326 AMMONIA AND NITRIC ACID. 



carbon, which presents to the farmer the possibihty of in- 

 creasing his store of active nitrogen in the soil. 



The extraorclmary effect of superphosphate of Hme in 

 augmenting the crops of corn, turnips, and clover, almost 

 without exception, upon all German lands to which these 

 non-azotised manures have been applied ; the operation 

 of the newly-introduced Baker and Jarvis guanos* (which 

 contain no ammonia) ; the action of lime, salts of potash, 

 gypsum, &c., all show without doubt that an accumula- 

 tion of nitrogenous food has taken place in the soil, the 

 source of which was, until lately, quite obscure. 



We had reason enough to beheve in a partial restora- 

 tion to the soil of nitrogenous food by air and rain, but 

 that it should be augmented was quite unexplained ; 

 because this presupposed that ammonia and nitric acid 

 were produced from the nitrogen of the atmosphere, in 

 evidence of which we had no facts whatever. Very 

 recently this source of the increase of the nitrogenous 

 food of plants was discovered by Schonbein, and the 

 problem was solved in the most unexpected manner. 



In his experiments upon oxygen, Schonbein found that 

 the white fume emitted by a piece of moist phosphorus 

 is not, as was previously behoved, phosphorous acid, but 

 nitrite of ammonia. I myself had an opportunity of 

 seeing this proved at a lecture, illustrated by experi- 

 ments, which Schonbein dehvered at Munich in the 

 summer of 1860. It is probable, as he states, that in 



* From a communication in the ' Official Gazette,' No. 3, of 1st 

 Marcli 1862, for the Agric. Union in Saxony, the following crops per 

 acre Avere obtained in 1861 : — 



Wheat 



Com Straw 



3 cwt. Jaiwis gnano produced . 2244 lbs. 4273 lbs. 



3 „ Baker „ „ . 2929 „ 5022 „ 



6 „ steamed bones „ , 3015 „ 4755 „ 



Unmanured „ . 1955,, 3702,, 



