IS the transmutation of base metals into gold possible? Is the idea one at which the learned of the modern world can afford to scoff? Alchemy was more than a speculative art: it was also an operative art. Since the time of the immortal Hermes, alchemists have asserted (and not without substantiating evidence) that they could manufacture gold from tin, silver, lead, and mercury. That the galaxy of brilliant philosophic and scientific minds who, over a period of two thousand years, affirmed the actuality of metallic transmutation and multiplication, could be completely sane and rational on all other problems of philosophy and science, yet hopelessly mistaken on this one point, is untenable. Nor is it reasonable that the hundreds declaring to have seen and performed transmutations of metals could all have been dupes, imbeciles, or liars. Those assuming that all alchemists were of unsound mentality would be forced to put in this category nearly all the philosophers and scientists of the ancient and mediæval worlds. Emperors, princes, priests, and common townsfolk have witnessed the apparent miracle of metallic metamorphosis. In the face of existing testimony, anyone is privileged to remain unconvinced, but the scoffer elects to ignore evidence worthy of respectful consideration. Many great alchemists and Hermetic philosophers occupy an honored niche in the Hall of Fame, while their multitudinous critics remain obscure. To list all these sincere seekers after Nature's great arcanum is impossible, but a few will suffice to acquaint the reader with the superior types of intellect who interested themselves in this abstruse subject.