THE NITRIC ACID OF THE SOIL. S61 



lost during three summer months eight-tenths of one per 

 cent of carbon. In the numerous similar experiments 

 made by Bonssingault with soils destitute of organic m<(t- 

 ter, no accumulation of nitrogen occurred beyond the 

 merest traces coming from condensation of atmospheric 

 ammonia. 



Certain experiments executed by Mulder more than 20 

 years ago ( Chemistry of Animal and Yegetahle Physi' 

 ology, p. 673) confirm the view we have taken. Two of 

 these were "made Avith beans which had germinated in 

 an atmosphere void of ammonin, and grown, in one case, 

 in ulmic acid prepared from sugar, and also free from am- 

 monia; and, in the other case, in charcoal, both being 

 moistened with distilled water free from ammonia. The 

 ulmic acid and the charcoal were severally mixed up with 

 1 per cent of wood ashes, to supply the plants with ash- 

 ingredients. I determined the proportion of nitrogen in 

 three beans, and also in the plants that were produced by 

 three other beans. The results are as follows: — 



White beans in nlmic acid. Brown beans in charcoal. 



Weight. Nitrogen. Weight. Xitrogen. 



Beans, 1.465 grm. 50 cub. cent. 1.277 27 cub. cent. 



Plants, 4.167 " 160 " " 1.773 54 " 



The white beans, therefore, whilst growing into plants 

 in substances and an atmosphere, both of which were free 

 of ammonia, had obtained more than thrice the quantity 

 of nitrogen that originally existed in the beans ; in the 

 brown beans the original quantity was doubled," Mulder 

 believed this experiment to furnish evidence that ammonia 

 is produced by the union of atmospheric nitrogen with 

 hydrogen set free in the decay of organic matters. To 

 this notion allusion has been already made, and the con- 

 viction expressed that no proof can be adduced in its 

 favor (p. 239). The results of the experiments are fully 

 explained by assuming that nitrogen was oxidized in nitri- 

 fication, and no other explanation yet proposed accords 

 with existins: facts. 



