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Experiments with Calcium Cyanamide. [fee., 



EXPERIMENTS WITH CALCIUM CYANAMIDE. 

 A. D. Hall, M A. 



The nature of calcium cyanamide, the new nitrogenous 

 fertiliser manufactured by combining the free nitrogen of the 

 atmosphere with calcium carbide, is now well known (see 

 Journal, 1906, Vol. 13, pp. 38, 216, 410) ; and numerous held 

 experiments, both in this country and abroad, have established 

 the fact that as a manure it is practically as effective, nitrogen 

 for nitrogen, as sulphate of ammonia. Certain practical 

 difficulties in its use have, however, been pointed out ; . it 

 is sold in so fine a powder that it is difficult to handle and 

 disagreeable to sow. It was regarded as so liable to change 

 in a damp atmosphere as to be dangerous to store, and when 

 first introduced it was recommended that it should never 

 be mixed with other manures but sown separately a week or 

 ten days before the seed. In view of the fact that the manu- 

 facture is now being undertaken on a large scale and that certain 

 improvements have been effected in the process, it seemed 

 necessary to re-examine the manure from these points of view ; 

 its efficiency as a fertiliser being no longer in doubt. 



The questions that seemed to require investigation were 

 as follows : — 



(1) How far is the material hygroscopic, so that it cannot 

 well be stored under ordinary conditions in bags in a manure 

 store or shed ? 



We are not concerned with its storage on a large scale by 

 the manufacturer or the merchant, but with the way it would 

 affect a farmer who might have a stock on hand for a month or 

 two before using but who had no special means of keeping it in 

 a dry atmosphere. Assuming further that some moisture will 

 be absorbed, is any loss of fertilising material brought about 

 thereby ? 



(2) Since calcium cyanamide is made from calcium carbide, 

 which by the action of water gives off inflammable acetylene, 

 is there any danger of the generation of this or other dangerous 

 gases from unchanged carbide remaining in the manure, when 

 it is stored and exposed to damp air ? 



(3) Can the cyanamide be safely mixed with other manures, 

 particularly superphosphate, or is there a generation of heat 

 or gases to a dangerous or inconvenient extent ? At the 



