66 HISTORY OF CHEMISTRY. [LECTURE IV. 



figures, to assume in carbonic acid, two equivalents of oxygen 

 for one of carbon. In this case, therefore, the combining 

 weight and the equivalent were no longer identical, but the one 

 was twice as great as the other. That such results were 

 unavoidable in his method, ought to have been clear to him at 

 once, since he was acquainted with the law of multiple propor- 

 tions. Wollaston does not, however, pause in the least on 

 account of this result ; he does not bestow a word upon it ; 

 and he continues his determinations of equivalents uncon- 

 cernedly, but we shall not follow him in these, as they possess 

 no further interest for us. 



I think I have now shown that Wollaston's equivalents 

 present the same uncertainties as Dalton's atomic weights, and 

 that the views stated by him must be called retrograde because 

 he believed that he was dealing only with real unambiguous 

 conceptions, free from all hypotheses. 



It may perhaps seem that the opinion stated here is severe 

 and unjust, but when the further development of chemistry is 

 followed up, and it is seen how a more rapid progress during 

 the succeeding decade was prevented by this very confusion of 

 equivalent and. atom (er combining weight), and how a most 

 vigorous struggle was necessary before the separation of the 

 conceptions could be re-introduced, the reader will probably 

 adopt my view. It is true that the blame does not rest with 

 Wollaston alone, because a school arose in Germany also, 

 probably stimulated by him, which represented the same ideas. 

 This school was at first, no doubt, dominated by the great 

 influence of Berzelius, but afterwards, especially at the beginning 

 of the fifth decade of this century, it took the lead itself. I do 

 not intend to withhold the details of these highly interesting 

 developments, but in the next lecture I must direct attention 

 to the electrical phenomena which at this time begin to exercise 

 a great influence upon our science. 



