The modern science of chemistry is relatively new. It gradually emerged from alchemy, which practically constituted the chemistry of the middle ages. The objects of alchemy were various: (1) the transmutation of the base metals into gold, by means of the so-called “Philosopher’s Stone”; (2) The fixation of Mercury; (3) The discovery of the elixir of Life, etc. These were the purely chemical aspects of alchemy, but we now know that the alchemists had much more than this in mind, in their experimental work, and that they hinted at their true meaning in many of their veiled writings. Many of the higher types of alchemists were also mystics, and when they wrote in chemical symbols, they really concealed their inner meaning; they referred, very largely, to the inner spirit of man, and the methods by which this could be changed or transformed into some higher spiritual being. (See “Alchemy Ancient and Modern,” by H. Stanley Redgrove; “Alchemy, Its Scope and Romance,” by the Rev. J. E. Mercer, etc.) Mr. Foster Damon has lately published a series of articles in which he has brought forward a mass of evidence tending to prove that the alchemists were also deep students of psychic phenomena, and that their experiments relative to the “First Matter” were really experiments in so-called “Materialization!” He has published his findings in a series of articles in the “Occult Review.” MODERN CHEMISTRY Modern chemistry may be said to begin with Robert Boyle (1626–1691). He defined an element as 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 an _experimental_ science, 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.