THE SOURCES OF THE NITROGEN OF VEGETATION, ETC. 457. 
four times that of the seed sown; and the Nitrogen in the total products was nearly 
double that in the seed. The dry substance of the produced Rye plants was five times, 
and their Nitrogen nearly three times that of the seed. In the experiment with Maize, 
the dry matter increased only about three times, but the Nitrogen nearly 43 times. 
The actual gain of Nitrogen in the total products of the four experiments, was 1:1803 
gramme. ‘The whole admitted in the form of atmospheric ammonia was estimated at 
0:0017 gramme, or less than 2 milligrammes. M. Viniz remarks, moreover, that an 
examination of the distilled water before being used to water the plants, and of the 
water afterwards removed from the apparatus, showed more ammonia in the latter than 
intheformer. The conclusion from this second series of experiments also was, therefore, - 
that a considerable quantity of free or uncombined Nitrogen had been assimilated. 
4, M. G. VILLE’s experiments in 1851 and 1852, in which the plants were supplied 
with a current of air washed free from anunonia. 
In 1851, one pot of Sun-flower, from seed, and two pots of Tobacco, starting from 
plants transplanted from good soil, were grown together, under circumstances similar to 
those of the preceding experiments, with the exception that now the air was deprived 
of its ammonia by passing over pumice-stone saturated with sulphuric acid, and also 
through a solution of bicarbonate of soda, previous to entering the apparatus. 
The Sun-flowers gave 95 rudimentary grains; but the Tobaccos did not flower. How- 
ever, taking the three experiments together, the dry matter increased nearly 200-fold, 
and the Nitrogen increased nearly 40-fold, during a period of growth of three months. 
The total gain of Nitrogen in the apparatus was 0:481 gramme. 
In 1852, the conditions of the apparatus were the same as in 1851. The selection of 
plants was as follows:—One pot of Autumn Colzas, starting with young plants; one of 
Spring Wheat, from seed; one of Sun-flower, from seed; and two of Summer Colzas, 
from plants. 
In every case the dry matter of the produce was many times that of the young plants 
or seed. In the case of the Sun-flower, it was more than 100 times that of the seed. 
In each experiment, there was of Nitrogen, also, much more at the conclusion, than at 
the commencement. In the experiment with Autumn Colzas there were 4:7 times, 
in that with Spring Wheat 2-2 times, in that with Sun-flower 25'5 times, in one with 
Summer Colza 3:4 times, and in the other with Summer Colza 6-7 times as much 
Nitrogen in the total products as in the original plants or seeds. The total amount of 
Nitrogen gained in the five experiments, was 1-624 gramme, which was 5:3 times as 
much as was contained in the total original plants and seeds. ~ 
To show the degree of luxuriance of growth of the different descriptions of plant, it. 
may be mentioned that the Winter Colzas flowered, but gave no seed; the Sun-flower 
gave 412 rudimentary grains; and the Wheat seeded completely, giving 47 grains. The 
Summer Colzas had little tendency to go to seed, but developed a great deal of leaf; and 
hence it was, it was supposed, that they gained large actual amounts of Nitrogen. 
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