2l6 



it had gained 17 per cent in weight, after which it began to lose 

 weight by liquid running away from it. The nitrate of soda after 

 five weeks had not gained appreciably in weight but had become 

 lumpy. After which it lost very little in weight, but did not be- 

 come distinctly damp. 



When a similar bag of nitrate of lime was covered with a few 

 sacks to protect it from the air, it gained weight much more slowly. 

 Even after 10 weeks, though beginning to get lumpy it was still 

 sowable. 



A portion was mixed with dry peat dust in the proportion of 

 5 of nitrate of lime to i of peat, but the gain in weight was more 

 rapid still. After seven weeks this mixture was quite wet, and liquid 

 began to escape from the bag. 



When i part of nitrate of lime was mixed with i part of po- 

 tash manure salt, i */ 2 of bone flour and i r / 2 of superphosphate the 

 mixture soon became damp. After 9 weeks it was wet and sticky, 

 and unfit for use. 



These experiments show that if nitrate of lime has to be kept 

 for any length of time it will require special packages, and that 

 it will be difficult to use it in mixtures unless used very soon after 

 they are made. 



Cyanamide of calcium is formed when nitrogen passes over cal- 

 cium carbide heated in furnaces to about 1000 C. 



Various modifications of the process of Frank and Caro for the 

 manufacture of cyanamide have been devised, among which one, 

 invented by Dr. Polzeniusz, has been employed on a large scale. 



According to this process a small quantity of chloride of lime 

 is added to the carbide of lime, and the resulting cyanamide con- 

 tains some chloride of lime. This addition is said to enable the 

 combination of nitrogen to take place more easily and at a lower 

 temperature. 



The first factory that started production of calcium cyanamide 

 on a large scale is situated at Piano d'Orta in the Xbruzzi, Italy. 

 It can produce 10 ooo tons a year. 



Large plants have been erected at other places in Italy. Im- 

 portant factories have been or are being erected in Dalmatia, in 

 France, in Switzerland, in Germany, in Norway, in Japan and in 

 Canada at the Niagara Falls. When completed they will be able 

 to turn out about 200000 tons of cyanamide per annum, by the 

 Frank & Caro process. 



In Germany the Westeregeln works produce cyanamide by the 

 Polzeniusz process. 



