surprising that a pro-
duct of so much value should be allowed to dis-
charge itself and become lost in the atmosphere.

At the late meeting of the British Associa-
tion at Birmingham, an interesting account of
a continued spontaneous evolution of gas from
the ground was communicated, which may be
transferred to these pages. " In a field by the
side of a lane near the village of Charlemont,
in Staffordshire, certain patches of ground had
been noticed, which, without any apparent cause,
were destitute of vegetation. The person who
first paid attention to the cause of these barren
spots was the tenant of a neighbouring cot-
tage, at which there is a cold bath, noted in
the vicinity for its sanative properties. From
certain circumstances he was led to believe
that something permeated the earth in these
spots, and having dug a hole he inserted a gas-

136 THE CHEMISTRY OF CREATION'.

pipe, and on applying a light to the mouth of
the pipe, he found, to his great surprise, that a
large flame issued from it. It was not long
before he conceived the idea of applying it to
domestic purposes, and, in pursuing his experi-
ments, he found that it was not necessary to
convey it -from the place where it was first dis-
covered, at a distance of about 150 yards from
his house, as in driving a pipe some inches into
the ground, under the floor of his cottage, he
procured a continuous flow of the gas. There
are, at the present time, seven burners in the
cottage, which enable the owners to dispense
with lire and candles ! The next cottage is also
supplied with two. It appears to make no dif-
ference to -the supply of gas if allowed to burn
for weeks together. The flame is always of the
same colour. In windy weather the flame is
unsteady : when there is a blast of wind outside
the flames of gas rise several inches, but as each
blast dies away, they return to their original
size. The escape of gas is larger in wet weather
than in dry ; but whether the gas is produced
near the surface or not, has not yet been satis-
factorily ascertained. The place where it issues
from the earth is quite a mile from any coal-pit,
and is outside the eastern edge of the Stafford-
shire basin. Upon analysis it turned out that
the gas was chiefly composed of light carburetted

THE SAFETY LAMP. 137

hydrogen. It also contained a little carbonic
acid and nitrogen. It burns with a pale bluish
white flame, emitting considerable light and
heat. As it issues from the pipe it has a moist
or slightly musty smell, as of sticks partially
decomposed ; but, after it has been kept a little
time, it becomes quite inodorous. It does not
appear that the employment of it entails any
evil consequences to the health of the family."
When it escapes into mines, it forms the awful
and dangerous gas too well known as " fire-
damp." This gas becomes explosive only when
mixed with a certain quantity of air ; if then
a flame is applied to the mixture, it explodes
with all the violence of gunpowder, and with
great noise. Still more recently the inflam-
mable gas rising from a bog has been made
to drive a steam-engine, by being carried under
the boiler.

In consequence of the awful accidents which
have occurred, owing to the escape of this gas
into coal mines, and to its subsequent explosion
by coming in contact with the lighted candle of
the miner, Sir H. Davy undertook the task of
endeavouring to discover some remedy for these
calamities. His labours were ultimately re-
warded by the discovery of the invaluable safety
lamp, with which his name will be connected
through all time. It may be interesting to

138

THE CHEMISTRY OF CREATION.

state the principles upon which the success of
this simple and beautiful invention depends.'
The lamp is, in reality, only a common oil-lamp,
surrounded by a wire gauze. It may be
trimmed by a small bent wire which projects
from the bottom of the lamp.
So completely is it shut in,
that the supply of air for its
combustion can nowhere come
to it but through the wire
gauze. Now, when this lamp
is put into an atmosphere con-
sisting of fire-damp and air, it
does not cause it to kindle and
explode, as a common candle
would do ; but, strange to say,
the light of the wick goes out,
and the interior of the gauze
cylinder becomes filled with a
pale blue lambent flame, caused
by the fire-damp and air taking
fire within it, and burning
without violence. On being taken out of such
a mixture, the wick again catches fire, and the
blue flame disappears. If, when the lamp is
plunged in a glass jar filled with this explosive
compound, we were to strip off its gauze pro-
tection, the whole would instantly explode, and
shiver the vessel to fragments. It is therefore

THB SAFETY LAMP.

PRINCIPLES OF THE SAFETY LAMP. 139

the wire gauze alone which protects the miner
when he gropes his way, with lamp in hand, into
a part of the mine where fire-damp may have
collected.

The common explanation of this is as follows :
The explosive mixture will not take fire unless
the ignited body applied to it is at a white heat.
The flame of the wick is, it is true, at a white
heat, and would therefore cause it to ignite
and explode immediately ; but before this flame
could pass to the fire-damp it must pass through
the wire gauze, and in so doing, it becomes very
much cooled by the conducting powers of the
metallic wire of which the gauze is made. The
consequence is, that it would be no longer at a
white heat, and that the fire-damp therefore
would not take light. The reason, then, why
the safety -lamp is a safe light, is that the cooling
properties of the wire gauze prevent the passage
of the flame at a sufficiently high temperature

to set fire to the explosive gas. If the reader

t .
will take a piece of wire gauze, and hold it over

the flame of a candle, he will find that for a
little time the flame will not pass through, and
that he can, in fact, look down into the centre
of the flame, which is hollow (fig. 2). After a
time, however, the wire becomes so heated, that
the flame does pass through, and then presents
the appearance represented at fig. 1 in the cut.

140

THE CHEMISTRY OF CREATION.

This seldom or never happens in the miner's
lamp if it is carefully managed. It has been
recently suggested that this can scarcely be
considered the true explanation of this fact :
and it is supposed, on the contrary, that the

particles of the gas forming the flame are in a
state of active repulsion over its surface, and thus
refuse to pass through the wire gauze.

A portion of the chemistry involved in the
production of this gas may be explained. A
progressive continuance of the decomposition,

" BLOWERS IN COAL-MINES. 141

which has been already described as taking
place in wood coal, results in the formation of
common bituminous coal. As this process
continues, carburetted hydrogen and other in-
flammable gases are constantly evolved, and if
able to reach the surface, appear in the jets
just mentioned. If not able thus to discharge
itself, the gas remains pent up in the coal mines
until some unfortunate blow of the miner's
pick-axe strikes the place, and the gas issues
forth with great violence, and in alarming
quantities. Such a stream of gas is called a
" blower " by the miners. While, however, it
remains extremely probable that in every in-
stance bituminous matters form the source of
this gas, it is not so clear by what series of links
the necessary decompositions are effected.

In addition to the evidences afforded us by
these gases of the really active operation of
deep-seated chemical forces, we may enumerate
sulphuretted hydrogen, sulphurous and hydro-
chloric acid fumes, sulphur itself, and ammonia,
as occasionally emitted from the earth's crust in
different countries, and under differing condi-
tions. The causes leading to their extrication
it is not possible to ascertain with certainty.

The highly remarkable phenomenon of mud
volcanos ; that is, volcanos which instead of
lava, pour down enormous streams of mud,

142

THE CHEMISTRY OF CREATION.

frequently without giving the least intimation
beforehand, are probably also of chemical origin.
The mud it appears difficult to account for,
but the cause of the overflow is probably the
elastic pressure of gases acting beneath the
surface. They are commonly at first preceded
by violent explosions and flames, but after-

AIB VOLCANOS.

wards the mud is cold, so that its source is
probably at no great distance from the surface.
The eruption of the mud volcano of Galungung
in 1822 was among the most fatal catastrophes
of this kind ever recorded. Without warning,

SPEINGS OF KOCK-OIL, 143

an immense volume of mud filled the crater, and
streamed down in a great torrent upon the val-
leys and plains beneath. In its course it filled
up the river courses, covered over hollows from
forty to fifty feet deep, and turned a fertile area
of land, forty miles square, into a desert. This
extraordinary eruption destroyed hundreds of
thousands of coffee-trees, many acres of rice-
fields, and, besides a vast number of inferior ani-
mals, overwhelmed not fewer than from ten to
eleven thousand human beings. In certain parts
of South America are volcanos which only emit
water and gas. They are called air-volcanos.
In all probability the " air " consists chiefly of
carbonic acid. The cut represents some of these.
We can give a somewhat more satisfactory
account of another natural phenomenon, in the
production of which the powers of the chemistry
of the interior are intimately concerned — the
springs of rock-oil, or petroleum, or naphtha,
which are found in certain districts. It has
been found by experiment, that when pit-coal
is distilled with water, a certain quantity of an
oily liquid is obtained, which resembles in all
respects the mineral oil obtained from these
springs. Hence it is reasonably concluded,
that the production of this fluid is due when it
occurs in nature, to the action of heat upon beds
of coal under the surface, causing the petroleum

144 THE CHEMISTRY OF CREATION.

to be, as it were, distilled, by a very slow process,
into the layers of earth lying just above them,
where this substance is generally found.

In a coal pit near Alfreton, in Derbyshire, a
valuable spring of mineral oil has very recently
made its appearance. The quantity thrown up
varies from 150 to 30 gallons a-day. The pit in
which the spring occurs is said to be the deepest
in that part of the country. Some years since,
a large spring of salt-water appeared in the same
pit, and has since flowed uninterruptedly. The
spring of mineral oil has accompanied the salt
spring since its appearance. The oil as it issues
is of a dark tarry colour ; but, on being distilled,
yields a volatile liquid, which has been used as
a substitute for ether and chloroform in the
painless method of operating ; and also a nearly
colourless oil, which forms a very valuable
source of light when used in a proper lamp. It
appears probable that this mineral oil may be-
come useful for the purposes of illumination.
Mr. Mansfield has proposed an apparatus for
impregnating atmospheric air with the vapour
of one of the products of distillation of mineral
oils, so as to produce, simply by passing Jt'ne . air
through the liquid, an illuminating gas. -Mijie-
ral oil springs are found in great abundance on
the north-west shores of the Caspian Sea, on
sinking wells to the depth of about thirty feet,

BORACIC LAGOONS OF TUSCANY. 145

whence it is collected by the inhabitants. In
Italy they are also common ; and the city of
Milan is illuminated with the product of such
springs. The surface of the sea near the Cape
de Verde Islands has been occasionally seen
covered with a film of mineral oil, which had
probably exuded from the bed beneath.

At the foot of volcanic mountains we have
often indications of great changes taking place
within the earth's crust in the appearance of
different sorts of springs. Frequently the
waters of some are quite sour, being charged
with sulphuric acid, and sometimes are of the
colour of yellowish milk, from the presence
of the powder of sulphur, abundantly diffused
through the waters. Sometimes, also, there
are springs, the waters of which contain a
quantity of dissolved silex, which petrifies the
objects upon which the spray falls. All our
chalybeate, sulphureous, and other medicinal
waters, indicate the occurrence of constant che-
mical changes in the earth's crust.

In further illustration of the subject of this
chapter, an instance of a highly interesting
nature may be selected, which gives us a most
lively and pleasing picture of the importance
to man of several of the chemical phenomena
occurring in regions to which he has no pos-
sibility of access. The substance commonly

L

146 THE CHEMISTRY OF CREATION.

called borax is a product of these deep che-
mical processes. It is largely employed in
glazing earthenware, in soldering metals, in
medicine, and in the operations of fluxing and
assaying. A part of what is used in commerce
is obtained from the waters of certain lakes in
Thibet and Persia ; it is also imported from
India under the name of " tincal ;" but its most
important and singular source is in what are
called the " Boracic Lagoons of Tuscany."

The scene where these lagoons are situated
is one of peculiar wildness. Conceive a region
in the heart of bleak and solitary mountains,
where the earth seems to be pouring out boil-
ing water, where clouds of hot vapour come
bursting from its surface, drenching the visitor
to the skin, and impregnating the whole sur-
rounding atmosphere with a strong sulphureous
smell. . The heat is intolerable ; the rugged
surface of -the ground seems ready at every
moment to break up and disclose some awful
pit beneath, whence the boiling springs and
clouds of steam arise. The ground trembles
and shakes beneath the feet, and loud concus-
sions are both heard and felt without cessation
in the vicinity of the spot. The surface of the
earth is covered with beautiful crystals of sul-
phur and other minerals. Need we wonder
that the poor and ignorant peasantry regarded

EEMAKKABLE NATURAL BAROMETER. 147

such a spot as the very mouth of hell, and never
passed it without an agony of terror, nor with-
out counting their beads, and praying for pro-
tection— to the Virgin !

The " lagoons " consist of rude circular basins,
partly excavated, partly built, which are situ-
ated exactly over some of the fissures in the
ground, from which the bursts of vapour rise.
These basins are ranged one above the other,
so that the overflow from the highest runs in
succession down to the lowest; and they are
filled with water by allowing a rivulet to run
into the uppermost of them. The hot vapours
rising by their natural conduits from that dis-
turbed region below where the chemical pheno-
mena combining in their production take place,
bring with them the borax, which, on entering
the water of the lagoons, becomes condensed and
dissolved by it. After the water has passed
through all the basins, it is evaporated in an
ingenious manner by pans, which are heated by
the vapours rising from the earth. It is then
crystallized, dried, and sent to the market.

It is very curious that the inhabitants of the
surrounding districts judge of the state of the
weather by the quantity of vapour which they
observe to rise from these lagoons. If there is
an unusually large quantity, it betokens wet ;
if less than usual, it foretells fine weather. And

148 THE CHEMISTRY OF CREATION.

the peasantry strictly watch this remarkable
natural barometer, and by its indications regu-
late their own agricultural proceedings. We
may conceive that it is connected with the
varying pressure of the air. When the pressure
is less than usual, the escape of the vapours is
rendered easier, and more difficult when its
weight is increased. The increase or diminu-
tion in the amount of the united vapours forms
thus, in reality, a barometer that serves to indi-
cate the weight of the superincumbent air.
Such is certainly the case in regard to our coal
mines, in which it is found that fire-damp
escapes more abundantly when the barometer
is low than when high.

It is probable that yet more important
applications of the active chemical phenomena
of this singular district will be made. " It
appears," writes a gentleman* who paid an
official visit to the spot, "that the powers
and riches of these extraordinary districts
remain yet to be fully developed. They
exhibit an immense number of mighty steam-
engines, furnished by nature at no cost, and
applicable to the production of an infinite
variety of objects. In the progress of time,
this vast machinery of heat and force will pro-
bably become the moving central point of
* Dr. Bowting.

METAMORPHISM OF ROCKS. 149

extensive manufacturing establishments. The
steam which has been so ingeniously applied to
the evaporation and concentration of boracic
acid will probably hereafter, instead of wasting
itself in the air, be employed to move large
engines, which will be directed to the infinite
variety of production which engages the atten-
tion of labouring and intelligent artizans; and
thus, in course of time, there can be little
doubt that these lagoons, which were fled from
as objects of danger and terror by uninstructed
man, will gather round them a large intelli-
gent population, and become sources of pros-
perity to innumerable individuals."

At all periods the earth's crust has ' been in-
cessantly under the influence of the powers of
chemistry within; and, consequently, the cha-
racter of its constituents has been constantly
undergoing remarkable changes. The peculiar
process, called by geologists the metamorphism
of rocks, is a striking illustration of this. In
various parts of the earth's crust there is evi-
dence of a heated mass of rock having been
pushed up from below completely through the
overlying beds. Such rocks are called Eruptive.
Their temperature at the time when they broke
through the overlying or sedimentary beds must
have been very great; probably not less than
1,000 Fahrenheit. The result of the application

150 THE CHEMISTBY OF CREATION.

of this intense heat to the sedimentary strata
has been in many cases to produce the most re-
markable alterations in their chemical compo-
sition, or in the arrangement of their particles.
Thus, rocks have been metamorphosed into sub-
stances very different to their original constitu-
tion. The celebrated Carrara marble, which,
from its unsullied purity of composition, has for
ages afforded the principal supply of marble to
the sculptor and architect, appears to have un-
dergone this peculiar change; and beds, repre-
senting the original limestone previous to its
metamorphosis, have been discovered. It ap-
pears to have been melted under high pressure,
so as not to have lost its carbonic acid, and
afterwards to have cooled dowri and crystal-
lised. The common blue slate used for roofing
is another instance of a substance altered by the
same process. Every volcanic eruption pro-
duces, only in a more limited degree, chemical
and molecular changes upon the substances with
which the heated matter comes in contact.

But, in addition to the chemical alterations
effected by the contact of a heated mass, most
important decompositions have taken place, and
are still proceeding, from the discharge of va-
pours from the interior. Vapours of sulphuric
acid passing upwards from the interior have
acted upon large masses of lime-rock, and ex-

EXPERIMENTS OF MITSCHERLICH. 151

pelling the carbonic acid, have transformed it
into gypsum or sulphate of lime. Sublimations
of metals and other elements are also found in
fissures in the crust of the earth, driven upwards
by forces acting from below. Veins of various
minerals appear to have been thus produced.
We see the powers of chemistry thus acting
far below the surface, and we learn again how
small is our every-day perception of the mighty
works which are going on beneath us. It is
highly satisfactory to be able to add that the
connexion of chemistry with all these pro-
cesses taking place in the earth's crust, and pro-
ducing changes upon the masses of rock there
existing, have been practically exhibited in the
laboratory by Mitscherlich. By a careful series
of chemical investigations, some of the most
important simple minerals — felspar, mica,
blende, &c., garnets, and rubies — have been
artificially produced, thus completely establish-
ing the correctness of the principles upon
which geologists are accustomed to explain the
phenomena of which we have spoken.

To the student of nature's chemistries few
countries present an aspect so attractive as
does the waste and desolate country of Iceland.
There may be seen in operation those mighty
forces which in more peaceful soils are kept
in bondage below the surface. Professor Bun-

152 THE CHEMISTRY OF CREATION.

sen has communicated a most valuable and
important memoir on the chemical history of
this formidable land, from which some interest-
ing extracts may be presented. The physical
character of this remarkable country forms an
important element in its chemical history. A
little observation of the several peculiarities
distinguishing it will convince us that an inti-
mate connexion exists between the phenomena,
the fame of which filled the ears of our child-
hood, of the boiling springs, geysers, fume-
roles, &c., and the active volcanoes of the
island. While volcanic dykes and fissures
abound in the crust of the earth, and volcanos
are continually emitting their molten contents
from their lofty summits, inaccessible fields of
snow cover the mountains, and reveal at great
distances the limits of the regions of glaciers,
which penetrate with their huge masses of ice
for a length of many miles, even to the lower
range of the plateaux. A tenth part of Ice-
land is covered with these glaciers ; and it
appears that, in consequence of their presence,
an excessive abundance of water is deposited
from the atmosphere, which, in its progress
downwards, appears as springs. Vast masses
of water break through the fissures and arches
of the glaciers, or rush in cascades down the
icy walls of the mountain slopes, not unfre-

CHEMICAL PHENOMENA OF ICELAND. 153

quently converting a district of many miles
into a bottomless mass of moving mud. Innu-
merable inland seas, vast marshes, and swarnps,
make this barren and desolate country appear
even more terrible to the eye of the traveller.
This abundance of water, finding its way into
the deep declivities along the gently inclining
strata of rocks, seems to nourish the various
systems of springs. The volcanic fissures thus
become the channels of these subterranean
waters, and cause them to diverge into those
deep ravines where a process of heating and
evaporation must unavoidably be induced from
the action of the heat of the volcanic soil. The
water then, elevated by the combined force of
elastic vapour and hydrostatic pressure, rushes
forth in boiling springs.

This connexion between atmospheric deposi-
tion of water in the form of rain, snow, &c., and
the deep volcanic phenomena of the country, is
highly interesting. It is proved by the fact
that the gas nitrogen is found rising from the
hot springs. Nitrogen is not a product of vol-
canic activity, and it is therefore probable that
this gas had its origin in the solution by rain
of the gases of the atmosphere previous to its
penetrating into the bosom of the soil. The
proportion also in which it is found is just
what we should expect, knowing the solubility

154 THE CHEMISTRY OF CREATION.

of this gas in water. In all probability, there-
fore, the boiling column of the mighty Geyser
itself is formed of particles of water which fell
as rain-drops on the mountain slope !

Having thus traced the origin of the springs?
let us seek in the depths of the earth, in this
singular region, the explanation of its varied
chemical phenomena. Exhalations of sulphur-
ous acid, sulphuretted hydrogen, sulphurous and
aqueous vapours, burst in certain districts in
wildest confusion from the hot soil, and spread
themselves far over the steaming fields, the soil
of which must be traversed with caution by the
traveller who would avoid the danger of being
drowned in the hot mud. On the declivities
of the mountains these exhalations burst, foam-
ing and hissing, in the form of vast columns
of vapour from the fissures and clefts of the
rocks, giving rise to sounds like thunder. In
the valleys, the traveller meets with pools of
boiling mud, in which a horrible bluish-black
clayey paste rises in huge bubbles, which, on
bursting, often throw the boiling mud to a
height of upwards of fifteen feet. These phe-
nomena constitute a picture of the wildest de-
vastation, only to be surpassed in horror by
the dread waste of the dark rocky masses by
which the scene is enclosed.

The most important of the strata of rocks

PALAGONITE EOCK. 155

concerned in the chemical phenomena of Ice-
land is a rock called Palagonite. The consti-
tuents of this rock are, silica, iron, alumina,
lime, magnesia, potash, soda, and water. These
ingredients, -united in one substance, and ex-
posed to the volcanic gases which are continu-
ally penetrating the earth, become acted upon
in a variety of ways, and form with the latter
and each other a number of different combina-
tions. The gases thus permeating the strata
beneath the surface, consist, as is generally the
case, of, sulphurous acid, sulphuretted hydro-
gen, carbonic acid, and hydrochloric acid. The
palagonite becomes, by the chemical decompo-
sitions thus set up, converted into beds of fer-
ruginous clay, interpenetrated by beds of gyp-
sum or sulphate of lime. Around the smoking
orifices of the fumeroles, thick crystalline
crusts of sulphur are deposited. The source of
this sulphur appears to be the mutual decom-
position of the volcanic gases, sulphurous acid,
and sulphuretted hydrogen, the result of which
decomposition is the deposition of sulphur.
The existence of the latter gas in the column
of gaseous emanations rising from one of the
highest craters of Mount Hecla, was not sen-
sible to test paper, but was detected . in a very
peculiar manner. This gas, when burnt in con-
tact with air, undergoes a peculiar process of

156 THE CHEMISTRY OF CREATION.

combustion, of which the principal product is
sulphuric acid. But this combustion is ren-
dered visible to the eye in a striking degree.
On holding a lighted cigar near the stream of
gas from the volcano, although all other tests
failed to indicate the presence of sulphuretted
hydrogen in it, it was by so doing instantly ren-
dered sensible. A dense cloud of vapour in-
stantaneously emanated from the burning body,
and diffused itself, like the smoke which in
Arabian fable poured from the fisherman's bottle
until it assumed the form and magnitude of a
geni, far over the ravine and the plain of the
fumeroles. At almost all the hot springs, this
remarkable phenomenon could be produced.
Even the light vapour which rises from the clear
bluish-green water of the basin of the large
crater was converted, on the approximation of
a burning body, into a dense cloud of vapour,
which would envelope the whole mirror of the
water, spreading in all directions, and almost
leading the astonished traveller to anticipate
the appearance of some giant form in its
wreathing folds. By the constant passage of
the volcanic gases through the palagonite, a
number of chemical phenomena are continually
proceeding; and the changes thus produced are
manifest on the surface in saline incrustations
and mineral productions of various kinds.

FORMATION OF THE GEYSERS. 157

Perhaps one of the most interesting features
in the chemistry of this wonderful country is
the formation of its geysers. Professor Bunsen
explains the whole process in a beautifully
clear and simple manner. In the mutual re-
action of carbonic acid, sulphuretted hydrogen,
and heated water, and the palagonite, are com-
bined all the conditions required by nature
to convert, in the course of centuries, simple
boiling springs into geysers, whose clear, va-
poury, and foaming columns of water shall
burst from the summits of their self-created
craters, either continuously, or at periods of a
few minutes, hours, or days. The explanation
of this remarkable fact is as follows. The
water of these boiling springs contains a dis-
solved hydrate of silicia, which on its evaporation
is deposited around the mouth of the spring, on
the margin projecting beyond the level of the
water. Of course, in the basin of the spring,
and below its surface, no evaporation takes
place, and therefore no incrustation can occur.
Imagine, then, this process of incrustation
around the edge of the spring to continue for
years, the natural result would be that the
margin would become higher and higher, form-
ing a rocky tube of silicious matter. As the
margin rises, the water, of course, rises also,
being always a little below the latter. The

158 THE CHEMISTRY OF CREATION.

consequence is, that the spring, by this con-
tinued process of deposition, increases in height,
until, reaching a certain altitude, it becomes
converted into a regular geyser. Surrounding
the tube formed in this simple manner, is a
hillock of silicious matter, formed by the over-
flowing of the water of the spring. These
tubes are fed with water from the mountains
above them, which becomes heated in the vol-
canic subterranean channels along which it is
conducted. This high temperature converts a
part of it into vapour, and the result is that the
water, elevated by its expansive force, foaming,
and hissing, rises up through the tube which
the incrusting waters have reared,' and rushes
boiling out of the mouth of the spring. Ice-
land abounds in these springs.

But the Great Geyser, as is well known, is
an intermittent spring. Its phenomena are dif-
ferent from the smaller geysers or hot springs.
Instead of continually discharging a boiling
stream of water, as the other springs, an in-
terval of time occurs in its eruptions. The
cause of this has been generally explained to
be, the existence under ground of great caldrons,
in which steam accumulated, until its elastic
force drove up the water through the geyser
tube, after which it subsided again. But this
explanation is incorrect : the mouth of the Great

THE GREAT GEYSER. 159

Geyser tube is so wide, that although the water
at the bottom is heated, and partly converted
into vapour, yet the loss of heat at the surface
by evaporation and radiation is so great, that
the whole volume of water in the tube. is not
brought up to the boiling point excepting at
stated times. When this is the case, then, it
appears that a powerful volume of vapour accu-
mulates at the lower part of the tube, which,
acquiring fresh elastic force, at length lifts the
immense body of water above it into the air,
driving it in a roaring, rushing column 28 feet
in circumference, and 100 in altitude; after
this the spring becomes .quiet again, until its
column is again heated up to the boiling point.

As the incrustation continues, the sides of the
tube rise, higher and higher, until they and the
surrounding ground attain a height which puts
an end to these singular phenomena. As soon
as the supply of heat from below and the cooling
at the surface are so far in equilibrium that the
temperature of the mass of water is not any-
where able to reach the boiling point, the ac-
tion of the spring ceases spontaneously. Large
reservoirs rilled with hot stagnating or running
water are thus formed. Old geysers abound in
various districts, appearing in the form of large
reservoirs filled with hot water, in the depths of
which the old mouths may still be seen. These

160 THE CHEMISTRY OF CREATION*.

springs are extremely beautiful, and in one
region of this wild country, in particular, their
aspect is highly interesting. In the depths of
the clear unruffled blue waters in this district,
from which still rises a light vapour, the dark
outlines of what once formed the mouth of
a geyser may be faintly traced amid the fan-
tastic forms of the white stalactite walls of
the basins.

The silicious deposit, the grand agent in pro-
ducing all the splendid phenomena in question,
is produced by the decomposition effected in the
palagonite rock by hot water, carbonic acid, and
sulphuretted hydrogen. Altogether, viewing the
whole of the geyser phenomena, in connexion
with the laps§ of time necessary to the formation
of one of these vaporous fountains, and contrast-
ing the magnitude of the result with the appa-
rent feebleness of the cause, we cannot fail to
be struck with the view it presents to us of the
grandeur, force, and beauty of the chemistry of
nature in this wild and wonderful region.

There is something deeply interesting in
contemplating these great chemical phenomena
of nature, whether we consider their intrinsic
importance to man and to the created scheme,
the magnitude of the scale on which they are
carried on, or the depth from the surface where
their seat is. They show us that the inner

COUNTRIES RISING. 161

regions of the globe are regions of active life,
and by no means the dark and unstirred abysses
of our usual imaginings. It is satisfactory to
add the testimony of one of the most learned
philosophers of the day upon this point. " Geo-
logical phenomena of all kinds," writes Baron
Humboldt, " indicate alternating periods of
activity and repose. The repose we are now
enjoying is only apparent. The shocks which
the surface experiences under every variety of
climate, and along with every description of
rock, Sweden rising in its level,* and the ap-
pearance of new eruptive islands, bear no testi-
mony to quiescence in the internal life of our
globe."

But these phenomena impress upon us con-
siderations of more moment even than those of
science. How precarious is the position of the

* The northern provinces only of Norway and Sweden are
rising ; the southern are subsiding. This gradual elevation of
a whole region is a most wonderful circumstance. It has been
ascertained by certain grooves being cut in the rocks on the
sea-coast, marking the ordinary level of the water at a proper
state of the tide on a calm day. Fourteen years afterwards,
the spot was visited, and, under precisely the same circum-
stances, the level was taken, and it was found to be four or
five inches lower than before. The fishermen also state that
they now find they cannot sail through many channels easily
passed in their younger days. Many sunken rocks have also
become visible. If this rising goes on, in course of time,
sea-port towns will become inland !

M

162 THE CHEMISTRY OF CREATION.

human family when we remember these pent-
up powers, which are scarce restrained from
convulsing and tearing asunder the firm and
massive crust on which we rest in such un-
thinking security ! How entirely hopeless an
attempt to escape, were it to please God to
break the yoke he has imposed upon them, and
set them free ! Happy are they who are able, in
the humble confidence of children redeemed by
Christ, to commit the keeping of body and spirit
to Him as to a " faithful Creator."

THE AIR.

VAKIOUS FOBMS OF CLOUDS.

PART II -THE AIR.

" THE FIRMAMENT SHOWETH HIS HANDIWORK."

CHAPTEE I.

ITS PHYSICAL CONSTITUTION.

WE who have been for so long a time with
our thoughts directed earthward, must now turn
them toward the sky, and look into the che-
mical mysteries of the blue heaven above us.
Can chemistry inform us, then, upon the
changes which take place in the invisible sea
of matter which on every side surrounds us?
We might suppose it could not, for we can
scarcely appreciate by any of our senses the
presence of this amazingly thin and transparent
fluid — the air. Yet the chemistry of creation,
thanks to the well-directed labours of talented
men, so far as it relates to the air, is more exact
and complete in its information, than in any
other of its departments. It is expedient,
however, before we listen to the wonders of

166 THE CHEMISTRY OF CREATION.

aerial chemistry, that some particulars should be
mentioned as to the physical constitution of
our air.

There are only one or two other planets of
our system beside the earth which are considered
to be provided with an atmosphere, or envelope
of gas. We cannot recognise in other systems
of worlds a similar provision, though doubt-
less it may exist in some altered form with-
out our being able to perceive it. What is
called " space " is considered to be destitute of
any fluid like our air, or indeed like any gas
with which we are acquainted. Our globe is
revolving on its own axis, at the immense rate
of, at the equator, upwards of 1,000 miles
an hour. It is also moving in its orbit at
a speed exceeding 68,490 miles in the hour.
Now if such be the case, if there is a vast air-
empty space above us, constantly attracting, or
endeavouring to attract, our air into it, and if,
in addition, the rapid motion of the earth lias
a tendency to scatter its airy garment to the
ends of heaven, as it undoubtedly has by virtue
of the centrifugal force, by what power is it
that the atmosphere nevertheless still closely
clings to our globe? And the same inquiry
is applicable to such other planets as may be
thus provided. The atmosphere travels .with
us, as with them, at an enormous velocity,

THE AIR TRAVELS WITH US. 167

through a void and air-less region ; y'et no par-
ticle of it leaves us. Why is this ?

The reason is that the earth exerts upon the
atmosphere, as well as upon every gaseous fluid,
or solid body over its surface, the influence of
the attraction of gravitation. This force, which
pervades the whole created universe, and en-
chains worlds and systems lying beyond the ken
of unassisted mortal eye, holds this elastic and
delicate robe, and binds it fast about the earth.
As we travel, it travels. As we revolve, it
revolves with us. In fact, could the globe for
the space of one hour continue its revolution
on its own axis, while the air stood still, the
resistance offered by the air to the passage of
the earth would be such as to produce, to all
appearance, such a tremendous blast, as would
not only level trees and -houses, but would lift
men and animals, and every moveable thing
into the air, hurling them in a common de-
struction against the first mountain range that
might present itself. Simple and interesting
as the fact is, it is greatly lost sight of in our
thoughts. We are apt to imagine that the
earth moves through the air, not that it car-
ries the air together with it. Were it other-
wise only for a little while, the fair landscape
at our feet would be turned into such a scene
of desolation and destruction as the eye of

168 THE CHEMISTRY OF CREATIOX.

man has never rested on. It will be necessary
to revert to the force of gravitation exercised
on the air, with the view to explain a part of
the phenomenon of the trade winds, on another
occasion.

Looking upwards into " this vaulted firma-
ment," we seek in vain by the eye to fathom its
actual depth. Lying at the bottom of this sea
of air, we endeavour, without success, to obtain a
measure by which some just conception thereof
may be formed. As it rolls its thin waves above
us, bearing at an immense altitude, apparently,
those clouds which seem set there to tell us how
immeasurably deep is the aerial ocean, and as
we vainly seek some limit where the surface of
the air might be supposed to lie, the inquiry
presents itself, Has the atmosphere any actual
limit? There is a great conflict of opinions
upon this question. In the estimation of many
talented persons, it is illimitable, or at least is
supposed to extend greatly beyond what others
consider to be its bounds. This also is the
popular opinion, for most persons, uninformed
on the science, would give answer that the air
extended as far as the sun, moon, and stars.
The learned Bishop Wilkins, who was a man
of great talent, but of somewhat eccentric turn
of mind, in a little treatise written by him,
urged the importance of endeavouring to make

A JOUENEY TO THE MOON. 169

a journey up to the moon. This was by no
means a mere joke. He advocated the impor-
tant results of a commercial intercourse with
the lunar inhabitants, and evidently thought
the only difficulty in the way was a proper
flying machine ! Some one objected to the
learned bishop the little difficulty of there being
no baiting-houses or taverns by the way. To
which the bishop briskly replied, that his ob-
jector ought to have been the last person to
raise that obstacle, as few were more famous
than he for building castles in the air! Such
schemes have been far from uncommon, and on
the first discovery of the balloon, there were
great hopes that man would rise to regions to
which every human being- has hitherto been a
stranger.

The belief of the illimitableness of the air is
now generally considered to have been proved
to be erroneous. Had these would-be aerial tra-
vellers made the attempt at navigating the thin
air, they would soon have found their sad mis-
take, and have discovered that an impassable
gulf is fixed between us and all the heavenly
bodies, and this gulf is the air-void region lying
beyond the boundaries of our atmosphere. The
investigations of philosophers make it appear
probable that the extreme limit of the atmosphere
does not reach beyond forty-five or fifty miles ;

170 THE CHEMISTRY OF CREATION.

but it is right to add, that others extend its limits
much more, even as far as from one to two hun-
dred miles. Dr. Wollaston, in a valuable paper
upon the Finite Extent of the Atmosphere,*
enters "into an elaborate discussion of the sub-
ject, and proves that if the atmosphere were
illimitable it must necessarily pervade all space,
and accumulate around the sun, moon, and
planets. Now, astronomical observations are
clear in demonstrating that no atmosphere, or at

o j.

any rate none similar to our own, surrounds most
of the larger planets, which ought to collect a
considerable mass of this gaseous matter around
them, in consequence of their size. From such
and similar reasonings we are led to conclude
that our air has a real limit. The fact also rests
upon deductions of chemical importance. The
laws of the great atomic theory forbid that
infinite divisibility of matter implied in the
supposition of such extreme rarefaction of air
as is demanded by the theory that it lias no
bounds. It is held, for instance, as certain,
that we cannot subdivide matter beyond a cer-
tain point ; at this point, its particles are called
atoms, and these atoms have a certain size and
weight. Applying the same reasoning to the
air, it is considered that there is a point at
which it cannot be expanded further ; and this
* Philosophical Transactions, 1822.

LIMITS OF THE AIR. 171

point is supposed to be the true limit of the air.
The air has consequently a true surface or level,
like that of a fluid.

Could we take our stand upon the surface of
our fair satellite the moon, as she " walks in
brightness," and look toward the earth, sup-
posing that the atmosphere enveloping it were
coloured throughout, so as to be visible to our
eyes, it would be seen to be of the form of an
oblate spheroid, the lesser axis of which would
pass through the poles of the earth. In short,
its outline must correspond pretty nearly to
that of the globe which it envelopes, supposing
it to be of equal thickness in every region.
This, however, is not the case, since it is more
dense near the poles, and more rare near the
equator. But the effect of this would be sim-
ply to exaggerate the oblately spheroidal out-
line of the air. It has been conjectured by
M. Biot, and others, that beyond the limits of our
own air there exists a ' sort of ether, which per-
vades all space. In confirmation of this hypo-
thesis, it has been supposed by some astrono-
mers that it is only on such grounds that the
retardation of the motion of certain comets is to
be explained, the cause lying in the resistance
to their motion offered by such a medium. If
such a fluid exist at all, it must possess elas-
ticity and tenuity in a degree, probably, as far

172 THE CHEMISTRY OF CREATION.

superior to that in which these properties are
possessed by our atmosphere, as the air tran-
scends quicksilver in the same properties.

The condition of things on the surface of the
air is, allowing that it has bounds, one of a very
peculiar kind. At a certain limit the air is
supposed to have lost its elasticity ; and the
balance between the forces of elasticity and the
earth's attraction may be considered as the real
limit of the atmosphere. This equilibrium is
supposed, as has been stated, to have its situation
at a height of from forty-five to fifty miles.

It is very certain that an extreme degree of
rarefaction may take place at an elevation up to
which it is quite within the power of man to
attain. Travellers on the high lands of South
America relate that they experienced the most
distressing symptoms in consequence of the
extreme tenuity of the air ; these were, great
difficulty of respiration, uneasy symptoms in
the head, and loss of 'muscular power. Mr.
Darwin informs us, that he himself experienced
this sensation, which is called by the natives,
the puna ; they recommend onions as a remedy,
perhaps with some benefit, as Dr. Pereira tells
us that raw onions are occasionally useful as an
expectorant. Strangers who come to reside in
some of the villages situated at the elevation
of from 10,000 to 12,000 feet above the level of
the sea, do not get over the sensation for almost

GAY LUSSAC S BALLOON ASCENT. 173

a year. The natives of the Himalayas ascribe
the difficulty of breathing experienced in the
higher alpine passes, 15,000 to 16,900 feet
above the sea, to the exhalations of poisonous
plants. It is, in reality, due simply to the
rarefaction of the air. Gay Lussac ascended
in a balloon to the enormous altitude 'of
nearly 22,000 feet above the earth. In these
lofty regions the gas of his balloon expanded
so much as to require the relief of the safety
valve ; and he himself underwent the most
acute sufferings from the intensity of the cold,
and extreme rarity of the air. Even birds
flying over the summits of lofty mountains,
are said to labour incredibly when they reach
the highest points ; and pigeons dropped from
balloons at great heights, fall like stones to
the earth. All these facts show us, that as
far as man is concerned, the limits of the atmo-
sphere are about three miles; for beyond this
his respiratory system would cease to act. And
if such is the tenuity of the air at the distance
of a few miles, what extreme thinness must be
attained just at its verge ; such perhaps as is
attained in the imperfect vacuum of the air-
pump ; which is known to be almost imme-
diately fatal to animal life.

In the study of this fact we are forcibly im-
pressed with the truth that an impassable
barrier exists, which shuts in the world from

174 THE CHEMISTRY OF CREATION.

the rest of the heavenly bodies, so that we who
" would pass from hence to them, cannot ;" but
whether other beings from them to us may pass
or not, cannot be so clearly demonstrated.

It is one of the curious and interesting dis-
coveries of modern meteorology, that the airy
ocean is agitated like that of water by tides.
These are, apparently, of two kinds, the first
being the result of the heat of the sun's rays,
the second being due to the attraction of the
moon. The atmosphere is heated, to some
extent, by the transmission of the heat-rays from
the sun through it, but chiefly by contact with
the earth heated by the sun. Air, when heated,
expands, and becomes lighter, and consequently
rises ; by this law the occurrence of the aerial
tides is easily and simply explicable. It is
perhaps necessary to mention, that the manner
in which the fact is observed, is by carefully
noting, at different periods of the day, the
height at which the mercurial column stands in
the barometer tube. Between the tropics, the ebb
and flow, as it might be expected, of the atmo-
sphere, is one of the most remarkable natural
phenomena. The periodic rise and fall of the
barometer in these regions is, in fact, due to
the ebb and flow of the atmospheric tides. The
variations occur daily in the following order,
according to Humboldt : — Twice a day the baro-

TIDES IN THE AIR. 175

meter indicates the highest pressure, or, as we
might say, the flow of the tide, at 9, or 9^, A.M.
and 10, or lOf , P.M. ; and twice a day the lowest
at 4, or 4£, P.M., and 4, A.M., or nearly the hottest
and coldest hours in the round of the twentyrfour.
It is highly remarkable that this periodic rise
and fall in the atmospheric ocean, takes place in
the torrid zone of America, without sensible
disturbance by elevation, winds, storms, or rain,
or earthquakes. Such, in fact, is the regularity
of this phenomenon, that the hour may almost be
told by looking at the column of mercury instead
of the clock ! It has also been observed, that in
Europe the same phenomenon takes place, but
is affected to a great extent by the season. In
winter, the highest pressure takes place about
9, A.M., and the lowest about 3, P.M., after which
the pressure again increases up to 9 in the
evening. In the summer, these periods are
slightly different. It is, however, very difficult
to distinguish the occurrence of these aerial
tides, in consequence of innumerable accidental
causes, which disturb their indications.

The explanation of the phenomenon arises
out of what has been said as to its periods. At
the hottest part of the day, the air expanding
ascends, and passes over into neighbouring re-
gions, and the barometer at the same time falls.
This is the " ebb " of the tide. At the coldest

176 THE CHEMISTRY OF CREATION.

part, the pressure of the superincumbent masses
of cool air, keeps the column up at its highest
point; and this we have called the "flow" of
the tide.

With reference to the attraction of the moon
upon the air, it may be well to extract the
following sentences from the admirable address
of Sir E. H. Inglis, at the meeting of the
British Association, in 1847 : — " The doctrine
of the influence of the moon and of the sun
on the tides was no sooner established, than it
became eminently probable, that an influence
exerted so strongly upon a fluid so heavy as
water, could not but have the lighter, and all
but imponderable fluid of air under its grasp.
It is now clear, as the result of the obser-
vations at St. Helena, by my friend, Colonel
Sabine, that as on the waters, so on the atmo-
sphere, there is a corresponding influence exerted
by the same causes. There are tides in the air
as in the sea ; the extent is, of course, deter-
rainable only by the most careful observations
with the most delicate instruments, since the
minuteness of the effect, both in itself, and in
comparison with the disturbances which are
occasioned in the equilibrium of the atmosphere
from other causes, must always present great
difficulty in the way of ascertaining the truth,
and had, in fact, till Colonel Sabine's researches,

LUNAR ATTRACTION ON THE AIR. 177

prevented any decisive testimony of the fact
being obtained by direct observation. But the
hourly observations of the barometer, made
for some years past at the Meteorological and
Magnetical Observatory, at St. Helena, have
now placed beyond a doubt the existence of a
Lunar Atmospheric Tide. It appears that on
each day the barometer at St. Helena stands, on
an average, four thousandths of an inch higher
at the two periods when the moon is on the
meridian, above or below the pole, than when she
is six hours distant from the meridian on either
side; the progression between this maximum
and minimum being, moreover, continuous and
uninterrupted ; thus furnishing a new element
rn the attainment of physical truth ; and to quote
the expression of a distinguished foreigner,
'We are thus making astronomical observations
with the barometer ! ' that is, we are reasoning
from the position of the mercury in a barometer
which we can touch, as to the position of the
heavenly bodies, which, unseen by us, are in-
fluencing its visible fall and rise. 'It is no
exaggeration to say/ — and here I use the words
of my friend, the Eev. Dr. Eobinson, — 'tthat
we could, even if our satellite were incapable
of reflecting light, have determined its exist-
ence ; nay, more, have approximated to its
eccentricity, and period.' "

N

178 THE CHEMISTRY OF CREATION.

A phenomenon yet more extraordinary is
that of Atmospheric Waves. As yet the dis-
coveries made on this singular subject are very
incomplete ; but Mr. Birt, who has made them
his peculiar study, is zealously engaged in
prosecuting the research. It cannot now be
doubted, that though invisible to us, there
occur, at certain periods of the year, phe-
nomena in the atmosphere, which are clearly
analogous to waves. Not mere undulations of
a slight extent, like those of the surface of the
sea, but great wave-like movements, pervading
the whole depth of the atmosphere, and occu-
pying several days in their duration. The most
remarkable of these is a vast wave, which has for
several years been observed about the middle
of the month of November. It lasts, with some
modifications, for about sixteen days ; that is, it
begins, rises higher and higher, until it reaches
its highest point; then subsides again, and the
atmosphere returns to its usual condition, in
the space of a fortnight, or sixteen days. Some-
times it has been observed to set in with a gale
of wind, and to end with one also. We are
not yet in full possession of a sufficient number
of facts to enable us to determine its cause or
causes, with accuracy.

It has been remarked, as a curious coincidence,
that the period at which this great November

WAVES IN THE AIR. 179

wave is at its highest point in our country, is
precisely that given by American travellers, for
the occurrence of that most remarkable me-
teorological phenomenon — the Indian Summer.
In America, at this period, generally from the
12th to the 17th of November, after a foretaste
of the severities of winter has been felt, a
sudden change of temperature takes place, a
delicious warmth is felt, the sky is without a
cloud, not a breath of air is stirring, and the
whole atmosphere is filled with a glowing trans-
parent haze. In three days this is all gone,
and winter comes on quickly afterwards. In
Switzerland, the same phenomenon has been
remarked from time immemorial. About the
llth of this month, the fete of St. Martin is
celebrated, and the inhabitants call the delightful
four or five days' return of summer weather at
that time, after, to all appearance, the summer
has ended, TEte de St. Martin, or St. Martin's
summer. Whether these interesting facts are
more than mere coincidences, whether the
great wave has anything to do with them or
not, it is not at present possible to ascertain.

Some curiosity will, doubtless, be felt to
know how, seeing that the phenomenon cannot
be rendered visible to our eyes, its existence
has been ascertained. It is true, we cannot see
this wave, but its presence may be felt by

180 THE CHEMISTRY OF CREATION.

means of the very simple instrument — the
barometer; — to some mention of the phenomena
and construction of which we are now conducted.
Light and thin though the particles of the
atmosphere are individually, they have in the
mass a sensible weight, and exert a pressure
altogether enormous upon the whole surface of
the earth. This pressure is not felt by our
bodies, because it is equally distributed both
within and without. It might even be very
much increased, if very gradually, and yet we
should not become sensible of its increase, on
this account. But were it possible to disturb
this equilibrium, by suddenly exhausting the
air from any part of the frame, the lungs, for
instance, then immediately the pressure of the
air would be painfully felt, and if the exhaus-
tion were carried on to any great extent, the
sides of the chest would be crushed together
by the weight of the external air. The entire
amount of its pressure on our globe may be
conceived by stating, that could we place at one
end of a balance a hollow sphere of mercury,
8,000 miles in diameter, and about 30 inches in
thickness, it would exactly counterpoise our
atmosphere, could it be appended to the other
extremity. Upon each square inch of surface
at the level of the sea, the air presses with a
weight of about 151bs.

PRINCIPLE OF THE BAROMETER.

181

The principle of the barometer is very sim-
ple. It is an instrument, which, by virtue of
its peculiar construction, weighs or balances 'a
column of air, forty or fifty miles high, and of
the diameter of the barometer tube.
Suppose the diameter of this tube
to be equal to that of a goose quill.
Now, suppose that we could take a
piece out of the air of the size of
that quill, which extended from its
summit to the level of the sea, and
weigh it ; and that we then filled the
tube of the barometer with mercury,
up to the height of 30 inches, and
weighed it ; we should find the
weight of this short column of mer-
cury, and the forty or fifty mile-long
column of air, precisely equal ! This
may be easily put to the test. We
are able actually to weigh the one
against the other, in the following
manner. Let us, by means of the
blow-pipe, melt one end of a tube of
glass about 33 inches long until it is
quite closed at that end, and then fill
it with mercury, and putting the open end into
a saucer with a little mercury in it, let us invert
it. Yet the mercury does not run out. The
reason is, the tall, thin column of air, of which

THE
BAROMETER.

182 THE CHEMISTRY OF CREATION.

we have spoken, presses upon the surface of the
mercury in the cup, and counterbalances it, so
preventing its running out Should the weight
of this column of air be by any means dimi-
nished, the fact will be immediately exhibited
by the mercury falling ; should it be increased,
it will rise. In other words, when the weight
of the column is greater, it counterbalances
more, and when lower, less mercury in the tube.
An ascending current of air rarified, and there-
fore made lighter by heat, causes the ebb of the
daily aerial tide in the tropics beforementioned ;
and this ebb is duly registered by the mercury in
the tube, standing at a lower mark.

Elevation produces a similar depression, the
barometer falling gradually for every step of
ascent gained ;* and if it were possible to rise
to the very surface of the atmosphere, not a
drop of the mercury would remain in the tube.
This fact is of the utmost importance in the
admeasurement of heights, and proper formulae
exist by which it is easy to ascertain, after
certain corrections are made, the amount of
perpendicular elevation possessed by a moun-
tain, or other eminence. On the contrary,

* The ingenious instrument called the anezoid barometer,
a pocket weather-register, consisting of an exhausted receiver
with a moveable lid and index, has proved very useful in
these investigations.

WEIGHT OF WATER IN THE AIR. 183

were we to descend with the barometer into the
earth, so increasing the weight of the column
of air pressing upon the mercury, it would
rise exactly in proportion as we descended.
So also any cause acting in the upper regions
of the air to increase the weight of the column,
would produce the same effect. Thus the great
November wave renders its passage obvious
even to the eye, for by reading the height of the
barometer, we are able to perceive its gradual
rise to its crest, and its gradual recession
again.

