Biography of BerzeUus. 215 



not be regarded as a mere hypothesis, but, if the doctrine of 

 definite proportions is admitted, as a demonstrated truth." 

 He assumed that an unknown radical — nitricum — existed, to 

 which he assigned the symbol N, subsequently retained for 

 nitrogen, which was then regarded as the suboxide of this 

 supposed radical, and the highest oxide — nitric acid — as con- 

 taining six atoms of oxygen. oiq is «jsw ahtt ixulJ -gal mm 



It was, however, in truth, the circumstance that the pro- 

 portion of the oxygen in nitrous acid to that in nitric acid 

 was as 3 to 5, which alone misled him so obstinately to as- 

 sert the existence of oxygen in nitrogen, in which case that 

 proportion would have been as 4 to 6. When a short time 

 afterwards he made his researches on the composition of 

 phosphorous and phosphoric acids, in which he found, almost 

 simultaneously with Dulong, that the quantities of oxygen 

 were in the proportion of 3 to 5, and after having in vain 

 attempted to detect oxygen in phosphorus, his views respect- 

 ing the compound nature of nitrogen were shaken, and he 

 finally relinquished them, after having convinced himself 

 that a similar relation obtained between very many, we may 

 perhaps now say most, of the different oxides of simple 

 bodies which form acids. Subsequently, he sometimes made 

 the remark, without, however, assigning any particular im- 

 portance to it, that from the production of nitrogenous com- 

 pounds in the organisms of herbivorous animals, whose food 

 frequently appears not to correspond in composition with 

 them, the existence of oxygen in nitrogen might be inferred. 

 However, in the last edition of his "Lehrbuch," even this 

 remark does not occur. o xlonrn && somii &V 



This too great faith in the extreme simplicity of chemical 

 combining proportions induced Berzelius, in some other in- 

 stances, to assume the existence of oxides which had no 

 reality. In the investigation of the oxides of tin, he assumed 

 that the oxide obtained from the Spiritus Libavii, which cer- 

 tainly differs greatly in its characters from that obtained by 

 means of nitric acid, was, in reference to the quantity of 

 oxygen which it contained, intermediate between the prot- 

 oxide and peroxide. Shortly afterwards Gay-Lussac shewed 

 that it did not differ from the oxide prepared with nitric acid 



