lis MB. .1. B. l. \ \Vi:s. itj;. GULBBEIj \\U DH. JT'.ii 



A. — M. D"! 3BHT6 Ml. 'I '- I.M'I.RIMK.VT.-. 



1. M. Boussingault's experiments in 1837 and 1838,. in which the floats were adorned 

 free access of air, but were protected.from rain and dust, 



In 1837* Borssixo.u'i/r grew; in burnt soil, watered with di-tilh <1 water, and with 

 the access of free air, a pot of Tri folium for two months, and another for three month- ; 

 also a pot of Wheat for two months, and another for three montl, 



The total Nitrogen in the seeds sown in the two experiments with Trifolium. amounted 

 to 0'22"4 gramme. The Nitrogen in the produce, soil, pot, &c, amounted to 0'276 

 gramme. There was a gain, therefore, of 0*052 gramme of Nitrogen = nearly 20 per 

 cent, of the total Nitrogen of the products. The development of vegetable matter, 

 implying, of course, the assimilation of carbon, hydrogen, and oxygen, was, however, 

 in a much greater proportion ; the dry matter of the produce in the two experiments 

 amounting to nearly three times that of the seed sown. 



In the two experiments with Wheat, the total Nitrogen in the seed was estimated at 

 < l-l (HI gramme. The Nitrogen in the products was exactly the same amount. In the 

 case of the Wheat, there was, therefore, no gain of Nitrogen indicated. Nevertheless 

 the dry matter of the produce amounted to nearly double that of the seed. 



In 1838f, Boussixgault, in a similar manner, sowed Peas containing 0-04G gramme 

 Nitrogen. The plants obtained; yielded flowers and ripe seed, and their dry matter 

 was more than four times as much as that of the seed sown. The Nitrogen of the total 

 products amounted to 0T01 gramme. Here again, therefore, the Leguminous plants 

 seemed to gain Nitrogen from some undetermined source. 



Boussixgault made experiments in the same year (183S). with Trifolium, and with 

 Oats. In these cases, he commenced with carefully selected plants instead of with seeds. 

 The Trifolium nearly trebled its total vegetable matter during growth ; and it gained 

 0-023 gramme of Nitrogen out of - 05G gramme in the total products. The Oat, on the 

 other hand, indicated only 0-053 gramme Nitrogen in the total products, whilst it was 

 estimated that there was 0-059 gramme contained in the plants taken for the experi- 

 ment. The total vegetable matter was, however, doubled. 



The substance of M. Boussixgault's conclusions from the above experimental results, 

 may be stated as follows: — That under several conditions, certain plants seem adapted 

 to take up the Nitrogen in the atmosphere ; but that it was still a question, under what 

 circumstances, and in what state, the Nitrogen was fixed in the plants. He submitted 

 — that the Nitrogen might enter directly into the organism of the plant, provided its 

 green parts were adapted to fix it; that it might be conveyed into the plant in the 

 aerated water taken up by its roots ; that, as some physicists suppose, there may exist 

 in the atmosphere an infinitely small amount of ammoniacal vapour. He further 

 suggested that the gain of Nitrogen beyond that supplied in manure, which he had 

 observed in agricultural production on the large scale, and which he thought evidently 

 * Ann. de Chim. et de Phjs. scr. 2. tome kvii. 1S38. t Ibid, tome Lrix. 



