458 MR. J. B. LAWES, DR. GILBERT, AND DR. PUGH ON 
5. M. G. Vinix’s experiments in which known quantities of Ammonia were admitted into 
the atmosphere of the enclosing apparatus. 
In each of the three seasons 1850, 1851, and 1852, M. G. Vitue had a duplicate 
apparatus, enclosing, in each case, similar plants to those in the other, but with this 
difference in the conditions—that ammonia was supplied to the atmosphere of the 
second apparatus. As might be expected, the increase, both in dry substance, and in 
Nitrogen, was much the greater, in relation to the amounts of them contained in the 
seed or young plants, when ammonia was thus employed. In no case, however, did the 
plants take up Nitrogen equal in amount, much less exceeding, the whole of that sup- 
plied to the air in the combined form, as ammonia. The results have not, therefore, so 
direct a bearing on the question of the assimilation of free or wacombined Nitrogen, as 
to require that we should quote them in any detail. Their chief interest’ was in show- 
ing the influence of ammoniacal supply, not only upon the vigour and luxuriance of 
growth generally, but upon the order, or course of development, of the plants, according 
to the stage of growth at which the application was made. 
6. Comparison of M. G. ViLE’s results with those of M. Boussineavtt up to 1853 
inclusive. 
It will be remembered that, up to 1853 inclusive, M. BoussincauLt’s experimental 
plants had been grown either in free air—in which case they had fixed, from some source, 
slightly larger amounts of Nitrogen than were contained in the seed,—or in fixed and 
limited volumes of air (carbonic acid being added), in which cases no gain of Nitrogen 
was observed. ‘The gain of Nitrogen in the free air was, moreover, considered to be too 
small to indicate, under all the circumstances, any assimilation of free or uncombined 
Nitrogen. On the other hand, M. G. VILLE’s experiments up to the same period had 
indicated an enormous gain of Nitrogen. The Nitrogen in the products, indeed, some- 
times amounted to more than forty times that contained in the seed. 
Results so strikingly contradictory could hardly fail to excite great attention and 
interest among Chemists and Vegetable Physiologists. But M. Vituz’s plants had been 
grown in a constant current of renewed air, and not in only a fixed and limited volume 
of it. This fact, and some other points, were alleged to account for the difference in 
result. At any rate, on the one hand, M. Boussincavtt commenced in 1854, to expe- 
riment with a current of air; whilst, on the other, a Commission, composed of Members 
of the Academy of Sciences of France, was appointed to superintend the conduct of a 
new set of experiments by M.G. Vite. “It has already been shown, that M. Boussiy- 
GAULT'S new experiments in which a current of air was employed, did not indicate any 
assimilation of free or uncombined Nitrogen, any more than did those in which the 
plants had grown in limited volumes of air only. 
