FORMATION OF NITRITE OF AMMONIA. 309 



into combination ; and consequently that the same pro- 

 cess, whereby carbon is converted into carbonic acid, 

 forms also an ever-renewing source of nitrogenous food 

 for plants. 



Soon afterwards, Kolbe showed (' Annal. d. Cliem. 

 u. Pharm.' bd. 119, s. 176) that if a name of hydrogen 

 gas is allowed to burn in the open neck of a flask con- 

 taining oxygen, the interior is filled with the red fumes 

 of nitrous acid.* 



Further, Boussingault observed that, in the con- 

 sumption of common illuminating gas, the water in 

 Lenoirs gas machine contained ammonia and nitric 

 acid ; and shortly after, Bottger mentioned, in the 

 4 Annual Keport of the Physical Society of Frankfort ' 

 (meeting of Nov. 2, 1861), that, according to his experi- 

 ments, not only in the case of hydrogen, but generally 

 when hydro-carbons were burned, a certain quantity of 

 nitrite of ammonia was always formed, together with 

 water and carbonic acid. Almost contemporaneously 

 with this notice, I received from Schonbein a written 

 communication announcing the very same results which 

 he had obtained in the same way, so that no doubt can 

 remain as to the correctness of this fact. 



The practical farmer, who is really anxious to im- 

 prove his method of cultivation, must be led by these 

 undoubted facts to determine upon ascertaining, with 

 the greatest clearness, the effect of nitrogen in his ma- 

 nures. Before he lias been convinced that the atmos- 

 phere and rain convey the necessary amount of nitro- 

 genous food to his plants, no one could expect him to 

 renounce the employment of ammonia as a manure. 

 When it is asserted that a farmer can give a maxi- 

 mum of fertility to his land without supplying to it any 

 nitrogenous matter, it is not meant that he must re- 

 nounce the use of farm-yard manure ; but the assertion 

 implies the existence of the latter, and is, in fact, based 

 upon it. 



For the restoration or augmentation of productive 



* The formation of nitrous acid in eudiometrical experiments was 

 already known. 



