THE CHEMICAL ELEMENTS. 737 



dents of chemistry down to the time of Lavoisier, and the aims 

 and practice of alchemy, which for many centuries was the only 

 phase of chemistry studied, were wholly in harmony with this 

 conception. If the metals were all manifestations of the same 

 underlying essence, and differed only in the accidents of external 

 qualities, it was reasonable to suppose that these accidents might 

 be changed. The alchemists were often intelligent men, and 

 knew as well as ourselves that " all is not gold that glitters " ; but 

 the resemblances to the precious metals which they sometimes 

 obtained by their empirical methods were sufficient to stimulate 

 effort. They also clearly saw that the value of the prize they 

 sought would vanish in their keeping the moment the secret be- 

 came known ; but this only led them, as it does so many manu- 

 facturers of the present day, to invest their processes with all 

 possible mystery, to conceal known facts beneath non-essentials, 

 and to adopt a conventional and highly figurative language for 

 communicating with each other, so that, even with our knowledge 

 of chemistry, the writings of the alchemists are for the most part 

 an unintelligible jargon. Still, their hopes were based on what 

 they regarded as sound philosophy ; and, although their efforts 

 were frequently exposed to ridicule on the ground of ill success, 

 no convincing objections were ever raised to the philosophy by 

 which they were guided. That the aims of the alchemists must 

 have appeared reasonable to thinking men is shown by the fact 

 that, even at a late period in the history of this apparent delusion. 

 Sir Isaac Newton, whose scientific sobriety can not be questioned, 

 devoted a great deal of time to experiments on the transmutation 

 of the metals. 



During the two thousand years through which the doctrine of 

 a few elementary principles of nature prevailed, the precise form 

 which the elements assumed naturally varied with the general 

 point of view of the students at the time, although for the most 

 part philosophical writers adhered to the statement of Aristotle. 

 By many of the alchemists mercury, sulphur, and salt were re- 

 garded as fundamental principles, because the crude materials 

 under these names played such an important part in the hermetic 

 art. Here, however, it was not these crude materials which were 

 regarded as the elements of matter, but sublimated forms of these 

 substances, known as the mercury and sulphur of the philoso- 

 phers ; and for a long time the conceit was cherished that, if once 

 the elemental mercury and sulphur could be isolated, all metals, 

 and, of course, gold and silver among the number, could be manu- 

 factured by mixing these elements in the right proportions. 

 Later, when chemistry assumed a pharmaceutical character, the 

 elements were often said to be water, spirit, oil, salt, and earth, of 

 which the first three were regarded as active and the last two as 

 VOL. XXXIV. — 4Y 



