HISTORICAL INTRODUCTION. 19 



pected light on chemical combinations. It has 

 contributed very materially to simplify and per- 

 fect the mode of analyzing compound gases. It 

 agreed admirably with the views of Mr. Dalton, 

 as Gay-Lussac hints in his paper j and might 

 have been employed by him in his investigations ; 

 and would have enabled him, had the specific 

 gravity of gaseous bodies been more accurately 

 known, at the time when he wrote, to have 

 determined the atomic weights of the acidifiable 

 combustibles with much more accuracy than he 

 did. But Mr. Dalton's first volume was pub- 

 lished, and probably the greater part of his se- 

 cond volume printed, before he had an opportu- 

 nity of seeing Gay-Lussac's paper. And when 

 he did see it, instead of welcoming it as an im- 

 portant addition to his own views, he set him- 

 self to show that Gay-Lussac's opinions were ill 

 founded. But the subsequent researches of 

 chemists have left no doubts about their accura- 

 cy ; and if Mr. Dalton still withholds his assent, 

 he is, I believe, the only living chemist who 

 does so. 



V. When Professor Berzelius of Stockholm 

 thought of writing his elementary treatise on discoveries 

 Chemistry, the first volume of which was pub- itJ s Berze ~ 

 lished at Stockholm in 1808, he prepared him- 

 self for the task by reading several chemical 

 works, which do not commonly fall under the 

 eye of the chemist. Among others, he read the 



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