It is generally said that it is the pressure
merely of the air which causes the rise of the
mercury in the tube of the barometer. Recent
researches of Professor Dove and Colonel Sabine
are tending gradually to develop a very dif-
ferent view of this matter. The air constantly
contains water in a vaporous and invisible state,
which, as well as the gases forming air, properly
so called, presses upon the mercury in the cistern
of the barometer. When the air is warmer the
pressure of this watery vapour is greater than
when it is cold and dry. Hence, during the
summer, the pressure of the vapour has an im-
portant influence in keeping up the level of the
mercury; during winter, on the contrary, its
pressure is least, but then the pressure of the
gases is greater than in summer. When,

184 THE CHEMISTRY OF CREATION.

therefore, we state that the pressure of the
atmosphere is 151bs. on a square inch, we must
not forget that a part of this is due to the pres-
sure of the watery vapour in the air, though only
a small part in comparison with that caused by
the gaseous constituents of the air.

Proportionally to the decrease of tempera-
ture, the elastic force of the vapour, or, in other
words, its pressure on the barometer, will be
diminished. In the late Antarctic Expedition,
the effect of a decrease of temperature on the
barometral pressure was particularly striking.
From the tropic of Capricorn, southward, a gra-
dual diminution in the height of the mercurial
column was observed as the latitude increased.
At Kerguelen's Island the mean height of the
barometer was 29.497. In S. lat. 66°, 29.078 ;
and in lat. 74°, it was only 28.928. Thus the '
mean position of the mercury in the higher lati-
tudes of the antarctic regions, was nearly an inch
lower than in other parts of the world. Similar
results have been observed in Siberia.

The manner of estimating the pressure of the
watery vapour, independently of the gaseous
atmosphere, is by calculations based upon an
ingenious little instrument called Daniell's Dew-
Point Hygrometer, which will be -noticed on
another occasion.

Although insensible to ourselves, the pressure
of the air is of great consequence to our well-

PRESSURE OF THE AIR. 185

being, and is also highly necessary to that of
every living thing, and to the preservation of
natural things in their present condition. To
ourselves, it is important in various ways. It
prevents that excessive evaporation from the
surface of our bodies, which would otherwise
exhaust and destroy us. It also determines, in
an important manner, the proper density of the
volume of air which is requisite for our com-
fortable breathing: hence the laborious respi-
ration of persons at high elevations. It is im-
portant also to us in an economical point of
view : it is found, for instance, that if we by
any method diminish the pressure on the surface
of liquids, as, for example, by exhausting a part
of the air from a close vessel, that they will
boil at a much lower temperature than when
' the full pressure of the atmosphere is allowed
to exert itself upon them. In sugar refineries
this is taken advantage of, by boiling down the
sugar in pans, out of which the air is pumped
by a steam engine; in this way all risk of
burning is avoided. Again, if the pressure is
increased, the boiling point rises also, and it
will be more difficult to bring liquids up to this
point. As a curious result of the diminished
pressure lowering the boiling point, it may be
mentioned, that much inconvenience is occa-
sionally felt by travellers on high mountain
regions. Darwin relates a humorous anecdote

186 THE CHEMISTKY OF CREATION.

of this nature ; he was at that time travelling
in the Andes : — " Our potatoes, after remain-
ing for some hours in the boiling water, were
nearly as hard as ever. The pot was left on
the fire all night, and next morning it was
boiled again, but yet the potatoes were not
cooked. I found out this by overhearing my
two companions discussing the cause ; they had
come to the simple conclusion, that the potatoes
were bewitched : or that the pot, which was a
new one, did not choose to boil them" The
monks of St. Bernard, living as they do at an
elevation of 8,600 feet, are sorely distressed at
the same phenomenon, and are compelled to
subsist almost entirely on fried, roasted, and
baked food in consequence of the water boiling
at so many degrees under the usual boiling
point, 212°, as to render its heat insufficient to*
render wholesome the food which they procure.
It seems a great pity no kind traveller should
have carried a Papin's digester to them ; for as
that is a close vessel, fitted with a pressure valve,
they could easily remedy the inconvenience
under which they labour, by substituting an arti-
ficial pressure in place of the deficient atmospheric
weight.

It is easily conceived, that since the density
of the air is directly proportionate to its
pressure, how important it must be for the

RESULTS OF ATMOSPHERIC PRESSURE. 187

feathered tribes, that the air should be suffi-
ciently dense to offer resistance to the play of
their pinions ; so also, though in a less degree,
to insects. Some birds, taken up on one occasion
by an aeronaut in a balloon to a great height, and
set at liberty, refused to leave the machine, and
clung to its sides in great terror, being appa-
rently sensible that the air was too thin to
trust the weight of their bodies to. To fishes,
the atmospheric pressure is also of vital con-
sequence. If this pressure were removed the
result would be, that the air now dissolved by
water, would immediately rise from it, and
the inhabitants of our lakes, rivers, and seas,
would die in consequence. To plants, it is also
of great moment ; it restrains that excessive
loss of fluids which would follow if it was in
* any degree removed ; for just as a diminished
pressure lowers the boiling point,* so it increases
the facility with which the evaporation of fluids
takes place. In various ways atmospheric
pressure exerts a beneficial influence upon their
growth and functions, and upon the motion of the
vegetable juices.

If we place a piece of solid ice under the
exhausted receiver of an air-pump, and take
care that the experiment is conducted in a room

* Water in the imperfect vacuum of an air-pump, will boil
at the low temperature of 67° !

188 THE CHEMISTRY OF CREATION.

below freezing point, so as to insure its not
melting, we should find in a little while that all
the ice had disappeared; the reason would be,
that it had evaporated away. From this we may
learn, that if the atmospheric pressure were
removed, not only would liquids evaporate, but,
in all probability, many solids also. From all
these considerations, we may learn the wisdom
and beautiful adaptation to existing circumstances,
exhibited even in the apparently less important
particular of atmospheric pressure.

There is yet another circumstance to be
noticed in reference to the physical constitution
of the atmosphere, and that is, the temperature
of its higher regions. It has been mentioned
that in proportion as we rise from the earth, the
density of the air becomes continually less and
less. The balloon of the aeronaut, after rising
to a certain height, can rise no longer. It then
remains stationary, for above it the air is so
thin as to be unable to support it, with its car
and weights, even in spite of its buoyant con-
tents of hydrogen gas. This effect is due to
the elasticity of the air. In proportion as
the pressure on its particles diminishes, their
tendency is to separate farther and farther from
each other ; or, in other words, the air expands.
By calculation it has been found that this ex-
pansion of the air, as we ascend takes place in

LIMIT TO AERIAL NAVIGATION. 189

what is called a geometrical progression. For
instance, if at the level of the sea a certain
quantity of air occupied one square foot of
space, at a little more than two miles and-a-half
it would fill a space of two square feet ; at about
five miles, four ; at eight miles, eight ; at ten
miles, sixteen ; at thirteen miles and-a-half,
thirty-two ; and at sixteen miles, sixty-four
cubic feet. Hence we very soon reach a limit
by means of the balloon beyond which we
cannot pass. The limit appears to be about
22,000 feet; that, at least, is the highest point
yet attained in aerial navigation.

Now, it is a remarkable fact that one of the
consequences of this expansion is a diminution
of temperature. It has been found by experi-
ment that this is due to the fact of expanded
air having a greater capacity for heat than com-
pressed air. It seems, — although it must be
carefully remembered the subject is still very
obscure, — it seems as if expanded air contained
more room for heat than compressed air : for it
is found that we may, as it were, squeeze out
heat from air by a well-fitting syringe, by
forcing it violently down ; and a peculiar syringe
is constructed, with a piece of German tinder
at the bottom, which, when forcibly worked
once or twice, produces so much heat by com-
pressing the air, as to set fire to the tinder!

190 THE CHEMISTRY OF CREATION.

On the contrary, if we cause air to expand, as
in the air-pump, we can produce a great degree
of cold, because the expanded air absorbs heat
into itself from all surrounding bodies. By the

little contrivance
represented in the
cut we may readily
manufacture a small
quantity of ice. A
little water must be put into a watch-glass,
supported by a triangle of wire, over a saucer
of strong sulphuric acid, or oil of vitriol, placed
over the plate of an air-pump, and covered
by a flattened receiver; the pump, being then
worked, the water will in a few minutes be
converted into a solid mass of ice! Sir John
Leslie actually formed an apparatus for making
ice artificially on a large scale by the adaptation
of this principle ; and large ice-making machines
have been sent out to India with this view.
The facility with which we can now procure the
beautiful lake-ice of America, renders these
contrivances no longer interesting except as
curiosities. *

It is partly in consequence of this increased

* Recently a machine has been patented in America for
making ice by the expansion of previously compressed air.
It is a kind of steam-engine, and at every stroke produces a
shower 'of snow ! The idea is, however, not altogether new.

LINE OF PERPETUAL SNOW. 191

capacity for heat that the upper regions of the
atmosphere are so intensely cold. Part of the
effect is likewise due to the loss by radiation into
space. This loss of temperature as we ascend
must be familiar to every visitor of mountain
scenery. Frequently it is picturesquely painted
by the snowy cap which envelops the summits
of the loftiest mountains ; and where the moun-
tains are of the most elevated description, at
a certain height there is a distinct line, visible
from afar, and forming a very peculiar feature
of landscape, which is well known as " the
line of perpetual snow." It is, in fact, in most
cases, an almost straight line between the fringe
of hardy and scanty vegetation, and a snowy
covering which clothes the mountains from its
summit to that point. This appearance suf-
ficiently indicates, by a sort of natural ther-
mometer, the temperature of the air at such
elevations. The line varies in height in dif-
ferent countries; and although highest in hot-
test countries, as at the equator, as a general
rule, and becoming lower as we approach the
poles, when it enters the earth, this law is by no
means without its exceptions, some of which are
of a very singular character.

Of these exceptions, one of the most remark-
able that have recently presented themselves is
the account given by a missionary of a supposed

192 THE CHEMISTRY OF CREATION.

snow-covered mountain in Eastern Africa. This
discovery is mentioned in the following extract
from his journal:* — "The mountains of Jagga
gradually rose more distinctly to our sight. At
about ten o'clock I observed something remark-
ably white on the top of a high mountain, and
first supposed that it was a very white cloud, in
which supposition my guide also confirmed me ;
but having gone a few paces further, I could no
longer rest satisfied with that explanation ; and
while I was asking my guide a second time
whether that white thing was indeed a cloud, and
scarcely listening to his answer that yonder was
not a cloud, but what that white cloud was he
did not know, but supposed it was coldness, the

* The cut exhibits the variations with great accuracy. In
its composition, the great and admirable work, Johnson's
Physical Atlas, has been followed.

BBFEBKNCE TO CfT OPPOSITE.

1. Erebus. | 20. Etna.

2. Sarmiento, Tierra del Fuego. 21. Pyrenees.

3. Nose Peak, Tierra del Fuego.

22. Ben Nevis.

4. Mount Stokes, Patagonia. | 23. Mageroe.

5. Yanteles, Andes of Chile. •• 24. Sulitelma, interior of Norway.

6. Osorno, Andes of Chile. 25. Osterjokul.

7. Egmont, New Zealand. 26. Interior of Norway.
• 8. Vol de Peuquenes, Chile. 27. Northern Ural.

9. Gualatieri, Western Cordillera, j 28. Kamtschatka.

10. No. de Sorata. i 29. Oonalashka.

11. E. Cordillera. 30. Altai.

12. Chimborazo, Quito. | 31. Mont Blanc.

13. Cotopaxi. 32. Elbrouz, Caucasus.
14 Purace. j 33. Kasbek, Caucasus.
15. Tolima. ; 34. Ararat.

16. Sierra Nevada de Marida.

35. Bolor.

17. Abba Jaret, Abyssinia. j 3$. Hindoo Koosh.

18. Popocatepetl. j 37. Dhawalagiri, Himalaya.

19. Sierra Nevada.

0.

194 THE CHEMISTRY OF CREATION.

most delightful "recognition took place in my
mind of an old European guest called mow.
All the strange stories we had so often heard
about the gold and silver mountain Kilima dja
aro, in Jagga, supposed to be inaccessible on
account of evil spirits, which had killed a great
many of those who had attempted to ascend it,
were now 'at once rendered intelligible to me,
as, of course, the extreme cold, to which the
poor natives are perfect strangers, would soon
chill and kill the half-naked visitors."

Further on this gentleman, Mr. Rebmann,
writes, — " May 12, at about five o'clock, P.M.,
we had to ford another river, called Gona, which
was considerably larger than the Loomi, its
breadth being from thirty to forty feet, and its
depth three feet, with a most rapid stream.
Its water was cold enough to prove its source,
which evidently is nothing else than the eternal
snow of the Kilima dja aro." Mr. Rebmann
adds to these remarks some particulars respect-
ing a large exploring party sent by the late
king of the country to " examine into the
nature of that strange white guest in the neigh-
bouring mountain, when only one man was
spared, though with his hands and feet destroyed
by excessive cold, to tell his despotic sovereign
the sad tidings of all his companions having
perished in the expedition."

BLUENESS OF THE AIR. 195

Although loosely stated, the account of this
mountain is considered by many to be accurate,
and if so, it undoubtedly forms one of the most
remarkable exceptions to the general rule, with
regard to the temperature of high air in the
tropics. It is but right to add, that it has been
much disputed whether the white cloud on the
mountain really was snow. The white and
glistening appearance has been supposed to
have been caused by something else, because by
ordinary calculations a mountain in East Africa
to be covered with perpetual snow must approach
16,000 feet in height; and it is by no means
clear that Kilima dja aro approaches this degree
of altitude. The mean height of the line of
perpetual snow is at the equator 15,200 feet*

We say that the air is transparent,! and
without colour ; why then, it may be asked, as
we gaze upwards, do our eyea rest in every
direction upon a vault of so intense and beau-

* Since the above was written, intelligence of a more de-
finite character as to the nature of this mountain has reached
England. It now appears to be without a doubt that its
summit is capped with perpetual snow.

t Mr. Darwin says that while ascending the Bell mountain
in Central Chile " the evening was fine, and the atmosphere
so clear that the masts of the vessels at anchor in the bay of
Valparaiso, although no less than twenty-six geographical
miles distant, could be distinguished clearly as little black
streaks."

196 THE CHEMISTRY OF CREATION.

tiful a blue? The truth is, the air is not per-
fectly transparent when seen in bulk ; and the
cause of the blue colour is the reflection of the
rays of light from its particles, and from
those of the watery vapour it contains. As we
ascend, the colour deepens in intensity, in con-
sequence of the dark space beyond our atmo-
sphere being seen through it more distinctly, and
at the great elevations which have been attained
by means of the balloon it almost approaches a
black. On the summit of high mountains it is
often seen to be of an intense Prussian blue.
M. de Saussure made some singular observations
upon this subject, and formed a scale of the
shades of colour as we ascend. In Coleridge's
sublime lines, entitled the Alpine Hymn, this fact
is alluded to in speaking of the " Sovran Blanc."

" Around thee and above

Deep is the air, and dark, substantial black,
An ebon mass. Metliinks thou piercest it
As with a wedge."

Sometimes, apparently in consequence of the
presence of a large quantity of water in the
air, the blueness becomes very remarkable. The
following letter describes a most curious ex-
ample of the occurrence of this phenomenon at
Bermuda:— "On the 10th of August, 1831,
the weather," observes the writer, " was remark-
ably fair ; but as evening drew near, a change

BLUE AIR. 197

took place. The sky began to lower, and put
on an awful and gloomy appearance. The
clouds collected voluminously, and very heavily,
in every direction over the island, indicating a
prodigious fall of rain. At this time I do not
recollect any threatening of a storm of wind,
save a moderately-hollow sound of the sea
dashing against the shore, but by no means
equalling that which we frequently witness at
this season of the year, when a storm is im-
pending, or has passed by us. Thunder and
lightning began to be severe, and the weather
more threatening. Next morning, the llth,
I rose early for the purpose of writing, and
soon discovered the light was so dim that
I could not proceed. I removed to another
room, and finding my situation not improved,
I said in the presence of one of my family,
I apprehended a sudden failure of sight. I
was then asked if I had not observed a very
peculiar appearance of the sun's rays the day
before. I had not ; but had perceived the floor
of the room to look blue, especially where the
sun shone on it : indeed, every object in the
room appeared of a sickly blue colour. The
next day, the 12th, a mail-boat was put under
weigh, for the first time, with a party on board.
The day was so mild and tranquil, we could
only reach a few miles : the sails, which were

198 THE CHEMISTRY OF CREATION.

new and pure white, nevertheless appeared to
be stained of a bluish colour, and the sea was
of a dingy yellow. On the first arrival from
the West Indies, we heard of the devastation
at Barbados; but with us there were no sub-
sequent unusual appearances ; on the contrary,
we had very fair weather, although 1 heard this
singular blue colour was observed even to the
coast." This letter was read by Sir D. Brewster,
at the tenth meeting of the British Association ;
and in alluding to the cause of the phenomena,
he expressed the conviction that the blue colour
was produced by the interposition of water, in
the form of vapour, between the sun and the
observer.

It has been ascertained by M. Arago, that
the light thus reflected from the sky is in the
peculiar condition known by chemists as polar-
ised, exhibiting different effects from that of
the direct rays of the sun. Upon one of the
peculiar phenomena exhibited by the polarised
light of the sky as the sun changes its position
during the day, Professor Wheatstone has con-
structed what he calls the Polar clock or dial.
It is impossible in this place to enter into an
explanation of the principles upon which this
beautiful invention depends, as it would be
unintelligible without a full discussion of the
difficult subject of polarisation of light; but it

THE POLAR CLOCK. 199

may be stated, that by its means the time may
be most accurately ascertained, simply by di-
recting the instrument to the North Pole of the
sky. It is found that it will indicate the time
even before sunrise and after sunset ; in fact, as
long as the rays of sunlight are reflected from
the atmosphere.

The beautiful and gorgeous colouring of
clouds depends upon the decomposing effect of
their watery particles upon the rays of the sun.
In tropical countries there is a ' peculiarly beau-
tiful appearance in the atmosphere which we
do not meet with in temperate zones. Baron
Humboldt frequently alludes to it as a sort of
thin haze or vapour, which, without changing
the transparency of the air, renders its tints
more harmonious, and softens its effects. This
appearance was also noticed by Mr. Darwin.
" The atmosphere," he says, speaking of Bahia
in Brazil, " seen through a short space of half
or three quarters of a mile, was perfectly lucid,
but at a greater distance all colours were blended
into a most beautiful haze, of a pale French
grey mixed with a little blue. The condition
of the atmosphere between the morning and
about noon, when the effect was most evident,
had undergone little change, excepting in dry-
ness."

The atmosphere contains a large amount of

200 THE CHEMISTRY OF CREATION.

electricity, which acts in various- ways an
important part toward both organic life and
inorganic matter. The whole vegetable and
animal world are largely influenced by this
electricity, and it is doubtless intimately con-
nected with their life and well-being. It is
also greatly concerned in the formation of
clouds, rain, and similar phenomena. When
developed in intensity, as in the explosions
accompanying tempests, it effects various che-
mical decompositions in matters present in
the air. It has been considered that ammonia
may sometimes be produced by its influence.
It also occasionally produces small • portions of
nitric acid. A peculiar ingredient, called
Ozone, is constantly produced by it. Its ser-
vices are very variable. Friction of currents of
air against each other, evaporation and chemi-
cal decompositions taking place on the earth's
surface, all produce it. It is generally, when
the air is clear, of the positive kind. This varies,
however, with the variations in its sources. The
earth, on the contrary, is always charged with
negative electricity.

With these remarks on the physical constitu-
tion of the atmosphere and its connected pheno-
mena, we may pass on to what is more peculiarly
our province, and speak next of the Chemistry of
the Air.

CHAPTEE II.

CHEMICAL CONSTITUTION OF THE AIR.

DIFFICULTIES which appeared quite insur-
mountable had long beset the investigations of
chemists upon the composition of the air. Long
after the revival of experimental chemistry the
most erroneous impressions were afloat; and
chemists, in their discordant analyses, only in-
creased the confusion by the vast discrepancies
which occurred between the results of one
analyst and those of another. Until the middle
of the eighteenth century, the opinion was very
prevalent that the atmosphere formed one of
the four elementary bodies, — that it was, in fact,
a simple, undecomposable gas. It was reserved
for the talented Dr. Priestley to dispel this
error. He discovered the existence of a new
gas which formed one of the constituents of air.
In this gas it was found that combustion took
place with extraordinary intensity ; even iron-
wire, heated red-hot and plunged into it, caught
fire, and burnt away ! Other combustibles gave
out showers of the most brilliant sparks, and
produced the most intense heat, when placed in

202 THE CHEMISTRY OF CREATION'.

the jar containing it : a lighted taper having been
blown out, instantly rekindled when put into it,
and blazed with much greater brilliancy than in
air. These extraordinary characters soon gave
the gas great celebrity.

Soon afterwards another gas was found also
to form a part of the composition of air. This
gas was the direct contrast of the other. Instead
of increasing the brilliancy of flame, it extin-
guished it as effectually as so much -water.*
Like the other, it was inodorous and invisible ;

* A very interesting application of this property of nitrogen
gas, mixed with carbonic acid gas, has been recently made by
Mr. Gurney. By some accident, a large and valuable coal
mine took fire. After vain attempts to quench the devouring
element, the galleries were reluctantly abandoned, and the
miners withdrew with their instruments. There seemed no
way of quenching the immense body of fire raging under-
ground, but by the enormously expensive one of turning a
stream of water into the mine, so as to fill it ! When the
idea was suggested that it might be extinguished just as
effectually by means of gas as of water, arrangements were
then made for conducting the air of a furnace — which consists
largely of nitrogen and carbonic acid — after cooling it by
passing it through water, down to the workings ; and a
steam-jet placed over the mouth of the pit, was caused to act
so as to produce a powerful draught. By this means a stream
of nitrogen, carbonic acid, and other gases was drawn from
an apparatus specially contrived for this purpose, passed
down the descending shaft, poured itself upon the body of
fire, and being sucked upwards by the steam-jet, returned
again up the ascending shaft. In a few hours the fire was
wholly quenched! and after a certain time pure air was

THE FIRE-AXNIHILATOR. 203

but while the first exhibited the utmost avidity
for combination, this was resolutely indifferent
to every substance. Animals were intoxicated
when immersed in the first ; they were suf-
focated on immersion into this. Such were the
opposing qualities which at the time of their dis-
covery were found to exist in the important gases,
oxygen and nitrogen.

The celebrated chemists, Scheele and Lavoi-
sier, both arrived, and each independently of
the other, and of Dr. Priestley, at the same
conclusions, and stated the composition of the
atmosphere in terms, which, considering the
great imperfection of their method of analysis,
were wonderfully near the truth. Thus the bare
fact was shaped out — air is not a simple or
elementary fluid ; its constituents are oxygen
and nitrogen ; and these are mixed together in a
certain proportion.

blown through the mine ; the next day it was inspected, all
was found safe, and the workings were resumed. From this
may be learnt the value of even a moderate knowledge of
chemistry. Mr. Phillips's " Fire Annihilator," which ia a
machine for pouring out a stream of gas upon a fire, and put-
ting it out by excluding the combustibles from the access of
the oxygon of the air, acts upon similar principles to this plan
of Mr. Gurney's ; but the gases evolved are different, consist-
ing of the products of the combustion inside the apparatus
of sulphuric acid, chlorate of potash, and sugar, together with
some portion of steam.

204 THE CHEMISTRY OF CREATION.

It will be readily conjectured that the ulti-
mate process of obtaining an accurate statement
of the composition of air, that is to say, one
of sufficient accuracy to satisfy the chemical
philosopher, was yet to be long deferred. The
investigation was one of unusual difficulty. The
methods of analysis were to the last degree
rude and imperfect, and the consequence was
that the results were invariably discrepant, and
more or less distant from the truth. The prin-
ciple upon which they were conducted was in
every instance the same, — the methods were
very dissimilar. The chemical energy of the
gas oxygen has already been mentioned, and
offers a striking contrast to the inertness
of nitrogen. This was taken advantage of by
chemists. It was easy to select substances
which seized upon oxygen with avidity, while
the nitrogen was left wholly uninfluenced by
their presence. These substances were of many
kinds. To enumerate a few — we find employed,
sulphuret of potassium, phosphorus, lead turn-
ings moistened, spongy platinum, and the gas
hydrogen. When the first three of these sub-
stances are exposed to air, they immediately begin
to oxidate, that is, to absorb its oxygen, leaving
all the nitrogen behind. The experiments with
spongy platinum and hydrogen were differently
conducted to those with the former substances.

RUDE ANALYSIS OF AIR.

205

That a definite idea may be formed of this
singular process, by which we learn this im-
portant part of the chemical constitution of
the air, the method of conducting the expe-
riment with the substance Phosphorus, may
be shortly stated. A portion of air should be
confined in a glass tube, over
distilled water, in which a small
piece of phosphorus, fixed to the
end of a wire, should be placed.
The tube should be graduated into
a number of divisions, by which
the height of the contained water
may be ascertained. After the
lapse of some hours, the water in-
side the vessel will be found at a
higher mark than before. This
indicates that a certain amount of
air, equal to the amount of increase in the
height of the water, has been abstracted. After
a time, the water ceases to rise, and then the
process is complete. On removing the jar and
putting a lighted taper into the remaining air,
it will be found to go out directly, and a small
animal would be suffocated by it. These are
not the characteristic effects of oxygen ; the
residue is therefore nitrogen, the oxygen having
entirely disappeared. The calculation is now
easy, — the water indicates the amount of oxygen

EUDIOMETER.

206 THE CHEMISTRY OF CREATION.

removed, and nearly all the rest is nitrogen.
Such was the simple analysis which was long
considered best for the determination of this
point. This process was called Eudiometry,
which signifies the measuring of the beneficial
principle (oxygen) of the air.

But in this plan the solvent power of water
for oxygen, the uncertainty whether the whole
of this gas had been completely removed, with
several other causes of error, interfered with the
result ; and we may, in the recollection of these
errors, satisfactorily point to the real source of
those analytical inaccuracies which had long
perplexed chemical science.

To place this subject on a sounder basis was
felt to be a national subject by Messrs. Dumas
and Boussingault, two of the most eminent
chemists of the French school. They resolved
to attempt to remove the stigma from chemistry,
and to determine finally the true chemical con-
stitution of the atmosphere. Impressed with this
idea, they conceived a method of analysis of per-
haps unparalleled ingenuity and accuracy, in the
employment of which every conceivable source of
error appears to have been guarded against. The
following account of it is derived from their own
published memoir, in a recent volume of the
Annales de CTiimie et de Physique.

The air selected for analysis was collected in

ADMIRABLE CHEMICAL INVESTIGATION. 207

several large glass flasks, which were first en-
tirely exhausted of air by means of a very
powerful and perfect air-pump, the vacuum
being properly tested before the vessels were
used. On arriving at the proper locality, the
mouths of these vessels were opened, the air
immediately rushed in and filled them ; they
were then closed and conveyed to the labora-
tory, and the analysis of the air was commenced.
One of these flasks was connected with the tube
of the analysing apparatus ; and at the opposite
end of the apparatus was attached a similar
flask, only perfectly vacuous. By this means
it was intended that the air of the first flask
should be drawn through the apparatus, into
the second. The flasks and whole apparatus
were now carefully weighed. The stopcock of
the vacuous flask, and that of the one filled with
air, were then opened, thus causing the air from
the one to pass on to the other, through several
liquids, in which its watery vapour and other
impurities were arrested, and finally over metallic
copper, finely powdered, and heated to redness,
a substance which has the remarkable property
of instantly arresting and absorbing every par-
ticle of oxygen from the air as it is passing
over it. Thus at length nitrogen only re-
mained, and passed on into the flask. After
the process was completed the apparatus was

208 THE CHEMISTRY OF CREATION.

again weighed. By this means the amount of
oxygen in the whole quantity of air that had
passed through was accurately ascertained, as
by uniting with the copper it gave additional
weight to the apparatus, consequently all that
was necessary to ascertain the precise quantity
of oxygen in the flask of air was to find out
how much the copper had increased in weight ;
all the grains of increase represented grains of
oxygen.

The result of a large number of experiments,
although occasionally some striking variations
were noticed,* gave an average which exhibits
the composition of ths air in the following pro-
portions :

One hundred parts of air consist of, by weight —
Oxygen ..... 231-lOth
Nitrogen ....'. 76'9-lOths

100-

This question was therefore at length satis-
factorily decided. But it had often been much
disputed by philosophers whether air was uni-
versally of a similar composition. Is it the
same in the loftiest regions as it is on the level
ground, on Mount Blanc, or Chimborazo, as on
the sea-shore? The late Dr. Dalton held the

* According to analyses made by M. Lewy, it appears pro-
bable that the quantity of oxygen varies slightly in different
seasons of the year, lover sea and over land.

ANALYSIS OF AIR TAKEN BY A BALLOON. 209

contrary opinion. He believed that the oxygen
and nitrogen of the air were always in the pro-
portions just stated in the lower regions; but
that as we ascended higher and higher, in con-
sequence of the superior heaviness or density
of oxygen over nitrogen, the proportion of it
became smaller; the oxygen being supposed to
gravitate more towards the earth than its com-
panion nitrogen. The analysis of air from these
regions would therefore indicate, if this sup-
position be correct, the presence of less oxygen
and more nitrogen, in a certain amount of air.
This subject is one of great interest. Some
curious and inexplicable phenomena connected
with the variable quantities of these gases,
appear to countenance it. Dr. Dalton also con-
ceived that he had actually proved the fact, by
analysing a portion of air from the summit of
Snowdon, which certainly contained less oxygen
than a similar quantity taken from the neigh-
bourhood of Manchester.

But when all the facts are inquired into, it
seems almost certain that such is not the
case. Gay Lussac, by means of the balloon,
brought down air in a vessel from the height of
between three and four miles. On being analysed
it was found to be in no respect different from
the air of the lower strata of the atmosphere.
A distinguished French chemist also spent a

210 THE CHEMISTRY OF CREATION.

considerable time on the high Alps, in analysing
the air of those altitudes ; but he found that
air taken from the summit of Faulhorn was of
the precise composition of air at Paris. The
air contained in particles of snow was also ex-
amined, being expected to furnish a fair sample
of the qualities of air in those lofty regions of
the atmosphere where snow is formed. In all
these cases the results were similar, and it ap-
pears therefore to be fairly established that the
composition of the atmosphere, so far as regards
elevation, is perfectly uniform.

Chemistry perhaps surprises us in few things
so much as in revealing to us the fact that the
composition of the atmosphere, as regards these
ingredients, is also invariable as respects locality.
Experiments have been conducted upon the
chemical constitution of the air of Egypt, of
the deadly breezes on the coast of Africa, of
England, France, the lofty Alps, of Santa Fe
de Bogota, of North America, and a number
of other localities, and it has been hitherto im-
possible to detect the smallest difference in its
composition. What is even more remarkable, —
the very air which was spreading the most .fatal
pestilence, the air of a great and crowded city,
and the air of a thronged hospital- ward, were
identical in their composition, so far as their
proportions of oxygen and nitrogen went. Che-

AIR NOT A CHEMICAL COMPOUND. 211

mical analysis cannot as yet render appreciable
the smallest essential difference between the hot
and dusty air of town, and the balmy breath-
ings of a country wind laden with the odour of
a thousand flowers. We shall have, on another
occasion, to show that a real difference does
always exist.

Is air, then, a chemical compound, that its
constancy of composition is so remarkable?
Few in the present day appear disposed to con-
sider the constitution of the atmosphere in this
light. In fact, the admirable analyses of Dumas
and Boussingault have presented positive evi-
dence to the contrary, of the most incontro-
vertible character. But it is still sufficiently sin-
gular that the composition of the air is apparently
as constant and unvarying as if it were fixed by
the unchanging laws of chemical combination.
Air is therefore simply a mixture of gases, not
held together by the force of chemical union.

The purely physical constitution of the air
was not ordained without a satisfactory object in
view. Whether we are sufficiently acquainted
with this subject to pronounce positively the
purposes for which it was thus ordained, may
be matter of question; but it is unquestionable
that a wise end was attained in its creation and
constitution upon simple physical principles,
and not upon the more complicated principles

212 THE CHEMISTRY OF CREATION.

of chemical combination. It might be thought
it was thus formed, possibly with a view to
facilitate the innumerable decompositions into
which the gases of the air so largely enter.
When we remember with what extreme dif-
ficulty a true chemical compound of oxygen
and nitrogen gases is • decomposed, the dissolu-
tion of union only taking place under the force
of violent chemical reactions, we believe there
is sufficient cause for admiration that the wisdom
of the Creator has otherwise ordered the com-
position of the air, in having formed it a mere
mechanical mixture of these gases.

If we should stop for a moment to consider
the enormous loss of oxygen which the atmo-
sphere incessantly endures, thousands of tons of
this gas being withdrawn from it year by year,
and yet that by all attainable evidence* we are
assured that the composition of the air has not
altered from age to age, the reflection comes
upon the mind with overwhelming force, How
is this loss repaired? What can be that ex-
haustless spring which pours back the exact
equivalent of these abstracted quantities into
our beautiful air? Had not some means of its
restoration been preordained, there can be no

* The air contained in a jar, buried in the destruction of
Pompeii, when analysed, showed no chemical difference from
air analysed at the same time on the surface of the earth.

SOURCES OF OXYGEN. 213

question that a most serious deficiency of this
gas would have been sensible at this period of
the earth's history. The Chemistry of Creation,
however, informs us that a never-failing spring
of oxygen exists, and its copious streams, by a
nice adjustment, replace by far the greater part
of the loss. In this green grass, in the leaves
of these unpretending herbs, and in those of
the clustering wood, we shall hereafter find are
hid those springs of this precious ingredient of
our air, without which desolation and death
might at no distant time gradually overwhelm
our globe.

From the preceding remarks, it must not be
supposed that the atmosphere is purely a mix-
ture of two gases. Such we may indeed truly
consider as the composition of air, but by no
means that of our atmosphere. Oxygen and
hydrogen in chemical union form water, but
pure water would ill satisfy the wants of the
countless inhabitants of the ocean. So, while
we may justly regard oxygen and nitrogen
in the given proportions as air, the atmosphere
would be totally unfitted to fulfil its present
functions, were there no other gaseous ingre-
dients present in it. Indeed, the salts and
dissolved gases of the great deep do not stand
in anything like the same relation of importance
to the tribes which people it, as does the admix-

214 THE CHEMISTRY OF CREATION.

ture of foreign gases in the air to both man
and vegetation. Possibly, had the atmosphere
been created for man alone, and could he have
existed on a different description of food to the
present, it might have been unnecessary to have
cast any other ingredients into its composition.
But the earth was to be adorned with plants,
and these were destined to supply man with a
pure, agreeable, and nutritious food. Vegetation
cannot exist in a pure atmosphere of oxygen
and nitrogen for any length of time, much less
thrive, blossom, and produce fruit. A provision,
therefore, was necessary for its wants. Yet
here another difficulty presents itself. The gas
which proves most nutritious to vegetation is
one which is deadly in its effects on the animal
tribes ! This gas is Carbonic Acid. The room
capable of containing one hundred cubic feet of
air, if filled by a mixture of ninety cubic feet of
air and only ten of this gas, would be speedily
fatal to any human occupant. How was this
difficulty to be surmounted? How was vege-
tation to live, and man not to die? By the
most beautiful adjustment this problem has
been solved, for it is found that a proportion of
carbonic acid gas, which appears disproportion-
ably small, and is in reality so minute as to be
altogether without effect upon the human con-
stitution, yet at the same time sufficiently great

CARBONIC ACID I3ST AIR.

215

to meet and satisfy all the requirements of the
most profuse vegetation, has been widely mixed
with the other gaseous constituents of the atmo-
sphere. The quantity of carbonic acid present
in the atmosphere is variable. Represented by
figures, it may be thus stated: —

In 10,000 volumes of air :
The maximum of carbonic acid is 6 volumes.
The minimum a little more than 3 volumes.

Other observers place it a little higher, and con-
sider it present in the proportion of one to one
thousand volumes, or about one-tenth per cent.

Carbonic acid, however, is a remarkably
heavy gas : so heavy, that it may actually be
poured like water
out of one vessel
into another, as
may easily be prov-
ed by filling a jar
with this gas, pro-
cured by action on
a little chalk with
hydrochloric acid
and water, and
holding it in the
position represented
over the mouth of another jar containing a
lighted taper, which will be immediately extin-
guished. If at the temperature of 60°, and

216 THE CHEMISTRY OF CREATION.

barometric pressure 30 inches, one hundred
cubic inches of air weigh 30 grains, under
similar circumstances one hundred cubic inches
of carbonic acid will weigh more than 47 grains.
Its tendency, therefore, is to collect and accu-
mulate near the surface of the ground. This
may be seen by any one who will pay a visit to
a large brewery. Standing by the side of one of
the large fermenting vats, and in such a position
that it may be seen against the light, he will
perceive trembling transparent floods of this
gas pouring over the top and down the sides of
the vessel. The same appearance is also fre-
quently visible in a glass of soda-water, which
is charged with carbonic acid. This gas, as has
before been noticed, is poured into the air in
enormous quantities. Why does it not obey the
laws of gravity, and remain near the ground?
What is there to hinder its falling down and
overwhelming the human race and the whole
animal world with its deadly floods ? The
answer is, the power of diffusion. What, then,
is the "power of diffusion?" This question
must be answered by an experiment.

If a glass jar or bottle were filled with car-
bonic acid, and the mouth stopped by a plug
of plaster of Paris, and left, in a little time the
vessel would be found only to contain com-
mon air. The heavy carbonic acid would have

REMARKABLE FORCE OF DIFFUSION.

217

entirely disappeared. As there is but one way
of escape through the neck, and even this pas-
sage is, apparently, very accurately closed, it is
evident, whatever the power, it was sufficient to
enable this naturally heavy gas to rise up and
leave the vessel, and the natu-
rally lighter air has descended
and filled it. A pleasing way
of performing this experiment
is to fill one jar with the light-
est of all known gases, hydro-
gen, and another with the heavy
carbonic acid gas, and to con-
nect them by two perforated
corks and an intervening tube,
as represented, and then to
place them in the position
shown, that containing the hydrogen being
uppermost. In a little while the heavy carbonic
acid gas will rise to the top of the upper jar,
and the light hydrogen will descend, and sink
into the lowest jar, until the two jars contain
a uniform mixture of both gases. The force
which produces this remarkable phenomenon is
the diffusive power of gases, the beautiful laws
of which were discovered and developed by the
eminent chemist, Professor T. Graham. By
virtue of this remarkable force, the heaviest
gases rise up into the air, though less rapidly

218 THE CHEMISTRY OF CREATION.

than the lighter, and, more singular still, actually
with as much force as if they were rushing up
into a vacuum ! Thus they have power to rise
to the very highest regions of our atmosphere,
and to spread to its remotest limits.

It would be difficult to select a more striking
illustration of the wisdom and design displayed
in assigning laws to the atmosphere, and to
gaseous fluids in general, than is thus presented
to us. The uniformity of the atmosphere is
mainly due to the incessant influence of this
dispersive force. Diffusion is, as it were, the
messenger between man and vegetation, for it
conveys to the one the carbonic acid produced,
and brings back to the other the oxygen
restored. By this means, also, is gradually
effected the dispersion of all gases, no matter
whether dense or rare. While the heaviest
vapours are thus made to rise and spread far
and wide, the lighter ones are also caused to
descend and intermix with air far more dense
than themselves. These are facts which expe-
riment has amply proved.

De Saussure found the heavy gas of which
we have spoken (carbonic acid) present in the
thin air of the Alpine summits, and even in
greater abundance than in the air of the low-
lands far beneath — an effect due, without doubt,
to the influence of vegetation ; thus clearly

INFLUENCE OF THIS FORCE. 219

proving that the mere circumstance of elevation
is no obstacle to the force which impels the gas
upwards.

The same diffusive force scatters gases abroad
laterally as well as in the perpendicular direc-
tion. A French chemist, M. F. Leblanc, insti-
tuted a series of experiments upon the amount
of carbonic acid present in confined air, and his
results show, in the most complete manner, that
by these ever-active agencies the air of our
chambers is renewed and preserved from an
excess of carbonic acid, and our habitations,
with all their comforts and warmth, are made,
as far as regards their amount of carbonic acid,
to enjoy a degree of purity of air not so very
far inferior to the open spaces in which they
may be placed, as might have been anticipated.

We owe to diffusion more than this. The
balmy air which every now and then comes to
us, odorous with the simple perfume of the violet
or hedge-row, or with the peculiar fragrance of
the new-mown hay, would be deprived of all its
scented properties, and would be felt without
pleasure and inhaled without delight, were it not
for the power of diffusion. As, while we stand
thus discoursing on nature's chemistry, we drink
in the pure fragrance of such flowers as lie
scattered around, and perceive such freshness
and delightful property in the air, let us remem-

220 THE CHEMISTRY OF CREATION1.

her that, did not diffusive force lend wings to
the fragrant vapours poured out from the flowers,
none of these pleasures would be experienced.
We see, then, in this force a most powerful agent
of intimate, although imperceptible, intermixture
of the various gaseous and vaporous ingredients
of the atmosphere, whether regular or accidental.
Accurate investigations have made us ac-
quainted with a less expected gaseous ingre-
dient in the atmosphere than the last, — light
carburetted hydrogen, or, as it is often im-
properly called, " coal gas." The amount of
this gas is not so considerable as that of the
former, but it is said to be very generally pre-
sent, in variable quantities, in the atmosphere.
The part it fulfils in the economy of the atmo-
sphere is not well defined. It does not appear
to undergo any great degree of increase or of
diminution, and we are therefore disposed to
believe that chemical relations between it and
other bodies actually exist, since it can be
clearly shown that large quantities of this gas
are continually discharged into the air. In
short, it is conceivable, on the supposition that
those analyses which state its constant presence
in the air are correct, that some force exists, as
in the case of carbonic acid, to decompose the
gas, and put a check to any excess in its quan-
tity. It arises from various sources, among

AMMONIA IN THE AIR. 221

which are the natural gaseous springs before
alluded to. It is also a product of the decay of
vegetable tissues, and is largely thrown into the
air from the countless economical processes con-
nected with human operations.

Who that has looked with grateful surprise
on his fields a few days since parched and
brown, now re-clothed with raiment of freshest
green, the herbage springing up with that
vigour and luxuriance peculiar to the growth
of the tender blade, when the " clear shining of
the sun follows rain," would suppose that this
sudden verdure owed anything to Ammonia?
Still less would one be disposed to admit that
our pastures are deeply indebted to a gaseous
constituent of the air, so minute in its amount,
as we shall learn, as to have long eluded the
search of the most eminent chemists. Am-
monia had long been suspected to exist in the
air. Philosophers, aware of the numerous
sources from whence this volatile compound was
disengaged, felt persuaded of its presence in the
atmosphere, but -were unable to confirm their
suspicions. At length, Liebig conceived the
happy idea of trying whether it might not be
found in rain-water. Since ammonia is very
soluble in water, it seemed rational to suppose
that if it really existed in the air, it would be
found in the waters of a shower. A consider-

222 THE CHEMISTRY OF CREATION.

able quantity was collected and evaporated
down carefully. After this operation had been
long continued, at length brownish crystals
appeared in the fluid. The chemist's search
was about to Ixj crowned with success ; and
to his great gratification on analysing these
crystals, they proved to be the long-looked for
ammonia in the form of an ammoniacal salt.

Quite recently, by a series of accurate expe-
riments, M. Fresenius has determined that
1,000,000 parts of atmospheric air contain,
during the day, 0'098 parts of ammonia; a
quantity equivalent to 0'283 parts of carbonate
of ammonia. During the night, singular to
state, the proportion is greater ; for the same
amount of air contains then 0'169 parts of am-
monia, or the equivalent of 0*474 parts of the
carbonate. It is not easy to trace the cause of
this excess during the night. This discovery
of the positive existence of ammonia in the
air proves of high importance, as we shall
immediately perceive. Ammonia is a com-
pound substance, formed of, by volume, three
of hydrogen, and one of nitrogen gases. Kow
it was long known that nitrogen was abso-

o o

lutely necessary to plants in order to supply
them with material for the formation of several
vegetable products containing nitrogen, such as
albumen, gluten, and fruits and seeds gene-

NITROGEN IN FOOD. 223

rally. But it was exceedingly difficult to
ascertain its true source. There exists now
little doubt that its chief source, when not
supplied artificially, is in the ammonia of the
atmosphere. Minute, therefore, although the
quantity of this ingredient be in the air, it has
an importance which can scarcely be exag-
gerated, when we consider the uses it fulfils.
" The quantity of food required by animals,"
writes Liebig, " for their nourishment, increases
or diminishes in the same proportion as it con-
tains more or less nitrogen." In other words,
that kind of food, as a general rule, is the most
nutritious, which contains the greatest propor-
tion of nitrogen in its composition.* This
element consequently becomes most essential
to the existence of animals ; and it is sup-
plied to herbivorous and graminivorous animals
chiefly by plants, in the food they derive from
the vegetable kingdom. Plants, as we have
seen, obtain their nitrogen chiefly from the
minute quantity of ammonia contained in the
air; and hence it is manifest that the health and
vigour, and even the very existence of the
whole animal world, is most intimately con-

* Bread is well called the staff of life. The gluten it con-
tains is a nitrogenised compound. It is well known that upon
bread alone life can be supported for a very long period ; a
fact due, in great part, to the circumstance of its containing
this nitrogenous substance, together with earths and salts.

224 THE CHEMISTRY OF CREATION.

nected with, and even dependent upon, the
existence of a gaseous ingredient of the air, so
small in quantity as to have long escaped
the detection of the most accurate experi-
menters.

Man, it is true, is an omnivorous creature.
His food consists of both kinds, animal and
vegetable. Il^ may be said, all the nitrogen he
requires he can obtain in the greatest abund-
ance from the flesh he consumes as food ; and
no doubt the greater part of those tissues of the
human body abounding in nitrogen, such as
muscle, &c., are nourished from this source.
But the difficulty is only put a step back by
this consideration ; for we must then inquire
from whence do these animals used as food, and
themselves feeding exclusively upon plants, ob-
tain their nitrogen? This discovery furnishes
us with a sufficient answer, — it is from the
vegetable kingdom ; and plants derive it chiefly
from the ammonia of the atmosphere. It is
thus by an interesting and beautiful series of
links that this important process — the supply of
nitrogen — is carried on. Ammonia, a minute
component of the atmosphere, containing the
essential element for the animal kingdom, is
essential to vegetation ; a vegetable diet is essen-
tial to the animals we use for food ; and a mixed
diet is, without doubt, essential to the healthy

SOURCE OF NITROGEN TO MAX. 225

existence of a man. Thus it is literally true,
that a large portion of our muscles and flesh
was once present in the air as a gas !* Such,
then, is the importance of an atmospheric in-
gredient, the whole amount of which, in up-
wards of eleven thousand cubic feet of air, has
been estimated to be about one grain !

The ordinary sources of ammonia in the atmo-
sphere are readily recognisable. It was a curious
fact, incidentally noticed in the experiments
which detected ammonia in rain-water, that the
ammonia thus procured always possessed the
" offensive smell of perspiration and animal ex-
crement;" and this plainly indicates one of the
most abundant sources of this valuable atmo-
spheric constituent. Whenever organic bodies
containing nitrogen undergo putrefaction, am-
monia is abundantly evolved. As the last pro-
duct of this process, it streams up from large
cities where heaps of decomposing animal mat-
ter pollute the pure air of heaven. It has also
been stated to escape from volcanos in the form
of a sulphate. A grotto exists near Naples in
which ammoniacal gas is discharged in large
quantities, apparently from some volcanic strata.
Combustion, and many economical and manu-

* The remarkable results of M. Regnault show that in some
cases animals appropriate the nitrogen of the air and increase
in weight simply by the process of respiration. — Vide p. 340.

Q

226 THE CHEMISTRY OF CREATION.

facturing processes, are also abundant sources of
this ingredient. In London it is said to be often
seen in the form of an ammoniacal salt, in little
star-like spots upon dirty windows, which serves
to show that it exists in greater measure in the
air of populous cities than elsewhere.

The principal means by which atmospheric
ammonia is rendered available .for the purposes
of vegetation, is by its being dissolved in rain-
water. It is curious, however, to notice that
some manures, which the agriculturist's expe-
rience has taught him the value of without
revealing its cause, owe some part of their
efficacy to the peculiar property* they possess
of absorbing ammonia from the air. Gypsum,
or sulphate of lime, is a valuable manure, yet it
is very insoluble in water; therefore, merely as
sulphate of lime, it is not possible that it can
directly contribute, to any large amount, to the
fertility of our fields. Burnt clay, and pure
vegetable mould, are also considered to be of
little value as direct fertilizers. It is therefore
thought by many chemists, that their principal
function is to withdraw ammonia from the air
and supply it to vegetables. This is effected in
a remarkable manner, which may be illustrated
by an experiment. If a piece of freshly-burnt
charcoal is put, after cooling, into a glass vessel
* Professor Liebig.

OPERATION OF MANURE. 227

full of the vapour of- ammonia, and standing over
mercury, it will be presently noticed that the
mercury rises up into the jar, and a considerable
quantity of ammonia has disappeared. The char-
coal has undergone no change, neither has the
mercury ; on what prin-
ciples, therefore, are we
to account for the disap-
pearance of the ammonia?
The explanation is to be
found in a very peculiar
property of gases, allot-
ted to them, it may be,
for this very purpose we
have been speaking of.
By virtue of this property, ammonia, like other
gases, is capable of becoming condensed on the
surface of bodies, or absorbed into their sub-
stance ; some possessing a greater aptitude than
others for • effecting this process. Charcoal,
burnt clay, gypsum, and vegetable mould, all
possess this property in a high degree. Dr.
Daubeny considers that the use of gypsum
arises in part from its property of fixing am-
monia, and in part from its being itself directly
serviceable to certain species of plants, by sup-
plying them with a salt which they require for
their development.

Thus endowed, these substances form appro-

228 THE CHEMISTRY OF CREATIOX.

priate manures. Minute though the quantity
of ammonia present in the air may be, by a
slow process of this kind, it is extracted,
and the first shower causes it to be brought
into solution in a form in which it is readily
appropriated by the roots of plants.* The
Chinese, those original and practised agri-
culturists, says Sir J. F. Davis, will often pull
down the plaster of their kitchens, deeming the
trouble, labour, and expense of replacing it,
amply repaid by the rich stock of manure ob-
tained in the old plaster. It has been supposed
that the old plaster contains ammonia, and that
we have in this proceeding the artificial appli-
cation of a pripciple which, in nature, is in con-
stant operation on a larger scale; but the
quantities of ammonia absorbed are smaller.
A recent writer in the Paris Horticultural
Review mentions the following curious par-
ticulars illustrative of the value of powdered
charcoal as a manure : — " About a year ago I
made a bargain for a rose-bush of magnificent
growth, and full of buds. I waited for them to
blow, and expected roses worthy of such a noble
plant, and of the praises bestowed upon it by

* In addition to the ammonia obtained br plants from the
air, it appears that, according to the researches of Professor
Mulder, a slow process of formation of this substance takes
place in the soil during the putrefaction of bodies not contain-
ing nitrogen in their composition ; the nitrogen appearing to
be derived from that of the atmosphere.

