THE SOURCES OF THE NITROGEN OF VEGETATION, ETO. 459 
7. M. G. Vinte’s experiments conducted under the superintendence of a Commission 
comprising MM. Dumas, REGNAULT, PayEN, DEcAIsNE, PeLicot, and CHEVREUL, 
These experiments were conducted at the Muséum d’Histoire Naturelle, Jardin des 
Plantes, Paris, in the autumn of 1854. M.Ctozz was appointed to assist M. VILLE; 
and M. CuEvrevt reported on behalf of the Commission, in 1855*. 
In an apparatus similar to that employed in-the experiments of M. Vine which have 
been already described, three pots of Cress were placed. The soil consisted of ignited 
brick and sand, to which was added some of the ash of the plant. Carbonic acid 
was supplied artificially ; and the plants were watered with distilled water. The Cress 
in one of the pots did not thrive well; and, in this case, analysis showed a loss of 
2 milligrammes of Nitrogen. In one of the other cases, there was a gain of 0:0492 
gramme of Nitrogen, upon 0:0038 gramme supplied in the seed; and in the other, 
there was a gain of 0-0071 gramme of Nitrogen, upon 00039 gramme contained in the 
seed. 
At the suggestion of one of the members of the Commission, a smaller vessel was also 
attached to the aspirator, in which one pot sown with Cress was placed. ‘The soil being” 
duly watered with distilled water, the apparatus was then closed, and not opened (as 
the other frequently was) until the conclusion of the experiment. In this case also, 
there was a considerable gain of Nitrogen indicated, namely, 0-0287 gramme gain, upon 
0:0063 gramme in the seed. 
Unfortunately, an element of uncertainty attached to the evidence afforded by these 
experiments made under the superintendence of the Commission, which is very much to 
be regretted. A quantity of distilled water taken from the same bulk as that used for 
watering the experimental plants was saved for analysis. The examination of this: 
water devolved on M. Ciozz; who, unfortunately, was called away for some days, during 
the evaporation of the water with oxalic acid, with a view to the after-determination of 
any ammonia it might contain. M.Pricor determined the ammonia in the acid residue 
of the evaporation of this water, as well as in that of the water removed from the cases, 
after it had served in the experiments. The result was, that there was indicated such 
an excess of ammonia in the water before being used, over that in the residual water 
after removal from the larger case, as more than covered the increase in the Nitrogen 
of the plants over that in the seeds sown. M.Ctorz found, however, that, in his 
absence, the evaporation of the water had been conducted by the side of ammoniacal 
emanations from other processes. But when new portions of the original water were 
evaporated with proper precautions, less ammonia was indicated in it than in the water 
at the close of the experiment; and then, also, a gain of Nitrogen by the plants in the 
larger apparatus was indicated. 
At any rate, however, the result with the single pot, in the small apparatus, showed 
a considerable gain of Nitrogen, even supposing the first analysis of the supplied water 
to be correct. 
* Compt. Rend. 1855. 
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