Method of determining Nitrogen in Organic Compounds. 217 



performed by able chemists, vary in their percentage results 

 iar more than we find to be the case in determinations of car- 

 bon and hydrogen. These differences resulting from the diffi- 

 culties and uncertainties of the usual methods, made chemists 

 feel the want of one more simple and accurate. 



M. Dumas has already, in his examination of oxamide, de- 

 termined the nitrogen by collecting it in the form of ammonia ; 

 and the experiments of H. Rose left no doubt that ammonia 

 could be most accurately weighed in the form of the ammo- 

 nio-chloride of platinum. These, and direct experiments of 

 Woehler, who had succeeded in determining correctly the ni- 

 trogen in uric acid by converting it into ammonia and weigh- 

 ing it as ammonio-chloride of platinum, led us to hope that 

 this experiment might conduct to a sure method for all nitro- 

 genous bodies, and we believe that our endeavours have been 

 attended by complete success. 



The method to be described is as simple and as certain as 

 the determination of carbon and hydrogen according to Prof. 

 Liebig's method. It is founded on the action of the hydrates 

 of the alkalies on nitrogenous organic substances at high tem- 

 peratures, and consists in determining the weight of the nitro- 

 gen in the form of ammonia, /. e. as ammonio-chloride of pla- 

 tinum, or as metallic platinum. 



Gay-Lussac showed that if any organic substance free from 

 nitrogen be melted with hydrate of potash, the water of that 

 hydrate is decomposed, its oxygen combining with the car- 

 bon and hydrogen of the organic body, while its hydrogen is 

 evolved in the gaseous state. The products which arise from 

 this powerful process of oxidation vary according to the tem- 

 perature to which the mixture is exposed, and according to 

 the constitution of the organic substance. It is sufficient to 

 know, that with substances free from nitrogen, hydrogen is li- 

 berated; this hydrogen combines when a nitiogenous substance 

 is subjected to the same kind of decomposition, with the entire 

 amount of nitrogen, and forms ammonia. Hitherto this ac- 

 tion has been employed merely to ascertain whether a body 

 contains nitrogen or not. 



In substances which contain much nitrogen, for instance, 

 uric acid, melamin, mellon, &c., the whole of the nitrogen is 

 not converted into ammonia at the commencement of the de- 

 composition ; a portion of it combines with a portion of the 

 carbon of the substance to form cyanogen, which, as such, 

 and probably also in the shape of cyanic acid, combines with 

 the metal of the alkali, in the latter case with the alkali itself. 

 The permanent nature of these cyanides at high temperatures 

 made us suspect that in such substiinces the whole aujount of 



