MAXURES 33 



then mixed with lime and sand, and gently dried at a low heat. 

 The product usually contains 3 % to 4% nitrogen and 8 % to 9 % 

 potash." 



Calcium Cyanamide, or Nitrolim. A new nitrogenous fertiliser 

 in the form of fine friable powder, which is prepared from 

 the atmosphere by the aid of a powerful electric furnace, said to 

 be now becoming a rcognised substitute in Europe for nitrate of 

 soda and sulphate of ammonia. The process of manufacture is 

 stated to be " by heating lime and coke to a temperature of 2,500 

 degrees centigrade in electric furnaces of the resistance type. 

 Calcium carbide is thus produced ; the carbide is then heated in 

 retorts, and at 1,100C., atmospheric nitrogen is introduced and 

 absorbed, the new compound being known as calcium cyanamide 

 or nitrolim. This is usually guaranteed to contain 20 % nitrogen. 

 It is said that nitrolim has sometimes an injurious effect on young 

 plants and that, in order to obtain the best results, it should be 

 mixed with nitrate of lime, in the proportion of 2 parts of the 

 former to 1 part of the latter. 



Salt (Chloride of sodium). Common Salt, which contains soda, 

 chlorine, and other substances, has been used for manurial 

 purposes from very early times, and in some countries is still so 

 employed to some extent. Especially for such plants or crops as 

 are indigenous to the sea-side, as Coconuts, Asparagus, Beetroot, 

 etc., salt is considered by some to be very beneficial as a manure. 

 Yet it is a disputed point whether it has any manurial value, direct 

 or indirect, it being often asserted that it has none. The presence 

 of sodium and chlorine in the ash of most plants is considered by 

 some to be due to accident rather than necessity, the quantities 

 present being very variable. Further, it is stated that even were 

 salt a necessary plant-food, its presence in all soils is already 

 sufficiently abundant to obviate any necessity for its application. 

 It is, however, as an indirect fertiliser that the beneficial effect, if 

 any, of salt chieHy lies. DR. AIKMAX, in his book on "Manures and 

 Manuring" remarks that "the action of salt in decomposing the 

 minerals containing lime, magnesia, potash, etc., is similar to the 

 action of lime ; it acts upon the double silicates and liberates these 

 necessary plant-foods, also on the phosphoric and silicic acids, 

 which it sets free." As a preventive of rankness of growth, how- 

 ever, the effect of salt is generally admitted. On the other hand it 

 is thought that, having a great affinity for water, the application of 

 salt is of benefit to crops by absorbing moisture from the sub-soil as 



