84 HISTORY OF CHEMISTRY. [LECTURE V. 



carbonic acid, hydro-carbonic acid. On saturation with a 

 metallic oxide, the oxygen of the oxide combines with the 

 hydrogen of the oxalic acid to form water which can then be 

 driven off, and a compound of carbonic acid with metal remains 

 behind. Here we find the view for the first time represented 

 (by Dulong and Davy) that the water produced during salt 

 formation was not already contained in the (oxygenised) acid, 

 and that, in a salt, it is not a metallic oxide but the metal, as 

 such, that exists. 



It is stated that Dulong made a similar assumption for the 

 other acids, but unfortunately the development of his ideas 

 has not been handed down to us. Besides, hypotheses of this 

 kind met with little approval at that time ; voices were loud in 

 their condemnation from the most different sides. Gay-Lussac 

 declared himself emphatically against them ; w and Berzelius 

 (who was then beginning to exercise a predominant influence) 

 seeing that he was obliged to admit the existence of acids free 

 from oxygen, introduced a strict distinction between the latter 

 and the acids containing oxygen, and so between the haloid 

 and the amphid salts. 



This single point irj the system of Berzelius must not, 

 however, be treated of separately, but the system must be dealt 

 with as a whole. His views are of the utmost importance, 

 since they dominated theoretical chemistry for twenty years. 

 I shall devote the next lecture to their consideration. 



64 Ann. Chim. [2] I (1816), 157. 



