LE HOY C. COOLEY. 31 



The alchemist could conceive nothing more supremely 

 to be desired than perennial youth ; and next to this, 

 than happiness and power. He therefore watched the 

 changes occurring in his crucible and alembic, hoping to 

 discover the elixir vitce^ which should banish age, and 

 the philosopher 1 s stone, by which to manufacture gold. 

 To the chemist, on the other hand, some exact and real 

 knowledge of matter, some better understanding of the 

 nature of forces, some further insight into the mechanism 

 and some revelation of the thoughts which underlie the 

 mechanism of the world, are more to be desired than 

 gold or youth. He therefore directs and watches the 

 transformations of matter, animated with the desire to 

 discover and make known the truth. 



If we consider some of the qualities of the alchemist 

 and of the chemist, we shall be the better able to 

 give due weight to the contrast of their motives. I know 

 not whether to regard the chemist or the alchemist as the 

 more industrious observer. As for facts, these in the 

 early times were the same for both, and both alike had 

 the power to reason well. M. Ferdinand Hofer illus- 

 trates this last thought as follows : " Let us fancy our- 

 selves for a moment transported to the laboratory of one 

 of the great masters of sacred art, and watch as neophytes 

 some of his operations. First experiment : Some com- 

 mon water is heated in an open vessel. The water boils 

 and changes to an aeriform body, leaving at the bottom 

 of the vessel a white earth in the form of powder. Con- 

 clusion : Water changes into air and earth. What ob- 

 jection could we (or a chemist), make to this inference 

 if we were wholly ignorant of the substances which 

 water holds in solution, and which are, after evaporation, 

 deposited at the bottom of the vessel. Another experi- 

 ment : Argentiferous lead is burned in cupels composed 

 of ashes or pulverized bones ; the lead disappears, and 

 at the end of the operation there remains in the cupel a 



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