^J^y CYANAMID — MANU]?ACTURE, CHE:MISTRY AND USES 



in the following table by G. Liberi,^ showing the content of 

 cyanamide and dicyandiamide nitrogen in solutions of lime- 

 nitrogen made by extracting with cold water and filtering and 

 maintaining at 27° C. The figures are given as percentages 

 of the original lime-nitrogen. 



The maximum amount of dicyandiamide occurs in each case 

 at the end of 6 days' standing. The decomposition of the 

 dicyandiamide is very slow, as is seen in the concentrated 

 solution after the 31st day, when all the Cyanamid has been 

 removed, and no more dicyandiamide can form. Its rate of 

 formation is somewhat faster, and is undoubtedly determined 

 by the concentration of both nitrogen and calcium. The per- 

 centage of the total nitrogen transformed to dicyandiamide 

 is about five times as great in the concentrated as in the dilute 

 solution. With the removal of the cyanamide it was observed 

 that crystals of pure calcium hydroxide settled out on the 

 walls of the vessel. 



The rapid disappearance of the cyanamide shows that the 

 formation of other derivatives of cyanamide in this solution is 

 much more rapid than the formation and decomposition of 

 dicyandiamide, and it is therefore evident that most of the 

 cyanamide decomposes directly to these other derivatives, and 

 not through the dicyandiamide form. The largest part of 

 ^ Annali Staz Chim. Agrar. Sper di Roma Series II, V, 1911. 



