Familiar Letters on Chemistry | Page 6

and more durable

than silver, infusible at all temperatures of our furnaces, and is left
intact by acids and alkaline carbonates. Platinum unites all the valuable
properties of gold and of porcelain, resisting the action of heat, and of
almost all chemical agents.
As no mineral analysis could be made perfectly without platinum
vessels, had we not possessed this metal, the composition of minerals
would have yet remained unknown; without cork and caoutchouc we
should have required the costly aid of the mechanician at every step.
Even without the latter of these adjuncts our instruments would have
been far more costly and fragile. Possessing all these gifts of nature, we
economise incalculably our time--to us more precious than money!
Such are our instruments. An equal improvement has been
accomplished in our laboratory. This is no longer the damp, cold,
fireproof vault of the metallurgist, nor the manufactory of the druggist,
fitted up with stills and retorts. On the contrary, a light, warm,
comfortable room, where beautifully constructed lamps supply the
place of furnaces, and the pure and odourless flame of gas, or of spirits
of wine, supersedes coal and other fuel, and gives us all the fire we
need; where health is not invaded, nor the free exercise of thought
impeded: there we pursue our inquiries, and interrogate Nature to
reveal her secrets.
To these simple means must be added "The Balance," and then we
possess everything which is required for the most extensive researches.
The great distinction between the manner of proceeding in chemistry
and natural philosophy is, that one weighs, the other measures. The
natural philosopher has applied his measures to nature for many
centuries, but only for fifty years have we attempted to advance our
philosophy by weighing.
For all great discoveries chemists are indebted to the "balance"--that
incomparable instrument which gives permanence to every observation,
dispels all ambiguity, establishes truth, detects error, and guides us in
the true path of inductive science.

The balance, once adopted as a means of investigating nature, put an
end to the school of Aristotle in physics. The explanation of natural
phenomena by mere fanciful speculations, gave place to a true natural
philosophy. Fire, air, earth, and water, could no longer be regarded as
elements. Three of them could henceforth be considered only as
significative of the forms in which all matter exists. Everything with
which we are conversant upon the surface of the earth is solid, liquid,
or aeriform; but the notion of the elementary nature of air, earth, and
water, so universally held, was now discovered to belong to the errors
of the past.
Fire was found to be but the visible and otherwise perceptible
indication of changes proceeding within the, so called, elements.
Lavoisier investigated the composition of the atmosphere and of water,
and studied the many wonderful offices performed by an element
common to both in the scheme of nature, namely, oxygen: and he
discovered many of the properties of this elementary gas.
After his time, the principal problem of chemical philosophers was to
determine the composition of the solid matters composing the earth. To
the eighteen metals previously known were soon added twenty-four
discovered to be constituents of minerals. The great mass of the earth
was shown to be composed of metals in combination with oxygen, to
which they are united in one, two, or more definite and unalterable
proportions, forming compounds which are termed metallic oxides, and
these, again, combined with oxides of other bodies, essentially different
to metals, namely, carbon and silicium. If to these we add certain
compounds of sulphur with metals, in which the sulphur takes the place
of oxygen, and forms sulphurets, and one other body,--common
salt,--(which is a compound of sodium and chlorine), we have every
substance which exists in a solid form upon our globe in any very
considerable mass. Other compounds, innumerably various, are found
only in small scattered quantities.
The chemist, however, did not remain satisfied with the separation of
minerals into their component elements, i.e. their analysis; but he
sought by synthesis, i.e. by combining the separate elements and

forming substances similar to those constructed by nature, to prove the
accuracy of his processes and the correctness of his conclusions. Thus
he formed, for instance, pumice-stone, feldspar, mica, iron pyrites, &c.
artificially.
But of all the achievements of inorganic chemistry, the artificial
formation of lapis lazuli was the most brilliant and the most conclusive.
This mineral, as presented to us by nature, is calculated powerfully to
arrest our attention by its beautiful azure-blue colour, its remaining
unchanged by exposure to air or to fire, and furnishing us with a most
valuable pigment, Ultramarine, more precious than gold!
The analysis of lapis lazuli represented it to be composed of silica,
alumina, and soda, three colourless bodies, with sulphur and a