We have now made a rapid survey of the history of chemistry, and
traced the evolution of thought which has rendered possible the newer
conceptions of the constitution of matter. We must now say a few
words as to the nature of the various elements themselves, and give a
brief account of some modern researches. A few practical hints as to
experiments may also be of interest to the reader.
We have seen that when two chemical elements combine, some third
substance is formed, quite different in properties from the original
two. Thus, water seems to us entirely different from the two invisible
gases which compose it--oxygen and hydrogen. Yet a simple experiment
will prove that such is the case. We can decompose water by means of
an electric current, when the original gases are given off, in the
proportion of two to one--hydrogen collecting at the negative pole, and
oxygen at the positive. This process can be kept up until all the water
has been decomposed, and only hydrogen and oxygen gases remain. This
process of electrical decomposition is known as _electrolysis_.
THE ELEMENTS
_Hydrogen_ is the lightest of all gases, and, as we have seen, the
simplest of the elements, in its constitution. Like all gases, it can
be liquefied, and even frozen solid into a hard lump, like ice. On the
other hand, even the densest of substances can be liquefied, and even
turned into gas or vapor at a sufficiently high temperature. (Gases are
rendered liquid or solid at a very low temperature.) Liquid air, for
example, is so cold that when a can of it is set upon a block of ice
the liquid air boils and gives off “steam”!
_Oxygen_ gas constitutes about one-fifth of our atmospheric air (the
other four parts being nitrogen) and is the most essential element
in supporting life. Without it, life would at once become extinct.
All forms of combustion take place very rapidly in oxygen, and the
combustion going on within the human body is no exception to this rule.
The atmospheric nitrogen acts as a sort of dilutant, being an inert
gas. If a mouse be placed under a jar of pure oxygen gas, it will
often run round and round until it drops dead with exhaustion. In an
atmosphere of pure oxygen, we should soon burn up, and live our lives
too rapidly.
Oxygen has a great tendency to combine with various other elements,
particularly metals. Thus, iron rust is due to the combination of
oxygen with iron; the blackening and tarnishing of cooking pots is due
to the slow oxidation of copper, etc.
In breathing, we take in oxygen from the air, which combines with the
gases in the lungs, forming carbon dioxide. Curiously enough, plants
thrive upon this gas, which is so poisonous to human beings, and in
turn give off oxygen. Hence the value of plants and flowers in the
room, or in any densely inhabited area.
_Nitrogen_ is a very important element, entering into many chemical
combinations. It forms the basis of explosives, used in war. Until
relatively recently, this element had to be obtained from substances
dug out of the ground, but during the late war, methods were devised
for obtaining it from the air. “Nitrogen fixation” became possible. If
it had not been for this discovery, Germany would have had to give up
the war in 1916, at the latest.
Nitrogen combines with hydrogen, to form ammonia; with oxygen and
water, to form nitric acid; with nitric acid and potash to form
gunpowder, etc.
Certain oxides combine with water, to form what are known as _bases_.
Bases can combine with acids, giving rise to _salts_.
_Carbon_ is an essential element for all living matter; it combines
with oxygen, to yield carbonic acid; with hydrogen, giving rise to a
great number of compounds, such as benzene, turpentine, etc. Marsh gas,
illuminating gas, acetylene, etc., are compounds of carbon.
_Chlorine_ is a very important element, combining with sodium to
form common salt. As we have seen, the saltness of the sea is due to
this substance. Owing to its great affinity for hydrogen, chlorine
decomposes water, setting free oxygen. The result of this is that a
mixture of chlorine and water has strong bleaching qualities.
Chlorine also combines with hydrogen to form hydrochloric acid. On the
other hand, it shows little sympathy for oxygen, forming but few stable
compounds. Chloroform, so long useful in surgical anaesthesia, is a
compound of chlorine, carbon and hydrogen.
_Sulphur_ can assume a variety of appearances (allotrophic variation)
as we have seen. Sulphuric acid, etc., are its compounds. The latter
substance is used for bleaching violets, but the flowers become violet
again when put into an ammonia solution.
_Sodium_ is a metal, which burns when thrown into water. It is the
other constituent of common salt, and enters into a great variety of
combinations. Carbonate of soda is one of these.
Many of the elements--iron, nickel, gold, platinum, silver, etc.,--are
too well known to necessitate more than a brief note. It is interesting
to notice, however, that there are certain “family relations” among a
number of the elements. Thus, sodium and potassium are “related”; and
so are barium, strontium and calcium. Again, oxygen and sulphur have a
number of points in common,--although one is a solid and the other a
gas! Gold stands rather apart from the rest.
