LATER EXPERIMENTS WITH CYANAMID 309 



marized the latest results of the experimental value of nitrate 

 and cyanamid of calcium produced by the electric process des- 

 cribed later. 76 The compound used by him was produced by a 

 factory in Norway, the term "Norwegian Nitrate" being used to 

 distinguish it from the nitrate of Chile. The calcium cyanamid 

 when subjected to the moisture of the soil produces ammonia. 



The commercial product contains from 20 per cent, to 22 per 

 cent, of nitrogen, while the sulfate of ammonia contains about 25 

 per cent. Pure calcium cyanamid CN 2 Ca, contains 35 per cent, 

 of nitrogen. The commercial cyanamid is a black powder, ground 

 extremely fine, which owes its color to the carbon which it con- 

 tains, in all about 17 per cent. 



Practical experiments made by Cart, and reported to Grandeau, 

 show that while the nitrate of lime acted very successfully as a 

 fertilizer, the cyanamid of calcium was somewhat disappointing. 

 There was difficulty in spreading this brown and black powder 

 regularly, and in applying it to the soil the fine powder was ex- 

 tremely irritating to the face and hands. The effect upon the 

 wheat after 24 hours was described as being similar to that pro- 

 duced by a solution of sulfate of copper, while the wheat treated 

 with the nitrate took on a beautiful green tint and grew rapidly, 

 and that which had received the cyanamid turned to a reddish 

 tint, which was retained for at least a week. 



The total amount of wheat harvested from the plot receiving 

 the cyanamid was less than that receiving no nitrogenous fertili- 

 zer at all. 



Muntz and Nottin conclude that the calcium cyanamid does 

 not interfere with germination when employed in ordinary quan- 

 tities, not exceeding 200 kilograms per hectare, and gives good 

 results. 



It is possible that the deleterious effects of the calcium cyan- 

 amid may be due to the fact which has been noticed by investi- 

 gators that in the manufacture of cyanamid it may be associated 

 with another compound, viz., dicyanamid, the poisonous proper- 

 ties of which for plants are well known. Perhaps the poisonous 

 action noticed above by Cart may have been due to such an ad- 

 mixture. The matter needs further investigation. 

 76 Journal d' Agriculture pratique, 1908, 72 : 229. 



