45(5 All;, .i.i;. l,\\\T.s DB. GILBBET, \M> DB. PUGffi QH 



and ignited Band, Band and brick, or sand and charcoal, with the addition of the aaa M 

 the plant to be grown. Be planted Beeda ox plants, the oompoaition of which a 

 mated by the analysis of parallel specimens. Several pota were for the naoet part 

 enclosed in an iron-framed glazed case of L50 litres (or more) capacity, through which a 

 current of air equal in amount to several times the volume of the vessel was aepired 

 daily. Carbonic acid and distilled water were supplied as needed. In some caaea the 

 air admitted into the apparatus was only previously freed from dust; and then the 

 amount of atmospheric ammonia that would be brought in was calculated according to 

 the determination of the proportion of ammonia in the air, above alluded to. In other 

 cases the aspired air was previously freed from ammonia by washing. In some experi- 

 ments, ammoniacal gas was passed, in known quantities, into the air of the apparatus. 

 Lastly, others were made, in which combined Nitrogen was added to the soil in the form 

 of nitrate, or of ammonia salts; and in these cases the plants were allowed to grow in 

 free air, only shaded from rain and dust. 



3. M. G. Ville's experiments in 1849 and 1850, in ivhich the plants were supplied 



with a current of unleashed air. 



In 1849, sand was used as soil; three pots of plants were grown for two months; 

 namely, one of Cress, one of large Lupins, and one of small Lupins. The air admitted 

 into the apparatus was not previously deprived of its natural ammonia. The dry sub- 

 stance of the produced Cress plants amounted to more than sixteen times that of the 

 seed sown. The Nitrogen in the Cress seeds amounted to O02G gramme; that in the 

 products to 0-147 gramme. The Nitrogen in the products was, therefore, between five 

 and six times as much as that in the seed ; and the actual gain of it amounted to 0T21 

 gramme. In the case of the large Lupins, the dry matter of the produce was about 

 3^ times as great as that of the seeds sown ; but there was neither gain nor loss of 

 Nitrogen. The small Lupins gave 2J times as much dry substance in the produce as 

 was supplied in the seeds ; and of the Nitrogen of the seeds sown, there was an apparent 

 loss of rather more than one-fourth, during the experiment. 



- The total gain of combined Nitrogen in the apparatus, taking the three experiments 

 ■ together, was 0T03 gramme. The Nitrogen in the ammonia of the current of unwashed 



air, was, however, estimated at only 0-001 gramme. M. G. Ville concluded, therefore, 

 .that the Cress had appropriated a considerable quantity of the free or uncombined 

 -Nitrogen of the atmosphere. 



- - The plants experimented upon in 1850, were Colza, Wheat, Eye, and Maize. In the 

 case of the Colza, the experiment commenced with young plants, but in the other cases 

 with seed. The four pots were placed in an apparatus similar to that used before, and 

 the conditions supplied were also the same as in 1849. 



The dry matter of the produced Colza plants amounted to between forty and fifty 

 times as much as that of the young plants when taken for experiment. The Nitrogen 

 was also increased more than forty-fold. The dry matter of the "Wheat plants was about 



