NITROGEN : WHY AND WHERE CROPS MUST GET IT. 195 



gault himself allowed, that there was any assimilation of free 

 nitrogen. In his later series, the plants were supplied with air 

 previously deprived of all compounds of nitrogen ; and this time 

 neither leguminous nor cereal plants made any gain in nitrogen. 



Ville's experiments were carried on from 1851 to 1856. In 

 these, several plants were grown together in a large, iron-framed 

 glazed case. His results were various ; in the case of some 

 plants and some series of trials there was no gain of nitrogen ; in 

 others there was a gain, amounting to from four to five times as 

 much as was contained in the seed and any other accessible sup- 

 pi}'. In still other cases there was forty times as much combined 

 nitrogen in the crop as was supplied. The power of gaining 

 nitrogen was not confined to leguminous plants, although they 

 seemed to possess it in greater degree than the cereals — wheat, 

 rj'e, or Indian corn. These startling contradictions of the results 

 obtained by the well known Boussiugault excited so much interest 

 that a committee of the French Academy of Sciences, one of the 

 most renowned scientific associations in the world, was delegated 

 to watch over some new experiments made by Ville. After dis- 

 charging their duty as well as they could, for they could not be 

 expected to keep watch at all hours of the day and night during 

 a three months period of growth of the experimental plants, they 

 couid state no other conclusion than that this new experiment, 

 made by Ville under their supervision, was consistent with the 

 conclusions that he had drawn from his previous labors. 



Finally, in 1857, '58, and '59, seeing that it certainly could not 

 be considered as a settled question, Lawes, Gill)ert, and Pugh 

 took the subject in hand. I wish I could take the time to show 

 here how carefully they went to work to guard their experiments 

 from all possible sources of error ; for then your conviction might 

 be as firm as mine, that free nitrogen is no food for plants. Let 

 it suffice now to* say that Boussiugault, accepting their invitation 

 to visit them while the experiments were in progress, was so well 

 satisfied with the manner in which the work was conducted, as to 

 .declare that he would abide by their results, whatever they should 

 turn out to be. Ville was also invited over to inspect their 

 methods, but he never came. He was, however, prevailed upon 

 to send over the identical case in which his own experiments "were 

 conducted, and in which such remarkable gains of nitrogen 

 were made. 



