MODERN CHEMISTRY
Modern chemistry may be said to begin with Robert Boyle (1626–1691). He defined an elementas a substance which could not be decomposed, but which could enter into combination with other elements, giving compounds capable of decomposition into these original elements. The number of elements which were thought to exist varied greatly,—some contending that they were but few in number, others that they were numerous. It must be remembered that all this was before the time of Dalton, and that the atomic theory had not yet been advanced as a scientific hypothesis, since the days of the ancient Greeks, when Democritus and Epicurus had defended this view. The swing of science, at that time was, therefore, toward the materialism of those older writers, and the atomic theories which they had then proposed.
Chemistry is that branch of science which investigates the nature and properties of matter in all its forms. It is, perhaps, the most materialistic of all the sciences, since it deals essentially with matter. Physics deals with forces or energies, or the energies manifested by and through matter, but the two are more or less inter-related—especially of late years, as we shall see. Chemistry is essentially anexperimentalscience, and practically everything which has been learned about it has been acquired by means of laboratory experimentation. But here as elsewhere theories have woven together the mass of separate facts, and of them made a consistent and philosophical science.
There are two main divisions of chemistry—inorganic and organic; that is to say, the chemistryof “dead” matter, and the chemistry of “living” or organic substances. Chemical experiments may be for the purpose ofanalysis—discovering the constituents of a given substance;synthesis, in which a compound substance is “created” from several simpler ones; or purelyexperimental, in which certain tests are made, and the results or reäctions noted.