114 j THE ROYAL SOCIETY OF CANADA 
These investigations have been a special feature of the work of the 
Chemical Division and have produced results of the greatest importance 
and value to Canadian agriculture. 
Results of Early Investigations. 
In 1900 the authors presented a paper to the Society dealing with 
the experiments that had been conducted in Ottawa with “ Nitragin,”’ 
a bacterial culture prepared in Germany from the nodules of various 
members of the leguminosæ and which, it was held, would be of practical 
value in encouraging the growth of clover, peas, beans and other 
members of this family. This work has been undertaken realizing the 
great value of the legumes as economic suppliers of nitrogen for soil 
enrichment and in recognition of the fact, discovered a few years 
previously by Hellriegel and Wilfarth, that the legumes were able 
through the agency of certain bacteria residing in nodules or tubercles 
on these roots to draw upon the free atmospheric nitrogen for the 
greater part of that element which was required in the building up of 
their tissues. 
These experiments conducted with special cultures for clover and 
peas and beans and extending over several seasons, furnished on the 
whole satisfactory evidence as to the value of the inoculating material. 
In a large number of instances increased yields were obtained from 
treated crops, showing that the preparation contained vital nitrogen- 
fixing bacteria and that through their association the growth of the host 
plant had been promoted. In certain cases analysis of the product 
demonstrated that with the increase in yield there had been an increase 
in the nitrogen-content of the dry matter. 
A second paper was presented in 1905, in which we discussed 
certain experiments undertaken to obtain definite information upon 
the nitrogen-content of the soil, as affected by cropping and cultural 
operations and other investigations to determine the practical value of 
various leguminous crops for the enrichment of soils in organic nitrogen. 
From the examination of a soil which had never received manure 
and which had been under cultivation for 22 years, during which period 
it had grown 6 crops of wheat, 4 of barley and 3 of oats with 9 summer 
fallows during the latter seventeen seasons, it was found that the 
nitrogen loss, to a depth of 8 inches, amounted to 2,206 lbs. per acre. 
Of this amount we estimated 694 lbs. had been removed in crops and 
1,512 lbs., or 68% of the total nitrogen lost, had been dissipated through 
cultural operations. 
This heavy depletion’ in the soil’s most valuable constituent 
would, if continued, inevitably lead to unproductiveness, no 
