Potassic Manures 



potash from the ashes absorbed the nitric acid which 

 was formed. 



In olden times nitrate of potash was chiefly 

 employed in the manufacture of gunpowder, and is 

 still used in some powders, and for fireworks, etc. 



Because of its industrial usefulness the price 

 has always been too high to permit of its being used 

 in agriculture, unless in the form of crude saltpetre, 

 containing from 5 to 20 per cent, impurities. 



Only tobacco and certain vegetables would 

 repay its application. Tobacco especially likes it 

 because of the quantity of potash and the absence 

 of chlorures. The relation between the potash and 

 the nitrogen is not favourable. It generally con- 

 tains 13 per cent, nitrogen and 44 per cent, potash. 



On account of its high price nitrate of potash is 

 subject to adulteration with many substances, such 

 as chlorure of potash, sulphate of potash, nitrate of 

 soda, and even chlorure of soda. 



Carbonate of Potash [KoCOg]. 



This is a white salt crystallised and caustic. 

 It is the potash of commerce and is used chiefly in the 

 manufacture of glass and of soft soap. This makes 

 its price generally too high for agricultural purposes. 



It is obtained from various sources, such as from 

 the decomposition of sulphates, when it contains 

 nearly 85 per cent, carbonate of potash, besides 

 3 per cent, chlorure of potash and 2 per cent, 

 sulphate ; and from Yolk, when it contains 75 per 

 cent, carbonate, 4 per cent, sulphate, and 7 per cent, 

 chlorure of potash. 



The salins of beetroot produce it, as we have 



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