20 HISTORICAL INTRODUCTION. 



writings of Richter, and was very much struck 

 with the explanation there given, of the compo- 

 sition of salts, and the precipitation of metals by 

 each other. It followed from the researches of 

 Richter, that if we are possessed of good analy- 

 ses of certain salts, we may, by means of them, 

 calculate with accuracy the composition of all 

 the others. Professor Berzelius formed imme- 

 diately the project of analyzing a series of salts 

 with the most minute attention to accuracy. 

 While employed in putting this project in exe- 

 cution, Davy discovered the constituents of the 

 alkalies and earths ; and Mr. Dal ton's theory 

 came to his knowledge. All this enlarged his 

 views as he proceeded, and induced him to em- 

 brace a much wider field than he had originally 

 contemplated. His first analyses were unsatis- 

 factory ; but by repeating them, and varying 

 the methods, he detected errors, improved his 

 processes, and finally obtained results, which 

 agreed exceedingly well with the theoretical 

 calculations. These laborious investigations 

 seem to have occupied him several years. The 

 first knowledge which we obtained of them in 

 this country, was in consequence of the publica- 

 tion of a letter addressed by Berzelius to M. 

 Berthollet, in the 77th volume of the Annales 

 de C/iimie, about the beginning of the year 1811. 

 In this letter he gives an account of his methods 

 of analyses, together with the composition of 47 



