104 PROCEEDINGS OF THE COTTESWOLD CLUB 



were conducted by Boussingault, who admitted known 

 quantities of gaseous plant foods into closed receivers in 

 which healthy plants were growing, and analyzed the 

 residues. His conclusion was that plants used none of 

 the Nitrogen of the air. A similar conclusion was arrived 

 at in this country by the experiments of Lawes, Gilbert, 

 and Pugh, carried out at Rothamsted. Such remained 

 the opinion of Botanists up till a few years ago. We find 

 all authoritative text books accepting this view. I quote 

 from one or two : 



" It is certain from a great number of experiments on 

 " vegetation, especially those of Boussingault, that plants 

 " have no power of using the free Nitrogen of the atmos- 

 " phere for the production of their nitrogeneous compounds. 

 " . . . . although the Nitrogen of the atmosphere 

 " is at the command of the plant in such great quantities." 

 (Sach's Text Book of Botany, EngHsh Ed., 1882.) 



" It was once supposed that there was a power in the 

 " living plant to fix free Nitrogen from atmospheric air; 

 " but this is conclusively negatived." (Henfrey's Botany, 

 4th Edition, 1884.) 



The researches of Hellriegel and Wilfarth which have 

 now conclusively demonstrated the fact that plants can, 

 under certain conditions, draw upon the free Nitrogen of 

 the atmosphere, for some of their su[)plies of that element 

 have been considered worthy of detailed attention in our 

 Proceedings. They may be described without euphuism, 

 as truly epoch-making, and their inductive thoroughness 

 and exactitude merit historical treatment. 



The experimenters themselves attribute the inception of 

 their enquiry rather to accident than to design. It has 

 been so in the history of many great discoveries. 



As early as 1862, at the Research Station at Dahme, 

 Hellriegel and Wilfarth were making observations of great 

 agricultural interest, on the action of certain manures, and 

 on the actual quantities taken up by plants. The 