ANECDOTE OF A ROSE-TREE. 229

the vendor. At length when it bloomed, all
my hopes were blasted. The flowers were of
a faded colour. I therefore resolved to sacri-
fice it to some experiments which I had in
view. I then covered the earth in the pot in
which my rose-bush was, about half an inch
deep with pulverized charcoal ; some days after
I was astonished to see the roses which bloomed
of as fine a lively rose colour as I could wish !
When the rose-bush had done flowering I took
off the charcoal and put fresh earth about the
roots. You may conceive that I waited for
the next spring impatiently to see the result of
this experiment. When it bloomed the roses
were, as at first, pale and discoloured; but, by
applying the charcoal as before, the roses soon
resumed their rosy red colour. I tried the
powdered charcoal likewise, in large quantities,
upon my petunias, and found that both the
white and the violet flowers were equally sen-
sible to its action. It always gave great vigour
to the red or violet colours of flowers, and the
white petunias became veined with red or violet
tints ; the violets became covered with irregular
spots of a bluish or almost black tint. Many
persons who admired them thought that they
were new varieties from the seed. Yellow
flowers are insensible to the influence of char-
coal."

These singular and simple experiments de-

230 THE CHEMISTRY OF CREATION.

serve repetition. Since charcoal itself is quite
insoluble, its effects are, in all probability, due
to the ammonia it condenses from the air. It
must, however, be added, that it is highly de-
sirable that experiments of a satisfactory kind,
as to extent and character, should be made upon
this subject.

It will now be useful to sum up the normal
constituents of the atmosphere from • the pre-
ceding observations. The atmosphere consists
primarily of two gases, four-fifths being nitro-
gen, and one-fifth oxygen ; but, in addition,
and to adapt it for the purposes of vegetation
and ultimately for the supply of the very con-
ditions of human and animal existence, it con-
tains, in small proportions, two ingredients, the
use of which is well ascertained ; and a third,
upon which some question still remains. The
two first are carbonic acid and ammonia ; the
last is carburetted hydrogen. The following
table will represent in a more satisfactory man-
ner what the chemist could find if he were to be
at the pains to analyse ten thousand volumes of
dry air : —

Nitrogen 7,912

Oxygen 2,080

Carlxmic acid 4:

Carburetted hydrogen ... 4
Ammonia —traces

10.000

PROPERTIES OF PURE AIR. 231

It is, however, always to be remembered,
that variations of considerable extent may take
place in these results ; but these do not affect
this table, representing, as it does, the average
composition of the atmosphere, deduced from
an extensive series of carefully-performed experi-
ments.

Professor Schmid, of the University of Jena,
has recently calculated the entire weight of the
atmosphere, omitting its watery vapour and
carburetted hydrogen, and he places it at
1,371977,266659,000,000 Ibs. Of this sum the
relative proportions of nitrogen, oxygen, and car-
bon, in pounds, are stated as follows : —

1,057245,681687,000,000 Ibs. nitrogen.
313634,003159,000,000 „ oxygen.
1097,581813,000,000 „ carbonic acid.

Total . . 1,371977,266659,000,000 Ibs.

In reality the weight of the air must considerably
exceed this.

From this it is apparent that the air which
floats around us, and in which we live and
breathe, is by no means a simple fluid. In its
regular constitution we find there are no less
than five different ingredients, oxygen and
nitrogen, however, infinitely predominating
above the rest. It is only the light of science
that has detected this fact. The evidence of

232 THE CHEMISTRY OF CREATION.

our senses fails to render us any account of the
ingredients forming the atmosphere, mingled
together in the proportions in which we find
them. Pure air is without odour or taste, and is
so transparent that the exhausted receiver of an
air-pump presents the same appearance to the
eye as it did when full of air.

While, then, we remain in this pleasant
country spot, far from the busy hum of men, and
listen to the important facts detailed upon the
chemical history of the gentle breeze, let us not
forget that we owe all that we know on this sub-
ject to the long-continued and persevering labours
of the experimental chemist in his often dark and
smoke-filled laboratory.

CHAPTER III.

OCCASIONAL INGREDIENTS IN THE AIR.

AT the extreme end of the valley upon
which we are supposed to be looking lies a flat,
marshy district, over which in the dewy even-
ings we may often see suspended a dense cloud
of vapour. The whole area of this district is
not above three or four square miles, yet its
inhabitants are more frequently in ill health,
and the annual proportional mortality is greater
there than in any other portion of the plain
beneath us. Were we to question them, they
would inform us that when in the hot weather
of autumn a current of air blew across the
marsh, they might certainly expect attacks of
ague to ensue. Their very countenances betray
their ill-health, and the long and sallow faces of
some are so peculiar, that we may well exclaim,
What can be the cause of this unhealthiness ?
The inhabitants say it is the marsh air. When
the same sort of district and effects occur in

234 THE CHEMISTRY OF CREATION.

Italy, the inhabitants attribute it to the malaria,
or bad air.

No doubt they are correct. The air of such
districts contains something in addition to those
ingredients which in the last chapter we found
to constitute the composition of the atmosphere
generally. Nitrogen, oxygen, carbonic acid,
carburetted hydrogen, and ammonia, although
representing the ordinary ingredients of the
atmosphere, are not, therefore, its only con-
stituents in particular cases. Dr. Prout says,
" The atmosphere may be conceived to contain a
little of everything that is capable of assuming
the gaseous form." We shall learn, however,
further on, that there are active chemical pro-
cesses taking place in the air itself, which in a
short time remove such "occasional ingredients"
from its contents.

What is known upon the chemistry of Malaria
at present is but unsatisfactory. When vege-
table matter is left to rot, with a limited supply
of water, and at an elevated temperature, it
begins to give rise to certain products of its
decomposition which escape into the air, and
constitute what is called malaria. Chemistry
is in great ignorance upon the nature of these
products; but the most curious facts exist, by
which, although we can neither determine their
nature nor analyse their constitution, we are

MALARIA. 235

yet able positively to affix certain general
characters to them. The poison infused into the
air appears to be ponderous : this is shown by
the fact that it accumulates near the earth, since
it is safer to sleep on the top of a house than at
the bottom ; persons occupying the lower stories
have been attacked with ague, while those on
the upper have escaped the complaint. It does
not appear to be altogether gaseous, for the
Italians are in the habit of wearing gauze veils
as an efficient protection from it, the infiltered air
being thus divested, as they state, of its injurious
powers. It is invisible, inodorous, and gives
no indication of its presence by any chemical
quality whatsoever. A variety of conjectures
have been made upon its nature, and some have
even supposed that it consisted of minute ani-
malcules. Probably one of the most happy of
the explanations given is that which refers it
to the existence in the atmosphere of certain
minute organic particles buoyant with every
wind, coming into existence as a product of the
putrefactive process in vegetation, and capable
when inhaled by the lungs and received thus
into the circulation, of inducing that peculiar
form of disease by which its effects are character-
ised. But after all it must be confessed, the ex-
planation itself wants to be explained.

The subject of Epidemic Disorders — that is,

236 THE CHEMISTRY OF CREATION.

of disorders affecting at one time large numbers
of persons — of all kinds, is equally enveloped
in obscurity. A few facts are known, but
these are of a sadly insufficient character.
Among these is the important and interesting
modern discovery, that some diseases, origi-
nally local, if they acquired sufficient intensity
in the spot where they originate, may pro-
ceed, and, gathering additional strength in
their progress, eventually become true epi-
demics— diseases of the people. " Like living
things," observes the Registrar-General, " epi-
demics do not cease with the circumstances in
which they are produced ; they wander to other
places, and descend to remoter times." Thus
the accumulating filth of a wretched metro-
politan alley may be the hot-bed of a disease
not confined to the miserable locality, but ex-
tending to the broader squares of the wealthy,
to the palace doors, and perhaps inner chambers,
of the great and noble, and perhaps descending
to posterity. As malaria appears to be an
atmospheric impurity resulting from vegetable
decomposition, so infectious and epidemic dis-
orders would seem in most cases to arise from the
putrefaction chiefly of animal substances, or in
some instances from that of both animal and vege-
table materials.

Reasons exist, to which it is not necessary

PROPAGATION OF EPIDEMICS. 237

here to refer, for believing that these disorders
of large masses of people are produced by some
peculiar organic poison, not gaseous, nor vapor-
ous. It is at least very certain that such organic
particles as are detrimental to the health, float
in the atmosphere of every great city, and may
often be perceived by the senses in the offen-
sive air of the habitations of its poor and dirty
inhabitants. Such particles cannot exist in the
air without \mdergoing chemical change, and it
is possible that by their existence in this state
of change, they may set in motion a series of
events which terminates in the appearance of
the disease we are alluding to. A simple
experiment will prove the truth of the assertion
that an atmosphere of organic matters is un-
doubtedly mixed with our air. It is a property
of strong sulphuric acid to char or blacken most
substances of this kind ; now, if a saucer, partly
filled with this acid, is exposed for a little period
to the air, its colour will alter, and ultimately
deepen almost to black, in consequence of a
large portion of organic matter having fallen into'
it from the air, and undergone the charring pro-
cess; and this will take place even in the open
air of the country.

As we look down upon yon distant village,
it is not necessary to call in the aid of che-
mistry to inform us that even its compara-

238 THE CHEMISTRY OF CREATION.

tively pure atmosphere is charged with im-
purities of various kinds. A pale bluish haze
rests upon it, and slightly tinges the air for
some distance ; and when a breeze blows along
the valley, it may be seen wafted for a mile or
two from the village. The larger the city, the
more dense this cloud of impurities, which is by
no means all made up of smoke, although its
opacity is chiefly due to that ingredient in its
composition. In London it is extremely rare
that even in the length of a street the air is
perfectly transparent; objects distant only a
few hundred yards are perceptibly enveloped in
a mantle of bluish haze. Some highly interest-
ing observations upon this subject have been
made by Dr. Smith, and read by him before the
British Association in 1848. Of these we shall
present an abstract. The town has always been
found to differ from the country. This general
feeling is more conclusive than any experiment
that can be made in a laboratory. The various
manufactures of large towns, the necessary con-
'ditions to which the inhabitants are subjected,
and the deteriorating influences of man himself,
all exert a powerful effect upon the state of
purity, or otherwise, of the surrounding atmo-
sphere. Dr. Smith caused a portion of air to be
passed continually through a certain quantity
of water for three months. He was thus able

CONDENSED DEW IN- ROOMS. 239

to detect a certain amount of chemical matter
in the air. A part of this was sulphuric acid,
with some chlorine, and an organic substance
resembling impure albumen. Such matters are
constantly being poured into the air, partly
from the lungs of men and animals, and from
manufacturing processes. On1 these substances
becoming condensed upon cold bodies and in a
warm atmosphere, the albuminous matter very
soon putrifies and emits disagreeable odours.
The oxygen of the atmosphere acts upon it,
and it gives rise in its decomposition to car-
bonic acid, ammonia, sulphuretted hydrogen,
and probably other gases. The matter con-
densing on cold walls in crowded assembly
rooms may be collected by means of a little
tube called a pipette. If allowed to stand it
thickens, and on examination under the micro-
scope is found to contain numbers of minute
confervse, between the stalks of which a num-
ber of greenish globules are seen constantly
moving about, accompanied by still more minute
animated particles, presenting a very interesting
and beautiful spectacle. If this animal exhalation
is allowed to accumulate on various objects by
its frequent condensation on their surface, and
subsequent drying up, it forms a gummy organic
plaster, which may often be found upon the
neglected furniture of dirty houses. In moist

240 THE CHEMISTRY OF CREATION.

weather it decomposes, and produces that pecu-
liarly disagreeable organic smell which no words
can describe, but which is only too familial* to
our senses in the abodes of misery and poverty.
In contrasting this condensed animal exhalation
with dew collected in the open air, the most
remarkable difference is found to exist. The
dew remained beautifully clear and limpid,
even when boiled down ; the odour was not re-
markable ; and when the small portion of solid
matter which remained dissolved in it was ex-
posed to heat, the smell was that of vegetable
matter, with very little trace of any nitrogenised
substance. It was also rather agreeable than
otherwise.

From these researches it is quite manifest that
organic matters are always present in the air of
towns. Occasionally, in close unhealthy neigh-
bourhoods, it may even be perceived by the
sense of smell, and that it is not more evident
to us when entering a large city from the open
country, and fresh air, is due chiefly to the cir-
cumstance of our becoming by degrees accus-
tomed to it during the time occupied in our
journey. Could a Highlander be suddenly
transported from his heather-covered hills, and
set in the midst of a densely-populated alley in
London, he would instantly be sensible of the
existence of a great degree of impurity in his

ORGANIC IMPURITIES IN AIR. 241

new atmosphere. Persons from the Highlands
of Scotland frequently experience this on enter-
ing Glasgow, the air of which impresses the
same feeling as that of a forge or glass-house ;
occasionally they are unable to bear its exces-
sive impurities. It has been found that such
matters are never absent from the air, and that>
let it rain ever so much, or long, in a large
city, with every shower a quantity of organic
ingredients will be brought down. This mat-
ter is capable of promoting animalcular life to
some extent, and small specimens may be seen
moving solitarily in it. If allowed to stand in a
bottle this may be more clearly detected. Vogel
and Dr. Southwood Smith have both found
organic matters present in the atmosphere.

Difficult, and intricate as the whole question
is, this general fact appears to flow out of the
preceding remarks — that whatever be the ex-
traordinary causes of epidemics and plagues of
an aerial kind, the sources of the commoner
disorders belonging to this class are discoverable
in the putrefying filth which the negligence of
our poorer fellow-countrymen suffers to accu-
mulate in death-productive heaps on the walls of
and round about their dwellings. Nothing, in
fact, can be more confidently affirmed than that
filth and fever stand in the relation of cause and
effect ; and that poverty, although the first, is

R

242 THE CHEMISTRY OF CREATION.

not the only victim in the case. There is no
doubt, therefore, that the negligence of all
classes of society, rich and poor, entails the most
terrible calamities on both. The poor man may
not, with impunity, live on in a state of dis-
gusting and unnecessary filth and dirt. Neither,
on the other hand, may the rich, with impunity,
neglect the sanitary and physical condition of
the poor that crowd around his mansion. It
has been well ordered thus, that no man may
be so much occupied with his own things, but
that each should look upon his brother's; and
where, in a simple scientific view of the ques-
tion, this is the case, there the best possible
human security exists against the invasion of the
most formidable and desolating diseases.

While upon this subject, it may be interesting
to mention some particulars upon the supposed
nature of what is considered by many to be a
disease of aerial origin — Asiatic cholera. In
so doing, we shall merely state a few facts, or
content ourselves with simply alluding to dif-
ferent theories. For some years Dr. Prout
had been investigating the chemistr^ of the
atmosphere, and for more than six weeks before
this awful malady made its appearance in the
metropolis, in 1832, he had been engaged
almost every day in endeavouring to determine,
with the greatest possible accuracy, the weight

ASIATIC CHOLERA. 243

of a given quantity of air. On the 9th of
February, 1832, the weight of the quantity of
air suddenly rose above the usual amount to a
slight but still very appreciable extent. Again
and again was the experiment made, and the
same result obtained, so that there was no possi-
bility of an error. At the same time, the wind,
which had previously been blowing from the
west, veered round to the east. These appeared
a part of the preparation for the tremendous
drama shortly to be played out, for precisely at
that time the first case of epidemic cholera ap-
peared in London, and from that period the pesti-
lence expanded until it enveloped the whole of
the mighty city in its embrace.

It is remarkable that the disease chiefly pre-
vails in damp situations, and in ill-ventilated
filthy neighbourhoods. The earliest cases, on
its recent visitation in the metropolis and its
vicinity, occurred on board the Justitia con-
vict-ship, at Woolwich, which was moored
opposite the mouth of a sewer. It raged most,
also, in the low damp districts of the metro-
polis. The returns of mortality exhibited a
striking aspect in the week ending Saturday,
July 21, 1849. In this week, on the south side
of the river Thames, the deaths from cholera
amounted to four hundred and forty- three. In
the same week, in the north districts — Mary-

244 THE CHEMISTRY OF CREATION.

lebone, Pancras, Islington, Hackney, and Hamp-
stead — all more or less elevated — the deaths from
this disease amounted only to seven-.

The Thames presents the large evaporating
surface to the inhabitants of London of about
2,245 acres. Mr. Glaisher calculates that each
acre evaporates 1,857 '6 gallons daily; conse-
quently, 4,170,000 gallons are raised from this
part of the Thames on an average daily through-
out the year! Thus about 18,000 tons of water
are daily thrown into the atmosphere of London,
and become intimately mixed therewith. The
contents of sinks and drains are disgorged by
the great sewers into the waters, and are
agitated with the mud, from which vapours are •
constantly given off in enormous quantities.
.During the prevalence of cholera, the mean
night temperature of this river from May 27 to
September 15, 1849, was 64°! Hence, evapo-
ration was largely taking place into the air of
the sleeping city. It is a fact well worthy of
attention, that after the temperature of the river
has risen above 60°, diarrhoea and dysentery be-
come prevalent, disappearing as the temperature
again subsides. This appears to show a con-
nexion between the atmospheric moisture and
impurities and the prevalence of disease, in a
very marked manner.

Cholera has been regarded by some as a

ELECTRICITY AND CHOLERA. 245

disease due to a deficiency in the amount of
the electricity of the air. Some curious state-
ments have been made. At St. Petersburgh it
was found that a large magnet had wholly lost
its power so long as cholera ravaged the city;
but, as the disease took its departure, the mag-
net gradually recovered its sustaining effect,
and when the disease had entirely gone it was
as strong as before. It has also been noticed
that the electric telegraph refused to act during
its prevalence. The most recent communication
on this point is contained in a letter addressed
by M. Andraud to the President of the Aca-
demy of Sciences (France), of which we give
the following extracts. The machine used in the
observations was a powerful electric machine,-
capable, at ordinary times, of giving out sparks
in profusion on being gently put into action.
" From the time the epidemic became general,"
writes M. Andraud, " I was no longer able, on
any single occasion, to produce a corresponding
effect. During the months of April and May
(1849), sparks could only be procured after
violent action .... These fluctuations were
then observed to coincide most exactly with the
fluctuations of the cholera! Nevertheless, I
was afraid lest the irregularities of the electric
machine should have been occasioned by the
hygrometric state of the atmosphere. I waited

246 THE CHEMISTRY OF CREATION.

with impatience the arrival of fine weather, to
enable me to continue my observations ; but,
far from the previous indications of the machine
showing any signs of diminution, they only
became stronger ; for although with the im-
proved weather an augmentation of electricity*
might have been expected, in a few days the
signs of its presence ceased altogether. On
the 4th, 5th, and 6th of June, it was only
possible to obtain a slight crepitation; and on
the 7th the machine became dumb. This sin-
gular decrease in the electric element fatally
accorded with a consentaneous increase of the
cholera. On the 8th feeble sparks reappeared,
and increased in number and intensity. In the
course of the day a thunderstorm announced
to plague-stricken Paris that electricity had
once more entered in its dominion. On the
9th, at the slightest touch, the machine gave
forth sparks in abundance. Meantime the
cholera was rapidly subsiding."

During the whole year 1849, M. Quetelet
has proved, by careful observation, that the
electrical intensity of the atmosphere has been
about one-half of that observed in former years ;
and that from January, in this year,* it regu-
larly diminished up to a certain period, when it

* Mr. Glaisher makes a somewhat similar observation for
the quarter ending Sept. 1849.

INORGANIC IMPURITIES IN AIR. 247

continued stationary. The following is M.
Que'telet's table of the mean electrical intensity
of the air, for the years from 1844 to 1848, both
inclusive, and the means of the same months in
the year 1849 : —

Means of

Means

i

Means of

Means

1844—1848.

of 1849.

i • i:

1844—1848.

of 1849.

January .

. 53°.

. 39°

June .

. 18°.

. 13°

February .

. 47 .

. 36

July . .

. 19 .

.14

March

. 38 .

. 27

August .

. 21 .

. 21

April .

. 27 .

. 20

September

. 24 .

. 24

May . .

. 21 .

. 16

Other scientific observers have detected the
same peculiarities. We are unable to say,
however, that a deficiency in the electric in-
tensity of this atmosphere can be the cause of
this mysterious disease ; it must rather be looked
upon as an accomplishment of the phenomena
which produce cholera, and in all probability
partly concerned in their operation.

In addition to the presence of organic par-
ticles, or, in other words, particles arising from
the decomposition of animal and vegetable
matters, it is certain that impurities of an inor-
ganic kind are often to be found in the air. In
large cities the rain which falls is always found
to contain coal ashes, soot, and sulphates and
chlorides of different kinds — the latter probably
derived from the former — thus proving the
large amount of impurity present in such at-

248 THE CHEMISTKY OF CREATION.

mospheres. A quantity of ammonia sufficient to
render rain quite alkaline is occasionally present.
The most curious illustration of the existence
of such impurities in the air has been noticed
at Manchester. The rain which falls in that
city, owing to the enormous amount of mineral
ingredients poured by its immense chimneys
into the air, is found to be harder, that is, to be
more charged with mineral and saline ingre-
dients, even than the water from the neighbour-
ing hills, which it is now intended to use instead.
Occasionally an adulteration of a more sen-
sible character is infused into the atmosphere,
increases to an enormous extent, and fills the
air with haze. A remarkable event of this
kind took place in 1782. The phenomenon
of which we are about to speak is commonly
called " Dry Fog," to distinguish it from the
ordinary humid mist called fog. The vast space
between Lapland and Africa was shrouded
over, during the years 1782 and 1783, with a
dry fog unequalled in intensity. It was in the
form of a pale blue haze, and was so thick at
noon-day that the sun looked of a blood-red
colour through it. It was not affected by rain,
and it extended alike over countries, like our
own, of " distempered climate," and others
where the air is usually serene and clear.
Voyaging was dangerous even in the Medi-

DRY FOGS. 249

terranean by reason of it; and it was just as
thick on the summit of the highest Alps ! Its
properties were peculiar. It was said to have
a strong disagreeable odour, and in some places
a viscid acrid liquid is said to have been depo-
sited by it. The greatest alarm prevailed ;
men's hearts failed them for fear. More ter-
rible visitations were expected. Public prayers
were earnestly made to avert the apparently
impending doom of all Europe; and such an
agitated state of the public mind was probably
never known. A tremendous volcanic eruption
in Iceland burnt up seventeen villages, and
ejected such a mass of matter as would defy the
united efforts of the whole human race to
remove, each man taking away as much as he
could carry. Awful thunderstorms visited the
continent, desolated France, and destroyed a
large number of human beings and cattle in
England. It was a time of terror, of tumult,
and of universal excitement. The summer of
1783 saw at length its termination ; violent
electric phenomena, with storms of wind and
rain, dispersed it, and before the autumn all
was gone ; the plague was removed. During
the whole period that it had lasted a severe
epidemic catarrh — something similar, probably,
to influenza — affected men and animals.

These remarkable years were singular as

250 THE CHEMISTRY OF CREATION.

regards " dry fog," principally in the enormous
extent of its distribution — a circumstance of
which history is unable to. offer a parallel
example. Dry fogs of a local, or more limited
extent, had been before known. Jussieu
relates, that " the influenza of the spring of
1733 appeared in France immediately after
offensive fogs, more dense than the darkness
of Egypt!" In the autumn of 1775, in France
influenza appeared with violence, and was
ushered in by thick noisome fogs, having been
preceded by diseases among the lower animals.
About the 7th of October, 1775, Scotland
appears to have been visited by the same fog,
for we learn that in certain districts a continual
dark fog, possessing a particularly smoky smell,
made its appearance, and lasted for five weeks.
During its continuance the sun could not be
seen to shine. During the year that the potato
disease was most extensive in its ravages, it
was noticed in some parts of the country, that
clouds of " dry fog " preceded its appearance in
some fields.

It has been remarked by some, who have
sought for the causes of these singular occur-
rences, that they often occur together with
volcanic disturbances. In 1782, besides the
tremendous eruption already mentioned, there
occurred several earthquakes in Calabria, and

SELEXIURETTED HYDROGEN. 251

other symptoms of disquietness in the deep
regions of the globe. In the years noted in
history for the appearance of dry fogs, in
526, 1721, 1822, and' 1834, several volcanoes
were in great activity. The meteorologist,
M. Koemtz, reasoning upon this subject, has
ascribed the occurrence of the dry fog of 1782
to the enormous volumes of smoke produced
by the devastations of the burning lava in
Iceland, as it descended on its fiery errand:
hence he conceives the smoky odour of dry
fogs. Several others of these phenomena he
attributes to the smoke emanating from the
peat-burnings of Westphalia and Germany.
A very prevalent opinion, in 1782, was that
the tail of a comet had become mixed up with
our atmosphere. The learned author of the
Bridgewater Treatise on Chemistry (Dr. Prout),
appears disposed to ascribe the fatal effects of
dry fog to the presence of a very minute quan-
tity of one of the most deleterious gases known
to chemistry, Seleniuretted Hydrogen. This
gas, since the metallic element Selenium is a
volcanic product, he conceives to have been
discharged by the volcanic eruptions, and to
have become widely dispersed, in a state of
extreme dilution, through the air. Berzelius,
who first discovered this gas, had a painful
experience of its virulent powers ; allowing

252 THE CHEMISTRY OF CEEATIOX.

a minute bubble, not larger than a pin's head,
to pass up his nostril, he immediately lost the
sense of smell for five or six hours, and suffered
for fifteen days afterwards from a most severe
catarrh, in all respects the same as that of in-
fluenza. The same effects, on another occasion,
followed the escape of only a bubble or two into
his laboratory, and he again suffered from cough
and catarrh.

M. Kcemtz's explanation can scarcely be con-
sidered correct. Dry fog is doubtless some-
thing more than smoke. When its remarkable
accompaniments, volcanic disturbance and severe
epidemic attacks, are remembered, it will be
evident that some other cause than that specified
must be called in to account for this pheno-
menon. It has been considered of electrical
origin.

It is difficult to assign to any of the causes
alluded to, the existence of a remarkable phe-
nomenon which took place in November, 1819,
at Montreal. On a Sunday morning the whole
atmosphere in this city appeared as if covered
with a thick haze of a dingy orange colour,
during which rain fell of a thick and dark inky
appearance, and apparently impregnated with
some black substance like soot. The weather
then cleared up, but on the following Tuesday,
at twelve o'clock, a heavy damp vapour enve-

BLACK RAIN. 253

loped the whole city, which was so dense that
the inhabitants were compelled to use artificial
lights. The appearance was grand in the ex-
treme. About three o'clock a slight shock of an
earthquake was felt, accompanied with a noise
like the roll of distant artillery. At twenty
minutes past three, when the darkness reached
its greatest depth, the whole city was instan-
taneously illuminated by the most vivid flash
of lightning ever witnessed in Montreal, im-
mediately followed by a peal of thunder so loud
and near as to shake the strongest buildings to
their foundations, accompanied by a shower of
black rain. Very recently a shower of black
rain took place in Ireland, which, together with
the alarming phenomenon here described, must
evidently have had its origin in the existence in
the air of impurities of some anomalous kind.

Occasionally light particles of a more easily
explained origin make their appearance in the
air. "On the afternoon of June 11, 1847,"
writes Dr. D. P. Thomson, " the wooded part
of Moray shire appeared to smoke, and for a
time fears were entertained that the fir planta-
tions were on fire. A smart breeze suddenly
got up from the north, and above the wood
there appeared to rise about fifty columns of
something resembling smoke, which wreathed
about like water-spouts. The atmosphere now

254 THE CHEMISTRY OF CREATION.

calmed, and the mystery was solved ; for what
seemed smoke was in reality the pollen of the
woods." Insects, fish, lichens, infusorial ani-
malcules, volcanic ashes, sand, earth, and many
other substances, occasionally enter into the air
by the attraction of rapidly revolving currents,
and are dropped often at a great distance from
the places whence they were snatched.

One of the most remarkable^ discoveries of
late years, upon the chemistry of the acci-
dental ingredients of the atmosphere, is that of
Professor Schonbein, in the body which he has
called Ozone. This is a compound of oxygen
and hydrogen, analogous to, though in some
respects differing from, that substance so long
known to .chemists under the name of Peroxide
of Hydrogen, to which reference was made in
the illustration of one of the fundamental laws
of chemical combination. The latter has been
considered chiefly as a curiosity by chemists.
Jt is a limpid transparent fluid, precisely re-
sembling water in its appearance, and remark-
able for its bleaching properties. It also pos-
sesses several very curious chemical peculiari-
ties. It is composed of exactly twice as much
oxygen to the same amount of hydrogen, as
in water. Such also appears to be the com-
position of ozone : yet, strange to say, it seems
that ozone and the peroxide of hydrogen are

OZONE IN THE AIR. 255

not similar in their properties, and it is Pro-
fessor Schonbein's opinion that they are not
the same substance. Like peroxide of hydro-
gen, ozone bleaches powerfully. It appears
to be produced even in the ordinary process
of combustion ; it is also formed during the
passage of a galvanic current through water,
and probably in many other artificial ways.
In nature, ozone is often produced in a large
measure during electrical changes in the air.
During the night, when plants rest from their
daily functions, they emit this remarkable
principle ; and it is said that a part of the pecu-
liar smell perceived in the early day when the

" saturated earth

Awaits the morning beam, to give to light,
Kaised through ten thousand different plastic tubes,
The balmy treasures of the former day,"

is due to the existence of a portion of this prin-
ciple in the atmosphere. It appears probable, also,
that organic matter about to decay has the property
of developing ozone, which then acts upon it.

We are not yet able to state with precision
what purposes are served by this highly inte-
resting substance, ozone. Without doubt they
are important. Since it is a substance which
readily yields up its excess of oxygen, and
then becomes simply an oxide of hydrogen,
or, in other words, water, it may be the means

256 THE CHEMISTRY OF CREATION.

of supplying this gas to various bodies, and so
acting a highly essential part in nature as an
oxidizing agent. Perhaps we may point to a
homely application of its bleaching properties,
in the linen which may be seen spread out on
many a grassy field and way-side hedge to
whiten. Formerly all our calicos were taken to
the green plains of Holland, in the spring, there
spread out, and allowed to lie until whitened ;
the goods were then sent home in the autumn.*
It is certain that the chemical rays of the sun
have a bleaching effect ; but it may be reason-
ably supposed, that, as ozone is also a powerful
bleaching agent, its elimination at night by
plants may help forward, possibly, to u large
extent, this process.

Some connexion between the presence of
ozone in the air and the existence of epidemic
diseases, such as the influenza, cholera, &c.,
has lately been imagined. In a recent com-
munication to the Athenaeum paper, Mr. R.
Hunt has propounded a view of this connexion
which deserves our consideration. He writes
as follows : — " Ozone is constantly produced
in the atmosphere, under every circumstance,
which determines either electrical or chemical

* In two or three days, at a Lancashire bleachwork, as
much linen is bleached as would carpet a large field all over.
This is effected by the chemistry of art.

EFFECTS OF OZONE ON THE AIK. 257

changes ; and its amount appears to vary in an
exact ratio with the electrical intensity. We
may produce it in a room, by exciting an ordi-
nary electrical machine, when it is detected by
its very peculiar smell ; we obtain it during the
decomposition of water by the voltaic battery, in
combination with the liberated oxygen; and
Schonbein has proved that ozone is formed in
every process of combustion.

" The use of this agent in the atmosphere
will, I think, be obvious after a very brief con-
sideration of the conditions which prevail during
the mutations of organized bodies. All living
animals and vegetables are constantly throwing
off from their bodies organic matter in a con-
dition the most fitted for recombination with
the chemical elements of the air. The gaseous
exhalations from all dead matter are also con-
stantly combined with organic particles in. a
state of extreme division. Thus the atmo-
sphere is constantly receiving exhalations from
the earth and its inhabitants, which, without
a provision for their removal, would speedily
become far more injurious to all forms of life
than carbonic acid . . .

" Ozone combines with, and changes in the
most rapid manner, all animal matters, except
albumen in its fresh state. I am, therefore,
disposed to consider it as the great natural

258 THE CHEMISTRY OF CREATION.

agent employed to convert all these deleterious
exhalations which the air receives, into" innocu-
ous matter. An atmosphere artificially charged
with ozone, immediately deprives the most
putrid solid or fluid bodies of all disagreeable
smell, and sulphuretted hydrogen is instantly de-
composed by it . . .

" It has been proved that the electrical in-
tensity of the atmosphere has, during the year
(1849), been diminished in a remarkable manner.
As this is the great cause, ever active in pro-
ducing ozone, we might, a priori, infer a rela-
tively diminished quantity of this chemical
agent; and experiment has proved, that during
the last three months (June, July, and August,
1849), an appreciable quantity of ozone nould
not be detected by the ordinary methods, in the
air of London . . . Certain it is, that we have
for several months had to endure an atmosphere
of low electrical intensity, deficient in ozone,
an agent which would remove or alter pesti-
lential miasma. Vegetation has exhibited, and
is exhibiting, peculiar abnormal indications de-
pendent upon solar influences, of which we are
absolutely ignorant; consequently, the atmo-
sphere has been receiving an excess of organic
poison from the thousand and one sources which
the congregation of masses of men in towns gives
rise to, and has remained unchanged, to do its
work of destruction upon humanity. . . .

EFFECTS OF OZONE ON THE AIR. 259

" Each time that cholera has disappeared from
amongst us, it has been rapidly followed by
influenza. At the meeting of the British Asso-
ciation at Swansea, Dr. MofFatt communicated
the remarkable fact, that the prevalence of in-
fluenza and the spread of catarrhal affections were
invariably connected with an excess of ozone in
the atmosphere."

From these considerations it may be gathered
that, upon this theory, the presence of cholera
is connected with the absence or deficiency of
ozone ; while the presence of influenza and epi-
demic catarrhs, is due to the excessive pre-
sence of ozone in the air. Also, that a certain
amount of ozone is necessary in order to sus-
tain -the entire salubrity of the atmosphere,
in consequence of its promoting the property
of destroying noxious occasional ingredients in
the air. It has been noticed that Birmingham
and Berlin have generally escaped the severity
of the infliction of cholera; and this has been
attributed to the metal manufactories of these
towns, which are abundant sources of ozone.
But in the recent epidemic, Birmingham was
visited with it, though only to a moderate ex-
tent. A great mystery still hangs, over the
cause and nature of this as well as of all pesti-
lences, but light may be expected to be thrown
on the subject as we advance in knowledge.
Known or unknown, we must not fail to ac-

260 THE CHEMISTRY OF CREATION.

knowledge a Divine Hand in these visitations, —
for the remedying of which there is little help in
man, — nor to inquire wherefore they are sent.

From the property possessed by ozone of de-
composing iodide of potassium, in such a man-
ner as to strike a blue tint when a solution of
starch is added, it is to be easily detected in the
air. Perhaps some of our readers may feel in-
clined to repeat the following plan for detecting
it in the air. The directions are: — "Slips of
paper are to be smeared with the following com-
position : a drachm of common WHITE starch is
mixed with an ounce of boiling water, and the
solution boiled until it is of the consistence of
that used in the laundry ; then twelve grains of
iodide of potassium are to be added, and the
whole well mixed together. The presence of
ozone is indicated by the decomposition of the
potassium salt, and the formation of a blue iodide
of starch." We may look forward with interest
to the fresh discoveries of chemistry upon the
uses of this occasional ingredient of the air.

Sulphuretted hydrogen gas is one of the most
common occasional ingredients in the air of
towns. It is perceptible by its peculiar odour
like that of rotten eggs, and is rendered pro-
vokingly sensible by effects on white paint, the
white lead of which it decomposes and turns
black It is emitted from sewers and drains
in large quantities. A house in Paris fresh

DECOMPOSITION IN THE AIR. 261

painted with white lead was turned black in a
single night by clearing out the drains, and so
setting free a large quantity of sulphuretted
hydrogen. In his day, Sir Kenelm Digby
complained much of the odours of the streets,
and declared that silver could not be kept
clean, an effect due to the agency of this gas.
It is often combined with or accompanied by
ammonia, which neutralizes its bad effects in
some degree. It is also probably oxidized and
decomposed by the effects of ozone.

In addition to these occasional ingredients,
it has been supposed by various writers, that,
in the words of Dr. Prout, before quoted, " the
atmosphere contains a little of everything that
is capable of assuming the gaseous shape." In
a recent work on science the same statement
is repeated in the following words : "A thou-
sand results daily and hourly accumulating as
truths around us, prove that the solid metals,
the gross earths, and the constituents of animal
and vegetable life, all pass away invisible to us,
and become ' thin air.' We know that, floating
around us, these volatilized bodies exist in
some form or other." The same idea prevailed
in the minds of the ancients,* and is repeated
in the following expression of Shakspeare —
" We must all part into this sea of air."

* Quodcumque fluit de rebus, id omne
Aeris in magnum fertur mare. — Lucretius, De Rer. Natitr.

262 THE CHEMISTRY OF CREATION.

It has been apparently forgotten, however,
that the air contains, in a condition highly
favourable to its activity, two principles of the
utmost energy in decomposition, the gas oxy-
gen and ozone. In all probability no such acci-
dental impurities can long exist in the gaseous
form mixed with the ordinary constituents of
the air. Even in water, which appears less
favourably circumstanced for such a result, a
natural process of purification takes place ; how
much more rapidly, then, in a medium consti-
tuted, like our atmosphere, of very large pro-
portions of an element which is ready for imme-
diate union, without having to be first set free
by a preliminary decomposition, and is furnished
also with a very easily decomposed substance
rich in oxygen — in ozone, which is ever active
in fulfilling a similar office. There can be, in
fact, little doubt that the oxygen of the air and
that of ozone are sufficient to reduce all, or
almost all these occasional ingredients, by suc-
cessive steps, to simpler and simpler forms,
until at length they are deposited in a solid
state, and thus are removed from the thin folds
of our earth's mantle, or are converted into
beneficial constituents of the air. Bodies
which are impure have generally a tendency to
volatilize ; in so doing they become exposed to
oxygen, the great purifier, and become pure.

CHEMISTKY OF PUTREFACTION. 263

It is by this means that that accumulation of
particles of every kind, which would otherwise
load the air, and interfere to a serious extent
with its purity and functions, is obviated. But,
particularly, these principles appear to have
the power to destroy those noxious organic
particles which are evolved in certain diseases.
The fresh air is the worst enemy of putrid
fevers; oxygen, whether derived from this ele-
ment in the air or from the decomposition of
ozone, combines with the fetid exhalations,
neutralizes their effects, and reduces them to
powerless and innocuous forms of matter.
Thus oxygen, in a variety of ways, assists to
preserve the purity of the air, and its freedom
from accidental ingredients for any length of
time. It sets up putrefactive processes, when
life has ceased, both in vegetable and animal
bodies ; these are the first powers of destruc-
tion, which are to be succeeded by others, and
these again by others, until all is destroyed.
It is on this account that the complete exclu-
sion of air prevents the putrefactive process
from commencing. Meat is preserved for
years untainted in close vessels.

When decomposition sets in, the tissues of
the animal frame become resolved into gaseous
and watery elements. The atmosphere seizes
again upon these, and takes quickly from them

264 THE CHEMISTRY OF CREATION.

their capacity for doing mischief. Such as may
be beneficial in their relation to created beings,
are simply taken up and distributed far and
wide for the service of creation. There is a
singular gradation observable in this process of
decomposition, which well deserves our atten-
tion. The process of destruction is slow, and
advances from one step to another. The air
attacking a compound of complex constitution,
reduces it to one of more simple nature, and
so on, until the simplest is arrived at, and this
is innocuous. The change is at length com-
plete ; the body is literally dissolved either into
gas or water ; its fluids and solids are dispersed,
and the bleaching bones and earthy materials
of the skeleton, alone remain to indicate that
the framework of an active and animated being
had once rested on the earth.

A singular exception to the general rule in
the decomposition of the body after death exists,
as we are told by Mr. Willis, in the bodies of
those which are deposited in the vaults of
St. Michan's church in Dublin. These vaults
are perfectly dry, and are occupied with the
remains of bodies which have been deposited
there for .centuries. From a published ac-
count of these vaults we make the following
extracts: — "The bodies of those long departed
appear in all their awful solitariness at full

CLIMATE OF UPPER EGYPT. 265

length, the coffins having mouldered to pieces !
but from those, and even the more recently
entombed, not the least cadaverous smell is
discernible, and all the bodies exhibit a similar
appearance, being dry, and of a dark colour.
The floor, walls, and atmosphere of the
vaults of St. Michan's are perfectly dry, the
flooring is even covered with dust, and the walls
are composed of a stone which is peculiarly cal-
culated to resist moisture. This combination
of circumstances contributes to aid nature in
rendering the atmosphere of these gloomy re-
gions more dry than the atmosphere we enjoy.
In one vault are shown the remains of a man
who died at the advanced age of one hundred
and eleven ; the body has now been thirty years
in this mansion of death, and although there is
scarcely a remnant of the coffin, the body is as
completely preserved as if it had been em-
balmed, with the exception of the hair." It is
more probable that the stones forming these
vaults are strongly hygrometric, than that they
resist moisture. They probably withdraw all
the moisture from the air, and thus render
the customary decomposition impossible.

The durability of animal and vegetable sub-
stances in Upper Egypt, in consequence of the
peculiar dryness of the air, is quite extraordi-
nary. In the most ancient tombs are to be

266 THE CHEMISTRY OF CREATION.

found sarcophagi, chests, chairs, tool?, and other
things made of wood, grains of corn, dried
fruits, almonds, dates, nuts, and grapes, plaited
reeds, papyrus, and a number of linen articles,
all in a state of perfect preservation. Mum-
mies that have lain there for centuries have
been discovered with the hair, skin, and features
entire.

Hence we learn, that though accidental im-
purities undoubtedly find a temporary lodgment
in the air, they instantly, if of a kind admitting
decomposition by oxygen, begin to alter, and if
of an unchangeable kind, they are at no distant
period removed from it. Thus the chemistry
of nature, rightly interpreted, teaches us that
the atmosphere is not only the grand receptacle,
but also the laboratory for the decomposition
of a large number of the constituents of the
animal and vegetable frame, and of such other
ingredients of a foreign kind as find their way
into it. All "flesh" and all " grass" part with
a majority of the elements which compose them
into this great reservoir, in the form of the
simple compounds, carbonic acid, water, and
ammonia, but not therefore to be irrecoverably
lost. The atmosphere is a faithful conservatory
for these constituents. They may be scattered
to the four corners of heaven, but they shall
reach their proper destination in the end. The

THE ATMOSPHERE —EARTH'S TREASURY. 267

watery vapour, the ammonia, the carbonic acid
take wings, and soar, it may be, to vast ele-
vations from the earth, as though they would
never more come into active duty on its surface.
But in process of time they must return again,
and take their allotted place in the operations
of the universe. Millions of animals may die,
leaving their putrefying carcases to rot in the
wilderness, or in the jungle, or in the depths of
the caves of the earth ; and it might be thought
that all the valuable constructive materials
which entered into their composition were ibr
ever removed from usefulness. But it is not so.
Every wind that sweeps over these remains
bear away the volatile portions round about
the world. The gentle rain comes down and
washes the soluble parts away, supplying a
fertilizing fluid to the roots of distant plants.
The interchange of ingredients never ceases.
Millions of animals feed upon the vegetation
nourished by the decay of former myriads.
Their time is then completed; their period of
utility is ended : they die. The air again
receives their elements, and again with con-
tinually succeeding generations do these enter
into activity in the economy of the "world.

CHAPTER IV.

THE WATERS OF THE AIR.

" Waters devour and swallow up the earth ; waters
quench and kill the flames of fire ; they mount up aloft
into the air, and seem to challenge a seignory and do-
minion in the heavens also ; while by a thick ceiling and
floor, as it were, of clouds caused by the dim vapours
arising from them, that vital spirit which giveth life unto
all tilings, is debarred, stopped, and choked."

ONE would almost think when Pliny wrote this
passage, that he must have had a sort of hydro-
phobia, a dread of that fluid, the absence of
which would turn our fair landscape into a
desert, and this fruitful plain into a waste and
barren wilderness. How differently old Gower
writes in the quaint but refreshing lines, —

" The moyst droppes of the reyne
Desceuden in to the middle erth,
And tempreth it to seed and erth,
And doth to springe gras and floure."

Surely the smiling grass and soft turf acknow-
ledge anything rather than that " waters devour

THE WATERS OF THE AIR. 269

and swallow up the earth." We might say
rather, in the words of an old poet of nature,*
that

" The earth waxeth proud withal
For sweet dews that on it fall."

In all the various forms assumed by this
beautifully-constituted fluid, as dew, mist, rain,
hail, and snow, we are presented with remark-
able illustrations of the importance of such an
ingredient in our air, and of the wisdom of
that great and glorious Being who employs
the simplest means to accomplish the greatest
amount and variety of beneficial results. No
one questions the fact, that the rivers, lakes,
seas, and oceans, are the great reservoirs of
water for the use of the globe ; but few re-
member that not only is the atmosphere a re-
servoir of water also, but that it ie the chief
medium through which, on the large scale, the
contents of- the rivers and seas become available
for the necessities of the land. Such is, how-
ever, perhaps as important a function of the air
as any that has been assigned to it ; — an office,
the cessation of which would render the earth
waterless, would dry up our rivers, and confine
both animal and vegetable life to the immediate
vicinity of the sea-shore.

We can easily prove the existence of water
* Chaucer.

270 THE CHEMISTRY OF CREATION.

in a gaseous form in the air. On putting a lew
lumps of ice into a tumbler, the surface of
which is carefully wiped clean, and carrying
the glass into a sitting-room, it will be imme-
diately found to be covered with a dense cloud
of dew, which will form again and again, even
after the first deposit has been wiped off. The
amount present in the air varies greatly, but a
certain portion is never absent, and the amount
is usually greater in warm than in cold air. It
arises from the evaporation of water on the
earth. The atmosphere on the summit of lofty
mountains is occasionally remarkable for the
absence of watery vapour. On the lofty passes
of the Cordilleras this degree of dryness pro-
duces some curious effects. Articles of food
become perfectly dry and hard, wood-work
shrinks ; and if a mule dies it is preserved from
putrefaction, as this process does not take place
in the absence of water for a length of time.
The atmosphere in such a condition is remark-
ably clear and transparent. Electricity also is
developed on the slightest friction ; articles of
flannel clothing, when rubbed in the dark, glisten
with the electric fire, and the hairy coats of ani-
mals crackle and emit sparks.

The state in which watery vapour exists in
the air is closely analogous to that of the other
gases, and it is influenced equally with them,

PHILOSOPHY OF "DEW." 271

within certain limits, by the laws of diffusion.
There is, however, this great distinction, that
watery vapour is liable to become condensed
and liquefied at common temperatures. Carbonic
acid gas* is likewise a liquefiable gas, but it is
only under the influence of cold and extreme
pressure. Watery vapour, on the contrary, is
readily made to assume the liquid condition.
When this takes place, that is, when the vapour
passes from the vaporous into the liquid state,
the phenomenon called " dew " is produced.
The philosophical explanation of the formation
of dew is simple. There exists for watery va-
pour a state of density which it cannot pass with-
out losing its gaseous condition, and becoming
liquid. This state is conveniently expressed
by the term, " the maximum density " of the
vapour. The point on the thermometer at which
watery vapour attains its maximum density is
dependent upon the temperature of the air,
increasing as the temperature increases, and
sinking as the temperature falls. Consequently,
if the temperature of the evening were 50°,
the point of the maximum density of watery
vapour would be lower, and the facility with

* Whether oxygen and hydrogen may become liquefied in
future experiments is uncertain ; at present it seems little
probable. Professor Faraday's laborious researches have
failed to show the least tendency of tliis kind.

272

THE CHEMISTRY OF CREATION.

which it would be deposited in the liquid form,
as dew, would be greater than if the temperature
were 70°. Now, when any substance or sur-
face becomes cooled down, whether naturally
or artificially, to a little below the point of
maximum density of watery vapour, the latter
immediately loses the form of vapour, and
becomes condensed in minute drops upon the
cold surface ; the point at which this takes
place is called the " Dew-point." The late
Professor Daniell invented an interesting little

instrument, of con-
siderable importance
in hygrometric pur-
suits, entitled the
'' Dew - point hy-
grometer." It con-
sists of a bent glass
tube, terminating in
two bulbs, one of
which is half filled
with ether, the whole
being vacuous as re-
spects atmospheric air. In the ether bulb is a
delicate thermometer ; a piece of muslin wetted
with ether covers the empty bulb outside. The
cold produced by the evaporation of this ether
condenses the ether vapour inside the tube, and
rapidly lowers the temperature of the ether bulb

DANIBLL'S HYGROMETER.

PHENOMENA OF "DEW." 273

until dew appears on its surface. When this
takes place, by looking at the little thermometer
inside, the dew-point is easily read off.

In nature, the deposition of dew takes place
under the following circumstances : — So soon as
the sun sinks beneath the horizon, the earth,
no longer absorbing the rays of heat from that
source, begins rapidly to lose by radiation its
temperature acquired during the day. This
cooling process continues until the surface of the
ground and the bed of air overlying it has
reached the dew-point, and then almost every
object becomes covered with a deposit of dew.

It is singular that gardeners have adopted
from experience, as a shelter ibr their flowers,
a plan which theory has subsequently shown to
be based upon purely scientific principles. It is
noticed, for instance, that it is chiefly on clear
calm evenings that dew is deposited, and rarely
on cloudy evenings. The cause of this is, that
the clouds prevent the loss of heat by radiation
from the earth, and consequently it is kept so
warm that the dew-point is never reached. It
has been found by the gardeners that a slight
screen will effectually preserve their plants from
severe cold, the radiation of heat being in this
simple manner effectually prevented. Bodies
which are good radiators, such as the hairy
foliage of some plants, since they lose heat more

T

274 THE CHEMISTRY OF CREATION.

rapidly than substances having smooth surfaces,
are always first and most abundantly covered
with dew. In the history of Gideon's fleece, the
most striking miracle, as we speak, of the two
performed was not that it should be full of water,
while all the ground around was dry, but that
it alone should be dry, while the surface of the
earth around was wet with dew ; for a fleece is a
good radiator of heat, and would naturally cool
before other bodies, and become saturated with
dew sooner than many other substances, but
unless shaded, all the ground around would be
more or less wet with dew, especially in the
East, where the dews are much more profuse
than in our country. It was consequently a
complete reversal of the ordinary laws of nature,
that the fleece alone should be dry ; and, as if to
mark the more special interference of God in this
case, it is sufficiently striking that the sacred
text with reference to it contains the expression,
" God did so."

