14 Meldrum, Development of tJie Atoinie Theory. 



my voice in this hall .... I owe it to the study I 

 made of Berthollet's ' Statics.' " " 



l^^inally, on the establishment of these two doctrines, 

 which seemed to be incompatible with one another — 

 Dalton's of invariable proportions and Berthollet's of 

 mass-action — there remained the problem of reconciling 

 the one with the other. That the necessity of doing this 

 was present in the minds of the leaders of chemistry is 

 proved by Berzelius's " Essay on the cause of Chemical 

 Proportions," etc., which begins with a section " on the 

 relation between Berthollet's theory of affinities and the 

 laws of chemical proportions." He remarks that " some 

 chemists have affirmed that the existence of chemical 

 proportions is contrary to the principles of the theory of 

 affinities with which the illustrious Berthollet has enriched 

 chemistr}'," and proceeds to show that this is really not 

 the case. He takes the case of solution in water of 

 copper sulphate to which hydrochloric acid is added ; 

 " . . . . the part of the acid really combined with the 

 oxide is neutralised according to the laws of chemical 



proportions This single example is sufficient 



to show that the principles of Berthollet's theory are not 

 inconsistent with the laws of chemical proportions." ^- 



Dalton, in his comments on this Essay, expresses his 

 full concurrence with the verdict. " The first division of 

 Dr. Berzelius's essay contains an admirable exposition of 

 those facts which Berthollet brought forward in so con- 

 spicuous a point of view in his chemical theory, and 

 which his zealous followers have magnified in a still 

 greater degree. A better explanation could, I think, be 

 scarcely given in fewer words." '^^ 



• *' " Lecons sur la Philosophic Chimique," pp. 379— 3S0 



■'- Ann. of Phil., vol. 2, p. 443, 1 81 3. 



*» Ann. of Phil., vol. 3, p. 174, 1814. 



