52 AN INTRODUCTION TO SCIENCE 



able into any other substance by a series of transitions, if 

 only the right means were employed ? The doctrine of the 

 indestructibility of matter essential as it seems to us as a 

 first principle of science has not been established for much 

 more than a century. Matter was a transitory phenomenon 

 the essential constituents of the universe, the "elements," 

 were earth, fire, air and water. And if matter was capable 

 of unlimited transmutations, as it appeared to be, it was 

 clearly possible to make out of any given substance any 

 other substance, even the most desirable, namely, gold. 

 Here was an object of research so promising that it 

 overshadowed all others. It was impossible to think of 

 alchemy or chemistry, as we now call it, without bearing 

 the possibility of this great discovery in mind. "Pure" 

 chemistry is a growth of the last hundred and fifty years. 



We are apt to smile at the delusions of the alchemist. 

 His expectation that at any moment he might find gold 

 in his crucible seems to us a "fixed idea." But what other 

 motive had he for research? Merely to mix things to- 

 gether, to heat them and cool them, to sublime and con- 

 dense, to dissolve in water or alcohol, in order that he 

 might see what happened, was to play the child. Anything 

 might happen. The result might be pretty or ugly, pleasant 

 to smell, or the reverse ; but it could not be useful. What 

 purpose was served when, at the end of a long succession 

 of processes, his chemicals disappeared into thin air, with 

 an unseemly haste perhaps which smashed his retorts and 

 laid the philosopher upon his back ? Nothing is more 

 difficult than to transport oneself back into a former age, 

 without carrying thither the mental preoccupations of the 

 age in which one lives. Had we lived at the beginning 

 of the last century what discoveries we should have made ! 

 No doubt. But what principle would have guided our 

 researches before the permanence and irreducibility of the 

 elements as we now know them was established? To pass 

 matter through one form after another was futile, unless it 



