210 SOURCES OF AMMONIA. 



number of analyses of compounds, in which the quantity of ni- 

 trogen was known, showed that this mode of procedure answered 

 completely the object in view ; until certain experiments by 

 Reiset were published, in which he obtained ammonia by this 

 process from substances such as sugar, &c, which were quite 

 destitute of nitrogen. Reiset, therefore, assumed that the nitro- 

 gen of air contained in the pores of the mixture was the cause of 

 the formation of ammonia, and that, unless this air were excluded, 

 the method of analysis was incorrect and objectionable. 



New experiments, repeated with the utmost care by Will, have 

 shown that in circumstances similar to those formerly observed 

 by Faraday, ammonia is actually obtained from matters destitute 

 of nitrogen, when they are heated to redness with potash ; but 

 that, by excluding ammonia itself, nitrogen cannot be made, to 

 unite with hydrogen in a nascent state, and that ammonia can- 

 not be produced from these elements. 



The admirable experiments of Faraday (Quarterly Journal of 

 Science, xix., p. 16) prove that, in all the cases in which ammonia 

 was obtained by heating to redness a substance destitute of nitro- 

 gen with hydrate of potash, the ammonia existed ready formed 

 in the substance, or in the hydrate of potash. There are no ob- 

 servations more convincing of the extraordinary diffusion of am- 

 monia, which exists in all places where atmospheric air is to be 

 found. That the reader may judge properly of Faraday's experi- 

 ments, I consider it important to describe them here in detail. 



After Faraday had observed that woody fibre, linen, oxalate of 

 potash, and a number of other substances free from nitrogen, 

 evolved ammonia on being heated with soda, potash, hydrate of 

 lime, &c, he endeavored to ascertain the conditions under which 

 the formation of ammonia ensued ; and in the first place, he ex- 

 amined the alkalies. Hydrate of potash, whether made from 

 potashes, cream of tartar, or potassium, behaved exactly in the 

 same manner. The organic substances, when heated alone, had 

 no reaction on turmeric ; but when heated with the alkalies, a 

 disengagement of ammonia ensued. 



It was then to be supposed that the nitrogen of the air sur- 

 rounding the substances might take a part in the formation of 

 ammonia : but this was very improbable : for it is known that 



