12 INTRODUCTION. 



advance, if not characterised by method, was rapid 

 and certain. 



.It was now time that chemistry should 

 receive the requisite framework of a science. 

 A vast number of experiments, with their results, 

 were on record, and these were continually in- 

 creasing. Gleams of the laws of combination, 

 like scattered rays of light, darted upon the 

 minds of experimenters. The comprehensive 

 mind which should seize these indications, and 

 reduce them to form and order, was yet wanting. 

 Nevertheless, chemistry was gradually assuming 

 the definite character of a science. The doctrine 

 of affinity, or of elective attractions, by which 

 it is taught that some bodies unite chemically 

 with others by preference, in the presence of 

 other substances for which they have a feeble 

 attraction, was promulgated by Bergman, and 

 became an important doctrine of chemistry. 

 That -a great and most salutary revolution had 

 been effected in the minds of the followers of 

 this science may be learned, when we read, 

 toward the close of this period, the good con- 

 fession of one who, scorning the pursuit of 

 science for the sake of gold, could write, " My 

 kingdom is not of this world. I trust that 

 I have got hold of my pitcher by the right 

 handle ; the true method of treating this study. 

 For the pseudo (or false) chemists seek gold ; 

 but the true philosopher, science, which is 

 more precious than any gold." It was in the 

 same spirit that a just reproof was given by 

 D'Alembert to an ambitious young man, and 

 as it deserves remembering, we venture to 

 record it. "Science," said he, "must be loved 



