85.

The Scientific Advance in the Eighteenth Century (Adapted from Taine)

In pure mathematics we have infinitesimal calculus, discovered simultaneously by Leibnitz and Newton; in astronomy, the series of calculations and observations which, from Newton to Laplace, transforms science into a problem of mechanics, explains and predicts the movements of the planets and of their satellites, indicates the origin and formation of our solar system, and, extending beyond this through the discoveries of Herschel, affords an insight into the distribution of the stellar archipelagoes and of the grand outlines of celestial architecture.

Inorganic sciences

In physics we have the decomposition of light and the principles of optics discovered by Newton, the velocity of sound, the form of its undulations, the primary laws of the radiation of heat, the experiments by which Du Fay, Franklin, and especially Coulomb explain, manipulate, and for the first time utilize, electricity. In chemistry the chief foundations of the science were laid: isolation of oxygen, nitrogen, and hydrogen, the composition of water, the theory of combustion, chemical nomenclature, quantitative analysis, the indestructibility of matter,—in short, the discoveries of Scheele, Priestley, Cavendish, Lavoisier.

In geology we have the verification and results of Newton’s theory, the exact form of the earth, the laws of the tides, the primitive fluidity of the planet, the aqueous and igneous origin of rocks, the structure of the beds of fossils, the repeated and prolonged submersion of continents, the slow growth of animal and vegetable deposits, the vast antiquity of life, the gradual transformation of the earth’s surface, and, finally, the grand picture in which Buffon describes approximately the entire history of our globe from the time it formed a mass of glowing lava down to the time when our own species, after so many lost or surviving ones, was able to inhabit it.

Organic sciences

Upon this science of inorganic matter we see arising at the same time the science of organic matter. Linnæus invents botanical nomenclature and the first satisfactory classifications of plants. Digestion is explained by Réaumur and Spallanzani, respiration by Lavoisier. Scientists penetrate to the lowest stages of animal life. Lyonnet devotes twenty years to portraying a species of caterpillar. Needham reveals his infusoria. Buffon and, above all, Lamarck, in their great but incomplete sketches, outline with penetrating divination the leading features of modern physiology and zoölogy. Organic molecules everywhere diffused, which multiply and combine with one another through blind and spontaneous development, without either foreign direction or any preconceived end, solely through the effects of their structure and surroundings, unite together and form those masterly organisms which we call plants and animals. In the beginning we have the simplest forms, followed by slowly developing, complex, and perfected organisms,—all indicated, by conjecture and approximation, the cellular theory of later physiologists and the conclusions of Darwin. In the picture of nature which the human mind now portrays, the science of the eighteenth century has drawn the general out-line, and indicated the perspective and the general masses so correctly that at the present day all its main features remain intact. Except a few partial changes, there is nothing to efface.