CYANAMID — MANUFACTURE, CHE:MISTRY AND USES 43 



That bacteria could take no part in the present experiment 

 is evident, since micro-organisms cannot live in the very con- 

 centrated solutions employed. 



INFLUENCE OF TEMPERATURE. 



Experiments carried out in a similar manner with lOO grams 

 of soil and 20 cc. of solution containing 4.2 per cent, cyanamide 

 at various temperatures gave the following results: 



At 0° At 12° At 30° 



The velocity of the reaction increases with the temperature, 

 but even at 0°, where micro-organic life is practically at a 

 standstill, there is a conversion of about 3.5 mg. of cyanamide 

 per 120 grams of damp soil per day. 



INFLUENCE OF SOIL AT 100° C. 



Two flasks, one containing icx) cc. of a solution with 21 per 

 cent, cyanamide, the other icxD cc. of 21 per cent, cyanamide 

 solution and 500 grams of soil, were heated in a Koch's oven 

 at 100° C. for six hours. After cooling, 400 cc. of water was 

 added to each, and after agitation and filtering, analyses were 

 made. In the flask without soil there was still a large quantity 

 of cyanamide present and considerable dicyandiamide. In the 

 flask with soil, however, there was no cyanamide or dicyandia- 

 mide remaining after the treatment, but abundant quantities of 

 urea. Under these conditions it is probable that the conver- 

 sion to urea is quantitative. The reaction must be one of 

 hydrolysis in accordance with the equation. 



CN. NH, -f H,0 -* 0C< 



