6 TRANSACTIONS AND PROCEEDINGS OF THE [Sess. lxi. 



He grew plants of various kinds in an air-tight case in 

 soils that were composed of sand, to which he added the 

 ashes of plants to serve as manure, but which contained no 

 nitrogen in any form of combination. Tubes were inserted 

 in the case through which he could water the plants with 

 pure distilled water, and others through which air was led 

 in after passing through sulphuric acid, to deprive it of any 

 ammonia, and over bicarbonate of soda, to deprive it of any 

 nitric acid. Thus no nitrocren was allowed to reach the 

 plants but that of the free nitrogen of the air. 



He weighed the seeds at the beginning, and the whole 

 plants at the end of each experiment, and you will see 

 from the table that the whole plant was usually only two 

 or three times the weight of the seed itself. He estimated 

 the nitrogen in the seeds from an analysis made of a number 

 of others of the same kind, and, at the end, he determined 

 the total amount of nitrogen in the plant and in the small 

 quantity of soil it grew in. You will see that there was 

 usually a loss of nitrogen, and in one or two cases a trifling 

 gain. 



He varied his experiments, afterwards, by giving the 

 plant a small ascertained amount of nitrogenous manure, 

 but the results were similar, and he felt entitled to conclude 

 from all his experiments that plants could not assimilate 

 the free nitrogen of the air. Coming from such a weighty 

 authority, this view obtained general acceptance. 



About the same time (1850) M. Georges Yille, Director 

 of tlie Ag. Exper. Station at Joinville, Paris, was engaged 

 in a series of experiments with a similar object in view. 

 He had no confidence in lioussingault's experiments on 

 account of the unnatural conditions under which he 

 attempted to grow his plants, and he despised a crop which 

 weighed only two or three times the weight of the seed. 

 He also grew his plants within an air-tight case, and had 

 complete control of the water and air supplied to them, but 

 he gave them some nitrogenous manure, and plenty of soil 

 and air. I'he result was that his plants grew to normal 

 size, 50 or 100 times the weight of tlie seed they sprang 

 from, and lie found that they had assimilated free nitrogen, 

 sometimes in a very marked degree. He grew cereals, 

 leguminous plants, and cruciferous plants, and found that 



