C. Crowther and a. G. Ruston 



215 



data given in the table were arrived at by incubating 5 gms. of soil 

 for three days at 28° C. with 80 c.c. of a nutrient solution containing 

 10 grins, of peptone per litre. In view of the small differences in ammonia 

 production thus obtained, further estimations were made with varying 

 amounts of peptone and different periods of incubation. The general 

 character of the results is illustrated by Fig. 2. It will be seen that 



260 



240 



220 



200 



g 180 



a 



-a 160 



3 140 



g 120 



100 



3 80 



60 



40 



20 



Plot 2 



I 100 cc of 1 % Peptone Solution 



II 100 cc •• 1-5% •■ 

 ID 150 cc " 1-5% '• 



30 40 50 60 



Hours of Incubatiou 



K2. 2. 



70 



JouiQ. of Agric. Sci. vn 



15 