Two very interesting groups should be mentioned in this place. The
first is the group of _rare gases_--argon, neon, etc.,--most of which
have been discovered only recently. They are inert, and partly on
account of this, and partly on account of their rarity, their discovery
was so long delayed.
RADIO-ACTIVITY
The second list is the _radio-active_ group of elements,--uranium,
radium, thorium, actinium, etc. These all possess their characteristic
properties in varying degrees,--giving off alpha, beta and gamma rays.
A certain mysterious “emanation” is also emitted by radio-active
elements, but the study of these rays and their influence would take us
into the realm of “physics,” and would more properly belong to a book
on physics than in the present, dealing with chemistry.
One very interesting fact should, however, be mentioned in this
connection, and that is the evolution of matter which has been
observed, as the result of spectrum analysis. We have heard much of
organic evolution, meaning the evolution of life upon our planet. It
is equally true that there is an inorganic evolution, in which the
gradual development of chemical elements may similarly be traced. Thus,
it has been noticed that, in the hottest stars, (gaseous) the fewest
chemical elements exist; in those of medium temperature (metallic),
more elements are found, while in those having the lowest temperature
(carbon stars) the greatest number of chemical elements are to be
distinguished. This seems to prove that the higher the temperature,
the fewer the elements, which in turn leads to the conclusion that all
elements are perhaps ultimately ONE--as Sir William Crookes suggested
many years ago. As these stars cool, more and more elements seem to be
“crystallized out,” so to say,--the many being formed from the fewer.
The newer researches on the constitution of matter render this idea all
the more plausible.
THE ORIGIN OF LIFE
Just here, it might be well to point out the late place occupied by
life, in this process of inorganic evolution. The Absolute Zero of
inter-stellar space is about -273°C. On the other hand, the temperature
of the hottest stars is more than 30,000°! (Argo, Alnitam, etc.) The
temperature must fall from this to a few degrees above Zero (the
boiling point of water), before life can become manifest at all. Life
as we know it can only exist between the boiling and the freezing
points of water. This point is only reached towards the very end of the
scale. It has therefore been said that, cosmically speaking, life is
only a “flash in the pan between two eternities”--but for us that flash
in the pan is everything!
The question of the origin of life upon our planet has been discussed
at some length in my little book on “Life: Its Origin and Nature,” in
the present series. It may be of interest to mention here, however,
a few of the experiments which have been made upon the artificial
creation of life, by means of inorganic chemicals, since these properly
fall into place in a book devoted to chemistry.
Dr. H. Charlton Bastian, of England, conducted many years ago a series
of experiments of this character, in which he claimed to have made
living matter from sterilized chemicals. He placed these in a glass
bottle which had been sterilized, heated the contents until steam
issued from the mouth of the flask, and then instantly sealed up the
bottle, preventing the entrance of air. The flasks were then put
away for several days, and at the end of that time were found, upon
examination, to contain living organisms.
“CREATION” OF LIFE
The reader will probably be interested in knowing the precise chemical
formulæ employed for obtaining these astonishing results. Several such
formulæ are given in Dr. Bastian’s book, “The Evolution of Life,” of
which the following are samples:
Sodium silicate, two, or three, drops.
Ammonium phosphate, four, or six, grains.
Dilute phosphoric acid, four, or six, drops.
Distilled water, one fluid ounce.
Another formula is the following:
Sodium silicate, three drops.
Liquor ferri pernitratis, eight drops.
Distilled water, one fluid ounce.
The reader can try the experiment for himself. It should be said,
however, that although Dr. Bastian’s results were undoubted, they
failed to carry conviction to the scientific world as a whole, since
they contended that some experimental error must have crept in,
to render these results possible; and it is significant, in this
connection, that the same experiments repeated by other men failed to
yield the same striking results.
Chemistry, then, enters into practically every field of inquiry--the
constitution of human beings, no less than that of metals, earths or
distant nebulæ. Everything material in the Universe is composed of
elements, of atoms, and these atoms are built-up, as we have seen,
of electrons, which are not matter at all, but bundles of energy. No
two particles of matter in the world actually touch, or come near to
touching one another. It is an interesting thought, when one stops
to think of it that, for instance, the steel pillar supporting a
“sky-scraper,” upon which rests an enormous weight (the whole of the
superstructure) is not really dense and solid, as it appears, but is
actually tenuous and shadowy, and that no two of its atoms ever touch
one another; they are separated by relatively vast spaces, filled only
with the hypothetical “ether.” The whole weight of the building may be
said to rest upon nothing,--or at most upon ether, which thus bears its
strain!
