PEEFACE 7 



Prof. Henrik G. Soderbaum of Stockholm, a Fellow of 

 the Royal Swedish Academy of Sciences, has already 

 published at my suggestion, in the series of Monographs 

 on the History of Chemistry which I am editing, a 

 number dedicated to the memory of Berzelius, a subject 

 with which he is peculiarly fitted to deal ; but I should 

 wish to contribute my mite personally, by giving to the 

 public on the day of the celebration in Stockholm the 

 correspondence between Berzelius and Schonbein which 

 has been placed in my hands. 



What I have to offer contains no startling novelties ; 

 no explanations that are to revolutionize our previous 

 theories can be derived from these letters. But to prove 

 what I have said of the importance of letters as the 

 original sources of the history of the development of 

 certain definite ideas, and of the knowledge of personalities 

 which we can derive from them, it is only necessary to 

 compare the letters which Berzelius wrote to Schonbein 

 with those which he wrote to Liebig \ for even these few 

 pages substantiate to the fullest extent the claims which 

 I have put forward. 



And yet how wholly different were the lines of research 

 which the two men followed. Berzelius, a master of the 

 methods of quantitative analysis, has his attention always 

 centred on the final product, considered in its quantitative 

 relations : Schonbein, for whom this branch of chemical 

 research possesses hardly any interest, is far more bent on 

 acquiring from characteristic indications the means of 

 disentangling the course of the reactions. While Ber- 

 zelius' mind embraced the whole range of chemical know- 

 ledge, Schonbein concentrated his attention on a narrowly 

 contracted field, but yet regarded that field from com- 

 manding points of view ; and both took an equal interest 

 in observing the interconnection of chemical and electrical 

 energy. The younger man from the beginning looked up 



