_Introductory Lecture to a Course of Chemistry and Natural Philosophy.
Delivered in Hampden Sidney College. By John W. Draper, M.D. Richmond:
T. W. White._
Mr. Draper's peculiar reputation is well known—and deservedly
acquired. In this Introductory Lecture he has given direct evidence of
scientific attainment—of comprehensiveness of mind, and of a thorough
acquaintance with the philosophy of instruction. He has inspired us,
and we have no doubt that he has succeeded in inspiring all his
hearers, with an earnest desire to hear what farther he shall say in
the lectures which are to come. We take the liberty of copying a
passage of unusual interest and beauty from the pages now before us.
Knowledge, like wealth hoarded up, has its compound interest,
increasing in an almost geometrical ratio. A single discovery in one
science sheds a light on all kindred knowledge, which is reflected
back again. It is thus that modern discovery proceeds with such rapid
steps. A first investigator, groping his way in the dark, cannot form
a just idea of the nature and position of objects he may encounter,
until time and circumstances make them more familiar. Change of
opinion is often produced by more extensive information, and the
possession of one new fact at variance with received theories, often
leads to an entire reformation of scientific faith. But though our
theories alter, our facts remain unchanged; and hence we ought not to
be discouraged, remembering that theory is only useful so far as it
enables us to collate and reason upon fact.
How many are the triumphs which the world of science can boast of,
even in our recollection! How much increased is the amount of all
knowledge within the present century! We have a new chemistry, a new
science of light, that has almost furnished us with one sense more
than nature intended we should have. Astronomy has had its Laplace.
Mechanics has produced its steam boats and rail roads. Many of the
most interesting geographical problems have received their
solution—the Niger has been navigated—and the British standard planted
on the magnetic pole. The magnet, that riddle of antiquity, has been
made to tell its secret in characters of fire. Electricity has
furnished its galvanic battery. Physiology has developed more of the
nervous structure of man than all the dreams of metaphysicians could
have painted. Geology has sprung from the dust and given us animals
and plants, the earliest tenants of this earth. New planets have been
found, and the periods and orbits of new comets determined. The laws
of the elementary constitution of bodies have been fixed, and the
relative weight of their _ultimate_ atoms assigned. Botany,
mineralogy, and indeed every science, has advanced with rapid steps,
and the last half century has added more to human acquirements than
the preceding thousand years.
On every hand philosophy still continues to push her conquests, and
discoveries crowd upon us. EHRENBERG has opened to us a new world in
his use of the microscope; those little insects, thousands of which
might stand on a needle's point, show to us how multiplied and how
minute the mechanism of the parts of living things may be. By feeding
these creatures on the purest carmine, and then bathing them in
distilled water, he has seen through their transparent bodies parts
which might rival for complexity the organs of the largest animals. In
another branch, FARADAY has explained all the phenomena of voltaic
electricity, in a series of experimental researches, unrivalled since
the time when Davy demonstrated that the alkalies and earths were
metallic oxides. In France, DUTROCHET has built up the doctrine of
Endosmose and capillary attraction, which has been extended in this
country, and furnished some remarkable results. The newly detected
facts of esormorphism and plescomorphism, are shaking chemistry and
mineralogy to their very foundation. The discovery of the mode of
polarising light—a subject upon which I propose to dwell at some
length, if time permits—has given us, to use the words of an eloquent
writer, new and infinitely refined perceptions of touch. We are
enabled, with mathematical precision, and demonstrative certainty, to
assign the exact form of atoms, millions of times beyond microscopic
power. We tremble upon the brink of discovering the elementary
constitution of the material world. We can feel as it were the
molecules of light itself, that most subtle of all fluids. We can
almost perceive their sides and their ends, and can actually control,
regulate and arrange the constituent parts of a _sunbeam_!