106 J. H. Gilbert— Points in ay, nectio wiil \egel t m. 



We have already discussed the results of M. G. Ville, as well 

 as those of others, in a paper published in the Philosophical 

 Transactions for 1859, and in a somewhat condensed form in the 

 Journal of the Chemical Society, vol. xvi, 1863 ; and we can 

 only very briefly refer to them in this place. The column of 

 actual gain or loss of nitrogen is seen to show in one case a 

 gain of more than one gram of nitrogen ; the amount of it in 

 the products being more than forty-one fold that supplied as 

 combined nitrogen in the seed, and air. This result was ob- 

 tained with colza. Those obtained with wheat, rye, or maize, 

 showed very much less of both actual and proportional gain. 

 Experiments with sunflower and tobacco showed a less actual 

 gain than that with colza ; but still it amounted in one case, 

 with sunflower, to more than thirty, and in two, with tobacco, 

 to more than forty-fold of that supplied. In M. G. Ville's ex- 

 periments (as a glance down the last two columns in the table 

 will show), although he still had generally some gain, it was 

 usually both actually and in proportion to the quantity sup- 

 plied considerably less than in his earlier ones. 



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

 leaf-surface. In explanation of the assimilation of free nitro- 

 gen by plants, he calls attention to the fact that nascent hydro- 

 gen is said to give ammonia, and nascent oxygen nitric acid, 

 with free nitrogen, and he asks, " Why should not the nitro- 

 gen 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 ozonize 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 ozonized oxygen with which it 

 is mixed, when we bear in mind that the juices contain alka- 

 lies, and penetrate tissues, the porosity of which exceeds that 

 of spongy platinum ?" 



The experiments of M. Boussingault, and of ourselves, on 

 the other hand, have not given an affirmative answer to the 

 question whether plants, by their leaves, take up and assimi- 

 late free nitrogen of the air. 



M. Boussingault commenced his experiments on this subject 

 in 1837, and Table VI, which follows, summarizes bis results, 

 obtained at intervals from that date up to 1858. 



