46 CYANAMID — MANUFACTURE, CHEMISTRY AND USES 



concentrations of cyanamide were used, and large quantities of 

 ammonia were formed, it is very likely that bacteria partici- 

 pated in the decomposition by reacting upon the urea and 

 determining its hydrolysis to ammonium salts. 



EFFECT OF CHANGING RATIO OF LiaUID TO SOIL. 



When loo grams of air-dried earth was covered with 20 cc. 

 of cyanamide solution practically all of the soil was wetted, 

 only a little at the bottom of the tube remaining dry. In this 

 condition the mass of water may be considered as being at its 

 maximum distension, each solid particle of the soil being sur- 

 rounded by a thin film of liquid. This liquid film on the in- 

 side, is in contact with a solid phase, and on the outer surface 

 with a gaseous phase, since the interstices of the soil were not 

 filled with liquid. 



When 100 grams of soil was covered with 50 cc. of 

 cyanamide solution the interstitial spaces were filled with 

 liquid. There was therefore practically no gaseous phase 

 present. 



One hundred grams of soil covered with 100 cc. of 

 cyanamide solution was completely submerged. Series III in 

 the table was thoroughly shaken twice a day during the test. 

 Series IV was not disturbed in any way. The results obtained 

 were as follows : 



Here again we must exclude bacterial participation, since if 

 bacteria were present they should grow better in the dilute 

 solutions than in the solution of 4.2 per cent, cyanamide in 



