THE SOTJECES OF THE NITEOGEN OF YEGETATION, ETC. 
459 
7. M. G. Ville’s exjperiments conducted under the superintendence of a Commission 
comprising MM. Dumas, Kegi^ault, Paten, Decaisne, Peligot, and Chevreul. 
These experiments were conducted at the Museum d’Histoire Naturelle, Jardin des 
Plantes, Paris, in the autumn of 1854. M. Cloez was appointed to assist M. Ville; 
and M. Cheykeul reported on behalf of the Commission, in 1855*. 
In an apparatus similar to that employed in the experiments of M. Ville which have 
been already described, three pots of Cress Avere placed. The soil consisted of ignited 
brick and sand, to Avhich was added some of the ash of the plant. Carbonic acid 
was supplied artificially ; and the plants were watered Avith distilled Avater. The Cress 
in one of the pots did not thrrie well ; and, in this case, analysis shoAved 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 0*0039 gramme contained in the 
seed. 
At the suggestion of one of the members of the Commission, a smaller vessel was alsa 
attached to the aspirator, in AA'hich one pot soAvn with Cress was placed. The soil being 
duly watered with distilled Avater, the apparatus Avas then closed, and not opened (as 
the other frequently Avas) 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, Avhich is A^ery much to 
be regretted. A quantity of distilled water taken from the same bulk as that used for 
watering the experimental plants Avas saved for analysis. The examination of this 
water deA'olved on M. Cloez ; who, unfortunately, Avas called aAvay for some days, during 
the eA'aporation of the Avater with oxalic acid, Avith a A*ieAv to the after-determination of 
any ammonia it might contain. M. Peligot determined the ammonia in the acid residue 
of the eA’aporatioii of this AA^ater, as Avell as in that of the Avater remoA^ed from the cases, 
after it had served in the experiments. The result Avas, that there Avas indicated such 
an excess of ammonia in the AA^ater before being used, over that in the residual Avater 
after removal from the larger case, as more than covered the increase in the Nitrogen 
of the plants over that in the seeds soAvn. M. Cloez found, howcAm*, that, in his 
absence, the evaporation of the water had been conducted by the side of ammoniacal 
emanations from other processes. But AA'hen neAV portions of the original Avater Avere 
evaporated Avith proper precautions, less ammonia Avas indicated in it than in the Avater 
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 AA*ater 
to be correct. 
* Compt. Eend. 1855. 
