MAMUREB. ;jor> 



POTASH MANURES. 



The soil of Egypt being particularly rich in potash, the 

 application of this plant food to land is seldom considered 

 necessary, and accordingly potash manures are only of 

 secondary interest to the Egyptian agriculturist. 



At the present day the world's supply of potash 

 manures comes from the great salt deposits of central 

 Europe, the principal mines being those of the Stassfurt 

 deposit near the Hartz mountains in Germany. These 

 deposits, made up of layers of different compositions, are 

 in many cases of great thickness and appear to have 

 resulted from the drying-up of inland seas. Anhydrite 

 and gypsum (forms of CaS0 4 ) and rock salt (NaCl) 

 compose by far the greater part of the mass and it was 

 for this last that the Stassfurt mines were originally 

 worked. The great commercial value of the deposits now 

 rests on the presence in them of certain comparatively 

 thin layers of salts of potassium and magnesium, the 

 principal one consisting of carnallit, a double chloride of 

 these two metals. It is from these layers that practically 

 all potassium compounds are now derived, whether for use 

 in agriculture or in the arts. 



The chief potash manures are : 



(a) Kainit. 



(&) Calcined double sulphate. 



(c) Muriate of potash. 