Dew does not in reality present the least che-
mical difference from pure water. It is, in fact,
the purest form in which water is found.* Rain
water is more or less charged with impurities ;

* Very minute traces of nitric and muriatic acids have-
been stated as discoverable in dew occasionally. In hoar
frost, which is frozen dew, none have been found. It is
therefore probable such impurities were accidental

MAGICAL EFFECTS OF DEW. 275

and even the distilled water of the chemist con-
tains them in a very minute degree, but dew
may be considered as perfectly pure water, when
it forms on a clean surface. Hence its brilliant
appearance and the splendid colours it displays
at that pleasant time, the charms of which
are told in the solemn and beautiful lines of
Milton, —

" Sacred light began to dawn
In Eden on the humid flowers that breathed
Their morning incense, when all things that breathed
From earth's great altar send up silent praise
To the Creator, and his nostrils fill
With grateful smell."

Strange properties have been ascribed to it.
The ancient alchemists seemed to regard it
with a singular veneration, as if it were some-
thing more than mere water, and used to
employ it in their attempts to dissolve gold.
The ladies of antiquity also attributed to dew
the magical power of preserving their beauty,
and collected it, as we are told, by exposing
fleeces to the night air, and wringing them
out in the morning. It is not uncommon to
hear country people jesting with young people
too much attached to their beds, by telling
them that if they washed their faces in the
morning dew they would never want any other
cosmetic. The ancients used to imagine that
dew dropped from the stars. How superior to

276 THE CHEMISTRY OF CREATION.

all these false ideas is the simple and accurate
expression of the Scriptures, contained in the
beautiful words, " My doctrine shall drop as the
rain, my speech shall distil as the dew."* For
if we liken the bedewed surfaces to the " con-
denser," we see the force and correctness of the
expression. The ancients imagined universally
that the dew fell, and the same erroneous idea
prevailed almost to the end of the last century !
Yet for more than three thousand years the
true account of its formation, namely, from a
vaporous to a condensed state, lay forgotten in
the Bible ! How satisfactory are such incidental
evidences of the Divine origin of the Sacred
Word.

If the earth continues to lose heat by radia-
tion, even after the formation of dew, it may
be reduced as low as 32°, the freezing point, or
even lower. The dew then freezes, its limpid
particles become set fast in solid beads and
crystals of various forms ; thus hoar -frost is
produced. The extraordinary beauty of the
crystallizations thus formed must have been
universally noticed.

There is something eminently interesting
in noticing the occasional glimpses of an ad-
justing principle which we may catch in a
survey of the kingdom of nature. The depo-
* Deut xxxii. 2.

HOAR FROST. 277

sition of dew is an illustration in point. The
heaviest dews, other circumstances being favour-

able, succeed the hottest, clearest, and driest
days. Hence the dew is most abundant when

278 THE CHEMISTRY OF CREATION.

it is most necessary. In hot climates the dews
are most profuse; and the morning sun rises
in its strength upon a landscape which the
gentle hand of night has cooled, refreshed, and
invigorated with a sea of dew-drops. Thus,
though no rain-carrying cloud may cross the
blue air during the day, to shed its supplies
of refreshing waters upon a parched earth,
the clear and brilliant evenings witness, in
the phenomenon we have been considering,
a grateful and efficient compensation ; and the
thirsty vegetation, satisfied with its evening
portions, is enabled without injury to endure
the rays of the burning luminary all the day
long.

Dew, in common with all water shed upon
the ground, has important duties to fulfil. Be-
sides quenching the thirst of plants, dew is
largely instrumental in facilitating the evapo-
ration of some important bodies. Thus, when
it is evaporated by the heat of the sun, it is the
vehicle by means of which ammonia escapes
into the air, and becomes subservient to the
wants, not only of the isolated spots in which
it was probably first produced, but to those of
vegetation at large. Hence, as has been before
observed, the farmer's carefully-stored heap of
manure becomes robbed of half its ammonia,
which escapes with the evaporating water, and

OFFICE FULFILLED BY DEW. 279

helps to fertilize his neighbours' fields as well
as his own, by rising into the air and diffusing
therein. That is, where science has not come
to his aid, and put a stop to the appropria-
tion by a shower of dilute acid, or a sprink-
ling of powdered gypsum, by means of which
the evaporation of ammonia is prevented, in
consequence of its being compelled to assume
a new and less volatile form. A certain amount
of moisture is almost essential to the escape of
odour from many bodies. The cause of this
appears to be, that the vapour forms a sort of
vehicle for the escape of volatile organic matter ;
and also, that moisture favours the decomposition
of bodies, so that as they decompose the vapour
is given out. Much of that pleasure which we
ourselves derive from the perfume of plants,
depends on the assistance to its vaporization
rendered by dew. " Who," writes the late Pro-
fessor Fownes, " does not inhale with rapture
the perfumes of a flower-garden, when the dews
of night, or the refreshing summer shower,
have awakened the thousand sweet odours of
its fair inhabitants? The breath of the haw-
thorn and of the rose have been always one of
the most favourite themes of the poet's song;
and yet this endless succession of pure and
simple pleasures is but a mere consequence of
the law which bids a vapour, arising by its own

280 THE CHEMISTEY OF CREATION.

elasticity from a volatile substance, mingle itself
with the surrounding air, and extend its in-
fluence until its effects become so enfeebled
by dilution, as to be imperceptible to the
sense."

The presence of moisture also favours the
escape of disagreeable odours; and it may be
noticed, that in damp weather, the exhalations
from reservoirs of putrid matter are more abun-
dant than at other times. It appears, also, that
alkalies favour the escape of vapours and organic
exhalations into the air.

We must, however, now proceed to inquire
how it happens that dew, or water in its
other form, becomes thus dissipated and lost
in air? By the way-side, a week ago, was a
pool, some six or twelve inches deep, a place
for ducks to sport in, and for thirsty cattle
to drink. Where is it now? The parched,
cracked mud at its bottom is all laid bare. It
is certain that it has not sunk into the earth, for
the subsoil is a heavy clay; it has all become
dissipated into the air, in the form of vapour :
in other words, it has evaporated. A saucer
full of water placed on a sunny window-sill,
becomes emptied by this invisible force before
night

It is found that water and all liquids evapo-
rate, or pass off invisibly into the air, even at low

FORCE OF EVAPORATION. 281

temperatures. Ice evaporates in the open air,
even when the temperature is below the freezing
point. This process goes on until the vapour
has attained what has been before called its
maximum density; evaporation then ceases, and
if its temperature becomes suddenly lowered,
the vapour condenses into the form of a liquid.
It is remarkable, that while the presence of air
checks the rapidity with which evaporation takes
place, it does not interfere with its amount.
Thus, if we could empty a sitting-room of air,
and put a basin of water into it, the vapour of
the water would rise almost instantly, and fill
the apartment, until it became as dense as it can
be in this form ; yet, if we put the same basin
of water into the room full of dry air, precisely
the same quantity of vapour would rise from it,
and fill the room just as in the former case, as
if there were no air present, — only it would
occupy a longer time in so doing. Hence we
may perceive, that liquids evaporate with a cer~
tain degree of force. In short, when a drop of
water spilled on a slab disappears, it does so
because it is able to pass into the invisible con-
dition of a vapour, in spite of the pressure of
the air on its surface. It has as much the power
to resolve itself into fine particles which elude
our notice, as if no air were present.

It has already been mentioned, that watery

282 THE CHEMISTRY OF CREATION.

vapour is never absent from the air. When,
owing to some reduction of temperature, this
vapour passes its point of greatest density, it
becomes visible to the eye in the form of a
mist, or fog. The fogs of London have long
acquired, owing to their density, a proverbial
celebrity. " There happened," writes the amus-
ing John Evelyn, " this weeke, so thicke a mist
and fog, that people lost their waye in the
streetes, it being so intense, that no light of
candles, or torches, yielded any, or but very
little direction. It began about four in the
afternoon, and was quite gone by eight, with-
out any winde to disperse it." On the twenty-
fourth of February, 1832, an intensely thick
fog prevailed in the metropolis, and was so
thick at mid-day, that it was impossible to dis-
cern objects or persons distinctly; and at night,
the streets being illuminated in consequence of
some public rejoicings, boys went about the
streets with torches, looking, as they said, for the
illumination! On these two occasions, the fog
appears to have attained an unusual degree of
opacity.

The cause of fog is considered to be the
intermingling of a cold and a warm current of
air, each pretty fully charged with watery
vapour: upon both thus mingling together, so
great a reduction in the temperature of the

VESICLES OF FOG. 283

warmer current takes place, that its excess of
moisture is immediately rendered visible as
fog, and is rapidly deposited. There has been
much question in the minds of the learned, as
to the exact nature of this phenomenon. The
greatest number of philosophers believe the
watery particles to be vesicular, or like so many
minute hollow spheres of water ; in fact, like
miniature soap-bubbles. These vesicles are
supposed to have repulsive tendencies towards
one another. M. de Saussure, who paid more
than ordinary attention to this subject, saw in
fogs which he examined on the Alps, vesicles
float before him as large as peas, the coating of
which was inconceivably thin. This view has
been recently doubted, and in a communication
read before the Eoyal Society, Dr. Waller has
attempted to prove that the watery particles of
fog are not vesicular, but are minute spherules,
or solid beads of water alone. Fog is probably
composed both of vesicular and solid particles of
water.

Whatever be their physical constitution, a
large aggregate of such particles in the higher
regions of the air produces the phenomenon of
Clouds. All that exquisite and inexhaustible
variety of effect, which the artist loves to
imitate, and the eye to rest upon ; all those
glowing pictures of mansions in the skies, of

284 THE CHEMISTRY OF CREATION.

fantastic landscapes, of fleecy snow-drifts, of
overhanging mountains, and rocks gilded by a
declining sun, are the results of the play of
light upon a mass of little particles of water.
The various forms of clouds have been arranged
under three principal classes : The Cirrus, or
curl-cloud; the Cumulus, or heaped-cloud ; and
the Stratus, or fall-cloud. These three classes
of clouds, with their various combinations and
varieties, are represented in the frontispiece
to this Part. However considered, the pheno-
mena of clouds are such as to fill us with wonder.
Held up mysteriously in the air, their ample
folds retain and convey to parched lands at a
distance, or to regions of high mountains and
cliifs, thousands of tons of the refreshing
draught. They are the water-bearers of the
skies. Laden with fresh-distilled liquid, at first
perfectly soft, and free from mineral or earthy
ingredients, and borne upon the wings of the
broad wind, they " turn about fulfilling God's
commands ;" they descend, water and make fertile
the earth, softening it, and making the green pas-
ture to sing with joy.

Our considerations of the " clouds dropping
down the rain," and thus watering the desolate
places of the earth, call us to an explanation
of the latter phenomenon, namely, Rain. It
is supposed to be thus produced : the watery

PHENOMENA OF EAIX. 285

particles of the clouds appear to lose their
mutual repulsion, and several unite into one,
probably in consequence of some change in
their electric relations, a drop is thus formed,
and its gravity causes it at once to fall towards
the earth. As the drop falls, being formed in
higher strata, it is colder than the air through
which it traverses in its passage to the earth;
it therefore condenses more and more vapour
around it, and thus increases in size until it
finally reaches the earth. Even the altitude of
an observatory will make a difference in the
size of a rain-drop, for it is constantly remarked
that rain-gauges at the summit of such a place
never indicate so great a fall of rain as others
placed at the basement, the drops in falling this
height undergoing an increase of size which
became sensible by means of this instrument.
Other explanations of the increase of rain near
the ground are given. Perhaps this is the most
simple and correct.

Although it is not difficult to assign the ulti-
mate cause of rain to a change of temperature,
or to define the process by which vapour be-
comes rain, it must be confessed that great
obscurity still rests upon the laws which in-
fluence its occurrence, and upon the actual
nature of the phenomenon. Rain occasionally
falls from a sky clear as crystal, and altogether

286 THE CHEMISTRY OF CREATION.

undimmed by a cloud. Such a phenomenon
does not appear to have been ever noticed in
our own country ; but an observer who was at
Constantinople relates that he was out in a
pretty heavy shower which lasted for ten mi-
nutes, while the sky was serene and cloudless !
In the island of Mauritius this phenomenon is
very common in the seasons when the south-
east winds blow. About evening time, while the
weather is most beautiful, and the stars shine
with the utmost brilliancy of lustre, a very fine
rain occasionally descends ; and Sir J. C. Eoss
relates that in the South Atlantic, it rained upon
one occasion for upwards of an hour, while the
sky was altogether free from clouds !

The wet season of tropical countries, a season
of almost unintermittent rain of the heaviest
kind, is a very remarkable and regular pheno-
menon ; but is explicable on simple principles.
At such periods the great atmospheric currents,
which in these countries are of great steadi-
ness and duration, receive an altered direction,
and the condensation of an enormous volume
of watery vapour, and its precipitation in the
form of rain, take place as a result of the accom-
panying intermixture of hot and cold streams of
air.

Important chemical functions are discharged
by rain. There are regions where, for five or six

CHEMICAL FUNCTIONS OF RAIN. 287

months in the year not a drop of rain falls, nor
is scarce a cloud to be seen on the molten sur-
face of the sky, yet many trees preserve all their
beauty and freshness of aspect. We are not,
however, therefore to suppose that the office of
rain to vegetation is either trifling or unim-
portant. In these peculiar circumstances, it
has been suggested that the appendages of the
stem, or the leaves themselves, are gifted with a
peculiar function of withdrawing watery vapour
from the air, and thus sustaining existence when
it would otherwise be impracticable. But it
must also not be forgotten that the soil itself
has the property, in a remarkable manner, of
absorbing watery vapour from the air, and no
soil possesses this property more remarkably
than that which is formed of decayed vegetable
tissues, and other matters called humus. Hence
in the tropics, where such a soil is rapidly pro-
duced, owing to the rapid decomposition caused
by the elevated temperature, plants do not
suffer as much as might be the case in time of
drought, were the soil not possessed of this
property. We may perceive, however, in the
picture of the effects of drought presented to
us by travellers in tropical regions, something
of the value and importance of rain to the
earth. The grass becomes burnt up, withered,
and dead. The leaves of the forest-trees hang

288 THE CHEMISTRY OF CREATION.

soft and drooping, and the gigantic flowers
become flaccid, scentless, and faded. The earth
is cracked and parched, animals and birds faint,
and men die for thirst.

In the generality of plants, the supply of
fluids is drawn exclusively, or nearly so, from
the delicate spongioles of the roots, which, with
their multitude of delicate cells, drink in from
the earth the newly-dropped rain, and transmit
the fluid to the stem.* The water, thus sup-
plied, enters .into the circulating system of the
plant, and undergoes decomposition to meet its
wants, while the excess flies off through the
stomata, or mouths of the leaves, or escapes,
with a rich load of odour, from the waxen cells
of the flower.

As the medium by which a number of solu-1
ble substances of importance to the well-being
of plants are conveyed to them, the importance
of rain to the vegetable economy appears still
more evident. Falling in the manner described,
rain is in the most favourable condition for dis-
solving any ingredients of a soluble kind pre-

* At times when no rain falls, and no free water is present
in the soil, which is merely damp, or charged with condensed
vapour upon water, plants obtain their fluid from.waterin this
condition. It appears from some observations and calculations
of Dr. Schleiden, that the greater part of the water used by
plants does not come from rain, but from the vapour silently
condensed by the soil from the air.

IMPORTANCE OF RAIN. 289

sent in the air through which it passes. Its
minute state of division, and the consequent
exposure of a vast amount of surface to the
soluble matters or gases present in the air, ren-'
ders it a most efficient and valuable medium for
bringing down the hoarded treasures of the air
to the needy and expectant soil. When the
chemist in his manipulations wishes to obtain a
saturated solution of a gas, he effects it by a
process as nearly as possible similar to that by
which in nature the same result is produced;
he violently agitates the liquid so as to reduce
it to a mass of drops, exposed on all sides to the
gas intended to be dissolved. Where machines
intended to charge water with gases, and partly
to dissolve the latter in the water, as in the
manufacture of soda water, are employed, the
same effect is produced by a revolving agitator
driven at such a speed as to beat the water into
a fine mist Now, M. Schubler has calculated
that upon a field of 26,910 square feet, the an-
nual fall of rain is about 2,520,000 Ibs. In this
large amount of rain-water is contained much
ammonia, on the lowest calculation about 80 Ibs.
All this ammonia existed previously in a gaseous
form in the air, having been brought down in a
dissolved state -by rain, and in this simple but
beautiful manner rendered valuable to vegeta-
tion ; to which, had it remained in the gaseous

U

290 THE CHEMISTRY OF CREATION.

form, it would otherwise have been little valu-
able.

Carbonic acid gas is also largely soluble in
water. At the ordinary temperature and baro-
metric pressure, water will take up about its
own volume ; a cubic foot will dissolve a cubic
foot of the gas. Carbonic acid exists in air in
still larger and less variable proportions than
ammonia. If the rain dissolves the one, it must
dissolve the other gas. There cannot be a
doubt, therefore, that the descending drops all
contain, in addition to a solution of ammonia, a
notable amount of dissolved carbonic acid. This
solution, coming in contact with the roots of
plants, is absorbed by them, conveyed into the
digestive organs of the vegetable economy, and
being decomposed there, contributes toward the
formation of the solid portions of the vegetable
structure. It appears, from some experiments
by Mr. Mallet, that rain-water, when fresh
fallen, frequently also contains one-fifth of its
volume of oxygen.

The beneficial duties of rain to vegetation
do not end here. When the emigrants of a
new colony set about clearing whole forest
districts, and destroy, by burning, the timber
they cannot store or transport, there are found,
in the ashes, large quantities of alkalies and
other mineral ingredients. These once existed

RAIN AND PLANTS. 291

in the structures of the trees, particularly in
the leaves and young brandies, and rain was
the chief instrument by which they were in-
troduced. Being produced in the soil by virtue
of processes which have already come under
notice, they assume a soluble form, become
dissolved in the rain-water as it trickles down
from the surface to the roots, and are then
absorbed and appropriated by the spongioles of
the plant. It is curious that a shower produces
a stream of water actually containing more salts
and earthy matter than the water which trickles
slowly through the ground. Rain, by softening
the ground, renders the matters therein con-

O *

tained more soluble. 'The frosts of winter break
up the ground, and the succeeding rains of
spring supply the roots of plants with an abun-
dance of soluble matter, then so important to
them.

As a mere mechanical agency, rain is also of
great service to plants. Any one who has seen
the accumulation of dust and dirt which the tur-
moil and bustle of human society causes to rise
and be deposited on all vegetation within its
reach, and has again noticed the fresh and cheer-
ful aspect of the vegetable creation when a new-
fallen shower has been succeeded by a clear sky,
will perceive the importance of this function also
to the well-being of vegetation. The particles

292 THE CHEMISTRY OF CREATION.

of dirt thus deposited, if not removed by some
means, would most seriously interfere with
the respiration of the plants. The stomata or
mouths of the leaves would become clogged up
and unfitted for the discharge of their peculiar
functions, and the most injurious consequences
to the health of the plant would ensue. But
the shower comes down, and, in a few minutes,
all is clean again ; every function is restored
to its due activity, and the scene assumes
a freshness of colouring quite peculiar to such
seasons. The remark does not seem to have
been previously made ; but, it may be sug-
gested, is not the glossy coating of evergreen
shrubs intended to facilitate this process, ren-
dered all the more necessary by the length of
time the leaves endure?

As it restores cleanliness and freshness oi
garb to the vegetable world, so rain also exer-
cises a most beneficial influence upon the con-
dition of the atmosphere. It carries with it
the mass of carbonaceous particles which, owing
to the bad construction of our fire-places, are
cast forth into the air. It also brino-s down

o

that invisible, though not always inodorous
cloud of organic matters which float in the
atmosphere of populous places, and very pro-
bably renders, in many cases, these otherwise
dangerous ingredients of the air of towns com-

RAIN AND MAN. 293

paratively innocuous. That organic matter
exists in rain-water, no one who has made the
experiment of keeping it for a day or two will
be disposed to deny. Its rapid putrefaction is
sufficiently indicative of the presence of such
impurities in it. Muriatic acid, salts, and earthy
matters, are very commonly found in rain-
water. It may be justly remarked that the
purifying influence of rain in this respect is of
a limited degree, and of local application princi-
pally, but it is not therefore to be considered as
unimportant. In fact, it may very reasonably
be doubted whether our large towns would be
able to exhibit such low rates of mortality as
many of them in average seasons do, were it not
for the frequent heavy showers, the occurrence
of which too often forms the subject of com-
plaint against our unstable climate. The dirty
and defiled condition of our public edifices in
England, especially in the metropolis, the inky
waters which roll down the most splendid of our
architectural fl^ades, obscuring the labour of
the sculptor, and greatly defacing the artistic
beauties of the structure, show, in a striking
manner, the mass of impurities contained in the
air, and the necessity for some effectual means
of ridding it from them. The rain which falls
through the smoke-filled air of our towns, con-
tains a large quantity of soot in a mixed state,

294 THE CHEMISTRY OF CREATION.

not in solution. Dust comes down with the
purest rain, consisting chiefly of coal-ashes,
which is apparently the source of the sulphates
and chlorides found in rain. It is sometimes
acid with sulphuric acid.

Though, doubtless, the presence of these
matters in the atmosphere is in a lesser degree
injurious to human respiration, it is far more so
to vegetable life ; for neither the most healthy
previous condition, nor the most careful tending,
will preserve plants in health in our large cities.
It appears, therefore, that we have a cause of
thankfulness, at least in some respects, even for
the proverbial fickleness of our climate, since its
copious showers are the appointed means for
counteracting that measure of mischief which
might otherwise arise.

Let us follow the rain-drops in their descent
into the earth. Whatever soluble matter is met
with by the rain at the surface of the soil, it
carries with it as it sinks downward into the
earth. All the unpleasant results of organic
decay on the surface that are soluble, are con-
veyed downwards by it, and the water, thus pol-
luted, sinks to the underground reservoirs, from
whence man draws his supply of this indispen-
sable fluid. What results might we not therefore
anticipate on an examination of water drawn
from such receptacles; and what a polluted

PROGRESS OF WATER IXTO THE EARTH. 295

condition might we not expect the soil to be in
which forms the filter through which this decay-
ing organic matter penetrates ! Yet, when we
come to examine into these matters, " we do not
find them," in the words of 'Dr. Smith, "present
that exaggerated character which we might sup-
pose." It is surprising, on the contrary, to find
that organic matters, properly so called, are
scarcely, in reality, found in these wells; and,
more singular still, the wells nearest to a source
of organic matter frequently contain less than
others farther removed from the apparent pro-
bability of contamination.

This seems highly paradoxical ; but it admits
of being very beautifully and simply explained.
The analysis of the waters of the wells in towns
shows that they contain a quantity of nitrates.
Liebig found nitrates in twelve wells in Giessen.
Dr. Smith found the same compounds in thirty
wells in Manchester. The wells of London all
contain nitric acid in various forms of combina-
tion. In an old well at Clerkenwell 148 grains
of solid matter were found in a gallon of water ;
there was much nitrate of lime among 'other
earthy salts. In a natural state, this water
ought not to have contained more than about
20 grains to the gallon. In a well near Totten-
ham-court-road, 130 grains of sulphates, chlo-
rides, and nitrates, were contained in a gallon of

7 P C

296 THE CHEMISTRY OF CREATION.

water; the water itself a highly nauseous and
disgusting fluid. Water taken from wells in the
country generally contains organic matter ; thus
presenting a striking contrast to those of the
towns, where much more organic matter exists
on the surface of the soil, but where the well-
water contains chiefly nitrates, not organic
matter, properly so called.

We are therefore led to inquire into the
source of this nitric acid in combination. How
is it formed, and why formed in the town and
not in the country also? The following expe-
riments, performed by Dr. Smith, will show
that it is actually formed by the simple process
of filtration. A jar, open at both ends, was
filled with sand, and some putrid yeast, which
contained no nitric acid, was mixed with pure
water and poured on the sand, allowing it to
filter through. Nitric acid was found abun-
dantly in the fluid which dropped from this filter.
It must have arisen without question, then,
from the combination of the nitrogen of the yeast
with oxygen, in its passage through the sand.
Putrefied meat, treated in the same way, gave
the same result. A bottle of strong sulphuretted
hydrogen water was poured upon the sand-filter,
yet the liquid which dropped through only con-
tained sulphuric acid. Water, from a certain
pump, exhaled strongly a smell of sulphuretted

SELF-PURIFYING PROPERTIES OF THE SOIL. 297

hydrogen which filled the neighbouring houses ;
yet, when filtered, such water had no smell at
all, and was commonly drunk by the inhabit-
ants. The sulphur of the sulphuretted hydro-
gen had been converted into sulphuric acid,
and thus the water was purified.

We may learn from these most interesting
discoveries a highly important fact, namely,
that there is a most active process of oxidation,
or union with oxygen, constantly taking place
in the soil. Nitrogenous matters are carried
down into the soil, there filtering through
various loose materials, — upon the surface of
which oxygen is supposed to be condensed, like
ammonia by charcoal, undergo oxidation, and
nitric acid is the result, which then combines
with the various salts and bases it meets with,
forming nitrates. What is very curious, is, that
the more organic matter is on the surface, the
more certainly will nitric acid be thus formed ;
it seems as if a certain excess of organic matter
favoured the process of its conversion into nitric
acid. The sulphur and nitrogen of organic mat-
ter being thus oxidized and rendered compara-
tively harmless, it appears probable that its
carbon is also oxidized, and forms in many
instances the sparkling carbonic acid gas which
we so familiarly know to abound in most spring
water.

298 THE CHEMISTRY OF CREATION.

Thus there is in nature a grand process of
filtration incessantly continued, the fulfilment
of which is intimately connected with the health
and well-being of the inhabitants of both city
and field. By this means a most powerful
oxidation of all injurious matters is constantly
taking place, and the perfect purification of
the most impure substances is effected. The
ditch-water of our fields differs widely in purity
from the water of a subsoil drain. The first
will be highly charged with animalcules and
organic matter; the second contains but very
little. The oxygen thus united to these mat-
ters alters their constitution in the most com-
plete manner. They are not left behind in the
soil, for it has been found that the sand used
in large water-works for filtering, after being
used for weeks, and thus becoming the instru-
ment of effecting the oxidation of an immense
body of organic matter, is not impure in a high
degree, only containing about one and a half
per cent, of organic and volatile matter. Hence
both the soil itself remains comparatively free
from contamination, and the matters passing
through it are, nevertheless, perfectly purified.
What a beautiful portion of the chemistry of
rain is this ! What an illustration of the per-
fection of the arrangements of God, to behold
the muddy and polluted waters sink into the

HAILSTORMS. 299

earth, there, by Nature's chemistry, become
perfectly ridded of their dangerous contents,
and rise pure and sparkling to the surface
again, now admirably adapted for all the pur-
poses of man and animals !

When rain-drops in their course toward the
earth become exposed to a degree of temperature
below freezing point, or 32° of Fahrenheit's
thermometer, they become congealed into solid
masses, and in this condition are known as Hail.
It has been considered by some that hail is pro-
duced by the rapid descent of the rain-drops
when first formed, causing a rapid superficial
evaporation, the cold produced by which freezes
the rest of the globule. Hail is also produced
from a nucleus of snow, which gathers weight
as it descends. As the frozen drop falls, con-
densing 'continually more watery vapour around
it, which, becoming also frozen, adds to its
size, it proceeds with accelerated rapidity until
it reaches the earth, striking on its surface fre-
quently with considerable violence. It is sup-
posed by others that the origin of hail is attri-
butable to the sudden encounter of two masses
of cloud of very unequal temperature. Hailstones
of a very large size are frequently found in
summer hailstorms; and the force with which
they fall is proportionate to their size. Hail-
stones of the size .of a. goose's egg have

300 THE CHEMISTRY OF CREATION.

sionally been picked up in the Orkneys. Fable
tells that there once fell near Seringapatam a
hailstone as large as an elephant ! At a late
meeting of the British Association, Dr. Robinson
stated, that an instance was on record of a mass
of ice having fallen from the air, fifteen feet
across ! It has been calculated that the rapidity
with which hailstones of a large size fall, equals
fifty miles an hour, their destructive force being
correspondingly great. The mischief done by
hail at times can scarcely be estimated. Many
thousands of pounds would not cover the damage
of the tremendous hailstorm of 1846 ; and in
vine countries their ruinous effects are felt still
more severely. Seasons are on record when the
whole vintage of large domains in Southern
France, and elsewhere, have been annihilated.
On the 14th of January, 1849, at a certain town
in the Deccan in India, there was a hailstorm,
during which some of the stones were from two
to two and a half inches diameter, and weighed
from 'one to two ounces each. Hailstones pre-
sent various crystalline appearances on exami-
nation. A hailstorm is frequently accompanied
by violent electrical phenomena.

Snow is formed under circumstances corre-
sponding to those accompanying the formation
of rain, but instead of condensing into drops,
it crystallizes from a previously vaporous

SNOW CRYSTALS.

301

form into a multitude of minute separate
forms, often possessing the greatest variety

SNOW CRYSTALS.

and singularity of appearance. After under-
going this change of condition, the snow begins

302 THE CHEMISTRY OF CREATION.

gradually to descend, forming in its course
small flakes, which, uniting with others in fan-
- tastic groups, at last reach the earth. Elegant
varieties of form are occasionally discoverable
in the structure of a snow-flake even in our
own temperate regions, but in 'the Arctic re-
gions their beauty assumes the most remarkable
character. The celebrated Arctic traveller,
Scoresby, has described a great number of
different crystalline forms, some of which re-
semble objects of which the imagination would
scarcely dream of their assimilating to in
form. Thus, among others, there are beautiful
varieties which resemble stars, others wheels,
pyramids, very complex mathematical figures,
rosettes, leaves, spines, feathers, and others
equally curious. These are represented in the
adjoining cut. Strange to think, a few degrees
less heat evolve these beauties of form and
aspect out of a drop of water ! Strange also to
remember that a few degrees more heat reduce
them all to the transparent mobile fluid out of
which they sprang ! It has been supposed that
snow favourably influences vegetation, from its
containing a solution of atmospheric oxygen ;
but in this respect it cannot be much superior
to rain ; and it is difficult to imagine that plants
must be indebted to snow for a principle
which in the adult state all the day long they

ELECTRICAL ORIGIN OF RAIN, DEW, ETC. 303

reject from their leaves ! Most probably the
non-conducting properties of snow, by prevent-
ing the dangers of excessive cold to plants, are
those to which its serviceable reputation is
chiefly due. It is, however, very certain, that
snow contains proportionably more ammonia,
and probably more carbonic acid, than rain-
water.

There can be no doubt now, that electricity
plays a most important part in these aqueous
phenomena of the atmosphere. Humboldt
writes — " In fogs, and at the beginning of
falls of snow, I have, in the course of a long
series of observations, seen the previous per-
manently vitreous " (or positive) " electricity,
change suddenly into the resinous " (or negative)
" electricity ; and these alternate repeatedly,
as well in the plains of the frigid zone as under
the tropics in the Paramos or Alpine wilder-
ness of the Cordilleras, between ten and twelve
thousand feet high. The alternate transition
was in all respects similar to that which the
electrometer had shown shortly before during
the continuance of a thunderstorm." Mr. Of. A.
Rowell, in a communication laid before the
British Association in 1847, states his convic-
tion, that most of the phenomena of evapora-
tion, rain, hail, and even of the winds of
temperate regions, are due to electricity. He

304 THE CHEMISTRY OF CREATION.

considers that the minute particles of watery
vapour are each, even in their most condensed
state, completely enveloped in a coating of
electricity, and are thus rendered sufficiently
buoyant to be carried away by the wind.
When expanded by heat, their specific gravity
being reduced, and their capacity for electricity
being increased by the increase of surface, they
are then buoyed up into the air by their elec-
trical coatings. When these particles are con-
densed, they are supposed to become surcharged
with electricity by the contraction of their sur-
face ; and if this takes place near the earth, the
surcharge escapes, and the particle falls as dew ;
but if the particles are condensed when they are
above the influence of the electrical attraction
of the earth, they are still buoyed up by elec-
tricity, and on the escape of the surcharge the
particles attract each other and produce clouds
and rain.

Connected with the theory of the influence
of electric changes upon and in the production
of rain, hail, &c., is the proposition which
has been seriously entertained of sending up
copper balloons in the vine districts of France,
by which means the electricity of the atmo-
sphere might be conducted harmlessly to the
earth, and the formation of the terrific hail-
stones which devastate those districts be avoided.

SINGULAR EFFECTS OF FIRES, ETC. 305

In the year 1788 the devastation committed
by a hailstorm amounted to twenty-five millions
of francs! It becomes, therefore, assuredly a
serious question whether means for averting
these wide-spread calamities might not be suc-
cessfully adopted.

Propositions proceeding upon similar prin-
ciples have also been made for bringing down

,&m I $Ki^>-gSs

PEAIEIE ON PIEB.

artificial rains ! It is well known that the
Indians of Paraguay, when their crops are
threatened by drought, adopt the expedient of

306 THE CHEMISTRY OF CREATION.

setting fire to vast plains of grass, and as the
result, expect storms of rain and even thunder;
nor are they, as it is said, often disappointed.
A similar effect has been also observed to follow
the occasional conflagrations which take place
in the American prairies and woods. It is con-
ceivable that in these cases great electrical dis-
turbances are occasioned which end in the
production of rain. It has been noticed at
Manchester, the weather has become constantly
and progressively more and more rainy as the
city has increased in size, and in the number of
its vast manufactories ; so that now the number
of rainy days is very large indeed.* M. Arago,
the French astronomer, appears disposed to
account for this singular fact by supposing that
the enormous chimneys of the cotton-mills, and
other factories, withdraw a large amount of
electricity from the atmosphere, and thus bring
about this effect. The effects of volcanos in
producing rain by their eruption are sometimes
very remarkable. It has been related, that
when a volcano bursts out in South America
during a dry season, it not unfrequently
changes it to a wet one. Great fires in dif-
ferent localities have been said to be often

* A person much exasperated with Manchester weather,
said to another that it rained every day there. " No," re-
plied the other, " it only rains six days out of every seven !"

AETIFIC1AL KAIN. 307

followed by violent rain, with thunder and
lightning.

Mr. Eowell proposes to bring down artificial
rain by raising electrical conductors to the
clouds by means of balloons. The following
extract from a letter quoted by him appears
to lend some probability of success to his pro-
position : — " It has several times happened,"
observes the writer, "that when my elec-
trical kite has been raised immediately under
a distended, light, fleecy cloud, at a mode-
rate elevation, and a free current of sparks
has passed from the apparatus for some ten or
twelve minutes, I have suddenly found myself
bedewed with a descent of fine misty rain,
and, on looking up, I have seen the cloud
upon which I was operating surprisingly re-
duced in magnitude !" " Electrical kites," ob-
serves Mr. Eowell, "cannot reach the clouds,
and can only be raised in windy weather, when
the clouds must be every instant passing away
from the influence of such apparatus; and if
they have such effects, what, may we not antici-
pate from the use of conductors which would
reach the clouds, and could be raised in calm
weather?"*

* Mr. Espy, an American writer, proposes to create arti-
ficial rains in time of drought by setting fire to large bodies
of combustible substances.

308 THE CHEMISTRY OF CREATION.

Whether such plans will ever succeed or not,
can scarcely be foretold. As yet, great obscu-
rity hangs over much that concerns the various
conditions of the " waters of the air," and we
may still address to philosophy the sacred
words — "Dost thou know the balancings of
the clouds — the wondrous works of him that is
perfect in knowledge?"* It may please the
Author and Giver of all wisdom to disclose to
human research much of that which now eludes
•our grasp with reference to this as to other sub-
jects. Until then, as regards rain from heaven,
it is his will to keep us the daily pensioners of
his bounty. Let us seek to cherish that hum-
ble and dependent spirit which accepts with
gratitude and love all the dispensations of his
wise and gracious providence, knowing that to
them that love him all things are working
together for good.

* Job xxx vii. 1G.

CHAPTER V.

MOVEMENTS OF THE AIR.

UPON the blue horizon of the scene we are con-
templating, something resembling a white cloud
may be seen gently gliding along the distant
waters. By the aid of a telescope we make out
this white object to be a vessel under sail. In
a little time it is lost to view ; it appeared to
sink into the vacancy between the water-edge
of the horizon and the sky which it almost
appears to touch. Turning our eyes toward
the sky, we perceive the light and fleecy clouds,
which seem at a great depth in the firmament,
to be also borne smoothly and slowly along.
The smoke of a cottage chimney beneath us
does not rise straight into the air, but is slightly
bent to one side, and stretches out slantingly
upwards for some distance. The browsing of a
sheep hard by has shaken a full ripe thistle.

" A whitening shower of vegetable down
Amusive floats,"

and is carried silent and smoothly over the field,
until it is lost to sight.

All these indicate movements in the air,

310 THE CHEMISTRY OF CREATION.

although where we are now placed they are
so soft and gentle that we do not feel them.
But some of the movements may be actually
seen. If we look attentively at certain objects,
as on a hillock, upon which the heat of the sun
has been directed all day long, we shall perceive
a number of minute undulations in the air just
above it. This is rendered still more apparent
if a telescope is employed, and so interferes
with the direction of the rays of light as to
make the objects appear distorted and indis-
tinct Upon the sea-shore this effect is some-
times curiously manifested, and at a little
distance off we may observe the whole shore-
line marked by the waving and trembling
stratum of air rising above it up to a certain
height. The cause of these tremulous move-
ments is undoubtedly the heat of the sun, since
on a cold or cloudy day they are not perceptible.
The grand cause, indeed, of most of the move-
ments of the air is the solar ray, and the mode in
which it acts is explicable in a simple manner.

It is generally said that the air only receives
heat from its contact with the earth, and absorbs
but a very minute portion of the heat rays of
the sunbeam as they pass through it. Recent
experiments have shown this idea to be in some
measure erroneous. In a series of experiments
conducted by Professor Forbes, it has been found

CAUSE OF MOTION IN AIR. 311

that the absorption of the solar rays by the
strata of air to which we have access is consi-
derable in amount, even for moderate thick-
nesses. By calculation it has been found that
about one-third of the solar heat is lost by the
transmission of the rays through our atmosphere.
The watery vapour present in the air absorbs
these rays in a remarkable degree. We are thus
shaded, as it were, at all times from the full
influence of the solar heat. While, however,
this is true, it is also certain that the atmo-
sphere receives a much larger portion of heat
from its contact with the heated earth. In
consequence of this the particles of air expand,
become specifically lighter, and are rendered
sufficiently buoyant to rise upwards, their places
being immediately supplied by cooler particles of
air drawn from the vicinity. If, therefore, we
suppose a particular spot or tract of land to be
heated by the sun, while a neighbouring part
remains comparatively cool, the immediate result
is that an upward current rises from that spot
and ascends into the higher regions of the air.
But as it rises, its place below must be occupied
by an equal bulk of air which is necessarily
derived from the sides. A current is thus im-
mediately established, an ascending stream in the
one case, and a horizontal flow of greater or less
force in the second.

312 THE CHEMISTRY OF CREATION.

It is related by an observer, that if in a still
day the atmosphere of London, or some equally
great city, were to be carefully observed in calm
weather, it would be found that in the morning,
streams of fresh air are flowing in from the
country round about the metropolis down all
its suburban streets, to supply the place of the
current which, heated by the vast city, rises up
into the air from its centre. Prevailing cur-
rents or other accidental circumstances, so con-
stantly interfere with this phenomenon, as to
make it difficult to verify the observation.
A common fire-place furnishes us with an ex-
cellent home-illustration of the same laws.
A hot ascending current pours up through the
chimney, and to take its place a cold horizontal
stream sets from under the door, or from open-
ings in the floor made for its accommodation.
In tropical climates this law produces the inte-
resting and vastly -important natural phenomenon
of Land and Sea breezes. During the day, under
the powerful rays of a vertical sun, the land
becomes greatly heated, much more so than the
sea; an ascending current consequently arises
from the land, and to supply the place thus
partially vacated, a body of cool air flows in from
seaward, producing the sensible effect of a fresh
breeze blowing from the sea, from about nine
in the morning until two or three o'clock in the

LAND AND SEA BEEEZES.

313

afternoon. The sun then beginning to lose its
power, the land also begins to cool, and towards

314 THE CHEMISTRY OF CREATION.

evening, and during the night, the land being
a better radiator of heat than the water, it be-
comes colder than the sea. The heated column,
therefore, now rises from the sea, and the cold
horizontal flow is from the land, the sensible
result being a fresh breeze to seawards. When
the heated column, in either case, reaches a
certain height in the air, it turns over, blows
along the upper regions, and then comes down
to supply the place of the descending current.
This will be readily understood by reference to
the figures, which rudely represent the state of
things during the day and at night.

A modification of the "same phenomenon which
has been frequently observed in mountainous
regions, is the hill and valley breeze, and it
arises precisely from the same cause, namely,
inequality of temperature setting in motion an
ascending and compensating current. Mr. Dar-
win makes particular mention of a powerful one
observed by him in his travels in Mexico.

Winds, due to a similar cause, whose peri-
odical occurrence was familiar to the ancients
under the title of the Etesian winds, take place
on land, when one district being more heated
by the solar rays than another, the cold current
of air flows from and across others, to supply
the place of the ascending hot current.

Incomparably the most important and grand-

THE TRADE WINDS. 315

est atmospheric movement is that of the Trade
Winds ; and we shall find in this phenomenon
another illustration on the large scale of the
fact of inequality of temperature producing
movements in large masses of air. There are
particular regions of the globe whose tempera-
ture is in the most violent contrast, as those of
the equator and the poles. Here, therefore, we
have all the conditions necessary for the pro-
duction of motion in the air. Under the beams
of a tropical sun, the equatorial regions become
heated to a high degree and over a vast area.
The result is, that an enormous body of air
rises from these regions, the place of which
must be supplied from cooler parts. Hence, if
the earth were not in revolution on its own
axis, a cold current would flow from both poles
directly to the equator, there rise with the
ascending heated current, and turning over, it
would proceed to the poles in the higher strata,
and would again descend to pursue the same
course. This is clearly indicated in the accom-
panying diagram.

But the earth revolves on its axis. In so
doing it carries its atmosphere with it. The
equatorial regions being further from the cen-
tral axis of the earth, are in more rapid motion
than the polar, just as the rim of a wheel moves
faster in the same time than any part of the

316 THE CHEMISTRY OF CREATION.

axle, and therefore the equatorial atmosphere
has a more rapid movement through space than
that of the poles. If now we suppose a current

to be dragged across the surface of the earth,
from the slowly revolving poles to the rapidly
revolving surface of the equator, it is necessarily
unable to proceed at once at the same rate as the
latter, and the consequence is, that the swiftly
moving regions of the earth brush against a
mass of air having a slower motion than them-
selves. Hence there are two forces to be con-
sidered in the production of the trade winds —
1st, the ascent of a heated equatorial column of
air, and 2nd, the resistance offered by a slowly
moving current of air proceeding in a horizontal-
direction from the poles to the equator. If the
earth were stationary, the under current would

PHILOSOPHY OF THE TRADE WINDS. 317

perpetually blow directly from the poles to the
equator; but in consequence of its revolution,
the direction of the current is bent aside, and
the wind becomes an easterly wind with a direc-
tion from the north, or from the south in south
latitude, instead of a strictly north or south
wind. Since the earth revolves from west to
east, a current of air having a less velocity than
the surface over which it was being drawn,
would be felt by one standing on the earth as a
wind from the east. As we approach the equa-
tor its northerly direction gradually ceases, and
it is felt as an east wind, and thus forms the
more proper trade wind, a current blowing from
east to west within the tropics. Thus the high
temperature of the equator sets in motion, and
the revolution of the globe modifies, the direc-
tion of the trade winds.

The effect of the earth's motion in producing
what is felt to be a wind, by its brushing
against a body of slowly moving air, may be
rendered somewhat more intelligible by refer-
ence to an every-day illustration. The outside
traveller on a railroad carriage, going at the
rate of thirty or forty miles the hour, expe-
riences apparently a very powerful current of
air blowing in his face, so long as the machine
continues in motion. Yet he may notice the
distant smoke curling up from the cottage

318 THE CHEMISTRY OF CREATION. '

chimney, and rising into the air in an almost
perpendicular column ; the leaves on the tall
poplars beyond are still, and the few fleecy
clouds which rest on the blue sky have no
sensible motion. The atmosphere, then, is
calm and motionless. The apparent wind is
the result of the resistance a swiftly moving
body experiences in passing through the air.
The current is, in fact, the difference between
the motion of the carriage and that of the air
through which it passes. In like manner the
mariner placed on the watery surface of our
swiftly rotating globe is whirled along insen-
sible to himself at a greater velocity than the
bed of air which lies above him, and the sen-
sible effect is that he perceives a strong and
equable wind in the opposite direction.

Having thus hastily traced the lower current
to the equator, let us now follow the ascending
column. Upon rising to a certain altitude, it is
there to some extent cooled, by parting with its
heat into space by radiation, and its upward
progress is necessarily arrested ; the current is
then deflected, and flows towards the poles in a
grand stream. As it proceeds it still loses heat,
and at about the 30th degree of latitude, it is
so cold as to descend and change places with
the lower current from the poles. Proceeding
onwards still it receives heat from its contact

DISCOVERY OF THE TWO CURRENTS. 319

with the earth, and again rises to form the
upper current, being displaced by the cold and
heavy, air flowing from the poles. There is
thus a sort of atmospheric chain formed, which

--— C'V. *T / H>*""^^^iw

^AxT^fi&L

™&

fwwa

m

mmm

Mfc~

will be more clearly understood by reference
to the cut. At all places, however, above the
latitude of 30°, in consequence of the variations
in the amount of heat received from the earth,
these currents are very irregular.

Now, this upper current, having a different
velocity, in consequence of its origin at the
swiftly rotating equator, to that of the more
northerly or southerly slower moving regions
which it has now reached, takes on the apparent
character of a wind from west to east, and thus
appears as a westerly wind. And when the

320 THE CHEMISTRY OF CREATION.

upper current descends to take the place of the
lower, at about the 30th degree of latitude, it
is actually felt as a violent westerly gale. At
the poles, and within the polar circles, there
is a constant steady polar gale toward the
equator on every side. The effect of the earth's
motion in altering the direction of these cur-
rents, is exhibited in the accompanying cut.

N

The upper current was long suspected to
exist, before its existence was positively known.
A curious accident at length decided it. In 1822
an immense volcano burst open in the island of
St. Vincent, and vomited to an enormous alti-
tude showers of stone and ashes. Strange to
say, although the trade wind blows so strongly
in the opposite direction, that a circuit of- one

LOCAL WINDS. 321

hundred miles is necessary to enable vessels to
reach Barbadoes from St. Vincent, a quantity
of volcanic ashes fell on the island of Barbadoes,
which undoubtedly had their origin in the
eruption at St. Vincent. The only explanation
of this singular event was upon the supposed
existence of this upper or back current. The
power of the volcano had projected these ashes
entirely through the lower current into the
upper, and after being carried by it, they were
dropped in Barbadoes. Another curious con-
firmation of its existence is recorded by Messrs.
Humboldt and Bonpland. They set out on an
expeditibn to ascend the Peak of Teneriffe; at
its base the trade wind was blowing strongly in
its customary direction, but upon reaching the
summit they found they had actually penetrated
through the lower stratum of air and got into
the upper, and they now felt a strong wind
blowing in a precisely opposite direction !

A variety of local winds, receiving their
peculiar modifications from the circumstances
in which they originate, are to be found treated
of in works upon meteorology. Many of these,
together with those here mentioned, appear to
be easily explained upon the great principle of
the inequalities of temperature. But many cir-
cumstances render it at least probable that other
causes of motion in air exist beside, or perhaps

Y

322 THE CHEMISTRY OF CREATIOX.

superadded to, those of heat and cold. Mr.
Eowell, whose views on the formation of rain,
and aqueous meteors generally, were mentioned
on a previous page, has also put forth some
curious speculations touching the origin of
irregular winds generally. He conceives that
as water in its vaporous condition occupies,
when suspended in the air, much more space
than when it falls as a rain-drop, it must in the
act of its falling cause a vacuum in the air
which must be filled up by a rush of air from
the surrounding districts. He supports his
views by various calculations" as to the average
vacuum per square mile caused by some heavy
storms of rain. He also mentions that in the
autumn of 1846, while France and other parts
of the Continent were deluged with rain, storms
of wind swept over England from the north-
west and west.

It has also been thought that electricity, in
its various modifications, was in some manner
connected with the irregular movements of the
air. And it has been remarked as particularly
observable, that in the regions where the mag-
netic influence* of the earth is at the lowest

* Although the phenomena of magnetism differ in several
curious particulars from those of the principle we commonly
call electricity, such as that developed by friction, both are
believed to be only the manifestations of one and the same

KOTATORY THEORY OF STORMS. 323

intensity, as in the midst of the Southern
Atlantic, storms seldom or never occur : while
in those where its intensity is greatest, hur-
ricanes and violent tempests are extremely
common. If importance is attached to the
views of the electrical origin of most meteoro-
logical phenomena, it may be readily conceded,
also, that alterations in respect of the electricity
of the air may have some direct or indirect
influence in setting in motion irregular currents
of air. Upon these points there exists at pre-
sent much ignorance ; but in consequence of
the greatly-increased amount of attention now
paid to the science of storms, it is to be hoped
that much of our present obscurity will in a
little time be dissipated.

One of the most remarkable and beneficial
discoveries hitherto made by meteorological
science is what is called the rotatory theory of
storms. By this is meant the remarkable fact
that hurricanes, typhoons, and it is probable
other violent storms in all regions of the world,
have a revolving motion. They do not blow,
that is to say, in a straight line from a point
many hundreds of miles distant, but they are
vast eddies in the air which whirl round like
the eddies of a stream of water, or like the
water let out of a basin by a plug at the bottom.
Besides this revolving movement, these storms

324 THE CHEMISTRY OF CREATION.

have also a movement from place to place, and
it is highly remarkable that this movement of
translation also takes place not in a straight line,
but in a curved direction.

