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Potassium. 



Kainit . This salt is the crude product of the mine 

 and the potash contained in it is practically all in the 

 form of a sulphate. It contains about 12,5 per cent of 

 actual potash and 33 per cent of ordinary salt, and small- 

 er percentages of magnesium chloride and magnesium sulphate. 



Sy lvinit . It is similar in composition to Itoinit. 

 The potash in Sylvinit, however, exists both in the forin 

 of a sulphate and of a chlorid. It contains on an aver- 

 age about 16 per cent of actual potash. 



Muriate of Potash . This is a manufactured product 

 and contains about 50 per cent of actual potash, equiva- 

 lent to 80 per cent muriate. The chief impurities are 

 comnon salt and insoluable matter. 



Hiph-^rade Sulphate of Potash . The salt is usual- 

 ly sold on a purity basis of 98 per cent, or an equivalent 

 of 53 per cent actual potash. It is usually considered 

 superior to the muriate although more e^qpensive. 



Lime . 



There are three forms: limestone, quicklime and 

 slaked lime, each differing from the other in composition. 



Quicklime absorbs moisture and slakes when exposed 

 to the atmosphere. Lime thus slaked is called "air-slaked 

 lime", and is usually less completely chmiged to a hy- 

 drate than when water is addBd. 



Marble lime is made from pure limestone, and the burned 

 limestone thus obtained is practically pure oxide of lime. 



