Nitrate of Lime 



Nitrate of Lime. 



Nitrate of lime, like lime nitrogen, is a valuable 

 manufactured manure in which the nitrogen is also 

 taken from the air. The manufacture of nitrate 

 of lime is based on the principle that the oxygen 

 and the nitrogen in the air combine under the 

 mfluence of an electric flame. This fact explains 

 why thundery years are generally fertile. The 

 lightning, which is only an electric flame, produces 

 in the air — which is charged with mists — nitrous and 

 nitric acids which the rain washes dowTi into the 

 earth to form nitrates. Here is the process : — 

 N + O = NO, oxide of nitrogen ; NO + O = NO2, 

 bioxide of nitrogen ; 2NO2 + HgO = HNO3 +HNO2. 

 nitric and nitreous acid. Birkeland and Eyde, two 

 Norwegian savants, discovered these facts, and a 

 factory at Nottoden in Norway produces considerable 

 quantities. Nitric acid is produced by means of an 

 electric spark from the air and dissolved in water, 

 carbonate of lime being added to the solution. This 

 is heated to saturation point and solidifies in 

 cooling. 



One essential condition of the manufacture is the 

 command of a cheap electric current. The nitrate 

 of lime thus obtained is in small, hard crystals, or 

 reduced to powder containing about 13 per cent, of 

 nitrogen which is soluble in water and very delique- 

 scent. It must therefore be kept in a very dry 

 place. It is packed in wooden casks lined with 

 paper which serves to keep out atmospheric 

 moisture. 



It contains about 12 to 13 per cent, of nitrogen. 



43 