It is possible that when all the phenomena
of these storms are fully developed, the mariner
will be able to direct the course of his vessel in
such a manner as to escape beyond their de-
structive influence. Very recently, the captain
of a vessel, by availing himself of the knowledge
of this fact, saved his ship, and escaped without
damage from a violent storm, which might
otherwise have endangered not only property
but life. Of all the glories of science, none
equals that of a well-directed and successful
attempt at diminishing the risk of human life.
Yet while we owe much to the labours of those
who have discovered its important truths, let it
not be forgotten that we owe all to that Great
Being, who from time to time permits his crea-
tures to obtain a view of those mighty govern-
ing principles with which He orders and directs
the course of natural events.

Should the inquiry be made as to the im-
mediate connexion between the chemistry of
nature and the movements of the air, the reply
must be that the connexion is most intimate.
The irregular capricious winds which constantly
agitate the air of temperate regions, fulfil a

INSENSIBLE MOVEMENTS IN AIR. 325

most important office in nature's chemistries.
Powerful as is the influence of the diffusive
force of gases in dispersing abroad the noxious
emanations of any particular district or region,
it may be reasonably doubted whether this
force is anything like sufficient of itself to pre-
serve the purity of a densely-populated region.
It is true we might not be sensible of any ill
effects from even a three days' calm in our own
temperate climate, although such a state of the
air seldom endures for more than a few hours.
But this could not long continue without
originating very serious evils. If we imagine
a crowd of human beings placed in a hall, how-
ever great its magnitude, and the air of such
a building entirely without motion, it is easy
to foresee the result. The impure emanations
from the lungs and bodies of so many human
beings would accumulate in this motionless mass
of air to such an extent as to render it in a lesser
or greater period of time altogether irrespirable,
and death would be the consequence of con-
tinuing under its influence.

Such also would be the condition of a great
city over whose hundreds of thousands of inha-
bitants hung an atmosphere totally without
motion, without a breeze to fan the cheek or a
storm to intermix the varioiis parts of air and
impurities together. Under such circumstances

326 THE CHEMISTRY OF CREATION.

a city were as surely doomed to destruction
as though the windows of heaven were opened,
and her living multitudes engulfed in a 'deluge
of waters.

It is, however, impossible for such a condition
as a dead calm to exist in the atmosphere of
any region. It is true that to the senses there
may be no apparent motion in the air, and every
leaf of the forest may hang idly and unstirred on
the branches. But there are invisible movements
incessantly occurring in the stillest air. Not
only by day, but even in

" The stillness of a moonshine heaven,"

these insensible commotions are constantly
taking place. Not only in the open air, but
in the closest shut apartment, the airy particles
are never at rest. This is easily proved. Let
the windows be closed up with shutters all but
a little hole through which a pencil of sunlight
may stream. Standing at a little distance, we
may perceive that the whole track of the sun-
beam is as it were animated. Particles of dust
are seen incessantly rising, falling, moving now
in this now in that direction, thus plainly indi-
cating that the air in which they float is moved
without ceasing.

A part of these insensible and imperceptible
motions of the air are due to its elasticity and

CAUSE. 327

to the facility with which its particles, like
those of all gases, move over or between each
other, at the application of the least force. If we
do but gently breathe upon the thick and num-
berless particles forming

" The gay motes that people the sunbeams,"

they are instantly thrown into the most violent
commotion, and the disturbance does not cease,
in consequence of the small amount of friction,
for a very long period.

Part also are due to the effect of heat upon
air. A body heated, whether naturally or arti-
ficially, instantly causes motion in the particles
of air by which it is surrounded. If, for ex-
ample, a cannon ball were heated to redness
and placed on a tripod, as in the cut, it would
cause the surrounding air
to be in rapid motion. A
stream of hot air, upon the
principles before alluded to,
would rise up, and a stream
of colder air would be con-
tinually called to occupy its
place. In this manner a
current would be set up
which would somewhat re-
semble, could its direction be rendered visible,
the appearance shown in the cut. Therefore

328 THE CHEMISTRY OF CREATION.

every object upon which the sun shines, every
tree, rock, and hill before us,- that feels the
genial influence of its rays, is an instrument
for communicating motion to the air, and, in a
degree by no means to be despised, assisting to
preserve the intermixture and purity of the
atmosphere.

The effect of these imperceptible movements
is perhaps slight for a given time, but in their
constant operation, at times when no breath of
air stirs around us, they contribute largely to
preserve the air of our apartments and cities in
a condition fit for respiration, or at least more
fit by far than if they did not exist. When we
reflect how soon by their agency and that of
diffusion a cloud of smoke is dispersed, until
not a trace remains ; how soon an offensive gas
is wafted away, or a volume of dust dispersed,
we shall be better able to appreciate this unseen
instrumentality.

Proportionately to its increased force is the
purifying influence of wind. The last-named
movements are able to dissipate impurities only
to a small extent, and within a very limited area.
Wind, on the contrary, is a body of air in move-
ment sufficiently powerful to sweep away every
accumulation of foreign ingredients in the atmo-
sphere generated by accident, or by the influ-
ence of congregated masses of mankind. How

BENEFITS OF A FICKLE CLIMATE. 329

often do we, who live in temperate latitudes,
vainly and thoughtlessly bemoan the incon-
stancy of the wind ! And yet there is un-
questionable wisdom manifest in the appoint-
ment of this very phenomenon. The masses
of human society, proportionally to the area
occupied by them in temperate regions, both
naturally and by artificial processes, vitiate
the air considerably more than do those of
tropical countries. Contrast, for example, the
purest atmosphere of England with that of
an American prairie, and while no chemical
difference in the quantities of ingredients might
be detected by our limited analysis, yet it is
positively certain, as a mere inference from
known facts, that the air of a country con-
taining upwards of sixteen millions of inhabitants
within a very limited area, possessing besides
immense manufactories, and consuming enormous

* Q

masses of fuel per annum, must be less pure
than that of a region where the eye in vain for
hundreds of miles seeks even the traces of a
human habitation. What, then, were the con-
dition of England, we may ask, but for her vari-
able winds ?

In all probability, were there a constant cur-
rent from any quarter, it would not accomplish
anything like the amount of intermixture which
is effected by the shifting winds of which we so

330 THE CHEMISTRY OF CREATION.

undeservedly complain. During the prevalence
of cholera, this was 'actually noticed by the
meteorological observers at Greenwich. On
many days when a strong breeze was blowing
on the top of the Observatory and over Black-
heath, there was not the slightest motion in the
air near the banks of the Thames ; and this
remarkable calm continued for some days to-
gether. On September 11 and 12, however,
the whole mass of air at all places was in
motion, and for the first time for nearly three
weeks the hills at Hampstead and Highgate were
seen clearly from Greenwich. These capricious
currents carry away the smoke of cities, and roll
the masses of aerial impurities hither and thither
until they become diluted indefinitely, and ulti-
mately entirely lost. Again they return, bearing
from the fields and woodlands the pure air, in the
words of Spenser, so —

" Gently attempered and disposed so well,
That still it breathes forth sweet spirit and wholesome
smell."

Thus by their ceaseless changes they so agi-
tate and intermingle the atmosphere of our
country, as to preserve in it a degree of purity
and freshness which could in no other way be
attained. In tropical countries the population
is not so large in proportion to the area occu-
pied, and manufacturing processes are scarcely

known among them. Hence they produce in
proportion little carbonic acid, and a steady
constant current in any direction would be
amply sufficient to remove the comparatively
small amount of foreign ingredients thrown into
the air. These thoughts deserve to be remem-
bered when we are disposed to declaim against
the fickleness of our climate, for it appears that
though it may prove a " partial evil/' it accom-
plishes an " universal good." Yet when the
changeful wind is accompanied frequently by
moisture and wetness, without a positive rapid
precipitation of rain, our complaints of the
fickleness of our climate and of its effects upon
the atmosphere of our towns are more remark-
able. When the day is dull and wet the smoke
of the city rises only a little distance above the
chimneys, and is then poured down into the
streets, enveloping men and houses in a dark
and gloomy mantle of offensive gases and
vapour. The carbon contained in the smoke
absorbs the moisture of the air, and becoming
too heavy to seek, as in dry days, the upper air,
falls slowly down to the ground. The mineral
substances of smoke fall with it, and these,
added to the empyreumatic odours developed in
combination, truly render a wet or damp day
in our towns in the last degree disagreeable.
A heavy shower, on the contrary, carries down

332 THE CHEMISTRY OF CREATION.

these matters at once, and the air is all the
clearer afterwards.

It will be necessary, in a future page, to
advert to the use of the Trade Winds in carrying
forward and preserving the purity of the at-
mosphere on the whole. They also subserve
another and scarcely less important function —
that of preserving in a sort of equilibrium the
temperature of the atmosphere, and to some
extent of the regions over which their influence
is felt. The tropics are thus the perpetual
sources of enormous floods of warm air, which,
rising up and flowing over, proceed ultimately
to the poles, and in all probability exert a very
considerable modifying influence over the seve-
rity of the arctic regions, as well as over those
which they traverse on their way thither.

How wonderful is the unity and dependence
of creation ! The movement even of a breath
of air is not without its purpose and its end.
Let this soft and scarcely sensible current,
which as we talk of these things here salutes
our cheek, when we are reminded of all the
marvels of its origin, and of the intentions for
which it has been put in motion, waft our
praises to Him whose divine power and love
reveals itself even in a summer wind !

CHAPTER VI.

THE ATMOSPHERE AND ANIMALS.

CONSIDERING that all animate and inanimate
bodies alike are immersed in a sea of gaseous
fluids, which possess affinities of a powerful
kind for the different elements of the organic
and inorganic kingdoms, it will not surprise
the reader to learn that important chemical
functions are perpetually discharged by the
balmy and apparently inert air which fans his
brow or cools his cheek. To these chemical
relations of the air we are now to draw atten-
tion, and in so doing we shall first direct the
consideration to the chemistry of one of the most
important functions of the animal frame — namely,
the function of breathing, or respiration.

When we expire the air we had previously
taken into the lungs — no matter whether from
the mountain-ridge, or in the less healthful At-
mosphere of a crowded town — an important
alteration in its chemical composition has taken
place. We are not conscious of this fact ; but
it is one which may be readily proved by the

334

THE CHEMISTRY OF CREATION.

simplest means. If a vessel is filled with water
in which some fresh-burnt lime has been slaked,
and the water decanted off clear — which is now
what is commonly called lime-water — and if then,
taking a glass tube, we breath some of the air
we are expiring from the lungs through it, we
shall have rapid evidence that a change of some
kind has taken place in this air in the altered
appearance of the pre-
viously clear and pellucid
fluid. It now becomes
quickly turbid and milky?
and eventually deposits a
whitish sediment. Air,
in its ordinary condition,
would not produce this
decomposition, whatever
it may be; for the li-
quid remains unclouded,
though a large volume of
air be passed through it
by a bellows. Therefore
the air we take into the
lungs has this striking difference from that we
expire from them, that while it produces no
alteration in the colour or composition of lime-
water, the latter decomposes it and renders it
turbid. It will be interesting now to inquire
— What is the nature of this difference ?

CHEMISTRY OF BREATHING. 335

The white precipitate is carbonate of lime,
an earth formed by the union of carbonic acid
gas with lime. From analyses already given
of the atmospheric composition, carbonic acid
has been found to be invariably present in air,
and therefore it might be said this precipitate
indicates nothing more than what might have
been expected. And it is true that lime-water,
after being exposed for any length of time to
the air, is decomposed, and carbonate of lime
falls to the bottom of the vessel But in the
simple experiments above mentioned this diffi-
culty disappears, for it will be found that the
bellows must be moved all day long to get a
sensible precipitation, whereas a single expira-
tion of air from the lungs will instantly render
the fluid turbid. Although, therefore, it is
certain that a minute portion of carbonic acid
exists in all air, it is, on the other hand, equally
certain that there is an enormous disproportion
in the quantities contained in ordinary and in
expired air. In the one the amount is merely
fractional ; in the other it is present to a large
per centage. The air which has done duty in
the lungs receives a large amount of carbonic acid
gas as it leaves them.

Let us now enter upon another range of
thought. In cases of disease it is very often
considered necessary to open a vein, and to

336 THE CHEMISTRY OF CREATION.

withdraw variable quantities of the blood circu-
lating- in the system. The fluid thus derived is
always of a dark colour, and sometimes is almost
black. But, occasionally, disease calls for the
opening of an artery, and then the most striking
difference is perceptible in the appearance of the
blood ; for it is of a vivid bright-scarlet hue. If
the dark venous blood is exposed for some little
time to the fresh air, it loses its dark colour, and
assumes the lighter aspect of arterial blood :
but it still differs from arterial blood in many
important particulars. This change is directly
attributable to the influence of air, for it would
not take place in a vacuum. If a moist piece
of bladder were laid over the fluid, it would
not prevent the change from dark to red ; and
it is known to physiologists, that when dark
blood becomes circulated in an organised living
structure over a large surface, upon which al-
ternate currents of fresh air play, the mere cir-
cumstance that air is not brought into direct
contact with blood does not interfere with its
chemical effects on that fluid. Direct con-
tact with air is therefore not necessary to
effect the change, since it will take place very
readily through the medium of an interposed
animal membrane. This is, in part, due to the
laws of the interpenetration or diffusion of
gases, and in part to the remarkable forces called

THE LUXGS. 337

endosmose and exosmose, which enable the solu-
tion of a gas to pass throTigh a moist mem-
brane with considerable facility.

The requisite conditions, then, for the che-
mical changes of respiration to take place be-
tween the air and the blood are, access of fresh
air, and the circulation of dark blood on one
side of a moist animal membrane. In the lungs
these conditions exist to their fullest degree.
There, perpetual influxes of fresh air play upon
an enormous surface of animal membrane, which
is covered with a dense mesh of blood-vessels,
all carrying dark blood. To these organs the
streams of blood from the remotest parts of the
body are directed by the propulsive energies of
the heart. At the same time, muscular arrange-
ments, externally and internally disposed with
miraculous skill, and kept in action by an un-
tiring power, continually partly fill and empty
these organs, which are subdivided into innu-
merable tubes, terminated by minute cells,
producing the ordinary phenomena of inspi-
ration and expiration, or, in other words, of
breathing. By this means, a measured quan-
tity of air is admitted to the chest, and then
expelled again, and so on alternately, about
eighteen times in each minute. The pure air
is thus received, and the impure is discharged.

At this stage, two facts about respiration are

z

338 THE CHEMISTRY OF CREATION.

brought prominently under our view. — 1st.
There is a discharge of carbonic acid gas from
the lungs. — 2nd. In the lungs, a remarkable
alteration takes place in the blood. And we
must proceed immediately to add to them
a third, of nearly equal importance; namely,
That while carbonic acid gas is discharged from
the lungs, a quantity of the oxygen of the in-
spired air is received by them, and disappears
in the process of respiration. Thus, to put the
changes in clear terms, from the measure of air
which goes into the lungs, a certain measure of
oxygen is abstracted, the place of which is
supplied by the addition of carbonic acid. We
are naturally, therefore, led to suppose that
these three chemical phenomena — the change
of the blood, the absorption of oxygen, and the
discharge of carbonic acid gas in respiration —
are in some measure connected with each other.
Their connexion is as follows : —

The blood — in circulating along the arteries,

GO *

through the fine capillary vessels, to the veins
which carry it back to the heart, and in the per-
formance of its various duties, as the source of
nutrient and regenerative matter, to every por-
tion of the animal frame — besides parting with
many other ingredients, loses a large amount of
oxygen which, in its condition as arterial blood,
it had previously contained. In so doing, it

REMARKABLE CHANGE IX THE BLOOD. 339

acquires carbonic acid and other principles, and
changes colour from the bright scarlet to the
dark hue. In short, from being "arterial" it
becomes "venous" blood. Blood upon which
this change has passed may now be considered
as unfit to fulfil the functions previously de-
volving upon it. To render it again serviceable
for the purposes of the animal economy, it must
be altered, and restored to the pure and health-
ful state of arterial blood. It is a well-known
fact, that venous blood cannot circulate for any
length of time without producing the most
serious and even fatal consequences. Some che-
mical agency, therefore, must interfere to re-
store its lost wholesomeness, or the functions of
the animal economy would soon cease, never to
be recommenced. After performing its round,
the blood is directed into the lungs, and poured
through millions of fine tubes which line the
walls of the air-cells. Here the blood comes into
contact with the air inhaled into these organs.

C

Exposed on such a vast surface to atmospheric
influence, the dark fluid loses the carbonic acid
with which it was laden, and receives from the
air a fresh, and exactly equivalent, supply of
oxygen gas ; and now it turns from dark red to
scarlet, and from the deleterious character of
venous to the healthful composition of arterial
fluid. This done, it is removed from the lungs

340 THE CHEMISTRY OF CREATION.

as quickly as possible, in order that its newly
acquired properties may not be lost, by means
of several large blood-vessels, singularly straight
and simple, with a view to facilitate this ob-
ject, and re-enters the heart, which, by its in-
cessant toilings, despatches it on its life-giving
errand throughout the frame.

The most recent results on the chemistry of
respiration discloses the following facts : — *

1. Warm-blooded animals exhale nitrogen in
proportion of from y^ to -^ of the oxygen con-
sumed in breathing. 2. Animals fed on fari-
naceous food exhale a measure of carbonic acid
exactly equal to the oxygen inspired ; but if fed
on animal food, they absorb oxygen sometimes
equal to ibur parts in ten of that inspired ; and
if on leguminous food, they absorb a quantity
intermediate between that in the tAvo former
cases. 3. The consumption of oxygen is di-
rectly proportionate to the surface of the body,
and inversely to its bulk, so that a sparrow is
found to consume ten times more oxygen in a
given time than a fowl. This arises probably
from the cooling effect of the greater surface.
Lastly, in their winter-sleep, or hybernation,
animals in some cases actually increase in weight,
though without food, living only upon the air,
and appropriating its oxygen and nitrogen.
* M. Regnault.

ANIMAL HEAT. 341

Such is a large part of the chemistry of re-
spiration. Professor Schonbein throws out the
hint that ozone may perform an important part
in the chemistry of respiration. Other philo-
sophers have engaged themselves with the
question — By what agency are these processes
carried on? but hitherto only to arrive at con-
flicting results, and to indulge in unsatisfactory
speculations.

Let us now put the following inquiry: — If a
thermometer were placed under the tongue of
an Arctic seaman, and the degree marked by
the instrument compared with that indicated by
another placed in the mouth of a Hindoo, or
any other inhabitant of the burning tropics,
would there be any difference between the two
points ? In the one case, an icy air seventy or
eighty degrees below the temperature natural
to the body, would surround the individual ; in
the other, a scorching heat, many degrees above
that temperature, might envelope him. Yet,
notwithstanding this extreme degree of con-
trast in external circumstances, there would be
actually no difference, or but a very trifling
one, between the degree of heat indicated in
each case !

This wonderful truth informs us of two
things — 1st. That the animal frame has an in^
ternal source of heat, unaffected by external

342 THE CHEMISTRY OF CREATIOX.

cold ; and, 2nd. That it has a power of refrigera-
tion, or of reducing its temperature, by which
it is enabled to prevent its natural temperature
rising beyond a certain point. The latter func-
tion, upon which we shall not further speak, is
due to the cold produced by the enormous eva-
poration which takes place from the surface of
the body, and the extent and rapidity of which
are proportioned to the external heat. The
former and more mysterious power is known to
physiologists under the title Animal Heat.

It is found that whenever the element carbon
undergoes, in any of its combinations, the pro-
cess of oxidation or union with oxygen, the
change is invariably accompanied by the evolu-
tion of more or less heat. It is no matter where
the combustible material is burnt, that is, is
united with oxygen ; whether in a furnace of
iron, or in the animal frame, the same quantity
will give out the same amount of caloric. Eea-
soning upon this fact, ingenious speculators
have been led to suggest that the organs of
respiration are the heat-furnaces of the body,
and that -fuel supplied to them produces just
as much heat in them as it would do if burnt
in a fire-place or consumed in a lamp.

It has been seen above, that in the lungs a
continual process of union of the constituents
of the blood, carbon, hydrogen, with oxygen,
takes place. Chemistry positively assures us

COMBUSTION IN THE BODY. 343

that this cannot occur out of the body without
the extrication of heat ; therefore the union of
blood-materials in the lungs with oxygen must
produce heat. Again, in the minute vessels,
called capillaries, which exist in almost every
portion of the frame, oxidation takes place, for
the arterial blood gives oxygen to the tissues,
among which it circulates ; here again, there-
fore, heat must be eliminated. Thus we see
that the body possesses two sources, or rather
two localities for the evolution of heat — the
lungs and the capillaries ; in other words, heat
is evolved all over the frame, and particularly
in the lungs. The perpetual ingress of cold air?
and the enormous loss of heat by evaporation,
demand that the lungs should be specially pro-
vided for; and this is considered to be effected
by the perpetual oxidation taking place there.
While, however, this is true to some extent,
there can be little doubt that the animal frame
possesses other sources of heat in addition to
that of respiration derived from the process of
oxidation.

The carbonic acid given out in respiration
is a sufficient proof that carbon has been burnt
somewhere, for when carbon burns in air it
forms carbonic acid gas, and the above consi-
deration indicates the locality where this heat-
producing process takes place. Respiration is
really and truly a process of combustion. The

344 THE CHEMISTRY OF CREATION.

chief fuel consumed is the carbon and hydrogen
contained in the materials of the blood; and
therefore derived indirectly, or immediately, as
the case may be, from the food. Calculations
have been made as to the actual amount of fuel
necessary to keep up the temperature of the
human body for one day, and it appears, that
of all economical furnaces the animal frame is
that which evolves the most heat from the same
amount of fuel ; for an adult healthy man only
consumes for the purposes of respiration about
fourteen ounces of fuel-carbon every day ! * A
large quantity of hydrogen also is consumed in
respiration, and produces a notable amount of
that sum of heat, which, with the thermometer
at ' Temperate,' is required to keep the body
at 96° or 97° for one day.

The function of respiration, therefore, alone
makes large demands upon the body for fuel.
Man supplies this, together with the other
demands for his nutrition, &c., by the food he
consumes. A large part of the food is fuel.
Just as in winter we find it necessary to heap
up our fires, and thereby to increase the con-
sumption of fuel in order to keep up the tem-
perature of our dwelling-houses to an agree-
able point, so with man. In proportion to the

* No artificial furnace whatever can compare with these
animal furnaces, for the most economical consumes, according
to Baron Liebig, not less than from ten to twenty times this
amount of fuel in producing the same amount of heat.

THE ESQUIMAUX AND HINDOO. 345

intensity of external cold must be the amount
and heat-giving quality of the food he requires.
Food differs largely in the amount of heat
equal quantities will give out. Bodies into
whose composition carbon and hydrogen enter
largely, are those whose combustion will afford
the most heat. He who basks in the heated
air of the Tropics, requires but little combus-
tible food compared with him who is con-
demned to the rigours of a Polar atmosphere.
Hence the easily-satisfied Hindoo might con-
ceive it utterly impossible for an Esquimaux
or a Russian to devour his seven or eight
pounds of flesh per diem, with the addition of
train oil and tallow candles ! Yet, if he were
placed in similar external circumstances, he
would probably find his appetite so sharpened
as to compel him to adopt a somewhat similar
habit of life. The great amount of heat lost
by radiation from the body of the Esquimaux
must be made up, or life will be forfeited.
Respiration can make up a great part of it,
but it requires a proportionate supply of heat-
giving fuel,* and it is a familiar fact, that oils
and fatty matters are substances which in their
combustion eliminate a very large amount of

* We must however guard the reader against the error of
supposing that all the enormous quantity of extra food con-
sumed by an inhabitant of the Polar regions is burnt in the
lungs in order to supply heat to the body. Far from it : cal-
culations have been made, which show that if such were the

346 THE CHEMISTRY OF CREATION.

heat in consequence of the large proportion of
carbon and hydrogen entering into their com-
position. The appetite in a healthy man is
the beautifully-adjusted measure by which the
fuel-food requisite for the condition in which
he is placed is determined. In the keen air
of the north, it is much more loud in its calls
than in the heated and depressing atmosphere
of the Equator ; and a careful attention to this
natural index would enable men in these con-
trasted situations to regulate their supply of
food accordingly ; and would doubtless tend
in some degree to the preservation of health
of the body under these opposite circumstances.
It has been remarked, that over-warm clothing
and a keen appetite in temperate weather are
incompatible with each other; and doubtless
this curious fact is connected directly with
respiration. When the body is covered with
a number of non-conducting materials, its loss
of heat is greatly lessened, and the call upon
respiration is therefore lessened in proportion :
and this again tells back upon the appetite, and
informs the system, so to speak, that less food
is necessary for its wants. But reverse the
condition; — let a man be clad in rags, and the
intensity of his appetite increases proportion-

case the individual must inhale eight times as much oxygen
as an ordinary adult, and his pulse must move at the rate of
500 beats a minute— which is clearly impossible.

OTHER SOURCES OF ANIMAL HEAT. 347

ably. Hence it is a purely scientific fact, that
the poor and ill-clad creatures who tread our
streets, suffer most severely from the calls of
hunger, although the sensation may be, per-
haps, blunted in many instances by the fre-
quency of its exercise. In the case of the poor
man, respiration, supplied with but scanty fuel,
and called upon to do more than ordinary duty
to keep an ill-covered body warm, draws its
supply from the structures of the body, and is
no doubt the primary cause of that large amount
of diseases of debility whose victims are almost
exclusively to be found among the poor of this
world.

It is ascertained that, in addition to respira-
tion as a source of heat, there are several other
causes in the living animal body by which the
temperature of the whole system is maintained.
In digestion, which is in great part a chemical
process, a considerable amount of heat is extri-
cated. " Every mechanical movement of the
body," observes Mr. R. Hunt, " occasions the
development of heat; every exertion of the
muscles produces sensible warmth; and indeed
it can be shown by experiment that every ex-
pansion of muscular fibre is attended with the
escape of caloric, and its contraction with the
absorption of it. There is no operation of the
mind — not even the most idle thought — which
does not excite the latent caloric of the body ;

348 THE CHEMISTRY OF CREATION.

and frequently we find it manifested in a very
remarkable manner by a suddenly awakened
feeling. The poet, in the pleasure of creation,
glows with the ardour of his mind ; and the
blush of the innocent is but the exhibition of
the phenomenon under some nervous excitation
produced by a spirit-disturbing thought. Thus
we see that the processes of digestion and re-
spiration are not the only sources of animal
heat, but that many others exist to which much
of the natural temperature of the body must be
referred."*

Thus reminded of the importance of the air
to man and the animal world at large, we can
feel the full import and accuracy of the expres-
sion, the " breath of life ;" for only while we
breathe we live. There is more, therefore, than
health in the soft airs which float around us.*
Upon them our very existence is every moment
dependent. The breeze not only refreshes and
cools the cheek, but gives strength, activity,
and warmth to the entire frame. The learned
Dr. Derham well said, " It is the air the whole
animal world breathes and liveth by ; not only
the animals t inhabiting the earth and air, but
those of the waters too. Without it most ani-
mals live scarce half a minute, and others that are
the most accustomed to the want of it live with-
out it many days."

* The Poetry of Science, p. 382.

BREATHING OF INSECTS.

349

Yonder sleeping flock and those shade-seek-
ing cattle are not less debtors to the air for life
than is the cowherd on the river bank, or the
shepherd under the elm. And in the animals
the function of breathing differs but little from
the same function as carried on in the human
frame. In the animal world generally there is
found the same general principle to prevail with
respect to this function ; that is, the air is
drawn into a cavity upon the sides of which the
vessels containing the blood ramify, and so the
vital oxygen of the air becomes applied to the
blood and is re-
ceived into it, and
so also the impuri-
ties and waste mat-
ters of the system,
those at least which
can be thrown off
as gas or vapour,
become discharged.
There is a remark-
able exception in
the structure of in-
sects. Here there
is no organ like our
lungs : but, strange

. °. AIB-TUBES OF INSECTS.

to say, the air is

conveyed by a series of beautiful fine pipes

all through the body, even to the extremities

350 THE CHEMISTRY OF CREATION.

of the limbs ! This of course answers the
same purpose as the other arrangement, the
blood-vessels of the insect ramifying over these
air-tubes, or tracheae, as they are scientifically
called. The same objects are effected by
this arrangement as by the other, namely, the
oxygenization of the blood and the removal
of its impurities. The breathing of those
members of the zoological kingdom whose
abode is in the waters will be noticed in the
concluding part of this work.

Yet while fulfilling these important duties,
the air has others of an opposite kind also to
discharge with respect to all animal bodies. The
whole bodily frame is in process of incessant
change, to a large degree, by the influence,
direct or indirect, of the vastly important
function of respiration, and by the oxidation
which goes on to a greater or less extent through
the skin all over the body. No part remains per-
manent. Its tissues are nourished by the blood,
their waste parts are carried off into the air, or
rejected in other ways as excrementitious, and
new particles take their place. In a little time
these again, having served their turn, become
effete, and are cast out of the body. Yet these
ceaseless changes do not affect the form of
organs and their peculiar characters, unless,
indeed, disease has been established in them.
Curious truth ! even the accidental impression

CHEMISTRY OF STARVATION. 351

of a long-forgotten injury, the honourable scar,
or the effect of a severe laceration, remain in
enduring memorial of the event upon the un-
changing yet ever altered surface. Although
undergoing perpetual alteration of their parts,
the features with all their characteristics re-
main the same. Time may indeed brush the
down off the young man's face, and blanch the
ruddy hue of the maiden's cheek ; it may pinch
up the full features of youth into the withered
lineaments of age ; but a little mole on the skin
defies the effects of time, and even of death —
entering the tomb with the rest of the cold clay
it had so long distinguished.

The atmosphere must be considered as one of
the grand agents in the perpetual work of re-
paration and destruction. Its chemical ener-
gies are continually arrayed against the very
existence of the human body. It is only by
daily recruiting his strength that man is able
even for his brief allotted period of life to offer
a sufficient opposition to its effects to permit
of his healthy existence. If his means of so
doing fail, a destructive process immediately
commences. The active lungs continue their
incessant play, and the swift-flowing blood
demands and receives from the tissues of the
frame the fuel for which these organs call.
The stored-up fat quickly disappears ; the round
contour of health vanishes ; starvation begins.

352 THE CHEMISTRY OF CREATION.

The body slowly consumes away; the muscu-
lar tissues shrink and soften, and the haggard
face and incipient delirium assure us that the
work of death is going on at the nervous
centres. If no help arrives, if the poor starving
one is left to be " burnt with hunger," death
sooner or later ensues, and the expression of
the sacred text, which strikingly coincides with
the philosophy of starvation, is realized ; for the
unhappy person is burnt alive. This effect is
unquestionably principally due to the oxidizing
influence of the atmosphere.

Our " earthly tabernacle" is but a tent after
all ; a tent which each moment undergoes re-
pair and waste. The structure which is the scene
of such incessant conflicts between the powers
of destruction and reproduction, is already
doomed. The balance cannot always be kept
in equilibria; equalization of the forces cannot
always be secured. The surplus accumulates ;
the reparative powers give way before the on-
ward march of the destructive. The body
wastes down, as we say with old age, and when
not actually hurried into the grave by disease,
dies at last of exhaustion. Well is it for him
who is able to say with one of old, " I know
that if the earthly house of this tabernacle be
dissolved, I have a building of God, an house
not made with hands, eternal in the heavens."*
* 2 Cor. v. 1.

CHAPTEE VII.

THE ATMOSPHEEE AND VEGETATION.

LET us now proceed to make inquiry as to
the mutual relations subsisting between the
air and the luxuriant vegetation which sur-
rounds us. How and in what way are these
blades of grass affected by the summer breath-
ings which pass in wave-like movements over
them ? The direct connexion of animals with
the chemistry of the atmosphere can, as a
general rule, only be said properly to be imme-
diately established when they first draw the
breath of life, although undoubtedly they are
indirectly the recipients of its beneficial in-
fluences in their previous condition of imma-
turity. In birds, however, and oviparous
creatures generally, from the earliest dawn
of the principle of life within the shell, this
relation commences, only to cease with their
death. The presence of the atmosphere is in
like manner essential to the commencement
of vegetative life. The seed can only begin
to grow, or, in other words, to germinate, by

2 A

354 THE CHEMISTRY OF CREATION.

virtue of its presence. Much, therefore, of
the success of the florist, and, on a larger
scale, of the agriculturist, depends upon this
simple and often forgotten condition of things.
The seed must have access to air. It is also
necessary that it should be surrounded by a
medium sufficiently but not too moist, and
that a moderate degree of warmth should exist
in the bed into which it is cast. It is a singular
fact also, that while the luminous rays of light
interfere with or even prevent this process, by
some discoveries of Mr. R. Hunt it appears
necessary that the actinic or chemical rays of
the solar light should reach the seed in order to
its germination.

Placed in these favourable conditions, the
seed absorbs moisture from the soil and oxygen
from the air. A series of intricate chemical
changes is immediately commenced, the gluten
of the seed is altered, and its starch is con-
verted into sugar for the nutriment of the
young plant. Water and carbonic acid are also
formed during this process, and in a short time
the head of the young plant peeps above the
soil.

Passing by the less important period of vege-
table infancy, we are led on to that far more
interesting time when the plant and the atmo-
sphere enter into new relations with each other,

NUTRITION OF PLANTS. 355

on the fulfilment of which the most momentous
results to all animate creation depend.

In a previous section of this work it was
stated that plants derive but a small proportion
of their solid constituents from the soil in
which they grow. It has been before men-
tioned that the chief solid material of a plant
is its carbon ; also that plants live with their
roots buried in a material (vegetable mould)
extremely rich in carbon. Yet, on the ques-
tion being put, Do plants derive their carbon
from the mould? the answer has been, Certainly
not. This must now be proved.

Experiment has shown that it is impossible
for a plant to receive nutriment by its roots in
any other but a soluble and perhaps a gaseous
form. Be the nutrient material what it may,
it must first be in one or other of these con-
ditions, before it can be appropriated by the
vegetable economy. The rootlets cannot take
up solid matter ; nor, if they could, could the
plant grow upon such a diet. If the hungry
fibres wandered in their search for food through
a mass of dry sawdust, or threaded their way
through a pile of stones, they would find none,
— because they would find nothing dissolved
in such a situation.

Applying this to our present subject, vege-
table mould may be considered as almost in-

356 THE CHEMISTRY OF CREATION.

soluble. If its solubility were represented by
figures, one part of good mould would dissolve
in 100,000 parts of water. The same might be
said of many stones; in fact, some show a»con-
siderably larger solubility. A plant, therefore,
whose roots meandered through a mass of pow-
dered stones, would be actually in a better con-
dition, as regards its supply of soluble matter,
than one planted in pure vegetable mould.

It becomes clear, then, that while analysis
fully confirms the fact that the vegetable soil
abounds in one of the elements of wood, or in
carbon, yet, at the same time, we arc taught,
that it is in such a condition as to be utterly
useless to vegetation for food. The source of
wood in plants is, consequently, not in the soil.
Its true source is the atmosphere. This may
excite surprise, and even challenge belief, but it
is based upon the most incontestable evidence
afforded by vegetable physiology. The wood of
plants is derived from the thin air which they
breathe : thus air, or, more properly speaking,
one of its ingredients, is actually the food of
vegetation. The orchis-tribe, or, as they are
commonly called, the " airplants," furnish us
with a beautiful illustration of this fact. These
plants, in their native haunts, are found upon the
branches of lofty trees, seated as it were in state,
and surrounded with groups of flowers and leaves,

THE ORCHID TRIBE. . 357

whose fantastic forms and gorgeous aspect make
them objects of the most extraordinary character.
The glowing colours and delicious fragrance of
these plants have given them admission now to
our conservatories. In the plant-stoves at

ORCHIDS GROWING OK A DEAD TRUNK.

Kew, orchids are to be seen growing upon pieces
of dead wood, or out of a little moss in iron
baskets, or out of oyster-shells, cocoa-nuts, and
the like. Their long, naked, snake-like roots drop
into the air from the topmost boughs on which

358 THE CHEMISTRY OF CREATION.

the plant sits, but never reach the earth. The
sunshine, the heavy dew, the occasional shower,
and the balmy air, are all their dietary. There
are, it is true, a number of terrestrial orchids,
and they, as other plants, derive a part of their
carbon from the carbonic acid of the soil. In
addition to the orchids, the extraordinary plant
called the " stag's horn " fern, is almost exclu-
sively nourished upon the air. This plant is also
to be seen at Kew, where in one of the tropical
stoves it will be found growing upon a piece of
wood ! Its great leaves, in shape resembling
antlers, hang down in a singular manner } and
the whole plant presents us with a remarkable
instance of a vegetable deriving little or nothing
from the substance on which it grows, and yet
flourishing in the greatest luxuriance upon a diet
of water and air !

These plants are not strictly parasites, for
they do not live upon the natural juices of the
branches on which they grow ; therefore their
carbon could not have been derived from the
boughs on which they rest. The question may
then be put, If they do not derive their carbon
from the air, from whence do they obtain
it? Nor are orchids and these curious ferns
solitary in this property of living in the air
alone, for several other plants have the same
faculty. The conclusion therefore cannot be
resisted, that the air is the principal, if not

REMARKABLE FACTS ABOUT PLANTS. 359

the only, source of carbon in these instances;
and if in these, most probably in all other
plants.

Some other facts may be mentioned, on the
authority of Dr. Schleiden, which in a striking
manner set the same great fact with regard
to other plants before us. He observes : " The
oil-palms (Cocos nucifera, and Elais guineensis)
grow in sea-sand. The culture of the latter
is largely carried on on the west coast of
Africa in moist damp sand, not enriched by
manure. Between the years 1821 — 1830, Eng-
land alone imported from the coast of Guinea
107,118,000 Ibs. of palm-oil, and therewith
about 76 million Ibs. of carbon (contained in
the chemical composition of this oil), drawn
from a soil which in itself contained no carbon. . .
According to Darwin, the richest maize harvests
are obtained, from the interior of Chili and
Peru, from the most sterile quicksands, which
are never enriched by manure, and where only
small streamlets from the Andes supply any
water. . . . The soil of the entire district of
Brandenburg consists entirely of sea and down-
sand. It is still in many places composed of a
loose and pure quicksand of 100 feet deep, and
so movable that it does not, as I have had
opportunity of witnessing in the neighbourhood
of Berlin, require any very high wind to
change entirely the configuration of the surface.

360 THE CHEMISTRY OF CREATION.

Young pines are found sometimes standing with
their first branches buried in the soil, and after
eight days with a naked stem, and the roots so
exposed that one could creep through them!
(Yet) this soil, as is seen in the Spriewald, so
far as it is moistened by the rivers Sprie and
Havel, produces vigorous pine vegetation, which
most certainly cannot draw all its carbon from
sources furnished by the soil, for it has never
possessed it, nor has it been furnished to it by
artificial processes."

It is remarked by Colonel Campbell that the
cinnamon tree flourishes best in a soil which
consists chiefly of sand. He says : " The soil
of the cinnamon garden, in the neighbourhood
of Colombo, (as well as that near Galle and
elsewhere, in which the cinnamon-tree is grown ;
and in many places it is produced naturally,) is
a remarkable instance of the silicious kind.
The surface of the ground in many places,
where the cinnamon plant flourishes, is white
as snow : this is pure quartz sand. Below the
surface a few inches, where the roots penetrate,
the sand is of a grey colour. A specimen of
this, dried thoroughly, was found to consist of —

98'5 silicious sand.
TO vegetable matter.
0'5 water.

100-0 "

SOIL NOT CHIEF SOURCE OF CARBON. 361

If these facts are considered, it will become
apparent, that the true source of the carbon of
plants cannot be in the carbonaceous matter of
the soil, seeing that vegetation is luxuriant even
upon soils which contain little or none of this
element.

The carbonic acid furnished to the air by the
various processes of combustion, respiration, and
putrefaction, and from volcanic craters, is the
true source of the carbon of the vegetable
world. The composition of this gas is one
equivalent of carbon, united to two of oxygen
gas. If we could remove the two proportions
of oxygen, carbon is left. Wood is composed
of carbon, together with the elements of water,
oxygen, and hydrogen ; it contains other prin-
ciples, but it is sufficient for our present purpose,
to consider wood to be chiefly carbon. If there-
fore any structure is supposed to have the power
of decomposing carbonic acid, of rejecting its
oxygen, and of appropriating its carbon, model-
ling it for the peculiar purpose of its organ-
ization, the atmospheric origin of wood is ren-
dered perfectly feasible. All we have to do is
to show that plants possess this decomposing
power; that is, they really are able to destroy
the union between carbon and oxygen in car-
bonic acid. If it should appear that plants are
really endowed with this power, it is not diffi-
cult to believe that they should be able to use

362 THE CHEMISTRY OF CREATION.

the element which they set free, and by the
powers of vitality to apply it to the different
purposes of their economy.

The following experiment will doubtless be
considered decisive as to the chemical influence
of plants over carbonic
acid. Dr. Priestley took
a sprig of mint and put
it into a glass vessel (see
Fig.) which contained air
mixed with a considerable
quantity of carbonic acid.
He then put it in a posi-
tion where it was well
THE SPHIG OF MINT. exposed to the light, and
left it for a little time.

He subsequently analysed the air contained in
the jar, and to his astonishment found that all
the carbonic acid had disappeared, and the air
within the vessel contained more oxygen than
common air ! De Saussure performed similar
experiments; and he found that not only had
carbonic acid disappeared, but that actually a
notable amount of oxygen had been added to
the air, and the plants under examination had
also increased in weight. Boussingault per-
formed a yet more conclusive experiment. He
enclosed a vine-branch in a glass receiver ex-
posed to sun-light, and containing air with a
certain proportion of carbonic acid gas. The

FORESTS OF THE NEW WORLD. 363

vine-branch was found to have absorbed and
decomposed half the carbonic acid of this
portion of air in a very short time. These
plants, in decomposing the carbonic acid, had
appropriated its carbon and rejected the
oxygen.

Before, however, this theory of the origin
of wood can be considered to be satisfactorily
confirmed, we should inquire whether the air
really contains sufficient carbonic acid to supply
the wants of the vegetable world. Humboldt
says, that in some of the forests of the New
World, monkeys might run a hundred miles
in a straight line upon the tops of the trees !
The amazing mass of carbon contained in such
forests can therefore be scarcely represented
by the ordinary powers of numbers. Is it
possible that all this was derived from the air ?
Does, in fact, the atmosphere contain a sufficient
amount of this element to account for the sepa-
ration of so great a mass of it as exists in this
single instance, not to take into consideration
the entire vegetation of the rest of the globe?
The carbonic acid of the atmosphere has been
estimated at one-thousandth of its whole weight.
The entire weight of the atmosphere is known ;
and calculating upon it, it has been found that
the entire, weight of carbon contained at one
time in the atmosphere is about three thousand
and eighty-five billions of pounds. Calculations

364 THE CHEMISTKY OF CREATION.

have been made as to the actual demand upon
the atmosphere for carbonic acid, of the whole
vegetation of the earth. If we suppose the actual
surface covered by vegetation to be one-fifth of
the entire area of our globe, that will give a
space of two millions of square miles, or of
43,124 millions of acres. Let us suppose that
each acre derives every year 2,000 Ibs. of carbon
from the air; then the whole annual necessi-
ties of the vegetable world in a year amounts
to about 300 billions of pounds of carbonic
acid. How is this enormous annual drain to be
supplied? Dr. Schleiden calculates that from
tobacco smoking alone we have a supply of car-
bonic acid in a year equivalent to 1,000 millions
of pounds. He bases this odd calculation on
the following grounds. North America alone
produces in a year enough tobacco, on its
being burnt, to yield the immense sum of 340
millions of pounds ! The other tobacco-grow-
ing districts supply the rest. Yet when we
contrast the insignificant cloud of smoke rising
from a single pipe — more, perhaps, from those
used by Dr. Schleiden's continental country-
men than from our own — together with that
rising from our furnaces and factories, how in-
significant does even this enormous sum appear,
compared with that which from combustion of
fuel alone escapes into the air ! When it is

EFFECT OF VEGETATION ON AIR. 365

remembered that from a number of other
sources carbonic acid is discharged into the
atmosphere, little difficulty as to the existence
and constant supply of a sufficiency of this gas
in the atmosphere to account for all the wood
upon the earth's surface will be experienced.

Such is the chemical history of the formation
of wood from the air. Let us now inquire what
becomes of the other element entering into the
composition of carbonic acid gas — namely, oxy-
gen. Is it condensed and solidified, so as to
form a part of the vital structures of the plant?
or is it again rejected, and again returned to
the air ? Upon the answer we are able to give
to this question depends another important
point, — Do plants purify, or do they vitiate
the air ? If they retain the oxygen of the car-
bonic acid they decompose, they rather tend to
vitiate the air than otherwise, by removing one
of its most essential ingredients. But if, on
the contrary, they reject the oxygen, retaining
only the carbon, they purify the air in a double
sense ; for they not only remove from it a dan-
gerous ingredient, but add to it a salutary one,
in the element of oxygen.

The opinion popularly held is not altogether
correct. It seems to be a general impression,
that the presence of plants in a room, or to be
long in the air of a conservatory, is unwhole-

366 THE CHEMISTRY OF CREATION.

some ; for it is said, the plants vitiate the air.*
It is important to set the real state of this
beautiful case of nature's chemistry before the
reader, if only to assist him to a right know-
ledge of facts. To ascertain the point, the fol-
lowing experiment may be suggested to those
who are sufficiently expert in mechanical and
chemical manipulation to attempt it. Take any
plant, the branches of which are sufficiently
long and well-clothed with leaves (see cut), and
insert it in a dish of mercury, bringing it up
through the fluid into an inverted glass jar filled
with air containing a slight excess of carbonic
acid.f The apparatus may be easily arranged,
as in the cut, and the whole must be exposed
to sun-light. If now, in a few days' time, the
air in the jar is examined, by merely intro-
ducing a lighted taper into it, it will be found
that the flame is much more brilliant than in
open air, — which is due to the presence of an
increased amount of oxygen in the air of the
jar. From this we learn, and the experiments
of Boussingault, Saussure, and Priestley, have
with due accuracy proved the fact, that plants
in reality, while exposed to the sun, retain the

* Plants with a profusion of flowers undoubtedly vitiate the
air, to some slight extent, until the flowering season is over.

f Easily produced by pouring a little dilute hydrochloric acid
over a lump of chalk or marble, and then allowing the gas to
escape into a jar, out of which it may be poured into this jar.

FUNCTION OF PLANTS.

367

carbon and give out the oxygen of carbonic
acid — thus incontestably proving that their
function is to purify the air of this gas, and to
restore it to the element oxygen.

These grass-covered fields, and those leaf-
crowned forests, are not the mere ornaments of
the scene we contemplate. They do not flourish
for nought, or live in vain. The pure air which
lightly floats along the meadow, and softly
whispers the wood-leaves to sleep, parts not
with them as it finds them. It comes bearing a
deleterious ingredient ; it departs leaving it in
some degree behind, and bearing away a health-
ful exchange of a fresh supply of oxygen. Thus
in beautiful connexion are plants nourished and

368 THE CHEMISTRY OF CREATION.

strengthened; and in this very process the air
is purified, and rendered more suitable for the
existence of man and the animal world.

But this process only takes place under cer-
tain conditions. The popular belief about plants
is less inaccurate at night. Plants cease almost
entirely to decompose carbonic acid at night.
When the sun sinks below the horizon, and the
shades of evening lengthen out ; when

" twilight gray
Has in her sober livery all things clad ;"

and when man, beast, and bird are seeking re-
pose for the night, the vegetable world sleeps
too. The leaves cease their daily task, and
pour out carbonic acid back into' the air unal-
tered. Whether a little carbonic acid is not
decomposed during the night is not altogether
decided, but it is certain that a very large pro-
portion of the carbonic acid inhaled by plants
during the night is given back to the air in its
original state. At night plants actually absorb
a certain measure of oxygen gas from the air,
which is appropriated, on the return of day, to
the formation of oils, acids, and other vegetable
ingredients.

We must refer to the influence of sun-light
for the explanation of the cessation of this pro-
cess at night. It has . already been noticed that

SUN-LIGHT AND PLANTS. 369

the rays of the sun exert a most important
influence upon the vegetable kingdom. Per-
haps there are few more pleasing subjects
in the chemistry of creation than that of the
influence of light upon plants. The whole of
the three principles resident in the sunbeam,
namely, the luminous, actinic, and calorific rays,
produce highly interesting effects upon plants,
and are, together, strictly necessary to the
health, development, and perfection of the
vegetable being. Let us briefly advert to the
facts now known upon this subject. It has al-
ready been stated, that, at the commencement of
vegetable 'life, the actinic or chemical rays have
been found to be indispensably necessary for the
Commencement of the process of germination.
So soon as this process is ended, the plant having
now raised its tender head into the light, it
enters into a new connexion with the air, and
with the sunbeam. During germination the
seed absorbed oxygen from the air, under the
influence of the powers of vital chemistry and
actinism combined. But when the first ray of
unshaded sun-light falls upon the young leaf, its
processes undergo an entire change. It now
becomes green, in consequence of the action of
the rays of light upon some of the ingredients
present in the leaves. And now, almost to the
end of its existence, it pours out oxygen gas all

2 B

370 THE CHEMISTRY OF CREATION.

the day long, in return for the carbonic acid
it absorbs. It also begins rapidly to form
wood ; and we shall soon find that all the parts
of the plant have acquired the hardness and
firmness peculiar to woody tissues. The next
important period in the history of the plant is
its flowering season. The flowers, instead of
decomposing carbonic acid, on the contrary,
give out that gas, and absorb a considerable
quantity of oxygen from the air. At the time
of ripening, the fruit also absorbs oxygen
from, and gives carbonic acid to, the air. In
addition it is stated, that all the parts of a
plant not having a green colour, such as the
bark, absorb oxygen and eliminate carbonic
acid gas.

