It was believed by the philosophers of ancient and mediaeval times, especially by those devoted to the study of alchemy, that it was possible through mystical powers, often of a supernatural order, to annihilate matter or to create it from nothing. Men with such powers transcended all known laws of nature, and became objects of fear, often of worship to the masses of mankind. Naturally enough, the systems of religion became colored with the philosophical doctrines of the times; and it was held to be a fundamental religious truth that God created the world from nothing. Certainly, God could do what his creatures, the magicians, were able to do--that part of the reasoning was sound. In support of this doctrine, attention was called to some of the experiences of daily life. A piece of coal placed in a stove, in a short time disappear--it is annihilated. From the clear air of a summer's day raindrops start--created out of nothing. A fragment of gold placed in contact with sufficiently strong acids, disappears--it is destroyed. [Sidenote: Matter is eternal, its form only can be changed.] Towards the end of the eighteenth century, facts and laws of chemistry were discovered, which enabled scientists to follow in great detail the changes, visible or invisible, to which matter in its various forms is subject. Then it was shown that the coal placed in a stove unites with a portion of the air entering through the drafts, and becomes an invisible gas, but that, were this gas collected as it issues from the chimney, it would be found to contain a weight of the elements of the coal just equal to the weight of the coal used. In a similar manner it was shown that the raindrops are formed from the water found in the air, as an invisible vapor. The gold dissolved in the acid, may be wholly recovered so that every particle is accounted for. Numerous investigations on this subject were made by the most skillful experimenters of the age, all of which showed that it is absolutely impossible to create or destroy the smallest particle of matter; that the most man can do is to change the form in which matter exists. After this truth had been demonstrated, it was a necessary conclusion that matter is eternal, and that the quantity of matter in the universe cannot be diminished nor increased. This great generalization, known as the law of the Persistence of Matter or Mass, is the foundation stone of modern science. It began to find general acceptance among men about the time of Joseph Smith's birth, though many religious sects still hold that God, as the Supreme Ruler, is able at will to create matter from nothing. The establishment of this law marked also the final downfall of alchemy and other kindred occult absurdities. [Sidenote: Mormonism teaches that all things are material.]