5OO AGRICULTURAL, ANALYSIS 



position of sylvinit as it comes from the mines is given in the 

 following table: 



Per cent. 



Potassium chlorid 30.55 



Sodium chlorid 46.05 



Potassium sulfate 6.95 



Magnesium sulfate 4.80 



Magnesium chlorid 2.54 



Calcium sulfate i .80 



Water and insoluble 7.29 



This salt is richer in chlorin than any other of the Stassfurt 

 potash minerals, containing altogether 79.14 per cent, of chlo- 

 rids. Its potash content amounts to 23.04 per cent., but in pro- 

 portion to the potash which it contains, it is relatively poorer in 

 chlorin than kainit and carnallit. On account of its high con- 

 tent of potash the cost of a unit thereof as contained in sylvinit 

 is less than in kainit and carnallit. 



428. Kieserit. The mineral kieserit is essentially magnesium 

 sulfate and it does not necessarily contain any potash salts. 

 Under the name of kieserit, however, or bergkieserit, there is 

 mined a mixture of carnallit and kieserit, which is a commercial 

 source of potash. The mixture contains the following average 

 content of the bodies named : 



Per cent. 



Potassium chlorid 11.80 



Magnesium sulfate 2 1 . 50 



Magnesium chlorid 17.20 



Sodium chlorid 26. 70 



Calcium sulfate 0.80 



Water 20.70 



Insoluble 1.30 



This mixture contains only about seven per cent, of potash 

 and would not prove profitable when used at a distance from 

 the mines on account of the cost of freight. It has proved val- 

 uable, however, for a top dressing for meadow lands in the 

 vicinity of Stassfurt. 



429. Schonit. Among the Stassfurt deposits there occurs in 

 small quantities a mineral, schonit, which is composed of the sul- 

 fates of potassium and magnesium. The quantity of the mineral 