These effects — the alternate decomposition of
carbonic acid, and evolution of oxygen, with
the contrary process of absorption of oxygen,
and evolution of carbonic acid, — appear to be
all dependent entirely upon the alternate pre-
sence or absence of the solar beams. The plant
is influenced in succession by the chemical rays,
by the luminous, and by the calorific or heat-
rays. The luminous or pure light-rays cause
its leaves to decompose carbonic acid ; and
under their influence alone is the green colour,
which is due to a substance named chloro-
phylle, produced. By the light-rays, therefore,

ACTINISM, LIGHT, AND HEAT. 371

wood is formed, and upon their stimulus de-
pends the production of this refreshing green
which mantles over forest and field. But the
heat-rays are not less essential to the plant.
It appears that it is to the influence of the
heat-rays that we owe all those flower-beauties
in the vegetable world, which form such charm-
ing objects to the eye. It has been found that
by separating the heat-rays from light, by
means of a coloured glass, neither the light-
rays, nor the chemical rays, will enable the
plant to put forth flowers or fruit. For this
the heat-rays are essential, and, in some
wonderful and mysterious manner, by their
assistance, the plant becomes crowned with its
chiefest ornament. The influence of the che-
mical rays in germination has been already
noticed.

We may thus recognise three stages in vege-
table life, in each of which one of the three
principles resident in the sunbeam comes most
prominently into operation. 1. In the in-
fancy of vegetable life, Actinism. 2. In the
youth of the plant, Light, properly so called.
And 3. In its perfection, or flowering-time,
Heat. It must not, however, be imagined that
at no other period in the life of the vegetable
being are these principles in active operation ;
this would be in the last degree erroneous. In

372 THE CHEMISTRY OF CREATION.

every process it is probable that the whole three
forces are concerned — -in all the phenomena of
growth, and in the various and complicated che-
mical process taking place in the plant. But,
at the three periods mentioned, it would seem
that each becomes, in succession, of the greatest
and most prominent importance to the plant.
In connexion with this most singular discovery,
is one equally singular and beautiful. It ap-
pears, from researches which have been carried
on with care for some years by Mr. R Hunt,
by means of an instrument called the actino-
graph, for measuring the intensity of the actinic
power at different periods of the year, that the
actinic rays are most active in spring, the light-
rays in summer, and the heat-rays in autumn.
Thus, by a beautiful adaptation, it is found that
the various periods of the life of plants requir-
ing the predominant influence of one or other
of these principles, are admirably connected
with those periods of the year when these prin-
ciples are most actively exerted. Thus, in
spring, the slumbering seeds require actinism to
awaken vitality in them ; and actinic power is
then most prominent in the sunbeam. In sum-
mer, they need to have their tissues condensed
and consolidated by the formation of wood, which
is performed by the aid of light ; and then the
light-rays are most powerful. In autumn, the

RELATION BETWEEN PLANTS AND LIGHT. 373

fruits of the orchard need to be ripened by the
agency of heat; and at that season the heat-
rays are most predominant. It appears, indeed,
that even during the day, the relative force of
the three principles in the solar ray is modified.
.In the evening there is less actinic force than
in the morning; and at noon there is more
luminous and calorific power. All these re-
sults are of deep interest, and are entirely of
recent discovery. What wisdom is manifest in
this long unsuspected but marvellous arrange-
ment of vegetable functions and light ! What
views does it give us of the strict dependence
of one part of this fair creation upon the
other, and of the manner in which various
phenomena have been linked in such close
union by the Divine Creator ! He only is as
excellent in working, as He is Almighty in
power !

From these considerations we may learn,
first, the importance of light to the vegetable
world; and, secondly, the importance of light
in order to the preservation of the purity of
the atmosphere. Without light, no plant could
long exist ; without light, little carbonic acid
could be decomposed ; and the air would be so
much vitiated, as to become irrespirable to the
animal world. In how many ways is this cheer-
ful sun-light connected, directly and otherwise.

374 THE CHEMISTRY OF CREATION.

with the health and joy of all creation ! The
Fungi are a tribe of plants which grow best in
the dark ; and they are actually deleterious in
their influence on the air, absorbing oxygen,
and exhaling carbonic acid. It is therefore
certain that the influence of vegetation, when
in a healthy condition — for in decay its effects
are deleterious — improves the health of a
country, by its direct purifying influence upon
the atmosphere.

Dr. Franklin, in a letter to Dr. Priestley,
upon the subject of the then recent discoveries
of the latter philosopher, says, " I hope this will
give some check to the rage of destroying trees
that grow near houses. I am certain, from
long observation, that there is nothing unhealthy
in the air of the woods ; for wre Americans have
everywhere our country habitations in the
midst of woods, and no people on earth enjoy
better health."* Dr. Franklin's observations are
true, where the amount of. decay ing vegetation
does not produce a sufficient amount of malaria
and carbonic acid to turn the balance on the
other side ; since, in this case, the clearing a
country of superfluous trees, becomes a positive
gain to its sanitary condition. On the grand

* From recent statistical facts, it appears that the Ame-
ricans do not " enjoy the best of health of any people :" the
English are more long-lived, and necessarily more healthy.

PURIFICATION OF THE AIR. 375

scale, however, vegetation is one of the indis-
pensable provisions for the continuance of
animal life on earth ; and we find in the atmo-
sphere the link which connects these kingdoms
in a more intimate bond of mutual dependence
than might at first sight appear.

There appears to be a beautiful provision,
even in the succession of day and night, by
which the temporary loss caused by the cessa-
tion of plants from their labours in our hemi-
sphere is counterbalanced. For while in this
hemisphere, at night, all nature is asleep, both
animal and vegetable; in the other the sun
shines, and the wide domain of plants pour
out their daily streams of oxygen into the air.
Thus, the purifying influence of vegetation
upon the entire mass of air is never arrested
all over the world, the time of rest in one region
being that of activity in another. It has been
suggested by Liebig, that those vasts movements
of air,- the Trade Winds, are also instrumental
in preserving the general balance of purity in
the entire atmosphere, by conveying from the
tropics to the poles the pure air, rich in
oxygen, ascending from the profuse vege-
tation of these burning regions, to the frozen
north, where vegetation has scarcely a repre-
sentative. Mingling with the ascending flow of
warm air, this pure and highly oxygenated

376 THE CHEMISTRY OF CREATION.

stream is borne on its wings to the higher
regions ; there, out of all danger of contamina-
tion, it is wafted by means of the " upper
current," to the north ; and descending, to form
the ' ' lower current," on its circuit back to the
equator, carries with it health, life, and vigour,
over every region through which it sweeps,
until, robbed of some of its valuable properties,
and becoming laden with the impurities of colder
climes, it reaches the tropics, where its oxygen
is restored, and becomes again involved in the
great system of circulation. By this vast circu-
latory scheme, which we might almost venture
to designate the " respiration of the atmo-
sphere," the carbonic acid, produced in such
enormous volumes in northerly regions from
the innumerable sources already mentioned, is
conveyed by the returning current to the equa-
tor ; there, after feeding the luxuriant vege-
tation of the tropics, it becomes decomposed
into its constituent elements, its oxygen min-
gles with the ascending current, and, in pro-
cess of time, returns by the course just indi-
cated to enrich the air of temperate climates.
The interchange thus effected is perpetual ; it
rests not day nor night. Hence, while this
great current fills the canvas of the merchant's
vessel, and was long considered as the exclusive
agent of intercourse between the Kew and Old

THE AIR AND THE SOIL. 377

World, it is, at the same time, the great ven-
tilating process, by the instrumentality of which
the atmosphere of the teeming tropics, and less
fertile regions of the north, is properly inter-
mingled and purified.

It has been well said, it is " the earth-
girdling atmosphere which makes the whole
world kin." The air we inhale with pleasure
as it breathes fresh over these heath-clad fields
and hills, but a little while since bade farewell
to the splendid vegetation of Brazil, or to the
palm-trees of Ceylon ; and it will leave us to
be wafted among the forests of India, or the
spice groves of the islands of the east. How
strange the thought! — the gases gently rising,
discoloured with smoke, from yonder cottage
chimney, may soon become food to the vegetable
inhabitants of warmer regions than our own —
may become appropriated by the sugar-cane, or
sago-palm, or become part of the tea-shrub, and
may actually return to us in the form of sugar,
sago, or tea !

The atmosphere is connected with the well-
being of vegetation in a remarkable manner also
by its influence on the soil. When land has been
exhausted by successive crops, the remedy has
been to let it lie " fallow," or, in other words,
rest from bearing crops for a little time. The
recovery of its lost ingredients is effected by the

378 THE CHEMISTKY OF CREATION.

silent agency of the atmosphere. The com-
mand to the Jews of old, to let the land enjoy
her sabbaths, had, no doubt, a direct reference
to this object. The air and rain, with the
alternations of heat and cold, exert a powerful
influence upon the reposing surface. The mi-
neral ingredients previously insoluble, become
gradually dissolved under their operation, and a
store of them is collected for the uses of the next
year's vegetation. The land having " rested,"
the seed is again committed to the ground,
springs up, and luxuriantly flourishes upon this
gathered hoard. So on, alternately : the at-
mospheric influences continuing to reproduce
what man carries away as fast as it is ripened,
in his corn, and other plants, and appropriates to
his own use.

The atmosphere, in all these ways, influences
vegetation, and, indirectly also, animal life.
Its influence extends to the preparation of the
soil, is felt also in quickening the seed into
life, in supplying it with food, and, finally,
in reducing it when its course is ended — when
its functions are all fulfilled — to the dust of the
earth, and there preparing its ashes for the service
of a future race.

We are told in the word of God,* that " the

* Psalm xix. 1.

CONSTITUTION AND LAWS OF THE AIR. 379

heavens declare the glory of God, and the
firmament" or atmosphere, " showeth his handy-
work;" and, perhaps, in no part of creation
is the wisdom, beneficence, and power of God
more remarkably conspicuous than in the con-
stitution and laws of the atmosphere. In the
dews of evening — in the heaven-descending
shower — in the gentle breeze, nay, even in the
tempest — and in all the physical phenomena of
the air, we have tokens of the Divine wisdom,
goodness, and power, apparent to every mind;
but the wonders of its creation appear most on
a survey of its chemical constitution. Here we
are taught how wondrously are the animal and
vegetable worlds mutually dependent for exist-
ence on the atmosphere; and, more singular
still, how each depends also upon the other
through this very medium. We learn, also,
that the whole surface of the earth is more or
less under the influence of the same chemical
agents which connect the air with animals and
plants. In short, we learn that the atmosphere
not only surrounds all things, but is constantly
exercising the most important effects upon
their condition and character ; yet all is harmo-
niously arranged — countless chemical processes
are carried on without confusion, and innu-
merable ends are accomplished by the same

380 THE CHEMISTRY OF CREATION.

means, but without disorder. Perhaps the facts
which have been detailed in these chapters on
the air, may help the reader to a deeper per-
ception of the sacred truth to which allusion has
been made — the " firmament showeth his handy-
work."

PART in -THE OCEAN.

" THE SEA IS HIS — AND HE MADE IT.

CHAPTEE I.

I

ITS PHYSICAL CONSTITUTION, ETC.

LET us transport ourselves to the sea-shore,
to which the valley where we have lingered so
long conducts us. What matter of thought and
investigation lies before us in this restless and
majestic element, whose waves cast themselves
at our feet, shedding their salt spray over our
persons ! Are the principles of chemistry in
movement throughout this mighty deep, as we
have seen them on the earth and in the air,
producing their slow but ceaseless changes of
form and matter? This inquiry it is our pre-
sent object to satisfy. It may, however, be
premised that the chemistries of the ocean are
few and simple, far more so than those of earth
or air ; but they are not less interesting nor less
important.

384

THE CHEMISTRY OF CREATION.

It lias been seen that we know but little of
the real depth of our " sea of air," for it must
be admitted, after all, that our data for the de-
termination of this question are not wholly
satisfactory, but we know perhaps less of the
profundity of the great waters. All that can
be learned is the depth down to which our re-
searches have extended in the vain search for
the bottom. The greatest depth yet obtained
was by Sir J. C. Ross, in S. lat. 15° 3'. The

DliJiP SOl'XDINGS.

weather being calm and the water quite smooth,
soundings were tried for with 4,600 fathoms of

DEEP SOUNDINGS. 385

line, or 27,600 feet. The method of taking
this deep sounding is represented in the cut.
The depth of the ocean is, however, by no
means uniform, in consequence of the inequa-
lities of surface at the bottom. Could we
suppose the ocean emptied, and the bottom
exposed, we should behold a great cavity very
different from that of our imaginings. Far from
its surface being smooth and uniform, like the
sides and bottom of some vast bowl, it would
be seen that many of the varieties of hill and
dale, of mountain, rock, valley, and level plain,
which give variety to the aspect of nature on
land, are repeated in the ocean, though doubt-
less a certain smoothness of aspect would be
in general found to overspread these features,
greater than we behold on land, in consequence
of the levelling influence of currents, and of the
deposit of sand and detritus.* That such is
really the case, is evident from the facts ob-
served in sounding by means of the lead. Shoals,
for example, which extend for miles, and are
surrounded on every side by deep water, where
the lead cannot find a bottom, are manifestly
mountains in the ocean, and would be seen as
such were all the water removed. Sometimes
the shore of a country falls with a very gentle

* Locke well and simply says, "The sea is a collection
of waters in the deep valleys of the earth."

2 c

386 THE CHEMISTRY OF CREATION.

inclination ; sometimes, and particularly near
precipitous coasts, the bottom cannot be reached
within a few hundred yards of the rocks. The
one would appear as a gently-descending plain,
the other as an abrupt,, precipitous mountain
of great elevation. It must not, however, be
supposed that no limit exists to its profundity,
or that, except in the imagination of poets, it is
without a bottom. In all probability its depth
is only a fourth or a fifth part of that assigned
to the air; the greatest hollows being supposed
not to be deeper than from twelve to thirteen
miles, or thereabouts.

The pressure of the atmosphere is greatest
on the surface of the earth. Not so with the
ocean. We must not forget that on the sur-
face of the earth we are at the bottom of
the aerial sea ; while, on the contrary, we are
at the top, so to speak, of the sea of waters.
Hence, as we descend into the ocean, the super-
incumbent pressure increases in proportion to
the depth attained. How vast must this pres-
sure become at the depth of eight or ten miles,
when we reflect that the pressure even of such
a light body as our air, equals on the earth
15 Ibs. on the square inch, water when per-
fectly pure being 815 times heavier than air!
Experiments upon this subject have often been
made. It lias been common to sink bottles full

PRESSURE OF THE WATERS. 387

of fresh 'water, closely corked, into the ocean,
when it has been found that the corks have
been driven in, while the fresh water has been
replaced ,by salt, or the bottles have burst with
the enormous pressure to which they were thus
subjected. Pieces of light porous wood have
been weighted and sunk, and when brought up
again have been found to be so 'condensed in
their tissues, as to be incapable of floating any
more, sinking like stones when thrown back
into the water. In the experiments undertaken
by various observers upon the temperature of
the deep sea, by sinking thermometers, acci-
dents repeatedly occur from the pressure of
the waters above. What sailors term " water-
logged " occurs when a boat or vessel has been
sunk beneath the surface so low as to cause
the pressure of the superincumbent water to
drive the particles of water into its inter-
stices. Mr. Scoresby mentions that, during a
whaling cruise in the Arctic regions, a whale,
on being harpooned, dragged the boat under
water, the crew escaping on to a piece of ice.
When the fish returned for air to the surface,
it was again struck, and then killed ; it imme-
diately began to sink. Fortunately, a grapnel
was thrown over its tail, and its descent was
thus arrested, though at imminent risk to the
boat. On hauling up the line, it was found

388 THE CHEMISTRY OF CREATION.

to have an extraordinary stress upon it, no
fewer than twenty-five men being necessary to
raise it. After several hours of toil, the boat
which had been sunk was recovered, and was
now so heavy as to require a boat at each end
to keep it from sinking. On being examined, the
paint canle off in large strips, and the wood was
so penetrated with water by the enormous pres-
sure of the depths to which it had been dragged,
that a piece of it sank like iron in the water, and
it would not even burn when apparently dry and
placed on a fire.

Many interesting experiments have been
carried on, both in our own country and on
the continent, to prove what the Florentine
academicians, in their celebrated experiment
upon the compression of water in a sphere of
gold, considered they had finally -disproved —
the compressibility and elasticity of water.
Although much less compressible than air, or
gaseous bodies, it is still capable of diminution
or increase in bulk, according as the pressure
on its surface is greater or less. The experi-
ment with the bottle of water sufficiently indi-
cates this : but the fact has been accurately
ascertained by philosophers. By means of an
ingeniously constructed apparatus, Mr. Perkins
obtained a striking evidence of the compressi-
bility of water, in the index of the instrument,

/. LIGHT IN THE OCEAN. 389

after its having been lowered deep into the sea,
marking several inches lower than before it was
sent down. At the depth of 20 fathoms, 20
cubic inches of sea-water only occupy the space
of 19 at the surface.

In its profound depths, the ocean is darker
than the darkest night. No twinkling of the
stars gives variety to the dark expanse over
head ; and not even the brilliance of the noon-
day sun can enliven these gloomy regions.
Silent and black, it might be conceived to be
the abode of eternal night. It has been a ques-.
tion how deep it is possible for daylight to
penetrate into the waters. In the clear regions
of the tropics, where however the utmost bril-
liancy of natural light is attained, the bottom
of the ocean, at a depth of many fathoms, may
be distinctly seen, and navigators state that the
zoophytes and marine plants may be very clearly
beheld, and that they appear most delusively
near to the surface. Shells are visible in parts
of the Arctic Ocean at a depth of 80 fathoms.
In the seas around the West India Islands the
bottom is distinctly perceptible at 30 fathoms.
Ordinarily, about 700 feet appears to be the
extent to which light penetrates into the
ocean.

The colour of the ocean has engaged much
attention, although not in some instances with

390 THE CHEMISTRY OF CREATION.

that amount of entire success which could be
desired. Sometimes it is of a beautiful blue ;
this is its natural colour ; at others it is eme-
rald green. Sometimes it appears streaked
in brownish, or bright green, or olive-green
patches ; sometimes it is even milky, and some-
times red, or of a reddish cast. Scoresby
found, in the Arctic seas, that the green hue
appeared to depend upon the presence of a
vast number of semi-transparent spherical sub-
stances, with others resembling small portions of
fine hair; and noticed further, that the whales
delighted most to feed in these green patches
of water. Darwin, while cruising in the Beagle
off the coast of Chili, found the vessel passing
through a large area of water having a pale
red colour. Obtaining a bucket-full of this
singularly tinged fluid, and placing a drop or
two under the microscope, he found it full
of animalcules which darted about with great
rapidity. A cubic inch contained more than
a thousand of them, yet the surface tinged by
their bodies extended for several miles. What
an innumerable multitude must have been pre-
sent in the whole !

The ordinary colours of the sea, however,
depend undoubtedly in a great measure upon
the influence of the water upon light, and not
upon any colouring principle diffused or dis-

. .:•:." COLOUB OF THE SEA., 391

solved in them. Perfectly pure water, like
pure air, when seen in bulk, appears of a beau-
tiful blue colour, but the least admixture of
foreign matter destroys this effect, and renders
the colour dirty and variously shaded. By
taking a glass tube, two inches wide, and
six feet six inches long, blackened internally
Vith lamp-black and wax to within half an
inch of the end, the latter being closed by
a cork, and filling it with chemically pure
water, putting at the bottom a few pieces of
white porcelain, and now holding the tube ver-
tically in a white plate — we can develop the
naturally blue tint of water, and the column
of it acquires a beautiful pure colour of this
kind. Wherever water is clear and deep, it
has the colour natural to it. Professor J.
Forbes, in his travels in the Alpine regions,
says : " During an expedition which I made
upon the ice in the month of September,
during a snow-storm, I observed' that the
snow lying eighteen inches deep, exhibited a
fine blue at a small depth (about six inches)
wherever pierced by my stick. Nor could
this possibly be due to any atmospheric re-
flection, for the sky was of a uniform leaden
hue, and snow was falling at the time." Hence
it is probable that blue is the colour of pure
water. The exquisite blue colour of the glaciers

392 THE CHEMISTRY OF CREATION.

and crevasses is highly remarkable.* The colour
also of the bed upon which the water lies
greatly influences the colour presented by the
latter. At Capri, in the Gulf of Naples, are
two grottos remarkable for the exquisite colour
of the water seen in them; The sea at the Blue
Grotto is most remarkably clear to a very
great depth, so that the smallest objects may be
distinctly seen on the light bottom at a depth
of several hundred feet. All the light that
enters the grotto, the entrance of which is only
a few feet above the level of the sea, in the
precipitous rock opening on the surface of the
water, must penetrate the whole depth of the
sea, probably several hundred feet, before it
can be reflected into the grotto from the clear
bottom. The light acquires by this means so
deep a blue colouration from the vast body of
water through which it has passed, that the
dark walls of the cavern are illuminated by a pure
blue radiance, and the most differently coloured
objects below the surface of the water are
made to appear tinged with blue. In the Green
Grotto the depth is less, and the yellow tint of
the subjacent rocks alters the colour of the
reflected light from blue to green. Some parts
of the Mediterranean Sea are found to present

* Professor Bunsen notices the same appearances in the
glaciers of the Jokull in Iceland.

PHOSPHORESCENT SEAS. 393

a reddish or purplish hue ; and in a bay on the
west coast of Africa the waters always have
almost the appearance of being tinged with
blood: in both cases the effect is due to the
colour of the bottom.

The beautiful phosphorescence, familiar to
residents on the sea-coast, and well known to
fishermen, who term the sea brimy when its sur-
face, on being agitated by the air or tide, flashes
with phosphorescent light, is generally supposed
to be principally due to phosphorescent animal-
cules. Sometimes the appearance is so marked
as to form a most curious and splendid spectacle.
Waves of heaving fire rise and fall, flashing in
the dark night with a lustre of indescribable
brilliancy, and, as far as the eye can see, an
ocean of fire appears to toss its waves, emitting
a beautifully pure and pale light. Under the
bows of the vessel, or in the water-line in her
wake, ripples of flashing brilliancy play, and
the path of the ship becomes marked with a
long line of moving light. When water is taken
from the surface it possesses the same luminous
properties. Sometimes the luminosity has dif-
ferent tints ; in tropical waters it is often white
as snow, and the whole surface of the deep
appears like a field covered with new-fallen
snow. In the Gulf of Guinea the surface of
the water sometimes appears of the most bril-

391 THE CHEMISTRY OF CREATION.

liant white. The cause in this instance has been
supposed to be vast numbers of small crustaceous
animals, which have the singular property of
emitting a white light.

Sometimes it is of a ghastly blue, and the
appearance then presented is more than ordi-
narily terrifying to the superstitious. Again,
sometimes it is of a fiery red, or even scarlet,
as though some marine monster's blood did

" The multitudinous sea incarnadine,
Making the green ono red."

Sometimes also the tint is green, and sometimes
yellow.

In many cases this power of emitting light
appears to be a vital property connected with
the existence of marine beings. Dr. Macculloch,
who laboriously investigated this curious and
interesting subject, writes : — " I believe the
power of producing light to be an universal
property in the marine tribes. I have never
found a species in which it did not exist."
The luminosity of some fishes depends upon
the minute phosphorescent creatures, Nereis
noctiluca, attaching themselves to the scales
of fish, and? thus illuminating the surface of
the creature -on which they rest. Many of
these phosphorescent creatures are of extreme
minuteness. The little being represented in
the cut, Noctiluca miliaris, does not exceed

LUMINOSITY OF FISH. 395

'the one-thousandth of an inch in diameter.
Millions may be easily contained in a bucketful
of sea-water. On examination under the mi-
croscope, it appears that they possess the power
of squeezing out a phosphorescent fluid, which
leaves a line of light in the water.

ITOCTILTTCA MILIAEIS. (MAGNIFIED.)

In the British seas these little animalcules are
often found congregated together in innumerable
millions. Dr. Prinsr, in a paper communicated
to the British Association in 1849, details some
interesting results of experiments upon these
phosphorescent creatures. " Galvanism increased
the luminosity ; oxygen gas, and carbonic acid
gas, also increased the light; but the latter most
speedily killed the animal; sulphuretted hy-
drogen quickly destroyed the light; nitrogen,
nitrous oxide, and hydrogen, produced little 6t

396 THE CHEMISTRY OF CREATION.

no effect on the luminosity. Strong mineral
acids increased for a moment, but speedily
afterwards destroyed the light; ether instantly
destroyed the life of the animal; chloroform
increased the light, and then destroyed the
animal."

The light with which these creatures are
endowed, has been considered to be in many
instances the guide of the inhabitant of the
deep to his prey. It is a remarkable fact also,
and is directly connected with the chemistry of
the sea, that when the dead body of a fish is
still comparatively fresh, and before it becomes
putrid, it often possesses this luminosity, but
not after putrefaction commences. There is no
doubt this is a chemical phenomenon. Soon
after death, probably the first process of de-
composition is the disengagement of phosphorus
in the form of some luminous compound : as
the process advances, this becomes decomposed,
and putrefaction soon goes so far as to render
the body unfit for food. Then the luminosity
ceases. While the food is in a fit state for
consumption, the beacon exists which directs
the consumer to his prey ; but as soon as, from
natural changes, it becomes unfit for that pur-
pose, the light is extinguished. Here surely is
something more than a mere law of inanimate
matter. He who said, " Gather up the frag-

TEMPERATUEE. , 397

ments that nothing be lost," has written the
same lesson upon creation at large ; and the
instance in question may be taken as an inter-
esting illustration both of the care of God over
his creatures, and of that feature of his provi-
dence which will have nothing to be wasted.

The temperature of the atmosphere was
observed to decrease as we ascend; that of
the ocean, in temperate and tropical climates,
observes a rule exactly the reverse ; it decreases
as we sink into it. The recent interesting
researches of Professor Forbes during the sur-
vey of the JEgean Sea, have developed a very
singular fact in connexion with the tempera-
ture of the sea. Just as the progressive de-
crease of temperature in the air as we ascend
is marked by zones of vegetation which
become more and more northern; so as we
descend into the sea, there are zones of tempe-
rature marked by the character of the marine
animals which exist in them ; and in the lower
regions these animals consist of species, as
strikingly resembling the northern species, as
the higher vegetation in a lofty range of moun-
tains resembles that of the northern regions.
Even in the fourth region nearly fifty per cent,
of species are identical with northern forms.
Professor Forbes found a difference of tempe-
rature between the highest and lowest zone ;

398 THE CHEMISTRY OF CREATION.

the latter at the depth of 300 fathoms amounted
in summer to from 26° to 30° ; the temperature
of this zone was 55°, while that of the upper
zone ranged from 76° to 84 , during eight
months in the year. It is highly interesting
to find that the inhabitants of the deep are
thus carefully accommodated and distributed,
far out of sight of man, as is the case with
the vegetable and zoological dwellers on the
surface of the earth.

The warmest part of the ocean is, in tem-
perate and tropical regions, at its surface, and
it is in its usual and mean condition somewhat
warmer than the bed of air immediately resting
upon it. This is the result of a very simple law
connected with what is termed convection (or
carrying) of heat in fluids. The warmer parti-
cles of water, expanded by heat, become lighter
than the surrounding particles of colder water?
and consequently rise of the surface ; while the
cold particles sink, until they meet with a stra-
tum of water of similar temperature and density
to their own. It is thus that the fluid particles
convey or carry heat In the conduction of heat
there is no movement of the particles of a sub-
stance, but heat flies from particle to particle.
In the case of fluids, heat is actually carried by
the particles from one position to another, and
is thus very slowly diffused throughout a liquid ;

.TEMPERATURE OF THE OCEAN. 399

the coldest particles being at the bottom, and
the warmest at or near the surface. There is,
however, a remarkable apparent exception to
this rule, at a particular degree of heat, to
which allusion will be immediately made. In
the ocean, then, in these regions, the more
deeply we can penetrate, the colder will the
temperature of the water we obtain become.
The fact of the coldness of the inferior beds
of water was singularly illustrated by Messrs.
Kotzebue and Dupetit Thouars. Water was
procured by them from the abyss of the ocean,
in the tropics, and found to be at the unusually
low temperature of 35°, or only three degrees
above freezing point ! This, too, under the
full influence of a tropical sun ! This most
curious discovery led philosophers to conceive
the existence of inferior polar currents of water
proceeding from the poles to the equator, just
on the principle of the trade -winds.

Kotzebue and Sir James Ross have esta-
blished the fact, that there is a depth in the
ocean at which the water has a constant tem-
perature of about 39° 5'. This depth depends
on the latitude. At the equator the stratum
of invariable temperature was as low as 7,200
feet, from thence it gradually rises till it comes
to the surface in S. lat. 56° 26', where the water
has the temperature of 39° 5' at all depths ;

400 THE CHEMISTRY OF CREATION.

it then gradually descends to S. lat. 70°, where
it is 4,500 feet below the surface.

Proceeding northwards the same law still ob-
tains. Sir J. Ross therefore proposes to divide
the regions of oceanic temperature into three —
two polar and one equatorial. If we imagine
the bed of water of invariable temperature to
be represented by a curved line, we should find
this line beginning at the depth of 4,500 feet
in the southern polar region, rising nearer
and nearer the surface until it reaches S. lat.
56° 26', then sinking again to the depth of
7,200 feet at the equator; again rising in the
corresponding N. lat., and finally descending
again to the depth of 4,500 feet in the northern
polar region. This curve is determined by the
state of temperature at the surface. Near and
at the equator, the surface temperature is con-
stantly at 80° ; hence the depth of the line of
water at 39° is greatest here. At S. lat. 56° 26' .
the temperature of the surface is 39°. Such,
also, is the temperature of the surface in the
corresponding N. lat. Toward the poles the
surface is at the freezing point even in summer,
and the line of constant temperature is conse-
quently at a depth of 4,500 feet. Hence the
'water is warmer as we descend at all latitudes
below S. lat. 56° 26', and above the correspond-
ing N. lat. ; at these points it is of uniform

STRATUM OF UNIFORM TEMPERATURE. 401

temperature at all depths. At the equator it
is colder as we descend until we reach the depth
of 7,200 feet, after which the temperature does
not alter with the depth. These results, which
have been obtained with extreme care, are
highly satisfactory, and appear to set at rest
the vexed question of ocean temperature.

It .might be thought that, as it was found
that the internal temperature of the earth in-
creased on descending into it, the effect of this
increase of temperature would be experienced
by the deep ocean ; but Sir J. Ross is disposed
to believe that the internal heat of the earth
exercises little or no influence upon the mean
temperature of the ocean.

Dr. Williams assigns as one cause of the
existence of this stratum of uniform tempera-
ture, and which, in the two polar regions,
appears as a bed of warm water underlying the
cold surface, the effect of pressure upon water.
He asserts that he has found, by experiment,
that water acquires a considerable increase of
temperature under great pressure ; an effect
apparently due to the extraction of the latent
heat of its dissolved gases.

The temperature of the ocean, it is thus
seen, is greatly influenced by its depth. Under
ordinary circumstances, it appears that the
water close by the shore ^ is colder than that far

2 D

402 THE CHEMISTKY OF CREATION.

from land. Sailors might thus frequently be
made aware of the existence of shoals or sand-
banks without the aid of the lead, were it not
that a number of circumstances of local origin
interfere with the temperature of the water
near land, and thus render what might other-
wise prove a valuable sign, far too uncertain
to be relied upon. It is supposed that the in-
fluence of the seasons is not felt by the ocean
below the depth of 300 feet,

We must now advert to a remarkable fact in
the physical history of the ocean, and of water
generally. The particles of cold water, being
the heaviest, descend, while the lighter warm
particles remain on the surface. If we suppose
this process to continue, the ultimate result
would inevitably be that our lakes, and the
shallower parts of our seas, would soon be
covered with a dense solid layer of ice, which
would increase until they became almost choked
up with it. Such an altered condition of the
waters would rapidly affect the climate ; our
summers would become cold and cheerless, our
winters long and severe, and our climate would
rapidly deteriorate, until it became of almost
Arctic rigour. This result is obviated by a very
singular law observed in water as it is gradually
reduced in temperature. In cooling down to
within eight degrees of freezing point, or 32°

GROUND ICE. 403

of Fahrenheit's thermometer, it becomes gra-
dually heavier and more heavy ; but when it
has reached this point (40° F.), further cooling
reverses the state of things, and the particles
actually become specifically lighter ! The
descent of water cooled below 40° is thus effec-
tually arrested in the simplest manner. It is
difficult to explain this curious phenomenon.
It is supposed that, since the particles of ice, in
consequence of their angular form, are lighter,
in consequence of their occupying a larger
space than the particles which form fluid water,
the expansion of water below 40° may be due
to its particles being in a process of arrange-
ment preparatory to their becoming visible
crystalline, as they do below 32°. "Ground
ice,n as it is called, seldom is formed in still
water, but not unfrequently in shallow running
water. When ice is formed it is so light as to
float on the surface of the water, and, in so
doing, covers and protects water actually warmer
than itself below, the propagation of cold from
above downwards being extremely slow in fluids,
and being, in the case of water, rendered addi-
tionally difficult by the refusal of the cooled
particles to sink when their temperature is
reduced to the point in question.

A curious fact is related by Krusensteirn,
with reference to the temperature of a part of

404 THE CHEMISTRY OF CREATION.

the sea which was sounded in his travels. It
was found, in a series of experiments made in
some places in the Gulf Stream, on letting
down the lead to the depth of 600 feet, and
raising it again, it was so hot* as not to allow
being handled. The experiments were many
times repeated with the same result, and the
inference could not be denied, that below the
cool surface of the blue waters was a bed of water
not far off boiling point !

In consequence of the bad radiating proper-
ties of water, the temperature of the ocean is
much less subject to variations than that of the
air, and the variations which occur are small
in amount. The result of this is, that the air
overlying the ocean is much more uniform in
regard of temperature than that over the land.
In parallels where the range of the thermo-
meter suspended in air over land, amounts to
twenty or thirty degrees, or even more, a ther-
mometer suspended over the ocean's surface
does not range more than five or six degrees.
Thus the effect of the presence of the sea upon
a climate is to equalize it ; and this is remarkably
the case in the climatology of small islands. In
the Channel Islands, for example, in Guernsey

* This phenomenon was probably due to the existence
either of some submarine volcano, or of some spring rising
from the heated interior of the earth.

CLIMATE OF CHANNEL ISLANDS. 405

and Jersey, this influence is most remarkable :
frosts are of rare occurrence there, and of the
shortest duration, and the extreme of heat is
seldom experienced there. In the quarter end-
ing December 31, 1849, the mean temperature
of Guernsey was 49° 2', while that of Green-
wich was 44° 8' a difference of about five de-
grees. Thus summer and winter are not
separated by the chasm which divides them
in the climate of great continents, and the
excessive degrees of temperature are almost
unknown on either side of the thermometric
scale. The influence of such a climate upon
the floriculture and horticulture of these islands
can scarcely be believed. The most delicate
and beautiful plants which in England must
be carefully kept, during the winter, in our
conservatories, and cherished with artificial
warmth, are there exposed without injury all
through that part of the year ; and the markets
in summer exhibit an appearance of exuberant
fertility of soil scarcely to be expected even in
districts much farther south than is their posi-
tion. In all probability the equalizing influence
of the ocean is felt universally, through every
region of our globe, to a greater or less extent.
The waters heated in warmer regions are di-
rected by the various currents of the ocean to
others, where the solar influence is far more

406 THE CHEMISTRY OF CREATION.

feeble, and roll down the shores of countries
lying in latitudes far remote. There can be
little question that, were the present relation
altered, that alteration would speedily be at-
tended with a modification of climate, and,
as a result, with important alterations in the
number and varieties of the animals and plants
occupying the surface of the present earth.

The ocean is the great reservoir from whence,
raised by the process of evaporation, the earth
derives its supply of water, and to which all
springs and rivers carry back their contents.
A system of circulation is thus established on
the grandest scale. Water rises as vapour from
the ocean, assumes the form of clouds, descends
on land in the various conditions of rain, hail,
snow, and dew ; and becoming then collected
in larger currents, seeks the ocean again, to
undergo again the same series of changes. A
small portion of the saline contents of the sea
are thus made available to the necessities of
plants on land, by uniting with the ascending
vapour, and being precipitated in the descend-
ing shower.

CHAPTEE II.

CHEMISTEY OF THE OCEAN.

THE waters of the ocean have been re-
peatedly analysed; and, though some differ-
ences of result have arisen, they have been
principally of a trifling kind, and unimportant
amount. Sea-water consists essentially of
pure water, with the addition of various saline
and earthy ingredients. The analysis of sea-
water presented none of the difficulties at-
tending that of the atmosphere; for it was
comparatively easy, on evaporating down a suf-
ficient quantity, to obtain its constituents in so
concentrated a form as to arrive at their number
and nature, and to estimate their proportion.
The result of analysis has been to show that
upwards of three per cent, of saline matter
exists in sea- water; and that common salt, or
chloride of sodium, as it is chemically entitled,
constitutes a large proportion of the whole saline
matter present. As to its specific gravity,
if pure water is represented as 1000, sea- water
is from 1026 to 1030. The subjoined table pre-

408 THE CHEMISTRY OF CREATION.

sents us with a tabular view of the most recent
analysis of sea- water : —

1000 grains contained —

Water 964-745

Chloride of sodium .... 27'059

Chloride of potassium .... -766

Chloride of magnesium . . . 3'6G6

Bromide of magnesium . . . "029

Sulphate of magnesia .... 2-296

Sulphate of lime 1-406

Carbonate of lime '033

Traces of iodine, ammoniacal
salt, and organic matter.

1000-000*

From this it will be evident that sea- water
is a fluid containing a much larger number of
chemical constituents than have yet been dis-
covered in the atmosphere. In all probability
it is chiefly owing to the difiiculty of the
analysis that we are not yet able to detect
many ingredients in the air, which may be
present in minute quantities. While, however,
the analysis of sea-water, carefully conducted,
will generally exhibit the presence of these
ingredients, their proportion is subject to
variation under different circumstances : the
Mediterranean sea-water is considerably more

* In a recent analysis by MM. Malaguti, Durocher, and
Sarzeaud, the presence of copper, lead, and silver has been
detected in sea-water, and to a larger extent silver was found
in the ashes of sea-weeds.

SALINE CONTENTS OF SEA-WATER. 409

highly charged with saline matter than the
waters of the ocean outside the Straits ; an
effect which appears to be due to the immense
evaporation taking place from its surface, which
carries off an enormous volume of water in the
form of vapour, to supply the place of which a
strong current sets in from the main ocean,
through the Straits of Gibraltar. In other in-
land seas, on the contrary, the amount of saline
matter is diminished; and this is the general
rule. The explanation of this appears to be,
that such seas generally receive a very large
addition of fresh-water from the coast around
them, and from one or more great rivers which
may flow into them. The Baltic Sea is thus
remarkably contrasted with the Mediterranean;
for while the latter has a high density, pro-
bably about 1029 or 1030 — pure water being
1000 — the waters of the former have a density
very little higher than 1015. Near the mouths
of great rivers, as is naturally to be expected,
the quantity of the saline contents of sea-water
is much lessened; the fact being, that the
waters of the ocean are in reality diluted by
the intermixture of a large body of fresh-
water. It is said that the diluting influence of
the great American river, Amazon, is distinctly
perceptible for a distance of upwards of 300
miles from its mouth.

Professor Forchhammer has made some highly

410 THE CHEMISTRY OF CREATION.

important investigations into the comparative
analysis of sea-water, and his results are inte-
resting. The following extracts are from his
report on this subject : — " In the ocean be-
tween Europe and America, the greatest quan-
tity of saline matter is found in the tropical
region, far from any land: in such places,
1000 parts of sea- water contain 3 6 '5 parts of
salts. This quantity diminishes on approaching
the coast, on account of the masses of fresh-
water which the rivers throw into the sea: it
diminishes, likewise, in the westernmost part
of the Gulf Stream, where I only found it to
be 35-9 in 1000 parts of the water. By the
evaporation of the water of this warm cur-
rent, its quantity of saline matter increases
towards the east, and reaches, in N. lat. 39° 39'
and W. long. 55° 16', its former height of 36'5.
From thence it decreases slowly towards the
north-east, and sea-water, at a distance of
sixty to eighty miles from the western shores
of England, contains only 35*7 parts of solid
substances ; and the same quantity of salt is
found all over the north-eastern part of the
Atlantic, as far to the north as Iceland ; always
at such a distance from land that the in-
fluence of fresh-water from the land is avoided.
From numerous observations made on the
shores of Iceland and the Faroe islands, it
is evident that the water of the Gulf Stream

FORCHHAMMEKS ANALYSES. 411

spreads over this part of the Atlantic Ocean ;
and thus we see that water of tropical currents
will keep its character even in high northern
latitudes.

" The water of different seas is much more
uniform in its composition than is generally
believed. In that respect my analyses agree
with the newer analyses of atmospheric air, in
showing that the differences are very slight
indeed. Sea-water, it is true, may contain
more or less salt; from a very small quantity,
as in the 'interior part of the Baltic, to an
amount of 37*1 parts in 1000 parts, which I
found in water from Malta, and which is the
greatest quantity I ever observed; but the re-
lative proportion of its constituent saline parts
changes very little. In the longitude of Green-
land, and more than 100 miles to the south of
the southernmost point of that large tract of
land, sea-water contains only 35'0 in 1000
parts. In going from this point towards the
north-west it decreases constantly; and in
Davis' Straits, at a distance of about forty
miles from the land, it only contains 32'5 parts
of salt in 1000 parts of sea- water. This cha-
racter seems to remain in the current which
runs parallel to the shores of : North America;
and at N. lat. 431° and W. long. 46^° the sea-
water contained only 33'8 parts of salt. Thus
tropical and polar currents seem not only to be

412 THE CHEMISTRY OF CREATION.

different in respect to their temperature, but
also in the quantity of salt which they contain ;
from which it appears, that while the quantity
of water carried away from the tropical sea, by
evaporation, is greater than that which rain and
the rivers give back to that sea, the reverse
takes place in the polar seas, where evaporation
is very small, and the condensation of vapour
very great. The circulation must on that ac-
count be such, that a part of the vapour which
rises in tropical zones will be condensed in
polar regions, and in the form of polar currents
flow back again to warmer climates. Although
my analyses are only made in water from the
ocean between Europe and America, yet little
doubt can be entertained that that part of the
ocean which separates America from Asia is
constituted in a similar manner; and that cur-
rents flowing from the poles are the rule, and
currents flowing towards the poles are the
exception."

The chief cause of these variations in the
total quantities of saline matter present in the
water of different seas, are — 1st, the influence
of evaporation, which concentrates the fluid by
removing a portion of its watery particles ; and
2nd, the influx of fresh- water from the land, or
from the atmosphere. In consequence of its
saline contents, sea-water is more dense and
heavy than fresh-water. This is occasionally

FRESH-WATER OVERLYING SALT. 413

turned to some advantage by navigators ; for it
is found that, in calm weather, the fresh-water
overlies the salt, just as oil does in respect of
water: by drawing water, therefore, from the
surface, fresh-water may be obtained; whereas,
if the hose of the pump penetrates some feet
down, it may encounter a stratum of salt-
water. The saline matter of the lower stratum
mixes with the fresh-water by a force analagous
to that with which gases mix with each other —
the force of diffusion. In the narrative of the
voyages of the Adventure and Beagle, Captain
Fitzroy remarks, in their expedition up the
river Santa Cruz, in Patagonia, at . a particular
point : — " The water was fresh over the surface,
and sometimes it is quite fresh even into the
estuary ; but in filling casks, or dipping any-
thing into the stream for fresh-water, it is
advisable not to dip deep, or to let the hose, if
one is used, go many inches below the surface,
since it often happens that the upper water is
quite fresh, while that underneath is salt. This
occurs more or less in all rivers which empty
themselves into the sea: the fresh-water, spe-
cifically lighter, is always uppermost."*

* " Voyages of the Adventure and Beagle," vol. ii. p. 340.
— In the Bakerian Lecture delivered by Prof. Graham before
the Royal Society, in December, 1849, the diffusion of saline
fluids into each other was admirably discussed. The un-
equal rate in which different salts diffuse upwards into the

414 THE CHEMISTRY OF CREATION.

One remarkable feature of these investiga-
tions into the chemistry of the sea is too im-
portant to be passed by ; namely, the uniformity
of chemical composition of sea- water, notwith-
standing the circumstance of its varying saline
quantities. This apparent paradox may be
explained in the following manner : if a solu-
tion containing certain quantities of salts, six
in number, the relative proportion of each of
which is known, be dropped into, 1st, a pint
of water ; 2nd, a quart ; and 3rd, a gallon,
— and these waters are analyzed, we shall
have the following results : — In the first we
should find a considerable quantity of saline
matter, in the next less, and in the third still
less; but the proportion of the salts in this
saline matter would not vary in the least, just
for the same reason that a drop of this saline
solution has exactly the same chemical compo-
sition as the whole quantity. So in the great
ocean : in parts it has more, in parts less, saline
contents ; but their number and proportion are
pretty generally the same in all parts. If the
saline matter were of a blue colour, we should
find the sea deep blue at the tropics, paler
toward the poles, and along all our coasts a
pale blue hue would extend, reaching deeper

fresh-water above, explains the discordant mmlta obtained
by different chemists in examining the waters of the Dead
Sea.— Vide Athenaum, Jan. 12, 1850.

CONSTANCY OP COMPOSITION. 415

into the sea near the mouth of every large
river than elsewhere.

It is extremely difficult to account for this
fact, in the present state of our knowledge
on ocean-chemistry. Why are some soluble
constituents which ou^ht t<> timl their way into
tin- sea, we should say, at least as abundantly
as some of the dissolved matters, missed when
we come to look for them in analysis? Upon
what principle can we account for the enormous
presence of the metal sodium in combination,
and the comparative absence of potassium, the
compounds of which arc equally soluble, or
nearly so, with those of the other elements, and
much more so than the compounds of magnesium
and lime ? Yet, in 1 000 parts of sea- water, the
proportion of the chloride of magnesium to that
of potassium is as 5 to 1 : even sulphate of lime,
a compound comparatively insoluble, is present in
equal proportions to chloride of potassium.

Some suggestions of a solution to the pro-
blem of the pretty constant composition of sea-
water may be offered. It is to be remembered
that, by the laws of chemical combination, a
heterogeneous mixture of all kinds of ingre-
dients, if left to itself, would ultimately assume
a certain definite composition, according to the
nature of its contents, and their affinities for
one another. Were we, for example, to pour
certain quantities of sulphuric, hydrochloric,

41 1) THE CHEMISTRY OF CREATION.

nitric, and acetic acids into a vessel of water,
and to add to the fluid various substances, such
as iron, the alkalies, lime, magnesia, &c., a
number of chemical reactions would ensue, and
continue for a certain time ; but ultimately the
fluid would possess a certain definite composi-
tion, and several substances would lie at the
bottom of the vessel in an insoluble form.
What takes place in this vessel may be presumed
in some degree to illustrate what occurs in the
ocean at large ; it is impossible for several che-
mical compounds, each of which has an affinity
for the other, and a tendency to decompose and
unite with it, to exist in it at one time. The
result of the addition of such matters to it would
be, that they would react upon each other, pro-
duce some soluble and some insoluble compounds,
and the fluid part would be in that neutral con-
dition in which we find sea-water ; namely, as a
fluid holding dissolved several compounds which
have no disposition for mutual union. In the
language of science, the water of the sea is a fluid
holding " compatible " substances in solution.

A small part only of the difficulty is thus
removable. It is plain, it may be urged, that
sea-water could not consist of a compound
medley of substances, since the laws of che-
mical affinity would produce the separation of
many in an insoluble form, and the combination

ATTEMPTED EXPLANATION. 417

of the rest in a group, the parts of which are
in chemical harmony with each other; but a
fluid holding compatible substances in solution
might have a very different constitution to that
of the sea. This is true. Let us, however,
recall what was remarked on a previous page,
upon the gross composition of the earth, from
which the ocean has derived its saline contents.
It was there stated that the earth en masse is
chiefly composed of seven elements — silicium,
calcium, aluminum, magnesium, potassium, and
sodium, in union with oxygen. Hence it is
evident that the waters which wash the shores,
and receive the drainage of a world thus
framed, are not exposed, on the large scale, to
that mixture of heterogeneous ingredients,
which, upon a circumscribed view of the sub-
ject, we might be led to anticipate. With the
earth's gross composition in view, the number
and nature of the elements present in the water-
world might almost have been anticipated. Of
the seven elements, or the six oxides, silica, as
we are informed by chemistry, is not sensibly
soluble, and alumina, occurring in nature chiefly
in the form of clay, or locked up in the massive
granite as a silicate of alumina, presents little
probability of affording a solution. This re-
duces the list to the four elements which, in
combination with chlorine, iodine, bromine, sul-

2 E

418 THE CHEMISTRY OF CREATION.

phuric and carbonic acids, enter into the com-
position of sea-water. Of the four elements,
thus united, calcium in a state of nature exists
as a sulphate and carbonate. Sulphate of lime
is soluble in 500 parts of water, and carbonate
of lime is sparingly soluble in water contain-
ing carbonic acid — is, in fact, never absent
from either river or spring water, constituting
what is called the " hardness " of such waters.
All the salts of soda and potash are highly
soluble. Thus, from a review of the main
constituents of our globe, it would appear
natural to expect that the water which sur-
rounds so large a portion of it, and is the
greater reservoir for its water-shed, would con-
tain sodium, potassium, calcium, and magne-
sium, in combination : and such is actually the
case. Why chlorine and sulphuric acid are the
principal bodies united to these elements, it is
difficult to say. Sulphuric acid, it is true, in
the form of sulphate of lime or gypsum, forms
a large constituent of the earth's crust; but
chlorine is chiefly known in nature as in union
with the sodium of sea-water. The cause
of its preponderance is, therefore, buried in
obscurity.

When we come to ask, again, the cause of
the constancy of the relative proportions of
these ingredients in sea-water, a fresh per-

ORIGIN OF SALINE MATTERS. 419

plexity arises, for the solution to which refer-
ence must be made to the concluding chapter of
this work.

There are probably few subjects upon which
such erroneous opinions have been held, as upon
the origin of the saline matter in the ocean. For
a considerable time it was said, that the saline
matter was derived from the solution, by the
waters of the sea, of certain conjectural masses
of rock-salt, which were supposed to exist at
its bottom ; and that the ocean became salt, as
a dish of tea becomes sweet, by simply dissolving
the soluble matters conveniently arranged at its
bottom. Other views equally erroneous have
been entertained. The presence of the saline
matter is now accounted for, either on the sup-
position that, when God created our world, it
pleased Him to create the ocean of its present
composition, or upon the view already offered ;
namely, that the saline matter owes its origin
in a manner equally exhibiting the Divine wis-
dom and power as upon the former suppo-
sition, to the ocean being the receptacle for
the drainage and washing-out of the solid parts of
the earth.

