FROM THE AIR BY THE LEGUMINOS^ II 



hypothesis, Boussingault carried out several experiments in 

 which he employed a calcined soil, one thus completely 

 deprived of the slightest traces of organic matter. This soil 

 he watered with distilled water. 



Seeds, representing the average and comparable to those 

 planted, were taken, weighed and analysed. 



From these results Boussingault argued that the gain 

 in nitrogen might have accrued either from the absorption 

 of atmospheric ammonia or from the fixation of nitrogen 

 gas, and he favoured the second hypothesis. Liebig did 

 nothing to further the question of the absorption of nitrogen 

 from the air, although his works have benefited agricultural 

 science enormously. 



From 1849 to 1852, M. Georges Ville carried out experi- 

 ments on the assimilation of nitrogen gas by plants, and 

 came to a conclusion favouring the theory. We shall discuss 

 these works later, and return at present to those of Bous- 

 singault, carried out from 1851 to 1853 in order to check his 

 original experiments. 



The method followed was, in principle, the same as in 

 1838, only being modified in a few details. Thinking that 

 the slight gain in nitrogen obtained in his first experiments 

 might have been derived from traces of ammonia in the 

 open air in which the plants had grown, Boussingault 

 removed his second lot of plants from the air and only 

 allowed them an atmosphere saturated with 7 to 8 per cent, 

 of carbonic acid. 



Appended are the results of five experiments : — 



