Supposed Proofs of Transmutation.
§ 14. It must be borne in mind when reviewing the theories of the alchemists, that there were a number of phenomena known at the time, the superficial examination of which would naturally engender a belief that the transmutation of the metals was a common occurrence. For example, the deposition of copper on iron when immersed in a solution of a copper salt (e.g., blue vitriol) was naturally concluded to be a transmutation of iron into copper,[21] although, had the alchemists examined the residual liquid, they would have found that the two metals had merely exchanged places; and the fact that white and yellow alloys of copper with arsenic and other substances could be produced, pointed to the possibility of transmuting copper into silver and gold. It was also known that if water (and this is true of distilled water which does not contain solid matter in solution) was boiled for some time in a glass flask, some solid, earthy matter was produced; and if water could be transmuted into earth, surely one metal could be converted into another.[22] On account of these and like phenomena the alchemists regarded the transmutation of the metals as an experimentally proved fact. Even if they are to be blamed for their superficial observation of such phenomena, yet, nevertheless, their labours marked a distinct advance upon the purely speculative and theoretical methods of the philosophers preceding them. Whatever their faults, the alchemists were the forerunners of modern experimental science.
[21] Cf. The Golden Tract concerning the Stone of the Philosophers (The Hermetic Museum, vol. i. p. 25).
[22] Lavoisier (eighteenth century) proved this apparent transmutation to be due to the action of the water on the glass vessel containing it.