25 



3d 

 id 



a, 

 ts 

 jd 



nitrogen in the seed and air. The results with wheat, rye, or maize, 

 showed very much less of both actual and proportional gain. Experi- 

 ments with sunflower showed in one case thirty-fold, and with tobacco 

 in two cases more than forty-fold, as much in the products as was 

 supplied. It will be observed, however, that upon the whole M. G. 

 Ville's later experiments showed considerably less both actual and 

 proportional gain than his earlier ones. 



M. G. Ville in some cases attributed the gain to the large leaf 

 surface. In explanation of the assimilation of free nitrogen by plants, 

 he calls attention to the fact that nascent hydrogen is said to give 

 ammonia, and nascent oxygen nitric acid, with free nitrogen, and he 

 asks : Why should not the nitrogen in the juices of the plant combine 

 with the nascent carbon and oxygen in the leaves ? He refers to the 

 supposition of M. De Luca, that the nitrogen of the air combines with 

 the nascent oxygen given off by the leaves of plants, and to the fact 

 that the juice of some plants (mushrooms) has been observed to 

 ozonise the oxygen of the air, and he asks : Is it not probable, then, 

 that the nitrogen dissolved in the juices will submit to the action of 

 the ozonised oxygen with which it is mixed, when we bear in mind 

 that the juices contain alkalies, and penetrate tissues, the porosity of 

 which exceeds that of spongy platinum ? 



The following table (VII) summarises the results of M. Boussin- 

 ganlt. His experiments on the subject commenced in 1837, and were 

 continued at intervals up to 1858. The conditions of each set of ex- 

 periments as to soil, air, or application of manurial substances, are 

 given in the table. 



Table VII. 



Results of M. Boussingault's Experiments to determine whether Plants 



assimilate free Nitrogen. 



Plants. 



Nitrogen, grams. 



In Seed, 



or Plants ; 



and 



Manure, 



if any. 



In 

 Products. 



Gain 



or 

 Loss. 



Nitrogen 



in 

 Produets 



to 1 

 Supplied. 



1837 : Burnt soil, distilled water, free air, in closed summer-house. 



Trefoil 

 Trefoil 

 Wheat 

 Wlieat 



0-1100 

 0-1140 

 0130 

 0-0570 



0-1200 

 0-1560 

 -0400 

 -0600 



+ 0100 

 + 0-0420 

 -0 0030 

 + 0-0030 



1-09 

 1-37 

 0-93 

 105 



* Ann. Ch. Phys. [2], Ixvii. (1838). 