Dr. Fownes observes : " The rain which falls
upon the earth is due to condensation of aque-
ous vapour previously existing in the atmo-
sphere, and which is supplied in great part by

420 THE CHEMISTRY OF CREATION.

evaporation from the surface of the sea ; the
area of the latter, compared with that of the
land, being very great, — necessarily so, perhaps,
to furnish the requisite extent of evaporating
surface. This water is, as is well known, per-
fectly fresh and pure, the saline constituents of
the ocean having no sensible degree of volatility
at the temperature at which the vapour has
been raised. No sooner, however, does it reach
the earth, than it becomes contaminated with
soluble substances which it meets while flowing
on the surface of the ground, or percolating
beneath. It is thus that the waters of springs
and rivers invariably contain a greater or less
amount of alkaline and earthy salts, which all
eventually find their way into the sea, and there
remain, since there is no channel for their re-
turn. The saline condition of sea-water is but
an exaggeration of that of ordinary lakes and
rivers ; the materials are the same, and of ne-
cessity so ; the ocean being, in fact, the great
depository of all the soluble substances which,
during many ages, have been separated by a
process of washing from the land. The case of
the sea is but a magnified representation of
what occurs in every lake into which rivers
flow, but from which there is no outlet except
by evaporation. Such a lake is invariably a salt
lake ; it is impossible that it can be otherwise ;

SPECIAL AKKANGEMENT. 421

and it is curious to observe that this condition
disappears when an artificial outlet is provided
for the water. It will be remembered that the
saltness of the ocean is very far exceeded by
that of several inland lakes of the kind de-
scribed : that of Aral, near the Caspian, and
the Dead Sea, in Judaea, are remarkable
examples."*

Upon either supposition, we may not doubt
that a wise and gracious end was accomplished
in the constitution of the ocean being such as
it now is. If it was, in the beginning, formed
by the creative hand of God a mass of saline
water, we are sure it was not so formed in
vain; if, on the contrary, as seems natural to
suppose, its saline contents are the result of
the water drainage of the earth, we are not
to regard it in the cold and gloomy aspect in
which it is placed by the writer last quoted, as
" rather an inevitable result of the present dis-
position of things, than a special arrangement
expressly intended to fulfil certain objects."
When God formed the world in the mass, and
employed in its mighty fabric the elements to
which we have alluded, had He not, who knows
the end from the beginning, a gracious inten-
tion in so doing? The all- wise Creator suffers
nothing to be done by chance ; and if the ocean
* Fownes : Actonian Prize Essay, p. 17.

422 THE CHEMISTRY OF CREATION.

was to be made salt by the lixiviation of the
crust of the earth, can we suppose that so im-
portant a result, one so vitally connected with
the existence of all the inhabitants of the world
of waters, would be permitted to the operation
of accident? If, instead of employing lime-
stone, it had pleased God to employ baryta in
the important office of constructing the great
mass of the earth's crust, — or if many other
elements beside those enumerated had taken a
larger share in this work, — the ocean, receiving
the washings of the earth thus formed, would
have been unfit for the residence of a single
living creature. The saltness of the ocean is,
therefore, a wonderful instance of the fore-
thought and wisdom of the world's Creator,
linked — as it, upon this view of its origin,
inseparably is linked — with the number and
nature of the elements employed in the construc-
tion of the chief solid matter of the globe. All
nature is as one ; for its various parts have been
bound together by an Almighty hand.

Just as the power of diffusion tends to pre-
serve the uniform composition of the air, so the
same or a similar force tends to intermix the
saline contents of the ocean with the enormous
volumes of fresh water continually added to it.
Without this, the ocean would in time become
divided into an underlying constantly increasing

THE END IN VIEW. 423

stratum of salt-water, and an overlying stratum of
fresh- water.

It is not clearly ascertained what are the
precise objects in view in the saline constitution
of the ocean. The presence of the salts is use-
ful in checking evaporation to too large an
extent ; in causing sea-water to freeze at a lower
temperature than fresh-water, at 2S£° Fahr.
instead of 32°, thus rendering it more difficult
to solidify its surface than if it contained less
saline matter; and is also useful in communi-
cating to sea-water a greater buoyant power than
fresh-water. It likewise renders its putrefaction
less easy than if it were fresh. As we shall have
again to remark, there exists a strict connexion
between the functions of the tenants of the deep
and this saline matter. If, therefore, we are to
regard the presence of certain principles in the
air satisfactorily accounted for by the recogni-
tion of their usefulness to animals and plants, the
same reasoning may be applied to the ocean ; and
we may with justice regard its saline contents as
specially adapted to the functions and purposes of
its varied inhabitants.

In addition to the saline matter, a trace of
organic matter is generally obtained in the
analyses of sea-water. This organic matter
may be due to minute animalcules, or it may
consist simply of some products of animal

424 THE CHEMISTRY OF CREATION.

decomposition. Sometimes it exists in very large
proportions in sea-water. M. de Tessan ob-
served in the sea, near the Cape of Good Hope,
a very singular instance of this kind. Innu-
merable minute spherical bodies filled the water,
and thickened it to such a degree as to give rise
to a faint crackling sound on its being agitated
with the hand. Some of this water, when
strained through a cloth, left half its bulk of this
organic matter. In all probability this matter
consisted chiefly of the bodies of animalcules. It
was highly phosphorescent.

A very interesting question upon ocean che-
mistry is connected with this organic matter,
and is now awaiting the decision of investigators
into this neglected study. Among the several
causes of the phosphorescence of the sea, it
might have been mentioned that it appeared
occasionally due to the presence of organic par-
ticles soon about to become putrid. It is con-
sidered by many, and among others by the cele-
brated microscopical observer, Ehrenberg, that
the phosphorescence of the sea is at all times
chiefly attributable to the existence of organic
matter in this condition.

The following singular account of a large
luminous spot in the sea, observed by Captain
F. Eardley Wilrnot, deserves attention. On his
voyage home from the Cape of Good Hope, in

CHEMISTRY OF PHOSPHORESCENCE. 425

the spring of this year, he observed one night
a remarkable though not very uncommon
appearance of the sea. This was a large and
very luminous spot, which was clearly defined
by a sharp edge. He thus describes the ap-
pearance, and also the steps which he took to
obtain some of the water, for the purpose of
bringing it home to England and submitting it
to chemical examination : " The sea was covered
with so brilliant a surface of silver light that
we could see to read, and the shadows of the
ropes were strongly marked. We sailed through
it for about four hours ! In one place it ha<J
an edge, and we sailed out of it for nearly half
an hour, when we again entered it as abruptly,
and finally left it, where the edge of the illu-
minated part was strongly defined. The water
was taken up in a clean bucket, and put into
a carefully-cleaned bottle, about 10° north lati-
tude." This bottle was submitted to Dr. Fara-
day for analysis, the result of which is given in
the following note from this eminent chemist :
" I have examined the water, and it is peculiar
in some points. It contained much sulphuretted
hydrogen, and also a portion of solid deposit,
which was about one-half siilphur and the other
half organic matter. There has, no doubt, been
considerable change in the contents of the
water, and I cannot now recognise organic

426 THE CHEMISTRY OF CREATION.

forms; but the presence of the animal matter,
the sulphur, and the sulphuretted hydrogen,
all agree with the idea, that the water when
taken up was rich in animals or animalcules."
Nevertheless, in the absence of any evidence to
prove the existence of luminous animals in this
water, it is just as probable that it contained
simple organic matter in the first stages of putre-
faction.

Mr. Darwin states that after using his towing
net during one night, he allowed it to become
partially dry, and having occasion twelve hours
afterwards to employ it again, he found the
whole surface sparkle as brightly as when first
taken out of the water. It does not appear
probable in this case that the particles could
have remained so long alive. On one occasion,
having kept a jelly-fish of the genus Diancea
till it was dead, the water in which it was
placed became luminous. Professor Ehrenberg,
during a stay of five months at Tor, on the Red
Sea, was frequently engaged in examining the
sea-water, which was found to be very full of
small slimy particles without any determinate
form, often having the edges jagged, and which
emitted light on stirring the water in which
they were found. They covered the marine
plants, corals, &c., which consequently appeared
luminous ; every stroke of the oar caused them

DISCOVERIES OF EHRENBERG. 427

to sparkle ; but he was never able to detect
organization in any ' of these particles, and he
could never satisfy himself that any of the
microscopic animals which he found with them
in the water gave out light. They did not
unite and form large slimy masses, but were
dispersed about in small flakes. On examining
the water, after a violent storm at Heligoland,
Ehrenberg found no infusorial animalcules in it ;
but quantities of morsels of gelatinous matter,
often torn and ragged, which emitted light, and
small gelatinous globules, with jagged edges
occurred, similar to those which he obtained in
the Eed Sea. During his stay at Heligoland,
he often observed as it were chains of luminous
matter floating in the sea, which on examination
proved to be the masses of luminous medusce, de-
tached and torn by the violence of the sea.
Darwin says, . " The same torn and irregular
particles of gelatinous matter described by
Ehrenberg, seem in the southern as well as in
the northern hemisphere to be the common
cause of this phenomenon. The particles were
so minute as easily to pass through fine gauze,
yet many were distinctly visible by the naked
eye. The water when placed in a tumbler and
agitated, gave out sparks, but a small portion
in a watch-glass scarcely ever was luminous.
Observing," he adds, "that the water charged

428 THE CHEMISTKY OF CREATION.

with gelatinous particles is in an impure state,
and that the luminous appearance in all common
cases is produced by the agitation of the fluid
in contact with the atmosphere, I am inclined
to consider that the phosphorescence is the
result of the decomposition of the organic par-
ticles, by which process (one is tempted almost to
call it a kind of respiration) the ocean becomes
purified."

Recent discoveries render it highly probable
that this view, which is also held by Professor
Ehrenberg, is the correct one, and that while
it is certain that many marine creatures possess
the faculty of emitting light, yet that this
phenomenon, when occurring over a large sur-
face, is due to a sort of natural purification of
the water, by exposing these organic matters
to the influence of the air. Professor Schon-
bein, in his Report on Ozone (the remarkable
principle frequently before mentioned), adopts
a similar view, and explains the chemistry of
the process in a highly-ingenious manner. The
most ready method of procuring ozone is to put
a piece of moist phosphorus into a bottle full
of air. A peculiar chemical decomposition now
takes place. The oxygen of the air unites with
the water present, and oxidating it, produces
ozone. The ozone then reacts upon the phos-
phorus, and in oxidating it produces the peculiar

OZONE THE CAUSE. 429

light called phosphorescence. It is remarkable
that when phosphorus is put into perfectly dry
air, free from all moisture, it shines no longer,
or but very feebly, and ozone is not produced.
Thus it appears that phosphorus possesses the
peculiar property of causing the union of water
and oxygen so as to form ozone, which then
acts upon it. Bearing this singular action
of phosphorus in mind, Professor Schonbein
says, — " It is well known that the phospho-
rescence of the sea is intimately connected with
the motion of its waters, or, to speak more
properly, that the phenomenon is dependent
upon the particles of these waters being brought
into immediate contact with the atmosphere.
When a ship moves about, or the wind happens
to agitate the sea, the surface of the brine is
continually renewed, and consequently new
particles of organic matter are every moment
brought into contact with the surrounding air."
Just as the phosphorus has the property of pro-
ducing ozone, which then, oxidates it, and in so
doing causes the emission of light, so it is
supposed that this organic matter causes the
oxygen of the air to unite with water to pro-
duce ozone, which when produced, oxidates and
destroys it. Hence we are to consider the
light given out by the waters of the ocean as
the effect of a process of oxidation taking place

430 THE CHEMISTRY OF CREATION.

on a most extensive scale, which process is
carried on less by the free oxygen of the atmo-
sphere than by that of the ozone produced by
this peculiar property of the organic particles
in the sea-water.* The source of the organic
matter in the waters of the ocean lies in the
decomposition of innumerable marine animals
daily dying in its depths, and also in the or-
ganic matters brought down and swept into
the ocean by rivers.

It has been lately found by Professor Forch-
hammer, that in fresh-water also there is
generally a considerable amount of organic
matter. It is greatest in summer, and almost
disappears as soon as the water freezes. Its
quantity is diminished by rain, and also when
the water has to run a long way in open chan-
nels. Whether the results of an examination
into the organic constituents of sea-water will
furnish a similar series of facts, cannot at present
be stated.

In addition to the ingredients hitherto recog-
nised as producing a portion of the saline con-
tents of sea-water, another has been recently
discovered by Dr. Wilson. This is the remark-
able element Fluorine. By some ingenious
experiments upon the crust of the steam-boilers

* It is supposed by the discoverer of ozone, that the sliming
of rotten wood in the dark is due to its possessing the same
power with regard to atmospheric oxygen as phosphorus.

FLUORINE IN SEA-WATER. 431

of steamers, he obtained conclusive evidence
of the presence of this element, in the produc-
tion of hydrofluoric acid vapour, which has the
property of corroding glass almost instantly.
By properly treating the crust thus obtained,
he was able to etch several pictures on glass,
which were exhibited at the scientific meeting
before which his experiments were brought.
In all probability, as fluorine has been found
both in the waters of the German Ocean, of
the Firth of Forth, in the teeth of the walrus,
and in the ashes of marine plants, fluorine in
minute portions is one of the regular consti-
tuents of sea-water. Professor Forchhammer
states that he has examined many shells and
marine products from various localities, and they
all gave evidence of the presence of the same
body, the quantity being always greater in sea
than in land animals.

The shields of many infusorial animalcules
found in sea-water are largely comp_osed of
silica; yet silica is not found as one of the
mineral ingredients of sea- water. In all pro-
bability they are able to obtain it even when it
exists merely in a state of mixture in water.
Dr. Smith discovered silicious-coated animal-
cules in the water of the Thames only in those
parts of it which receive the drainage of the
metropolis, and he ingeniously conceives the
silex to be derived from the decomposition of

432 THE CHEMISTS Y OF CREATION.

wheat, &c., and to be conveyed into the river
in the exuviae of our sewers.

Eecurring to the important occasional in-
gredients noticed as being present from time to
time in the air, and considering the analysis
given at the commencement of this chapter as
the normal or standard representation of the
chemical constitution of the sea, it may be asked,
Are not "occasional ingredients" present like-
wise at times in the waters of the ocean?
Darwin says he saw a considerable tract of the
ocean on the coast of Mexico covered with a
thin iridescent coat of oil. This is supposed to
have arisen from the putrefaction of a whale.
The sea, as has been before remarked, near the
Cape de Verd islands, is not unfrequently
seen covered with a film of rock oil. In
the waters which bathe the coasts of volcanic
regions, evidence exists to show that occasional
ingredients, fatal to animal life, are added from
time to time to the sea. Thus we are informed
that at the eastern extremity of Java there is
a lake containing sulphuric acid, a quarter of a
mile long, from which a river of acid water
issues, which supports no living creature, nor
can fish live in the sea near its confluence. It is
one of the frequent phenomena of earthquakes,
that the sea-water of the regions where they
occur is covered with shoals of fish poisoned by
the addition of some deleterious ingredients to

SELF-PURIFYING QUALITY. 433

the water. After a volcanic eruption in Iceland,
the fish all deserted the sea coast, thus evidently
showing that something had been added to the
water unfavourable to their existence. It was one
of the plagues visited upon the obduracy of the
Egyptian monarch, that the fish that were in the
river died, the waters having become poisonous
to them by the remarkable change mentioned
in the Scriptures. Beyond these facts, which
have only a local bearing, ocean-chemistry is
not empowered to speak. It is possible there
may be a state of poisonous diffusion in the
waters analogous to our malaria, or even to our
epidemics ; * but we can scarcely be said to be in
possession of a single fact to justify this conclu-
sion. Doubtless, the inhabitants of the deep
are not exempt from disease and death ; but no
evidence exists to favour the supposition that
the regions of the deep are desolated as those of
the dry land by the infliction of epidemics.

There can be no question that a self-purify-
ing property has been given to the ocean, little
though its phenomena are as yet understood.
Dr. Smith, in the Researches in the Air and
Water of Towns, before quoted, has particu-

* It must not be considered that the brute creation arc
exempt from epidemics. Every agriculturist can add his tes-
timony to the fact, that epidemic disorders, frequently of a
most alarming character, appear among the lower animals.

2 F

434 THE CHEMISTRY OF CREATION.

larly adverted to the self-purification taking
place in fresh-water. The organic matter is
precipitated as it is in fresh-water when it-
comes into contact with clay at the bottom of
the sea or with the mud on its shore. It is thus
rendered insoluble and innoxious. Another
portion of it, which remains in solution, be-
comes acted on by the various living creatures
peopling the waters ; and what escapes both
these processes is no doubt decomposed in the
manner already alluded to by the influence of
the air and ozone. In consequence of the
continued deposit which is taking place over
a great part of the ocean bed, the products of
these decompositions, when insoluble, are buried
at the bottom, and soon so entirely covered
over with a layer of detritus, as effectually to
protect the overlying waters from their influ-
ence. This purifying process is largely assisted
by the mechanical action of the waves. The
occasional ingredients locally present in the
waters of certain coasts, are removed by the
ordinary effect of chemical decomposition.

Would that, as the result of the intelligent
and careful investigations of chemical philoso-
phers, we were in possession of more and better-
defined information on the chemistry of the
ocean than this chapter now contains !

CHAPTER III.

MOVEMENTS OF THE WATERS.

THE restlessness of the ocean is a fact so fami-
liar to us as to have passed almost into a pro-
verb. The " troubled sea " is an expression,
the frequency of the use of which sufficiently
indicates that the movements of the waters are
phenomena of the most familiar observation.
As the tide continues flowing in, and threatens
soon to cover the spot where we stand, it
is impossible not' to feel strongly impressed
with the fact, that ceaseless motion appears
to be a very law of the constitution of the mag-
nificent element we behold. Yet, in reality,
just as its particles are more dense, and less
elastic than those of the air, the movements
taking place in the waters are not nearly so
extensive or so various as those which inces-
santly agitate the air around and above us,
even when it appears in the most quiescent
condition. The fact that every ripple which
agitates the surface of the water is visible to

436

THE CHEMISTRY OF CREATION.

us, while the most violent commotions of the
air are wholly invisible, accounts for the dis-
position we feel to give to the waters, rather
than to the air, the character of restlessness.

The phenomena of the ocean present, in a
number of points, a striking contrast to those
of the air. One of the grand causes of atmo-
spheric movement was found to be increased
and unequal temperature : on the contrary, one
of the important causes of movement in the
particles of the ocean, though far from the most
important, is a diminished temperature. Heat
applied to the surface of the
ocean can produce little or
no movement in its parti-
cles; being expanded by
heat, and thus rendered
lighter, they of course can-
not sink, but remain sta-
tionary, or nearly so, at the
surface. A very simple ex-
periment will prove this: if
water is poured into a tall
vessel nearly to its brim,
and a very sensitive thermo-
meter be inserted in it, as
shown in the cut, so as that
the bulb should be just be-
low the surface, and then a

EFFECTS OF HEAT AND COLD.

437

quantity of pure spirits of wine is poured upon
the water, and lighted, it will burn for some time,
and of course communicate heat to the surface of
the water ; yet the thermometer, separated only
by a thin layer of water from the burning spirit,
will not indicate any, or only the smallest possible
rise of temperature. This is because fluids are
bad conductors of heat. If the flame were applied
to the bottom of the water, instead of its sur-
face, the result would now be different, and the
liquid would boil in consequence of what has
been, before called the convection, or carrying
upwards of heat, by the
light and expanded par-
ticles, as they rise to the
surface of the fluid. Let
us perform the converse
of this experiment, and
place, instead of a flaming
layer of spirit, a flat piece
of ice upon the surface of
the water. The effect is
immediately perceptible
by the falling of the ther-
mometer ; the particles of
water being cooled be-
come heavier, and sink ra-
pidly downwards. Hence
it is evident that while

438 THE CHEMISTRY OF CREATION.

heat, applied to the surface, produces little
or no movement in the particles of water,
the application of cold, on the contrary, is a
constant cause of motion. In the air, heat
causes the particles to ascend; in the water,
cold causes the particles to descend. Direct
observations are still required on this subject,
but it appears probable that this class of move-
ments takes place most actively in regions of
moderate temperature. Near the equator,
during the day the upper stratum of water
becomes greatly heated by the sun's rays, but
very little disturbance of its particles is thus
produced. Again, in the colder regions about
the poles, the surface of the water is covered
with a dense and solid stratum of ice, or the
water when not frozen is scarcely ever higher
than 40°, at which point its particles lose their
tendency to sink ; and here movement is of
course arrested. In temperate regions, there-
fore, while the nights are very cold, although
not so cold as to reduce the temperature to 40°,
this movement goes on most actively. The sur-
face particles constantly losing heat, and so
becoming specifically heavier than the particles
beneath, sink ; while their place is supplied with
warmer particles from below. Thus there is a
constant ascent of heated particles, and descent
of colder ones, producing, although it is not

WAVES. 439

perceptible to our eyes, a phenomenon analogous
in its character, though developed by a precisely
opposite state of temperature, to the first move-
ment of air on land. By placing several lumps
of ice in a tumbler partly filled with water, these
movements can be very distinctly perceived ;
the cold particles in descending becoming partly
visible, in consequence of the effect of their
greater density upon the refraction of light;
but, in consequence of a peculiar law in the
constitution of water before noticed, at the 40th
degree on Fahrenheit's thermometer, further
movement of its particles from above downwards
is arrested. The attention of this singular and
beautiful provision has been previously consi-
dered. On the whole, however, the actual ex-
tent and amount of movement arising from this
cause must be slight, although it is doubtless
important as a means of preserving uniformity
of composition, with regard to the saline con-
tents and the solutions of the gases throughout
the whole mass of water.

The movements with which we have thus
been occupying ourselves are removed from
ocular observation ; those which are next to
come under our notice, and which are among
the most sublime phenomena of the ocean,
appeal both to the ear and to the eye, as we
behold them agitating mass after mass of water,

440 THE CHEMISTRY OF CREATION.

until they dash at length, with a hollow
sound, in foaming breakers at our feet. Far as
the eye can reach across the surface even of
this comparatively tranquil ocean, it beholds
nothing but line after line of heaving waves;
now and then a taller and broader billow than
the rest marking its pre-eminence by a white
crest curling on its summit. It may appear
that little interesting to the student or to the
philosopher is to be found in the phenomena of
waves, beyond their beauty, or their sublimity,
or their force. To look upon this widely agi-
tated surface, it would seem a vain attempt to
discover anything like harmony or order in
phenomena so apparently confused and irre-
gular as those of waves. Yet there is much
philosophy, and that of a very abstruse order,
concerned in the explanation of their move-
ments ; and, incredible though it would seem,
there is a real harmony and order of a very
beautiful kind, observable in these seemingly
disordered and commingled masses of water.
Some of these waves are round and long, others
are high and sharp ; some advance with a great,
others with a less velocity ; and all present a
certain general form familiar to the mind as
the form of a sea in agitation, which at once
distinguishes it from all other phenomena.
How striking the thought, not one of these

ANALYSIS OF A WAVE. 441

apparently free and fetterless billows, which
have supplied poets with the most beautiful
similes of liberty and unrestrained action, can
move but in obedience to certain laws which
control and direct them. To us nothing in
nature appears so unshackled; in. reality not a
wave heaves but is under the influence of laws
which prescribe its movement, velocity, and
form. Is it not so in life ? The movements of
an hour, the fresh-rising events which appear
to us the most fortuitous things in the world —
these all have their time, their form, and pres-
sure, and place appointed, in the hands of Him
in whom we live, and move, and have our being.
The following parts are recognised in a wave :

Its highest part is called the crest, w in the dia-
gram. From w to a, is called the front ; from
w to w, the back ; from w to h, the height ; and
from w to «, the amplitude ; a is called the
origin, and w the end of the wave. The arrow
x x shows the direction of the movement of the
wave.

Wave-like movements in the waters of the
ocean arise from two causes — the attraction

442 THE CHEMISTRY OF CREATION.

of the sun and moon, and the power of the
wind. What are called tides are, in reality,
vast wave-like movements due to the attraction
of these heavenly bodies, but in their effects
influencing vast portions of the watery regions
of our planet. Mr. Scott Russell, who has ibr
many years paid much attention to this subject,
calls this the Great Primary Wave. In merely
beholding the phenomena of the ebb and flow
of the tide, it may be difficult to realize the fact
that these effects are due to the rise and fall of
one mighty wave, which rises in mid-ocean, and
in falling casts its wide-extending waters on the
shores of half the world. Under the influence
of the lunar, or at stated periods, of solar and
lunar attraction, a vast mass of the waters of
the ocean is raised above its general level ; obe-
dient to the laws of hydrostatics and of gravity,
this great mass of water sinks down again,
spreading in every direction around, until at
length it rolls its waves upon every shore, which
on attaining the highest point to which they
ordinarily extend, produce the phenomenon of
high tide. When again the waters are " ga-
thered into an heap," to use the beautiful and
accurate expression of the word of God, they
become withdrawn from our shores ; and it is
then low water. How sublime the reflection,
as we retire from this advancing tide, — these

GKEAT TIDAL WAVE. 443

onward-moving waters gathered and rose to
greet the gentle moon, it may be a thousand
miles hence, and separated to bear around the
world the evidence of the power and wisdom of
Him whose voice the great ocean itself trembles
at and obeys ! The velocity of this great tidal
wave varies from 10 to about 100 miles an
hour. It is supposed that fifty or sixty hours
are occupied in its reaching our shores, from the
time of its dispersion. Its appearance as a
great wave cannot, of course, be witnessed by
any eye but that of Him who " holds the waters
in the hollow of his hand," the general pheno-
menon of the rise and fall of the tide on our
coasts, exhibiting nothing of the wave-like form.
This great wave, however, is not the less real
that its length is so great, that while one end
touches Aberdeen the other reaches to the
mouth of the Thames and the coast of Holland.
Though its enormous extent and magnitude
render it impossible to be recognised as a wave
by any single observer, we are able by station-
ing numerous observers along different parts of
the coasts to compare its dimensions, and to
trace its progress at different points, and so to
represent its phenomena to the eye and mind,
in a small scale, as to comprehend its form and
nature as clearly as we do those of a mountain
range, or extensive country which has been

444 THE CHEMISTRY OF CREATION.

mapped on paper by the combination together of
trigonometrical processes performed at different
places by various observers, and finally brought
together and projected on one sheet.

Sometimes the great tidal wave, when met
by an opposing current from the waters of some
large river, raises a mass of water of great
height and force, called the Bore. We know
little of the power of this remarkable pheno-
menon on our coasts, although it is observable
in some of the rivers, such as the Severn and
Trent. But in India, the bore of the Ganges
has long had a fearful reputation. Sometimes
it appears as a roaring mass of many waters,
four or five feet high, often overwhelming with
destruction all the smaller craft exposed to its
power. In other rivers it attains a still greater
magnitude. But the grandest display of this
phenomenon is described as occurring near the
mouth of the great river Amazon. At the
ebbing of the tide this mighty stream pours
down at spring-tides a vast volume of water,
with great velocity, into the ocean. The
current, at a little distance from land, meets
with a powerful opposing oceanic current. The
result of this great conflict between opposing
waters is to raise a mighty mountain of water,
attaining, as it is said, the height of 180 feet,
which carries terror and desolation along its

ORDER AMONG WAVES. 445

track. It is even asserted, that such is the vio-
lence of this extraordinary phenomenon, which
is called by the Indians the Pororoca, that the
very islands tremble during its passage.

The second order of waves are produced by
the action of the wind. Poets speak of the
" inconstant billow ;" and vainly, as might be
supposed, might we attempt to reduce to form
and law, the irregular and agitated movements
whiclx are now throwing the whole sea-surface
into tumult. Yet even here order reigns.
These waves, which give its restless aspect
to the sea, are of the class called oscillatory.
Mr. Russell's definition of them is — that they
are gregarious, and of two species, progressive
and stationary. It appears that a certain de-
gree of adhesion takes place between a moving
mass of air and the water over which it sweeps.
The result is, that a certain portion of the
fluid is lifted above the general level of the
surface, and an oscillatory movement is thus
set up, which by the continued action of the
breeze is increased in magnitude, until waves
of considerable dimensions are formed. Waves
of this class exhibit a number of interesting
phenomena, into which it becomes not our
present inquiry to enter. In consequence of
perpetual changes in the direction of the over-
sweeping current of air, the direction and

446 THE CHEMISTRY OF CREATION.

character of the waves are altered. The con-
figuration of the shores reflects the waves,
some in one direction and some in another, and
new lines of movement are thus awakened.
Frequently, also, there are on the sea three or
four series of co-existing waves, each series
having a different direction from the other, and
the individual waves of each remaining parallel
to each other. Thus the primary appearance
of order is lost by the substitution of another
sort of order. The velocity with which wave
succeeds to wave varies in a heavy sea ; waves
have been found running at the rate of upwards
of twenty-six nautical miles an hour. Captain
Stanley has described an ingenious method by
which he marked the speed of waves in a heavy
sea, with the ship running before the wind. He
caused a spar to be veered astern by the marked
lead-line, until the spar was on the crest of one
wave, while the ship's stern was on the crest of
the preceding one. In order to ascertain the
speed of the sea, the time was noted when the
crest of the advancing wave passed the spar
astern, and also when it reached the ship. By
a little calculation it is plain that the speed of
the advancing wave could be easily ascertained.

The height of waves in moderate weather is
insignificant. Near shore they assume a greater
degree of curvature than at a distance from land.

SPEED AXD HEIGHT OF WAVES. 447

where they are generally long and low. But
when the stormy wind arises in its power, their
height and magnitude constitute one of the
grandest displays of elemental motion and
power in the world. For measuring the height
of waves the following plan has been most fre-
quently pursued: — When the ship is in the
trough of the sea, the person observing ascends
the rigging, until he can just see the crest of
the coming wave on a level with the horizon;
and the height of his eye above the ship's
water-line will give a very fair measure of the
difference of level between the crest and hollow
of a sea; deducting half from this for the de-
pression of the hollow below the general level
of the surface, we obtain in the remainder the
perpendicular height of the wave. It is con-
sidered by some that the utmost elevation of
waves produced by the action of the wind does
not exceed twelve feet. Others state their
occasional height at twenty feet. Few persons
can realize the magnificent effect of standing
on the cliffs of the west coast of Ireland, and
observing the great breakers rolling in from the
Atlantic, some of which have been ascertained,
by the method described, to be fifty feet high,
and occasionally they even reached the enor-
mous magnitude of 150 feet.

In addition to the oscillatory gregarious waves,

448 THE CHEMISTRY OF CREATION.

Mr Kussell describes another class of waves
which he calls Capillary. These minute waves
are amongst those phenomena which we most
frequently see. When the glassy surface of a
lake is broken into countless ripples by the
influence of a gentle breeze, the wavelets thus
produced are capillary waves. They are mere
oscillations of the superficial layer of water,
extending to a minute depth, and very short in
duration. The velocity of the capillary waves is
usually about eight inches in a second of time.

An observer, who will study the surface of a
sea during the successive stages of an increasing
wind from a calm to a storm, will find in the
whole motion of the surface of the fluid appear-
ances which illustrate these various classes of
waves, as well as exhibit the laws of their mo-
tion. If we suppose this heaving water to be
perfectly calm, and ourselves the observers of a
storm through all its stages of development, the
phenomena of the various forms of waves would
appear beautifully pictured before us by the
waters at our feet. A gentle movement of the
air, not exceeding half-a-mile an hour, leaves
the glassy surface unbroken; and, mirror-like,
it reflects the surrounding objects with minute
accuracy. Let this movement increase in velo-
city, and a playful zephyr flit across the sur-
face at the rate of about 17 inches a second, or

CAPILLARY WAVES. 449

a mile an hour, and the glassy smoothness dis-
appears, but on its departure the surface re-
mains polished as before. By and by this fitful
movement of the air .becomes regular, and the
mirror -like appearance is permanently lost ;
the surface is covered with countless wavelets,
and we have the phenomenon of capillary waves
produced. Still, any sheltered spot, where the
direct action of the wind is not felt, has the
same mirror-like surface at first possessed by
the whole, for these waves cease almost instan-
taneously upon the intermission of the disturb-
ing cause, not being able to travel spontaneously
to any considerable distance. The disturbed
surface now presents that appearance of black-
ness which is often justly regarded as the pre-
cursor of a storm. This results from the effect
of the unevenness of the surface upon the re-
flection and refraction of light.

The wind still rises ; the increasing clouds
gather blackness, and nature is overspread with
a certain indefinite appearance of gloom, which
is often the sure harbinger of a tempest. The
movement of the air is now not less than two
miles an hour. Small waves begin to rise uni-
formly over the whole surface of the water with
great regularity. On the ridges of these waves
the tiny capillary waves are seen riding, but as
the wind increases they disappear, and are then

2 G

450 THE CHEMISTRY OF CREATION.

found in the hollows between the waves and on
their anterior slopes. The true secondary waves
are now seen heaving their curling summits far
and wide over the agitated surface. Beginning
at about an inch of amplitude, and two inches
in length, they enlarge their dimensions, unite
with other waves, are now and then adorned
with a crest of foain, and the surface now pre-
sents the regular appearance of a stormy sea,
the waves being of nearly uniform magnitude.

When these waves are now impelled by the
wind against the shelving coast, they break on
the margin of the shoal, and they continue to
roll along in the shallow water towards the
beach, and becoming transformed into waves of
the first order, that is, waves of translation,
finally break on the shore. What a beautiful
scheme of harmony and order is ours, when we
find that from the first movement of a ripple
to that of the great waves which thunder upon
the coast in elemental power, all these move-
ments of the water are determinate and obedient
to certain laws !

From what has been said as to the cause of
movements of this kind in water, it will be
evident that could we in any way diminish or
annihilate the adhesion or friction between the
surface and the current of air which impels it
into motion, the movements would in a great
measure cease. This can be effected by means

OCEANIC CURRENTS. 451

of oil. There has been much question raised
upon the supposed effects of oil in calming the
waves of the sea, and no doubt its power has
been much • exaggerated ; but it appears certain
that pouring oil on the surface, by neutralizing
the force of the wind, has a certain tranquil,
lizing influence upon the agitated waters. The
same degree of adhesion does not exist between
oil and air, as between air and water.

We must now advert to movements in the
waters of a different kind to those hitherto
spoken of — these are Currents. It may be
surprising to learn, that in a body of water
apparently so little exposed to causes likely
to create a current as is the ocean, currents
of determinate direction, and of considerable
velocity, actually exist. There are mighty
rivers in the ocean as well as on land. Some
of these currents are merely due to the me-
chanical action of the wind ; others are ascrib-
able to differences of temperature; thus the
melting of a large iceberg, or of an ice-field,
would set up, during the whole period occu-
pied in the process, various irregular currents
caused by the cold water descending, while
its place becomes occupied by the lighter and
warmer fluid. In these respects, however, we
can trace little analogy between the phenomena
exhibited by the air and those of the ocean.

452 THE CHEMISTRY OF CREATION.

The most remarkable and well defined oceanic
current is the Equatorial. The Trade- winds
were noticed to have a two-fold cause, the high
temperature of the tropics, and the revolution
of the earth. This great current of water is due
to the latter cause, and in part to the impulse
of the Trade-winds which blow in the direction
which it pursues for a large part of its course ;
namely, from east to west. This current is
very evident, both in the Atlantic and Pacific
Oceans, between the parallels of 30°, on each
side of the equator, pursuing an average velocity
of from nine to ten miles a day. It is con-
nected with another system of currents called
the Polar. The direction of the latter is from
the poles toward the equator. A flow of water
in this direction is induced by two causes. In
the equatorial regions, in consequence of the
great power of the solar rays, a vast amount of
water is raised into the atmosphere by the force
of evaporation ; to supply this loss, a flow of
water sets in from the colder regions lying north
and south, and thus a current is produced. In
addition, the greater velocity of the earth at
the equator tends to draw the water from less
swiftly moving regions to that position, and
thus also a current is established. That such
a current, or system of currents actually exists,
cannot be doubted. The evidence of their
existence and power is found in the frequency

SINGULAE EFFECTS OF CURRENTS. 453

with which icebergs are found in the naviga-
tion of the Atlantic ; sometimes as low even
as 45°, and even 40° of latitude. It appears
probable, that the recent strange report of the
appearance of the great sea-serpent to the asto-
nished crew of H.M.S. Daedalus, is explicable^
as has been suggested by Professor Owen, upon
the ground of a polar current having borne
away — a very different creature to the sea-ser-
pent— a species of sea-lion, which had trusted
itself to the treacherous dwelling-place of a
floating mass of ice, which melting beneath it
on arriving in warmer regions, had left the
poor animal to breast the waves of the ocean
in a vain search for a resting-place. It was also
provokingly manifest that such currents existed
to the boat-sledge expedition of Captain Parry
to the North Pole ; for it was found that as they
advanced' over the fields of ice to . the north-
ward, they were actually carried at a quicker
rate south by the polar currents which bore
upon them the ice over which they travelled.

Orv the polar current reaching the equato-
rial regions in consequence of its possessing
a lesser degree of rotatory motion, owing to
its place of origin, than the region into which
it is now brought, it appears as a current from
east to west, upon the principle before ex-
plained under the head of the Trade-winds,

454 THE CIIEMISTKY OF CREATION.

and uniting with the equatorial currents, flows
in one broad current, like a great and mighty
river, half way across the globe.

The equatorial current striking against the
vast continent of America, divides into two
great currents. Of these, one flows down the
east coast of South America, and enters finally
the Pacific Ocean, through the Straits of Ma-
gellan. The other turns northward, enters the
Gulf of Mexico, sweeps round the coast in a
powerful current, as rapid and well defined as
it were a great river, and now known as the
Gulf Stream, proceeds on its onward course at
the velocity of four or five miles an hour. More
northward still, this large current of water tra-
verses the coast of North America, sweeps by
Newfoundland, passes eastward, and crosses the
world again, extending even occasionally to the
Avestern coast of the British Isles. After this,
it is supposed to bend downwards along the
western shore of Africa until its widely circu-
lating waters become once more commingled
with those of the great equatorial current from
which they originally proceeded.

This remarkable portion of the great circle of
oceanic currents receiving a large increase of
temperature in sweeping along the shores of
tropical America, and particularly in the Mexican
Gulf, is distinguished, by this increase of temper-

GULF STKEAM. 455

ature, from the waters of the cold ocean around.
The entrance into it becomes sensible even to
the thermometer ; sometimes its temperature is
86°, the waters around being 60°. Its waters
are also remarkable for their beautiful indigo-
blue colour, separating it from the green waters
of the Atlantic for hundreds of miles, and by
the fogs which in its course near Newfoundland
are produced from the condensation of the warm
and moist air overhanging them. It is also sin-
gular that it is chiefly in the warm waters of this
great current that the Gulf-weed is found in
long trails ; it is a species of fucus, and is known
under the name of Sargasmm Vulgare.

In the wide domains of the water-world, other
important general currents and countless local
currents exist, which have their importance and
their cause in the places where they appear.

It appears not unlikely that deeply concealed
from the perception and investigations of man,
a number or even a system of submarine cur-
rents exist. We are not to suppose all move-
ment is on the surface. From the singular
result obtained by Messrs. Kotzebue and Du-
petit Thouars, adverted to in a previous page,
it appears not improbable that some system
of circulation may be in operation in the lower
regions of the ocean. It is even stated that in
some parts -of the Caribbean Sea, where the

456 THE CHEMISTRY OF CREATION.

upper branch of the equatorial curreiit runs
strongly, a boat may be anchored without the
anchor touching the ground, and kept stationary
Avhile the waters on which it floats are sweeping
rapidly along. This is effected by lowering an
anchor or some similar heavy body down to
some depth ; it there appears to be impelled or
dragged by a current exactly opposite to that
on the surface, with sufficient force to neutral-
ize the drifting power of the upper current.
Although the particles of Avater move much less
freely over one another than those of air, it is
quite conceivable that extensive submarine cur-
rents pass in various directions in the abysses of
the ocean, as the lower currents of air over one
another and over the surface of the land.

With all these movements of the waters, with
the tide, the wave, the ripple, and the current,
the chemistry of the ocean is connected in a
simple but important manner. It is to be
regretted that the subject has hitherto received
so little attention from chemists, and that so
much is consequently left to mere conjecture.
In proportion as the chemistry of the ocean
receives that study by philosophers which has
been bestowed upon the phenomena of the
earth and air, will it assuredly be found
prolific in facts of value and interest in the
history of science. The chemistry of the tide,

CHEMISTRY OF THE TIDES. 457

as distinguishable from that of the wave and
ripple, must first occupy our consideration.
Let us ascend the hillock hard by, and thence
take a chemical view of the interesting phe-
nomena of the sea-shore.

In considering the tidal chemistries as distin-
guished from those of the wave, we have chiefly
to inquire into the probable effects of a periodic
flux and reflux of sea-water upon the objects
exposed to its influence. This phenomenon
exerts an influence upon the inorganic consti-
tuents of the shore, and also upon the various
inhabitants of the sea, vegetable and animal,
lying within the line of low-water, or ebb of
the tide. On almost all sea-coasts, and parti-
cularly on such a one as that we are contem-
plating, where a river brings down constant
supplies of material from a rich alluvial soil
inland, there exists a certain amount of organic
vegetable and animal matters, which, as is com-
mon with all such matters, is extremely prone
to decomposition, and is here placed in circum-
stances peculiarly favourable to it. The ebb
of the tide exposes such matters to the full
influence of the air, leaving them sufficiently
moist to forward the changes which immediately
commence in organic matter so exposed. A pro-
cess of putrefactive decomposition is set up, the
gaseous elements of the air unite with the solid

458 THE CHEMISTRY OF CREATION.

particles of such matters, converting them into
water, ammonia, and carbonic acid, and in contact
with the saline matter of the sea-water, combina-
tions are ibrmed with it, which await only the
return of the waters to be washed away. Upon
yonder sands, and particularly near the debouch-
ment of the river, lie various slimy patches,
which, if analysed, would be found to consist of
the remains of decaying fish and marine crea-
tures, and of decomposing vegetable matter,
united with the detritus of the distant river-
banks, rocks, and mountains. Exposed for
some hours during the day, not only to direct
contact with the air, but also to the heat of
the sun, these organic particles become rapidly
altered, and frequently give token of the activity
of chemical decompositions taking place in them
by a sensible odour of sulphuretted hydrogen
gas. Probably ozone is active in these pheno-
mena.

In addition to the exposure of organic par-
ticles to putrefactive decay by the departing
waters to the atmospheric influence, the ex-
posure of inorganic substances, comminuted
fragments of rocks, mud, and sedimentary mat-
ters of all kinds, to the same influence should
be considered. Alterations of their composi-
tion not complete before, are now completed
under the combined and alternate action of

EFFECTS OF AIR UPON MUD, ETC. 459

water and air, and a definite fixedness of com-
position is attained by the compounds thus
situated, preparatory to their removal and sub-
mergence beneath the waters of the great deep.

In our own mild climate these decompositions
are so slight, though constant, as to be without
any perceptible effect upon the air of their vici-
nity, and it is well known that the air near the
sea-coast is generally highly pure and salu-
brious. But in tropical countries the case is
widely different. The full influence of the
tropic's sun favours all these decompositions to
a fearful extent, and the most subtile and deadly
poisons are produced upon the sea-coast.

It was until recently considered that the
fearful mortality on the coast of Western Africa,
was due to the development of sulphuretted
hydrogen gas as a result of the mutual reaction
of vegetable matter and the sulphates in sea-
water. But Dr. Me William, in the Medical
History of the Niger Expedition, has shown
that it is erroneous to believe the sea on
the African coast to be impregnated with this
gas. A large number of experiments failed to
indicate the slightest trace of this gas in the sea-
water. It was most probably produced in the
bottles submitted to Professor Daniell, who first
proposed this theory, by a decomposition subse-
quent to the time of the collection of the water.

460 THE CHEMISTRY OF CREATION.

Sulphuretted hydrogen is, however, one of
the products of decomposition on the sea-shore.
In the neighbourhood of Copenhagen, the dis-
engagement of sulphuretted hydrogen gas is so
large that the silver at country places near the
shore is deeply blackened by it. But its pro-
duction appears to succeed to a sort of ferment-
ing process, produced on the shore by the heat,
moisture, and presence of organic matters in
the mud. Where in tropical countries the
forests come down to the beach, which is
covered with thickets of mangroves, \vhere the
small tides are sufficient alternately to cover
and uncover the roots and parts of the trunks
of the trees — there the mud, the dead leaves,
and animal matters putrefy, and give rise to
fearful poisons ; and also assist in the develop-
ment of sulphuretted hydrogen gas.

Recent investigations by Professor Forch-
hammer teach that important consequences
follow upon the putrefaction even of a mass of
sea-weed on the shore. When this takes place
upon a bed of clay containing iron, a series of
chemical decompositions is commenced, which
results in the formation of Iron Pyrites, which
penetrates the clay. When this is again ex-
posed to the weather it oxidizes, and Sulphate
of Iron is then formed, which reacts upon the
materials around it, and forms Sulphate of

THE EBBING TIDE. 461

Alumina. The clay thus acted upon may, at
some subsequent period, become a source for
obtaining alum; and out of clays so formed,
alum is now obtained in large quantities on the
continent.

The ebbing of the tide produces also im-
portant results to the animated and inanimate
dwellers on the sea-coast. Although this sub-
ject lies in obscurity, can we doubt that it is far
from being a matter of no moment to these
creatures that half their lives are to be spent
under water, and the remainder in the air?
Some may require more of the solar rays, or
more of the atmospheric oxygen than could be
obtained by total submergence. Or it may be
they require to separate and discharge gases into
the air in exchange for others which they re-
ceive, and that these processes could not be
accomplished in the water or in the air alone.
However this may be, it is highly probable
that the all-wise Creator, in appointing as He
has done a zone of exposure to atmospheric
and solar influence to some of these marine
inhabitants, which has been denied to others
which cannot live under similar circumstances,
has at the same time appointed it with a view
to the fulfilment of certain functions of which we
remain at present almost entirely ignorant.

The return of the tide is the signal to all

462 THE CHEMISTRY OF CREATION.

the marine plants to recommence their duties,
and as the fresh waters sweep over them they
gain new life and vigour, and proceed with
their periodical task of decomposition upon
the gases held dissolved in the water. By
their return also the waters put a stop to
such of the chemical changes taking place in
the substances composing the coast, as require
the presence of atmospheric air. Soluble matters
in the soil are also dissolved out, and a supply of
water, free from the impregnations of the coast,
is periodically afforded to all the zoological in-
habitants of the shore zone. The consideration
of the varied processes of vital chemistry taking
place in the waters, is deferred to the next
chapter.

As we look to the foaming edge of the ma-
jestic element now rolling at our feet, and
contrast the colour of the water, for several
yards off shore, with the purer and more trans-
parent tint of the waves at a greater distance,
we immediately become sensible of the fact,
that with every tide certain mechanical effects,
of greater or less amount, must be produced
upon the materials composing the sea-shore.
These heaving billows, which break so un-
ceasingly on the beach, creating that pecu-
liar sound, well described as the " voice of
many waters," in so doing churn up all the

MECHANICAL EFFECTS OF WAVES.

463

loose materials in their track, and violently
agitate and dash them one against another.
The power of water in thus destroying by its
mechanical effects the most solid masses of rock,
is wonderfully great — great not only in its sum,
but in each individual effect. Near Kilkee,
on the west coast of Ireland, exposed to the
buffeting of the long and mighty waves of the
Atlantic Ocean, their effects are most remark-
able. In consequence of some peculiarities in

ROCKS NEAR KILKEE.

the chemical composition of the strata, some
portions are more easily acted upon than others,

464 THE CHEMISTRY OF CREATION.

and the resisting portions consequently stand
out in relief, and present the most grotesque
appearances. The most curious resemblances
of pillars, bridges, and porticos appear as the
evidence of the destructive power of these
waves. Here and there one might imagine
that we beheld a vast cathedral in ruins, the
pointed arch is there, but the fretted aisle and
stately pillar are not. The roaring music of
tumultuous waters forms the harmony of these
natural temples, and the congregation, crowds of
sea-birds screaming to their young, which line
the shelf-like projections on the cliffs.

Dr. Hibbert gives an animated description of
the effects of these great billows upon certain
parts of the rocky coast of the Shetland isles :
"The most sublime scene is where a mural
pile of porphyry, escaping the process of disin-
tegration that is devastating the coast, appears
to have been left as a sort of a rampart against
the inroads of the ocean. The Atlantic, when
provoked by wintry gales, batters against it
with all the force of real artillery, the waves
having in their repeated assaults forced them-
selves an entrance. This breach, named the
Grind of Navir, is widened every winter by
the overwhelming surge that, finding a pas-
sage through it, separates large stones from its
sides, and forces them to a distance of no less

GRIND OF NAVIR.

465

than 180 feet. In .two or three spots the frag-
ments which have been detached are brought

GRIND OF NAVIB.

together in immense heaps, that appear as an
accumulation of cubical masses, the product of
some quarry." Mr. Stevenson states that during
the erection of the Bell-rock lighthouse, such
was the force of the waves, that drift rocks,
measuring upwards of thirty cubic feet, and
more than two tons in weight, have during
storms been thrown upon the rock from the
deep water which surrounds it.

Almost the whole coast of Yorkshire, from

• 2 H

466 THE CHEMISTRY OF CREATION.

the Tees to the Humber, is being gradually
destroyed by the action of the sea. " In the
old maps of Yorkshire," observes Sir C. Lyell,
'' we find spots, now sand-banks in the sea,
marked as the ancient sites of the towns and
villages of Auburn, Hartburn, and Hyde."
" Of Hyde," says Pennant, " only the tradition
is left, and near the village of Hornsea, a street
called Hornsea Beck has long since been swal-
lowed." In one place on the coast of Nor-
folk, there was at one point in the harbour, in
1829, a depth of twenty feet, sufficient to float
a frigate, where only forty-eight years before
there stood a cliff forty feet high with houses
upon it !

