36 CYANAMID — MANUFACTURE), CHEMISTRY AND USES 



Ulpiani explains their action as follows: The fungi may 

 decompose the glucose, when it is present, with the produc- 

 tion of various aldehydic substances, which, according to well- 

 known chemical reactions unite with the cyanamide with for- 

 mation of compounds of the type R.CH : N.CN. It is also 

 possible that the fungi produce various products of metabolism 

 which are able to react with cyanamide and so neutralize it, 

 probably in the manner of the formation of antitoxins. He 

 cites in support of this theory the well-known ability of 

 penicillum brevicaule to grow in the presence of arsenical 

 substances.^ 



The above experiments are in agreement with many others 

 by Kappen, as well as with the experiments of Ashby,^ 

 Behrens,^ Stutzer and Reis* and others, which show that bac- 

 teria are active in some stage of the process. 



From these experiments of Ulpiani, Kappen and others, the 

 following facts are evident: i. A solution of pure cyanamide 

 in the absence of other substances is quite stable, and is not 

 decomposed by ordinary soil bacteria. 2. A solution of pure 

 cyanamide may be decomposed by certain special fungi. 

 3. A solution of cyanamide in sterile conditions is decomposed 

 by lime, by ammonia, and by soil. 4. A solution of cyanamide 

 is decomposed by soil more rapidly in non-sterile conditions 

 than in sterile conditions, provided the concentration is not 

 too great. 



The course of the decomposition of cyanamide solutions 

 by lime is very complex (see also p. 28) and leads to the 

 formation of a mixture of urea, dicyandiamide, amidodicyanic 

 acid, ammeline, melammine and other complex derivatives. On 

 the other hand, the decomposition of cyanamide by soil is a 

 simple hydrolysis in accordance with the equation : 



- ^ B. Gosio, Studio suUa Bioreazione dell 'arsenico tellurio e selenio. 

 Roma, Tip, Mantellate, 1907. 

 2 Zent. Bakt. XX, 704, (1908) ; XX, 281, (1908). 

 'Jahrs. f. Agrik. 121, (1905). 

 * Jour. f. Landw. Vol. 58, 65, (1910). 



