The alchemists set forth on the quest. Their quest was barren. They made the great mistake of fashioning _The One Thing, The Essence, The Water of Paradise_, from their own imaginings of what nature ought to be. In their own likeness they created their goal, and the road to it. If we are to understand nature, they cried, her ways must be simple; therefore, her ways are simple. Chemists are people of a humbler heart. Their reward has been greater than the alchemists dreamed. By selecting a few instances of material changes, and studying these with painful care, they have gradually elaborated a general conception of all those transformations wherein substances are produced unlike those by the interaction of which they are formed. That general conception is now both widening and becoming more definite. To-day, chemists see a way opening before them which they reasonably hope will lead them to a finer, a more far-reaching, a more suggestive, at once a more complex and a simpler conception of material changes than any of those which have guided them in the past. INDEX Air, ancient views regarding, 129. ---- views of Mayow and Rey regarding, 129. Alchemical account of changes contrasted with chemical account, 169. ---- agent, the, 64. ---- allegories, examples of, 41, 97. ---- classification, 59. ---- doctrine of body, soul, and spirit of things, 48. ---- doctrine of transmutation, 47, 74, 123, 170. ---- language, 36, 96, 101, 102. ---- quest of the One Thing, modern form of, 179. ---- signs, 105. ---- theory, general sketch of, 26. Alchemists, character of, according to Paracelsus, 25. ---- made many discoveries, 87. ---- sketches of lives of some, 115. ---- their use of fanciful analogies, 31. Alchemy, beginnings of, 23. ---- change of, to chemistry, 126. ---- contrasted with chemistry, 202. ---- general remarks on, 123. ---- lent itself to imposture, 106. ---- object of, 9, 26, 32, 105. ---- probable origin of word, 25. ---- quotations to illustrate aims and methods of, 11-14. Alembic, 92. Apparatus and operations of alchemists, 90. Art, the sacred, 122. Atom, meaning given to word by Dalton, 173. Atomic theory of Greeks, 16. ---- additions made to, by Dalton, 21. ---- as described by Lucretius, 19. Atomic weight, 174. Atoms and electrons, 190, 198. Bacon's remarks on alchemy, 95. Balsamo, Joseph, 110. Basil Valentine, his description of the three principles, 51. ---- his description of the four elements, 49. ---- some of his discoveries, 88. Becquerel, his discovery of radiation of uranium, 181. Body, soul, and spirit of things, alchemical doctrine of, 48. Boyle, on calcination, 128. ---- on combustion, 141. ---- on elements, 161. ---- on the "hermetick philosophers," 95. ---- on the language of the alchemists, 55. ---- on the natural state of bodies, 43. Cagliostro, 110. Calcination, 129, 132, 135, 140, 142, 151, 155. Chaucer's _Canon's Yeoman's Tale_, 107.