When we come to inquire into the chemistry
concerned in this process of destruction, it
will be manifest that it must greatly vary
with the nature and character of the sea-coast.
Yet the grand chemical operations of nature
are all carried on in a remarkably simple man-
ner, and we find that water, carbonic acid,
and atmospheric oxygen, are, as in the waste
carried on inland, the chief agents of destruc-
tion. The hard granitic rocks of the northern
Isles cannot withstand the influence of carbonic
acid acting upon them in a state of solution,
and constantly applied to their surface by the
dashing upwards of the waves. Wherever the

DISINTEGRATION OF COAST. 467

spray touches them they begin to feel the slow
but certain influence of the process of decay.
Rocks of all varieties of composition, serpentine,
porphyry, clay slate, gneiss, limestone, granite,
all waste under the gentle touch of the air and
foam, and become thus prepared to submit to
the force of the overwhelming surges which at
times are cast upon them. The soluble portions
of the rocks thus exposed become separated and
dissolved out by the waves, the surface loses its
solidity and compactness, and may be found on
examination covered for some inches in depth
with a layer of disintegrated matter, which only
awaits the coming of the first tempest to be torn
off and borne away by the triumphant waters
to the depths of the sea. The oxygen and car-
bonic acid gases held in solution by the waves
are largely instrumental in effecting this process,
and those portions of the rocks which are sub-
merged, although less influenced than the parts
exposed to the air and consequently to greater
vicissitudes of temperature, are nevertheless gra-
dually destroyed by this means.

The matter thus produced accumulates at
the base of the cliffs, and it may be observed
forming a sort of low mound at their foot along
the rocky portions of the coast, there to remain,
however, only for a time. This leads us, there-
fore, to ask what becomes ultimately of this

468 THE CHEMISTRY OF CREATION.

disintegrated matter ? " The current which flows
from the north-west," remarks Sir C. Lyell,
" and bears against the eastern coast of England,
transports materials of various kinds. Aided
by the winds and waves, it undermines and
sweeps away the granite, gneiss, and trap rocks
and sandstone of Shetland, and removes the
gravel and loam of the cliffs of Holderness,
Norfolk, and Suffolk, which are between fifty
and two hundred feet in height, and which
waste at the rate of from one to six yards
annually. It also bears away in co-operation
with the Thames and the tides, the strata of
London clay on the coast of Essex and Sheppey.
The sea at the same time consumes the chalk
with its flints for many a mile continuously on
the shores of Kent and Sussex, commits annual
ravages on the fresh-water shells, capped by a
thick covering of chalk-flint gravel, in Hamp-
shire, and continually saps the foundations of
the Portland limestone. It receives besides,
during the rainy months, large supplies of
pebbles, sand, and mud, which numerous streams
from the Grampians, Cheviots,' and other chains
send down to the sea. To what regions, then,
is all this matter consigned ? It is not retained
in mechanical suspension by the waters of the
ocean, nor does it mix with them in a state of
chemical solution — it is deposited somewhere,

DEPOSIT OF SEDIMENT. 469

yet certainly not in the immediate neighbour-
hood of our shores, for in that case there would
soon be a cessation of the encroachment of the
sea, and large tracts of low land, like Eomney
Marsh, would almost everywhere encircle our
island."*

The sediment producing the line of disco-
loration to which we have alluded is extremely
fine. If a quantity of the water were removed
and allowed to stand for a time, it would be
found precipitated at the bottom as a fine
smooth mud. But the time occupied in its
subsidence is very considerable. The practical
chemist, whose business it is to prepare various
compounds, by precipitating them from a state
of solution, well knows how long and tedious
is this process. If we take a tumbler full of
lime-water and pour into it a little solution of
carbonic acid gas, the liquid will become turbid
and white as milk, from the formation of an
impalpable powder, but we must wait hours
before this powder becomes deposited at the
bottom. In like manner, doubtless, a period
of many hours is occupied in the precipitation
of the fine powder, consisting of the waste of
the cliffs and coast. During this time the tide

O

has receded, bearing its turbid water with it,

and currents of various kinds then sweep away

* Lyell ; " Principles of Geology," Book II., p. 108.

470 THE CHEMISTRY OF CREATION.

the fine powdery material, and convey it very
far from its place of origin.

Wheresoever transported, of its ultimate
deposition there can be no doubt. The bed
of the ocean is being constantly overlaid with
such matter, accumulating from age to age,
though with such extreme slowness as to defy
in most instances our detection. In 1,000
years the whole surface of the bottom would
not be raised a foot by the detritus washed
into it from the whole world. Shells and
marine creatures of various kinds are becom-
ing imbedded in it, and the time may per-
haps arrive when the sediment now washed
off in powder, and borne away, we know not
whither, may reappear and become dry land
again, become adorned with vegetation, and
peopled with animals and men.

A highly' interesting event, in connexion
with the chemistry of the waves, and important
as illustrating their combined mechanical and
chemical force, took place on the coast of Bal-
lybunnion in Ireland. The cliffs on this coast
contain a large quantity of alum and iron
pyrites ; and being incessantly exposed to the
violent action of the Atlantic billows, they
become worn away into the most strange forms.
Large caverns, natural bridges, and the resem-
blances of human architecture, abound on the

EXTRAORDINARY EVENT. 471

sea-coast, being produced by the unequal
wasting away of different strata. The roofs of
these caverns are painted with various hues by
the water percolating the overlying strata, and
carrying with it a solution of the mineral in-
gredients encountered in its passage. Stream-
lets also run down the sides of the cliffs,
staining them in ochreous colours, proving that
the water contains iron, and probably other
salts in solution. These solutions are conveyed
into the sea, and there undergo various decom-
positions in contact with the saline matter of
sea-water. Some years since, part of these
cliffs assumed an appearance of a very extra-
ordinary character : the waves by continual
dashing had worn and undermined the cliff,
which giving way, fell with tremendous violence
into the sea ; the consequence was, that several
great strata of pyrites were exposed to the
chemical influence of the air and sea- water ;
rapid oxidation took place, eliminating such an
intense heat as very shortly to set the whole
cliff on fire. For days the great rocks con-
tinued burning with much fierceness, torrents
of steam and smoke rising up as the heavy
billows of the Atlantic leapt upon the glow-
ing masses, and at a distance presenting all
the appearance of some violent volcanic dis-
turbance. After the fresh substances, thus

472 THE CHEMISTRY OF CREATION.

exposed, had become oxidized, the steaming
cliff gradually cooled down ; and now the slow
and silent work of mechanical and chemical
destruction is being carried on without any
external manifestation of its existence. The
heat given out during this singular and grand
chemical phenomenon was so great as to con-
vert masses of clay in its vicinity into red brick !
while melted slags lie about, giving to the whole
scene such an appearance as to render it a fit
representation of the workshop of the mytho-
logical Cyclops.

We have to notice another part of the che-
mistry of the waves, not less interesting, though
less sensible in its effects. It has been men-
tioned, in treating of the subject of rain, that
in order to obtain the solution of a gas, che-
mists and others have recourse to an apparatus
by which the particles of the fluid, generally
water, are separated from one another, and
beaten into a foam. In the action of waves
upon a coast we may observe a means of ob-
taining precisely the same end. If we watch
the breaking of a wave, we shall see, in the
manner in which it falls, a beautiful provision
for effecting this object. Advancing toward
the shore a sloping hillock of water, it increases
gradually in height as the waters become more
shallow ; and becoming higher still, and more

CHEMICAL EFFECT OF WAVES. 473

pointed, it at length totters, becomes crested
with foam, curves over, breaks with great vio-
lence, and, continuing to break, is gradually
lessened in a bulk, until it ends in a fringed
margin on the sea-shore — a broken and agi-
tated mass of foam. Nothing could be more
perfect than the manner in which the water
and air are thus commingled; and the hissing
of innumerable air-bubbles, as they burst on
the surface, impresses forcibly upon the mind
of the thoughtful observer, the conviction that
such a process of agitation as this is neither
without its effect, nor doubtless without its
intention.

From what has been already said upon the
chemistry of the sea, it will be evident that the
solution of the gas oxygen, in water, is of the
most vital importance to the marine inhabit-
ants. Much of this oxygen, as we shall yet
have to notice, is obtained by vital processes ;
but, as we look along the shore, white with the
foam of countless waves ; as we remember the
intimate manner in which air is thus mingled
with water, and reflect upon the incessant con-
tinuance of the same phenomenon, can we doubt
that, in the same manner also, a large quantity
of this valuable ingredient is added to the waters
for the service of the inhabitants of the sea ? In
consequence of the slight solubility of oxygen

474 THE CHEMISTRY OF CREATION.

in water the process is slow, and the amount
accomplished in a given time is small. But,
listening to the unceasing roar of wave upon
wave ; remembering that night and day this
continual agitation is maintained ; can it be
said that, with such means, and so continued,
a great result is not both attained and per-
petuated? And when we consider the large
number of marine' creatures which abound,
especially near our shores, it does not seem
improbable that this is one of the means by
which the purity of the waters is sustained.
The effect of storms at sea, particularly when
cross seas are produced, is no doubt similar,
and the same object may thus be accomplished.
The last point remaining for consideration,
in the chemistry of the movements of the
waters, is that of currents, and their chemical
phenomena. One great function fulfilled by
these ocean streams is the equalization of the
temperature of the ocean, and the communica-
tion of their temperature to the shores along
which they roll. The waters of the great gulf-
stream carry heat with them along the banks
of Newfoundland, as high into the northern
region as to Spitzbergen, where they are sup-
posed to set free great icebergs, by melting
their bases ; and, as it pours down the western
coast of Europe, it communicates the remains

OCEAN CIRCULATION. 475

of its tropical warmth to countries between
which and the source of heat in the current,
lies the broad bosom of the great Atlantic.
The polar currents, on the contrary, pour their
cold waters upon the heated shores of the burn-
ing tropics, thus mitigating the intensity of
their temperature, and communicating a grate-
ful coolness to regions otherwise comparatively
intolerable.

It has been before mentioned that there is a
notable difference with regard to the amount
per cent, of their saline ingredients in the waters
of the tropical seas, and of those lying more
to the north, in consequence of the greater
amount of evaporation suffered by the former
compared with the latter. A current, there-
fore, setting out from tropical regions, and ex-
tending to the Polar seas, will convey its high
charge of saline matter with it, and throughout
its track. On the other hand, a current setting
out from the Poles will carry with it water less
charged with saline contents. By this means
a perpetual circulation of these ingredients is
maintained, and the uniform composition of
ocean-water is secured. The importance of
these two classes of duties fulfilled by marine
currents to the preservation of an uniformity
of temperature and composition in the whole,
can scarcely be exaggerated ; and there can be

476 THE CHEMISTRY OF CKEATION.

little doubt but this grand system of ocean
circulation has a most intimate connexion, not
only with the inhabitants of the land, but with
the well-being of the varied tribes which people
the sea.

Imperfect as is our knowlege of the che-
mical phenomena connected with the move-
ments of the waters, these few considerations
may serve to indicate the interesting, character
of the subject, and to stimulate fresh inquiry.
How exalted should be our ideas of that great
God, who planned, formed, and set in move-
ment our creation, when we can discover a law
in the agitation of a ripple, and a variety of
wonderful effects dependent on the breaking
of a wave !

CHAPTER IV.

LIFE IN THE WATERS.

IT is a reflection calculated to awaken feelings
of wondering interest to remember that the
world of waters before us is not a blank and
desert world, but is tenanted with animals and
plants, and is the scene of as much of the bustle
of life as is the earth or the air. Little of this
appears to the eye, and in a still summer's day,
the mind, beguiled into this belief by the calm
and unbroken aspect of the water, is unwill-
ing to admit the scarcely-moved ocean to be in
reality the theatre where the drama of life
is played as universally as on land. But on
descending to the shore and investigating matters
a little more closely, this idea vanishes, and we
become filled with astonishment at the number,
beauty, and variety of the marine inhabitants.
The , chemical connexion of these with each
other, and with the water in which they dwell,
will form the subject of the present chapter.
The following extract from Dr. Greville's

478 THE CHEMISTRY OF CREATION.

work in the British Algce will furnish an inte-
resting outline of the peculiarities of the vege-
table tenants of the ocean : — " We find the
vegetation of the ocean no less conspicuous for
beauty and variety of form than splendour of
colour, admirably fitted for the place it is
designed to occupy, and of direct utility to
mankind. The marine Alga is no longer the
Alga inutilis — (the worthless Alga). Viewing
these tribes in the most careless way, as a sys-
tem of subaqueous vegetation, or even in a
merely picturesque light, we see the depths of the
ocean shadowed with submarine groves, often of
vast extent, intermixed with meadows, as it were,
of the most lively hues ; while the trunks of the
larger species, like the giant trees of the tropics,
are loaded with innumerable minute kinds as
fine as silk or transparent as a membrane. Nor
must we forget, that while thousands and tens
of thousands of quadrupeds, birds, and insects,
depend upon the vegetation immediately sur-
rounding us for their very existence, a count-
less host of creatures derive protection and
nourishment from the plants of the deep, ap-
propriated to their use by that merciful Power
in whom they live, and move, and have their
being, whose goodness is over all his works.
Some of the Algae, placed, on account of the
simplicity of their structure, at the bottom of

THE ALG^E. 479

the scale, are so small as to be invisible to the
naked eye, except by the appearance they give
to other species on which they happen to be
parasitic in prodigious numbers. From these
microscopic forms, Algse are found, of all sizes,
on our own shores, up to thirty or even -forty
feet in length, an extent to which Chorda Filum
not unfrequently attains. This plant resembles
an enormous piece of cat-gut, and is, in fact,
known by the name of Sea cat-gut in Orkney,
while in Shetland it goes by the name of Lucky
Minny's lines, and in England of 'Sea lace" In
the southern hemisphere the marine vegetation
takes on a more wonderful aspect. A plant
described by Bory St. Vincent, is twenty-five
or thirty feet high, and has a trunk often as
thick as a man's thigh, which divides into nu-
merous branches. A marine plant, abundant
on the Australian coast, furnishes the aborigines
with instruments, vessels, and food. A trumpet
is formed out of the hollow stem of another.

Some of these plants remain constantly
beneath the surface of the waters, their roots
firmly attached to rocks or stones at the bottom.
Others float on the surface, presenting the
appearance of green meadows, reposing upon
the ever-moving breast of the wave. Near the
coast of California these plants grow in such
thick masses as to have saved vessels from

480 THE CHEMISTRY OP CREATION.

the danger of being driven ashore by the long
and heavy swell of the Pacific. They are sup-
posed to grow without attachment to any rock,
carried about by the waters which bear them
and supply them with all necessary to their
existence. In the tropics, where the waters
are singularly pure and pellucid, and the light
very powerful, it is often a splendid spectacle to
look down over the ship's side, and contemplate
the beautiful vegetation adorning the sea-bed.

But there exists a limit to the vegetation of
the sea, beyond which it is unable to pass. The
dark bottom of the ocean is a water desert, un-
enlivened with a single species of plant. Thou-
sands of miles in area of the bed of the waters
are thus waste and barren. Professor Forbes,
in his dredging researches in the JEgean Sea,
found no plants below 100 fathoms. A more
singular part of their history is, that they are
distributed in zones, at various depths and de-
• grees of removal ' from light and warmth. The
first zone is the space included between high-
and low- water marks : this zone, on the British
coast, does not descend deeper than 30 fathoms.
It is occupied by distinct species of sea-weeds.
The second zone on our coast, beginning at
low-water mark, extends below it to a depth of
from 7 to 15 fathoms. This also has its peculiar
vegetable inhabitants. The great sea-tangle

DBEDGING EESEARCHES. 481

*Y

luxuriates here, together with broad-leaved fuci
of various kinds. The last plant of this zone is
the nullipora, a coral-like sea-weed, the lowest
in the British seas, where it does not extend
below the depth of 60 fathoms. In the Medi-
terranean Sea Professor Forbes has found fuci
at a depth of 7 9 fathoms ; below this they alto-
gether disappeared. Nullipore, so curiously
resembling coral as to have been long mis-
taken for an animal rather than a vegetable
production, still exists in that sea, forming the
food of various marine creatures, at a depth of
105 fathoms. Below this, vegetable existence
ceases. In all seas it will probably be found
that a similar system of order and arrangement
prevails. In the Mediterranean, as the depth in-
creases the number of the plants becomes fewer ;
until just before the depth of 105 fathoms, the
traces of submarine vegetable life are very scarce
indeed.

Until recently it was thought that the sea-
weeds known under the botanical titles Macro-
cystis pyrifera and the Laniaria radiata, which
have been met with on the antarctic coasts,
formed the utmost limit of vegetable life in the
south polar seas. Beyond the region in which
these plants were found, it was thought that the
ocean and land were alike barren of vegetable
forms. But an interesting account has lately

2 i

482 THE CHEMISTRY OF CREATION.

been given by Dr. Hooker of a peculiar class of
vegetable organisms, discovered between the
parallels of 60° and 80° south, which proves that
at the icy regions of the poles, vegetable life
is still to be found. This singular vegetation
occurred in such countless myriads as to stain
the sea everywhere of an ochreous brown colour,
in some cases causing the surface of the ocean,
from the locality of the ships as far as the eye
could reach, to assume a pale brown colour.
Though peculiarly abundant in the Icy Sea,
these plants are probably uniformly dispersed
over the whole ocean, but being invisible from
their minuteness, they can only be recognised
when washed together in masses, and contrasted
with some opaque substance. While the species
of these plants were found to increase in num-
ber with the latitude, up to the highest point
attained by man, they were also found by
Ehrenberg in both Americas, in the south of
Europe, and north of Africa, in a fossil state,
and even in volcanic ashes. Their remains have
been found floating in the atmosphere, over-
hanging the tropical Atlantic ; for Mr. Darwin,
during the voyage of the Beagle, collected an
impalpable dust which fell on Captain Fitzroy's
ship, when to the west of Cape de Verd Islands,
and it proved on examination to consist of
remains of these plants, including species com-
mon in the antarctic regions.

ANTAECTIC VEGETATION. 483

This vegetation forms undoubtedly the food
of many of the countless marine tribes peopling
the antarctic waters, and which are subsequently
themselves a prey to larger creatures. They
were invariably found in the stomachs of sea
animals, in all latitudes between that of the
north tropic and the highest parallel attained
by the antarctic expedition. The death and
decomposition of this antarctic vegetation are
gradually producing a submarine deposit or
bank of vast dimensions. This bank consists
mainly of the silicious coatings of the cells,
intermixed with infusoria and inorganic matter.
Its position is from the 76th to the 78th degree
of south latitude, and between the meridians of
165° east and 160° west longitude ; thus occupy-
ing an area of 400 miles long by 120 wide.
All the soundings taken over this deposit brought
up the finest green mud, mixed with sand
occasionally, from the depth of between 200 and
400 fathoms. The lead sometimes sank two feet
into this pasty deposit.

Let us now inquire how is the marine vege-
tation nourished, and what are the chemical
functions it discharges ? If we were to subject
sea-weed to chemical analysis, we should find
that it contained a large amount of carbon, a
certain portion of oxygen and hydrogen, and a
little nitrogen. But there would be more than
this; we should find also some earthy, some

484 THE CHEMISTRY OF CREATION.

saline, and some metallic matters. On the
northern shores of Scotland, a rude analysis of
this kind has been performed for many years by
the peasant manufacturers of what is called kelp.
At certain seasons of the year a lively scene
used to be presented to the spectator, which is
well described by Dr. Macculloch. " The kelp
season," he writes, " had now commenced, and
the whole shore was one continued line of fires ;
the grey smoke streaming away from each on
the surface of the water, till, mixing with the
breeze, it diffused its odoriferous haze over all
the surrounding atmosphere. The weeds being
cut by the sickle at low water, are brought on
shore by a very simple and ingenious process.
A rope of heath or birch is laid beyond them,
and the ends being carried up beyond high-
water mark, the whole floats as the tide rises,
and thus by shortening the ropes is compelled
to settle above the wash of the sea, whence it is
conveyed to dry land upon horseback. The more
quickly it is dried the better the produce ; and
when dry it is burned in coffers, generally con-
structed with stone, sometimes merely excavated
in the earth." * In the act of combustion a sort
of rude analysis is performed upon the sea-weed,
the carbonaceous and gaseous products arising

* This process has been now almost entirely stopped by
substituting salt for kelp in the manufacture of soda.

KELP. 485

from it in the form of smoke, while the earthy
and saline remain behind in the fused bluish
mass called kelp. Twenty-four tons of sea-
weed, at a medium, yield one ton of kelp. Kelp
contains chloride of podium, carbonate of soda
— a product of the combustive process, chloride
of potassium, and traces of the other mineral
constituents of sea-water. In addition to this,
kelp, after undergoing chemical treatment, is
found to contain sensible proportions of the re-
markable element iodine, and very minute traces
of another element, bromine.

The existence of these various elements in
the ashes of marine plants leads us to ask by
what means they were obtained? The roots
of sea-weeds differ from those of terrestrial
plants both in their structure and offices.
They are not the channels of nutriment be-
tween the soil and the plant. They appear
simply intended to anchor the plant, to enable
it to resist the violence of the waves. They
most commonly embrace a rock or a stone,
from the compact and obdurate surface of which
no soluble matter for the nutrition of the plant
can be extracted. Many float, unattached, hun-
dreds of miles from any shore, and in deep water.
It is plain, therefore, that the whole sum of
the ingredients forming a sea-plant is obtained
from the water in which it floats. A reference

486 THE CHEMISTRY OF CREATION.

to the analysis of sea-water will show that in
its composition are to be found all those elements
which are present in the sea- weed.

The saline and mineral ingredients forming
the food of marine plants must by no means be
considered as simply accidentally present, or
present merely by imbibition, as they would be
in a cotton wick plunged into sea-water. They
are absorbed into the plant by the powers of
vital chemistry, and are as important to its
well-being as the alkaline and earthy matters
present in land-plants are to them. This is
remarkably illustrated in the case of the
element iodine. The chemist can only detect
minute traces of iodine in sea-water, yet he
extracts it from sea-weed, though it is only
present in the proportion of one grain in one
million grains of sea-water. Were it not, in
fact, for this faculty possessed by sea-weed,
and wisely made essential to its growth, man
would be deprived of one of the most useful
of medicinal substances, in the element thus
extracted. All the iodine of commerce is ob-
tained from the fused ashes of the sea-weed.
Bromine also is chiefly known to us as one of
the minute products of a chemical operation to
which kelp is subjected. Both the elements
thus abstracted from the water for the use of
man by the sea- weeds could not otherwise have

ORIGIN OF CARBON. 487

been obtained in available quantities but by
the evaporation of the whole seas !

We have now to seek the origin of the carbon
in sea-plants. Here, it is very unlikely that its
source should be in the ocean bed. No beds of
softened humus line the ocean floor, or form a
resting-place for the few and simple roots of
the marine plant. It is compelled to derive all
its food from the medium in which it lives, and
has its being. Just as in terrestrial plants, the
source of the carbon in sea-plants is the car-
bonic acid of the element which surrounds them.
Sea-water, in common with all water in a state
of nature, contains a certain quantity of this
gas in a dissolved state. It is derived from
the respiration of fishes and other of the marine
tribes, and from a number of chemical processes
constantly taking place in the contents of the
water, or in the materials which form its bed.

In the decomposition of carbonic acid by
marine plants, a simple but highly important
part of the chemistry of the ocean is involved.
The fact of this decomposition under water
may be as strikingly exhibited as that effected
by land-plants upon air. If, when winter has
sealed with ice the waters of a wayside pond
or ditch, we carefully examine the spot on a
sunny day, beneath which some aquatic plants
are growing, we shall often perceive their leaves

488 THE CHEMISTRY OF CREATION.

to be bedecked with silvery bubbles of air. On
this air being collected it proves to be pure
oxygen gas, derived beyond a doubt from the
decomposition of the dissolved carbonic acid of
the water.

This is an exact type of the chemical pro-
cesses effected by plants upon the gas dissolved
in the ocean. It is true that they require a
peculiar constitution adapted to the peculiar
circumstances of their abode. But the mere
fact of their living in the water, and some of
them never coming into contact with the air at
all, does not affect their power to decompose
the carbonic acid of the surrounding medium.
They have been formed for their present posi-
tion, and are as active in the fulfilment of their
office as the waving grass or the leaf of the
forest. Carbonic acid is present in sea-water
in still larger quantities than in the air. In ten
thousand volumes of sea-water, six hundred and
twenty volumes of this gas have been found.
By taking a piece of a living sea- weed and pre-
serving it in a basin of sea-water, it will, by the
oxygen it gives out, keep the water sufficiently
fresh to enable various little marine insects to
live in it for some time. The singular plants,
called corallines, about which so many erro-
neous views have been entertained, on the sup-
position that they were animal in their nature,

PURIFYING INFLUENCE OF SEA-WEED. 489

and which occupy so large a tract of the sea-
bed, possess this function in common with the
rest of the vegetable inhabitants of the waters.
Dr. Johnston performed an interesting expe-
riment upon these plants, which pleasingly
illustrates their utility, minute and feeble
though they appear in the great waters by
which they are surrounded. He placed in a
small glass jar, containing about six ounces of
pure sea-water, a tuft of living coralline, about
the branches of which several little mussels, and
other animals, and a star-fish were crawling.
The jar was placed on a table and was seldom
disturbed, though occasionally looked at, and at
the end of four weeks the water was still pure,
the little animals all alive and active, and the
plant had grown sensibly larger. At the expi-
ration of eight weeks the water continued pure,
and many of the animals were living. Had the
coralline not been there, a day would have
sufficed for the animals to have extracted all
the oxygen of the water, and in a week or two
the water itself would have commenced the
changes of putrefaction. Nothing could more
conclusively exhibit the effect of plants upon
the waters of the ocean, for here was a sea in
miniature, the animal producing carbonic acid,
and the coralline absorbing and decomposing it,
and then emitting its oxygen.

490 THE CHEMISTRY OF CREATION.

Calling to memory the wonderful facts elicited
upon the chemistry of the sunbeam, and its
connexion with vegetation, the inquiry naturally
arises, whether the vegetation of the deep is
also dependent with that of the land upon the
various energies of the solar ray? There exists
every reason to believe it is so dependent.
Direct experiments of a trustworthy character
and sufficiently numerous are yet wanting. But
it is found that vegetation generally ceases
at such depths as mark the extinction of the
solar ray. The light received by these plants
is of a greatly diminished intensity. Many of
them must live in little better than an alter-
nation of twilight and night. Even those
which occupy the littoral region must enjoy
much less of the power of the sun's ray than
the humblest plant dangling' on the rock in
mid-air. The actinic and the luminous rays of
light are those which appear chiefly to influence
the marine vegetation. In what way, it remains
for us to learn. Enfeebled though the solar
influences may be by their passage through the
water, they suffice to quicken the plant and to
enable it to sustain an active existence. We
are apt to imagine that sea-weeds are very slow
in growth, but this is in the case of many of
them an error ; a few months sufficing to cover
rocks with plants which had before been per-

LIGHT AND SEA-PLANTS. 491

fectly clean and bare. We are apt also to forget
that in all the domains of nature organized
beings are fitted to the stations they occupy,
and exactly perform the duties required of
them. The sea-weed, low though it is in the
order of vegetable creation, and insignificant as
it appears in our eyes, is beautifully adapted to
the place of its abode, and amid many apparent
disadvantages faithfully executes its chemical
task of decomposing carbonic acid and evolving
oxygen.

As in the air, so in the water of the sea also,
ammonia may be detected. It is probably, as
in the former case, the source of the chief por-
tion of the nitrogen contained in such plants.
It originates in the death and decomposition
of the marine animals. Phosphates, earthy
and alkaline carbonates, are also present in sea-
water, and are found in the ashes of marine
plants, which is sufficient to show that they
are necessary to them.

The marine vegetation acts a part with refer-
ence to the preservation of the constancy of
composition in sea-water not less beautiful and
interesting than the decomposition of carbonic
acid by plants growing in the air. The sea is not
less exposed to the risk of deterioration than
the air. The sources of its 'gaseous deteriora-
tions and their remedies have just been noticed.

492 THE CHEMISTRY OF CREATION.

But in every shower falling on the land, wash-
ing out certain mineral ingredients, and by
various channels directing them into the great
receptacle, we may perceive a large source of
impurity, and the question comes to assume a
great importance when we note by what means
are the otherwise inevitable consequences of
these additions to the mineral constituents of
sea-water to be averted. The provision to
this end is to be found in the varied tribes of
marine plants. It will be most evident what
ingredients these plants appropriate and sepa-
rate from the element in which they live, if
we examine into the chemical nature of their
ashes. This will infallibly inform us in the
most correct manner how far they act in the
preservation of the purity and constant com-
position of the waters of- the ocean.

From analysis it is found that sulphuric acid
and chlorine, potash, soda, lime, and magnesia
are the chief constituents. The sulphuric acid
and chlorine occur in combination with the
other substances. The quantity of sulphuric
acid is very large ; on an average, according to
Professor Forchhammer, it amounts to four
per cent, in the dry plant. Thus it is evident
that a large amount of this acid, which would
otherwise, in the -form of various combinations,
accumulate in sea-water, is separated by sea-

FUNCTIONS OF SEA-WEED. 493

weeds. The quantity of potash is also great,
much greater than is contained in sea- water :
the fucoidal plants contain two and a half per
cent, of this element. They also contain a con-
siderable portion of magnesia, which occurs in
great quantities of sea-water, and not — as is the
case with regard to lime — being removed by
animal life, it would accumulate to a vast extent
in the sea but for these plants which absorb it.
They also contain a portion of phosphate of lime :
this ingredient they separate from sea-water ;
it is then received by various minute creatures
which feed on the sea-weed, and as these form
the food of greater marine beings, this ingre-
dient becomes ultimately handed over to them.
Thus, just as plants act with regard to ammonia
in the air, the sea-weeds may be considered to
act with regard to phosphate of lime, a highly •
important ingredient to animal life. They
absorb it from the surrounding medium ; it is
then received by minute creatures, crustaceous
animals and others living in the heaps of rotting
sea- weeds on our shores; to be afterwards ap-
propriated by the higher forms of marine life.
The process of conservation thus perpetually
going forward, not only purifies the water of the
ocean, and assists in maintaining it in a state
adapted for the existence of living things ; it
serves also to form a continually increasing

494 THE CHEMISTRY OF CREATION.

store of fertility against the time when the
sea bed upon which these plants will rot and
perish may become elevated above the waters,
and converted into corn-fields, gardens, and
vineyards.

If, however, sea - weeds merely separated
these ingredients for a short time, and when
they died if they were again to return to the
sea-water, their effect in preserving its con-
stant composition would be inconsiderable.
Such is not the case. When these plants die,
they are cast by the waves upon our shores in
vast heaps. On one point of coast where these
plants abound, it has been calculated that about
30,000 two-horse loads of sea-weed are annually
thrown on shore in the months of November
and December." This quantity represents not
less than the enormous sum of 450,000 Ibs. of
sulphuric acid. On the shore they putrefy ;
their carbon is dissipated as carbonic acid ; a
volatile substance resembling spirit of wine is
also given off, according to Professor Forchham-
mer; their nitrogen is dispersed as ammonia,
and the sulphuric acid, occurring in the form of
several sulphates, undergoes decomposition, sul-
phurets being formed, and sulphuretted hydro-
gen gas being given off. A part of the sulphur
also combines with the metallic ingredients of
the bed in which the heap of plants live. Thus

MINUTE BEINGS IN SEA-WATER. 495

in various ways the almost total sum of these
ingredients, separated by sea-weeds from sea-
water, are finally removed from it in such a
manner as that they cannot be restored to it
again.

The ocean is more prolific in animal even
than in vegetable life. From the minute infu-
sorial animalcule, imperceptible to the unaided
eye, up to the great animal — the whale, all
varieties of size and form exist. Of the vast
numbers of the more minute creatures lan-
guage can convey no idea. Just as the peculiar
vegetation, noticed by Dr. Hooker, by its num-
bers coloured the waters of the Antarctic Ocean,
so, minute animated creatures abound in the
arctic seas, turning the ultramarine blue of
the waters to a turbid green. The bodies of
these animalcules are exceedingly small, yet
they are found discolouring patches many miles
square, and of great depth. To afford some
conception of their numbers, Scoresby has made
the statement that in the space of two square
miles, supposing the animalcules to exist as low
down as 1,500 feet, there would be congregated
a mass of individual beings, which eighty
thousand persons would not have been able to
enumerate, though they commenced the task
at the Creation and continued it incessantly to
the present tune. Yet this would prove but

496 THE CHEMISTRY OF CREATION.

a very small portion of the entire sum of these
beings existing at one time in these seas.
Ehrenberg, after examination of various speci-
mens of sea-water sent to him by Sir J. C. Eoss,
states that in high " southern as well as in high
northern latitudes, and at great ocean depths,
the minute forms of organic life are intensely
and extensively developed." Near Franklin
Island a great quantity of ice of a brown colour
was observed. The colour was entirely due to
innumerable hosts of these minute organized
beings. Samples of water have been taken tip
in various latitudes, and on accurate micro-
scopic investigation, innumerable extremely
minute organisms have been detected, floating
generally in a fragmentary state. Thus, even
in the perpetual night of the depths of the
ocean, animal life abundantly exists, though of
a low type.

" On the coast of Chili," remarks Mr. Darwin,
" a few leagues north of Concepcion, the Beagle
one day passed through great bands of muddy
water, exactly like that of a swollen river ; and
again, a degree north of Valparaiso, when fifty
miles from land, the same appearance was still
more extensive. Some of the water placed in
a glass was of pale reddish tint ; and, examined
under a microscope, was seen to swarm with
minute animalcules darting about and often

INNUMERABLE HOSTS OF BEINGS. 497

exploding. They were exceedingly minute and
quite invisible to the naked eye, only covering
a space equal to the square of the thousandth
of an inch. Their numbers were infinite ; for
the smallest drop of water which I could remove
contained very many. In one day we passed
through two spaces of water thus stained, one
of which alone must have extended over several
square miles. What incalculable numbers of
these microscopical animals ! The colour of the
water, as seen at some distance, was like that
of a river which has flowed through a red clay
district; but under the shade of the vessel's
side it was as dark as chocolate. The line
where the red and blue water joined was dis-
tinctly defined. The weather for some days
previously had been calm, and the ocean
abounded to an unusual degree with living
creatures."*

The enormous shoals of herring and mackerel
which at times appear on our coasts, and on
those of other lands, — shoals, the number of
individuals in which defy the power of calcu-
lation and baffle conception, — these, too, fur-
nish us with a striking view of the vast numbers
of beings whose abode is the ocean. Yet, just
as in the case of marine vegetation, there are
laws which regulate the distribution of ocean

* Journal, p. 16.

2 K

498 THE CHEMISTRY OF CREATION.

life ; and there are in the depths of the ocean
tracts without any animated occupants, the
counterparts of the lofty and barren mountain
elevations of the earth.

The researches of Sir James Ross have shown
that as deep down as six thousand feet ani-
mated beings exist; but we are not therefore
to understand that all marine creatures can
endure the vast pressure of a superincumbent
bed of water so thick as this. Dr. Williams,
in some ingenious experiments, has shown that
the pressure of the ocean exercises a most im-
portant influence upon the distribution of life
at the bottom. On subjecting water in a glass
vessel containing a gold-fish to a pressure of
four atmospheres, or about 60 Ibs. to the square
inch, the fish became paralysed. From a num-
ber of experiments upon different fishes the
following conclusions were arrived at: — 1.
That round fishes having an air-bladder cannot
without injury be exposed to a pressure of
more than three atmospheres. 2. That the use
of the air-bladder is not so much to regulate
the specific gravity of the animal as to resist
the varying force of the fluid column, and thus
to protect the viscera and abdominal blood-
vessels against excess of pressure. 3. That
flat-fish exhibit a limited capacity only for sus-
taining pressure. It is stated that the animals

ZONES OF MARINE LIFE.

499

occupying the lower regions have experimen-
tally exhibited a greater tolerance of pressure
than those of the more superficial zones.

But the distribution of marine life is also
influenced by the laws of oceanic temperature,
and by the depth. The most systematic obser-
vations upon this subject are the researches of
Professor E. Forbes in the ./Egean Sea, to which
allusion has already been made. As the result
of long-continued and carefully-conducted expe-
riments in that sea, it has been found that eight
regions or zones of depth may be distinguished,
each characterized by its peculiar inhabitants.
These regions are exhibited in the accom-
panying diagram. But there is a gradual

transition observed in the character of the
inhabitants of these regions at their commence-
ment, and at their termination. A few from
below appear just before the termination of one
zone and the commencement of another. While,
however, this is the case, the lines of separation
are remarkably well defined, very few creatures
of the same species being found in more than

500 THE CHEMISTRY OF CKEATION.

one or two of the eight zones, while only two
species are common to them all. It is remark-
able, however, that the first zone or coast-
region, extending to the depth of two fathoms,
contains a greater number and variety of crea-
tures than any of the rest, or indeed than all the
others put together. The lower zone contains
fewer animated beings, and on its confines, at the
depth of 230 .fathoms, or at most at that of 300
fathoms, animal life ceases in the Mediterranean.
The remarkable fact has been already mentioned,
that as the depth of this sea increases, and the
same laws prevail in other seas which have
undergone similar investigation, the marine
animals occupying the deeper regions assume
more and more the characters of those found in
northern climates. The occupants of the coast
zone represent properly the peculiarities of form
and colour characteristic of the inhabitants of
southern latitudes. The sea thus, as we examine
its depths, presents us with a sort of map repre-
senting types of the occupants of the seas of
other climates. The more deeply the shell-
fish is found down, the more to the north
will lie the place where its allies are dwellers
on the coast. The coast zone shows the marine
inhabitants of the latitude of the region, the
lower zones those of higher latitudes.

While a considerable number of the dwellers

CHAIN OF ANIMAL LIFE. 501

in the deep feed upon the vegetation with which
to a certain depth it abounds, yet by a wise
regulation it is ordered that the greater number
prey upon their fellow-occupants of the waters.
In consequence of the limits to which marine
vegetation extends, it would not have sufficed
to sustain the wants of the countless millions
of marine beings, had they been confined to a
vegetable diet, or had the proportion of preda-
cious and herbivorous creatures been in the
deep as it is on land, where vegetation almost
everywhere abounds. Hence in the ocean
generally, and in the polar seas in particular,
where the vegetable kingdom which constitutes
the support of animal life in milder climates
has no representative, if we exclude the minute
plants before mentioned, a chain of animal exist-
ence has been constituted which as effectually
completes the great intention of the preservation
of life as that regulating the life of animals on
land. Creatures of a higher order prey upon
those of a lower, and these again upon those
next below them in the scale of created beings,
which in their turn feed upon the innumerable
infusorial animalcules thronging the ocean.

The vital function in marine creatures gene-
rally, with which the chemistry of the ocean
is chiefly concerned, is that of respiration.
Although not living in the air, these creatures

502 THE CHEMISTKY OF CEEATION.

breathe, and oxygen is as necessary to them as
it is to ourselves. A simple experiment will
illustrate this fact. If one or two gold-fish, in
a vessel of water, are placed under the receiver
of an air-pump, and the air is gradually ex-
hausted therefrom by working the pump, bub-
bles of gas will be seen arising from the water,
and in a short time the fish will be quite
dead after several violent struggles. If, again,
fish are placed into a basin of water, which
has had all the air expelled by boiling, they
will then likewise soon perish : this arises
from the want of oxygen, which was contained
in a dissolved state in the water. Chemistry
informs us, that the proportion of oxygen dis-
solved in 100 parts of water is very small
(100 cubic inches of water will dissolve about
three and a half oxygen); and it is certain,
that many other gases, carbonic acid for
example, are much more soluble than oxygen.
This small proportion is, however, sufficient
for the well-being of marine creatures. Had
oxygen been very soluble in water, there would
have arisen many bad results to the animal
world on land, and not less to those of the
waters themselves. The effect upon the in-
habitants of the deep of a higher charge of
oxygen in their respirable medium, would be
precisely analogous to its effects upon air-

RESPIRATION OF MARINE ANIMALS. 503

breathing creatures ; and the loss to the latter,
from the vast amount of oxygen thus removed
from the atmosphere, it might have been beyond
the power of the most profuse vegetation to
repair. Although sea-water contains nitrogen
in solution as well as oxygen, yet its propor-
tion is only small, and we may regard the water
as the diluent for oxygen in the ocean, as nitro-
gen is for it in the atmosphere.

The manner in which the dissolved oxygen
is received by fish from the medium in which
they live is very similar to that in which air-
breathing creatures receive it from the air. In
the gills, and other modifications of the respi-
ratory organs in marine beings, there exists a
similar provision for the exposure of the blood
to the influence of oxygen as in those of air-
breathers. The gills are composed of numerous
lamince, or plates of tissue, covered with innu-
merable minute blood-vessels, and exposing
a very large surface to the influence of the
oxygen dissolved in the water. The water
becoming partially deprived of its dissolved
oxygen, is discharged from under the gill
covers, a fresh portion being taken in at the
mouth. Thus a constant current of fresh water
is caused to flow over the Iamina3, from which
a constant supply of oxygen is obtained by the
fish. The blood, after becoming thus oxygen-

504 THE CHEMISTRY OF CREATION.

ated, is further propelled by the heart through-
out the body of the creature, and, losing its
oxygen in the capillary vessels, returns again
by the veins to undergo the same process
again. In so doing the venous blood parts with
carbonic acid, which is received and retained
by the surrounding fluid in a dissolved state.
The temperature of fishes is generally two or
three degrees higher than that of the water in
which they live. These facts render it apparent
that it is not less important to the residents of
the waters than to ourselves to be provided
with a full and free supply of oxygen, and ex-
plains the cause of the death of fish when placed
in a limited quantity of water, even though
the water may not have undergone any sen-
sible change. When fish are thus placed, and
have exhausted the stock of dissolved oxy-
gen in the fluid, they rise to the surface, and
swallow atmospheric air, the oxygen of which
becomes then subservient to their uses. This
can rarely occur in a state of nature, but it is
constantly seen when fish are kept in small
artificial receptacles. It is a most common and
painful sight to witness this action in gold-fish,
kept within the too narrow confines of a glass
globe.

The effect of the respiration of fish and of
the presence of other marine inhabitants upon

PRODUCTS OF RESPIRATION OF FISH. 505

the waters in which they live, is similar to that
of man, and air-breathing creatures generally,
upon the atmosphere ; the fluid becomes vitiated,
and a necessity is created for its renewal. This
process, as in the terrestrial world, is, as we
have seen, discharged by plants. There can
be little doubt also, that the mere effect of
constant agitation, as before noticed in the
phenomena of waves, causes the solution of a
large portion of oxygen ; for it is found that
sea- water contains also nitrogen in solution,
which has unquestionably been obtained from
the agitation of water and air together. The
oxygen of the rain which falls on the sea is
likewise an important addition to its contents.
We may, in fact, see in the grand circle of the
evaporation of water from the sea, of its conden-
sation in largest quantity over land, and of its
return by innumerable channels to the bosom
of its broad parent again, a beautiful system
for providing for the due oxygenization of the
ocean waters. For no method of dissolving
atmospheric oxygen could be devised more
complete than this. Rapids and cataracts effect
a similar object. Could the chemist draw from
the foaming pit of water into which the water-
fall at the other end of this valley leaped, a
sufficient amount of water to submit to analysis
for its gases, and were he to contrast it with a

506 THE CHEMISTRY OF CREATION.

similar quantity taken before the leap, he would
discover in the former more dissolved atmo-
spheric air than in the latter. These processes
are all subsidiary to the oxygenization effected by
marine plants ; but when we consider the com-
parative smallness of the number of these plants,
together with the fact that a large number of
them are for some hours out of every day in-
capacitated for their office by the departure of
the tides, and that probably these, and a still
larger number, which live always in deep
water, are also unable to fulfil it during the
hours of darkness, it will be perceived that the
relation subsisting between the ocean and its
vegetation is far inferior in importance to that
subsisting between the air and plants. Con-
sidering the vast preponderance of animal over
vegetable life in the ocean, it becomes more
than questionable whether the marine vege-
tation could, unassisted, preserve the purity of
the waters as a respirable medium. It has been
stated by M. Morren that he discovered a vast
number of infusorial animalcules in certain
regions of the ocean which, instead of vitiat-
ing the water, like all other members of the
animal kingdom, actually enriched it, by pro-
ducing oxygen ; but this statement requires
confirmation.

There remains another portion of the che-

MOLLUSCOUS ANIMALS. 507

mistry of the ocean in its connexion with animal
life which requires our attention. A large
number of marine creatures derive from the
waters the solid matter forming their hard outer
case. The shells of innumerable molluscous
animals, the hard shields of countless mil-
lions of animalcules, and the solid substance
secreted by the coral animal, are all derived from
the water by the processes of vital chemistry.
This hard matter consists chiefly of carbonate
of lime. It was found in the researches in the
^Egean Sea, that a most important influence
was exercised by the composition of the coast
and sea-bottom. Great tracts of a cretaceous
limestone border the sea, and by their constant
degradation fill its Avaters with a white sediment
of the carbonate of lime. In such water, there-
fore, those creatures which require this sub-
stance for the purposes of their economy, may
be expected to abound, and accordingly it was
found that large numbers of molluscous ani-
mals existed in these regions. On the contrary,
where the islands and coast consisted of ser-
pentine, the waters bathing them were almost
devoid of molluscous or testaceous animals,
owing doubtless to the comparative absence of
the necessary mineral constituents of the sea-
water.

Some idea may be formed of the vast extent

508 THE CHEMISTRY OF CREATION.

of this operation of the separation of the salts
of lime from the waters of the ocean, when it
is stated that the solid limestone rocks of our
own and other countries are often visibly made
up of the relics of animals possessing this
peculiar faculty ; and it appears probable that
all limestone, with some exceptions of small
moment, were thus obtained by the slow but
perpetual process of the separation of the salts
of lime from a state of solution in sea-water.
Professor Forchhammer states the remarkable
fact, that in the coral seas the proportion of
lime is much less than in other waters.

The coral formations, however, strike us as the
most surprising result of the slow but ceaseless
operations of vital chemistry upon the consti-
tuents of sea-water. Writing of Keeling Island,
litr. Darwin says, " I am glad we have visited
these Islands ; such formations surely rank
high among the wonderful objects of this world.
Captain Fitzroy found no bottom with a line
7,200 feet in length, at the distance of only
2,200 yards from the shore ; hence this island
forms a lofty submarine mountain, with sides
steeper even than those of the most abrupt
volcanic cone. The saucer-shaped summit is
nearly ten miles across : and every single atom,
from the least particle to the largest fragment
of rock in this great pile, which however is

CORAL SEAS. 509

small compared with very many other lagoon
islands, bears the stamp of having been sub-
jected to organic arrangement. We feel sur-
prised when travellers tell us of the vast
dimensions of the Pyramids and other great
ruins ; but how utterly insignificant are the
greatest of these, when compared to these
mountains of stone accumulated by the agency
of various minute and tender animals ! This
is a wonder which does not at first strike the
eye of the body, but, after reflection, the eye
of reason."*

Upon the outer shores of these lagoon-like
islands a great surf continually breaks, strewing
the solid flat of dead coral rock with huge
detached fragments. Yet the little creatures
build on. The long and massive swell of the
ocean incessantly dashes with immense force
upon the outworks of the fragile coral-builders.
"It is impossible to behold these waves without
feeling the conviction that an island, though
built of the hardest rock, let it be porphyry,
granite, or quartz, would ultimately yield and
be demolished by such a power. Yet these low
and insignificant coral islets stand and are victo-
rious; for here another power, as an antagonist,
takes part in the contest. The organic forces
separate the atoms of carbonate of lime, one by
* Journal, p. 465.

510 THE CHEMISTRY OF CREATION.

one, from the foaming breakers, and unite them
into a symmetrical structure. Let the hurricane
tear up its thousand huge fragments, yet what
will that tell against the accumulated labour
of myriads of architects, at work night and day,
month after month? Thus do we see the soft
and gelatinous body of a polype, through the
agency of the vital laws, conquering the great
mechanical power of the waves of an ocean
which neither the art of man nor the inanimate
works of nature can long resist."

On the east coast of New Holland a reef has
been described as being one thousand miles
long, and in one portion is unbroken for a
distance of between three and four hundred
miles ! Mr. Lyell states that some groups of
coral islands in the Pacific Ocean are from
eleven to twelve thousand miles in length by
three or four hundred in breadth. Coral islands
also exist in vast numbers in the Indian Ocean,
Thus, only in the instances in question it is
evident that the labours of these minute me-
chanics— the coral animals — have added no
insignificant mass of solid material to the great
earth itself. Yet the ingredients of sea- water,
from whence every particle was procured, exists
in extremely small proportions. In order to
add one pound of carbonate of lime to these
structures, a quantity of sea-water, not less than

CONCLUSION. 511

one hundred and twenty-four thousand pounds,
must undergo the processes of vital chemistry.
How forcible an illustration of the real import-
ance of things apparently insignificant !

The level rays of yonder descending luminary
streaming towards us over the heaving surface
of the waters warn us that the day is nearly
spent, and that night approaches. We must
therefore quit the scene where our steps have
so long lingered. But now with what different
emotions to those felt at its first contemplation !
What thoughts have not been awakened as the
Chemistry of Creation has unfolded part after
part of the beautiful scheme of nature before
us ! What links of inter-dependence ; what
variety of objects, causes and effects, and what
unity and simplicity of the whole ! Nothing in
nature but is now eloquent of the wisdom, love,
and power displayed in its creation. Each
blade of grass has a tongue ; the waters, hills,
and forests, and the very rocks and stones have
voices.

" In reason's ear they all rejoice,"

and proclaim that the hand that made them,
and that has regulated their various organic
and chemical phenomena, is indeed Divine.

512 THE CHEMISTRY OF CREATION.

Yet how shallow and imperfect are our
highest discoveries ! Here, alas ! with regard
to created things we are ever learning, but
never able to come to the full knowledge of the
truth. We see a little way into the mysteries
of creation, and there our progress ends. The
most advanced philosophy cannot carry us
beyond the threshold of knowledge. For the
rest we have to wait. It is the siibject of
many " great and precious promises," which
assure us that better things are in store for us ;
that the time will come when all who now
humbly trust in a Divine Redeemer, and are
guided by Him in the paths of righteousness,
shall attain to the complete renewal of their
moral and intellectual powers, and so be fitted
to walk in the light of His presence, " in whom
are hid all the treasures of wisdom and know-
ledge."

THE END.

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