THE SOUECES OF THE NrTKOGEN OF YEGETATIOX, 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 then 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 A.\ times. 



The actual gain of Nitrogen in the total products of the four experiments, was 1T803 

 gramme. The whole admitted in the form of atmospheric ammonia was estimated at 

 0-0017 gramme, or less than 2 milligrammes. M. Ville 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 

 in the former. 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 ammonia. 



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 Sim-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 grams ; 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. 



3 k2 



