NITRIFICATION 143 



nitrification is especially energetic, while for soils of 

 damper close texture, in which the activity of the 

 nitrifying organisms are retarded or checked, nitrate of 

 soda or calcium nitrate are more suitable nitrogenous 

 fertilizers. 



Ex. 71. Show the production of ammonia from proteins. 

 Prepare the following solution : 



IDi-potassium phosphate . . . 5 gr. 

 Magnesium sulphate . . . . 2.5 gr. 

 Sodium chloride , , . . . 2.5 gr. 

 Water . . ., . . . . . i litre. 

 Take three 200 c.c. flasks and pour into each 100 c.c. of the 

 solution. 



Add to one . i per cent, of gelatine. 

 another . i per cent, of fibrin. 

 a third . i per cent, of peptone, 

 and sterilize. 



Inoculate each with J3s. mycoides and incubate at 30 C. for 

 ten to fifteen days. 



(a) Test for ammonia with Nessler's solution. 



(b) Heat with calcined magnesia and test the gas given off 



with litmus paper. 

 Control tubes uninoculated should be tested also. 



Ex. 72. Add to a litre of the inorganic solution in previous 

 experiment. 



Glucose *.',/. . ' . . . 2 gr. 

 Sodium nitrate . . . . . 2 gr. 

 Sterilize; inoculate TOO c.c. of it with Bs. mycoides. Incubate 

 at 30 C., and every second day 



(1) Test for nitrites (Ex. 74). 



(2) ,, ammonia with Nessler's solution. 



(3) Find out when the nitrate disappears. 



Ex. 73, To a dilute solution of egg albumin add a dilute 





