Solids, liquids, and gases, atomic explanation of, 19. Stahl, his phlogistic theory, 130. Stone, the philosopher's, 32, 35, 49, 58, 72. Thorium, radio-activity of, 183, 193. Transmutation, alchemical doctrine of, 47, 74, 123. ---- character of him who would attempt, 63. ---- of metals, 33, 39, 46, 74. ---- of metals into gold, alchemical account of, 75. ---- of water to earth, 151. Transmutations, apparent examples of, 82. Uranium, radio-activity of, 183, 192; relation of, to radium, 192, 193. Vegetables compared with metals by alchemists, 33. Water contains hydrogen and oxygen, examination of this phrase, 167. Water, different meanings of the word, 53, 167.