158 HISTORY OF CHEMISTRY. 



from the conversion of the oxygen gas to a solid 

 consistence, according to the doctrine of latent heat. 

 Such opinions not being necessarily connected with 

 the general idea of the theory, need not here be 

 considered. But the leading generalization of La- 

 voisier, that acidification was always combination 

 with oxygen, was found untenable. The point on 

 which the contest on this subject took place was 

 the constitution of the oxymuriatic and muriatic 

 acids; as they had been termed by Berthollet, 

 from the belief that muriatic acid contained oxygen, 

 and oxymuriatic a still larger dose of oxygen. In 

 opposition to this, a new doctrine was put forwards 

 in 1809 by Gay-Lussac and Thenard in France, and 

 by Davy in England; namely, that oxymuriatic 

 acid was a simple substance, which they termed 

 chlorine, and that muriatic acid was a combination 

 of chlorine with hydrogen, which therefore was 

 called hydrochloric acid. It may be observed, that 

 the point in dispute in the controversy on this sub- 

 ject was nearly the same which had been debated 

 in the course of the establishment of the oxygen 

 theory ; namely, whether in the formation of muri- 

 atic acid from chlorine, oxygen is subtracted, or 

 hydrogen added, and the water concealed. 



In the course of this dispute, it was allowed on 

 both sides, that the combination of dry muriatic 

 acid and ammonia afforded an experimentum crucis; 

 since, if water was produced from these elements, 

 oxygen must have existed in the acid. Davy being 



