30 CYANAMID — MANUFACTURE, CHEMISTRY AND USES 



A sample of lime-nitrogen was exposed on a watch-glass 

 in a bell- jar, the atmosphere of which was kept saturated with 

 moisture by a beaker of water alongside the watch-glass. The 

 lo gram sample after 8 months exposure weighed 18.75 grams. 

 The analyses before and after exposure are as follows, the 

 third column showing the results corrected to allow for in- 

 crease in weight. 



After 

 Before After exposure 

 exposure exposure corrected 



Total nitrogen 17.08 8.99 16.84 



Insoluble nitrogen 1.30 0.38 0.71 



Soluble nitrogen in form of Cyanamid 15-05 0.14 0.26 



Soluble nitrogen in form of Dicyandiamid 0.25 6.87 12.87 



Soluble nitrogen in "other forms " 0.48 1.60 3.00 



The loss of nitrogen, in the form of free ammonia, has 

 apparently been 0.24 per cent. The soluble nitrogen in "other 

 forms" consists principally of urea, with a small amount of 

 amidodicyanic acid and ammeline. 



The above test is unusually severe, and has little bearing 

 upon the question of the storing qualities of Cyanamid. Under 

 similar circumstances it takes less than a week for sodium 

 nitrate, ammonium sulphate and calcium nitrate to entirely 

 dissolve in the moisture they absorb, while basic calcium 

 nitrate becomes pasty and sticky in the same time. The 

 Cyanamid, on the other hand, is still in good mechanical con- 

 dition at the end of eight months. 



A similar test but less severe, and therefore more nearly 

 approaching conditions that may occur in storage on a factory 

 scale, is the following experiment by G. Henschel.^ 



10 to II grams of commercial Cyanamid was placed in a 

 thin layer on a watch-glass of about 8 cm. diameter, and set 

 in a desiccator jar, in which was a beaker with concentrated 

 sulphuric acid and another with distilled water. This provided 

 a constant circulation of moist air. In addition, for an hour 



' Das Verhalten des technischen Calciunicyauamides bei der 

 Aufbewahrung sowie unter dem Einfluss von Kulturboden und 

 Kolloiden. Inaugural-Dissertation-Univ. of Leipzig, 1912. 



