CYANAMID MANUFACTURE, CHE:MISTRY AND USES 5 1 



with 50 cc. of 4.2 per cent, cyanamide solution. The tubes 

 were kept in a thermostat at 25° for different lengths of time. 

 Just before the analysis 200 cc. of water was added, stirred 

 for exactly one hour, filtered with suction, and cyanamide was 

 determined in the filtrate. The results were as follows: 



Cyanamide present Total nitrogen in solution 



nig. Per cent. mg. Per cent. 



Beginning 210.0 100 140 100 



After I hour 161. 7 77 112 80 



" 6 hours 153.3 73 1^5 75 



" I day 132.3 63 102 73 



" 3 days 107.6 51 87 62 



" 5 



7 



9 



15 



22 



96.6 46 89 64 



75.6 36 89 64 



59-3 28 83 59 



8.4 4 64 46 



0.0 o 77 55 



On the 22nd day the solution was distilled with magnesia, 

 giving up 66 per cent, of its nitrogen as ammonia. Hence, of 

 the 55 per cent, remaining in the solution on the 22nd day 22 

 per cent, was ammoniacal and 33 per cent, ureic nitrogen. A 

 test with nitric acid gave characteristic crystals of urea nitrate. 

 The experiment was repeated, sterilizing both the carbon 

 and the cyanamide solution. After 2 months the following 

 results were obtained : 



Mg. 



Initial nitrogen 560 



After 2 months, ammoniacal nitrogen 8 



Cyanamide '* o 



Dicyandiamide " o 



A test for urea showed the presence of abundant quantities. 



These experiments with carbon show that the decomposition 

 of cyanamide is an hydrolysis which is greatly accelerated by 

 the addition of catalysers of various kinds. 



EXPERIMENTS WITH NATURAL COLLOIDS. 



The experiments of H. Kappen^ confirm in general the 

 results obtained by Ulpiani. The following experiment of 

 ^ Zentr. f. Kunstdiinger-Industrie, XVII, 234-236, 248-251, 1912. 