THE ETHER
And what is this ether? Is it matter in some subtle form, or is it
something else? We do not know; certainly it is no form of matter known
to us, and its reality has even been called into question of late.
Hæckel, as we know, contended (“The Riddle of the Universe”) that the
ether must be like some extremely attenuated jelly, and that a sphere
of it the size of the earth would probably weigh about 250 pounds! Such
crude conceptions have long since been given up. It is far more subtle
than this. Is it analogous to the finest gas? Some have thought so; and
yet Sir Oliver Lodge, one of the greatest authorities upon the ether,
has contended that it is more dense and solid than platinum or gold,
and that matter represents mere “bubbles” within this dense medium,
capable of moving freely through it. In support of this view, he has
cited (in his “Ether of Space”) the enormous gravitational pull of the
earth upon the moon, _e. g._, or of the sun upon the earth. The mass
of the earth is approximately 6,000 trillion tons; that of the moon
one-eightieth of this. From these data, the gravitational pull of the
earth upon the moon can be calculated; and, regarding this, Sir Oliver
says:
“A pillar of steel which could transmit this force, provided it could
sustain a tension of 40 tons to the square inch, would have a diameter
of about 400 miles.... If this force were to be transmitted by a forest
of weightless pillars, each a square foot in cross section, with a
tension of 30 tons to the square inch throughout, there would have to
be 5 million million of them.”
Calculating the gravitational pull of the sun on the earth, in a
similar manner, it was calculated that the strain in this case would
have to be borne by “a million million round rods or pillars each
thirty feet in diameter.”
It may readily be seen, then, from these figures, that something
enormously dense, apparently, must exist in order to bear this strain,
and this must be the ether. And yet no physical experiments have proved
to us the existence of the ether; we only infer its presence, and
say that it _must_ exist, in order to account for certain phenomena
observed in physics. It was, I think, Lord Kelvin who remarked that no
man could believe in the ether without at the same time believing it
to possess opposite and contradictory properties! Indeed, it would seem
so!
CHEMISTRY AND META-PHYSICS
Such speculations as these lead us far afield, into the realm of
mathematics, metaphysics and ultimate realities. Even the most
material of all the sciences--chemistry--leads thither when pushed to
its final analysis. The visible, sensible universe vanishes, and is
replaced by the invisible, the super-sensible. Yet science has been
our guide throughout. William James once remarked that metaphysics
is merely “persistently clear thinking.” It endeavors to find the
ultimate causes of things, the _noumena_ behind phenomena, the reality
behind appearances. The physical world in which we live is a world
of phenomena only; real in a sense, and for all practical purposes,
and yet the greatest of all unrealities in another sense. It is a
mere world of appearances; a phantasmagoria of fleeting shapes and
shadows. We feel that reality must exist somehow, somewhere; yet we
can never find it. We can no more find it by chemical analysis than
we can discover the mind and soul of man by dissecting the brains of
corpses,--or even by vivisection! Something always escapes us--the Soul
of Things, the Ultimate Reality, the Great Unknown.
Such thoughts and speculations as these, however, need not occupy the
mind of the practical chemist. For him, atoms exist, so do elements,
so does “matter.” For practical, daily life, we certainly have to live
_as if_ matter existed, and the chemist has to proceed with his work
upon the assumption that matter actually does exist--it is “real.”
Certain it is that the practical furtherance and application of this
science can come about in no other way. Chemistry has revolutionized
our lives; it has penetrated all fields of commerce and industry, and
its practical application has rendered possible and pleasant the lives
of countless thousands of persons now living upon our planet. We owe
more to chemistry than we can ever repay--or rather to those brilliant
and unselfish men who have built up the modern science of chemistry. It
is my hope that the present little book may in some degree have helped
to emphasize this fact.
Transcriber’s Notes
Punctuation, hyphenation, and spelling were made consistent when a
predominant preference was found in the original book; otherwise they
were not changed.
Simple typographical errors were corrected; unbalanced quotation
marks were remedied when the change was obvious, and otherwise left
unbalanced.
This book uses both “reactions” and “reäctions”.
Page 17: “Cobalt” was printed as “Cobolt”; changed here.
Page 23: The “constitutional” formula in the original book was printed
with the two “B”s stacked, one above the other, and in a smaller font
that could fit both of them on one line of normal-sized text.
Page 49: “allotrophic” was printed that way; probably should be
“allotropic”.