80. Crude Kieserit, (Crude Sulphate of Magnesia), of Bowker 

 Fertilizer Co., Boston, Mass. 



Moisture at 100° C, 31.90 



Calcium Oxide, 2. GO 



Magnesium Oxide, 13.50 



Sulphuric acid, 29.10 



Insoluble matter, 5.00 



Magnesium in form of chloride, 0.60 

 Magnesium in form of sulphate, 38.70 



Valuation for 2000 lbs. from $8.00 to $10.00 



The "Kieserit" occurs among the salines of the saltmines at 

 Stassfurt in Germany, which of late have acquired a particular im- 

 portance as leading resources of potash compounds for agricultural 

 purposes. Although it forms distinct layers of considerable thick- 

 ness, it is quite frequently found more or less saturated with a solu- 

 tion of magnesium chloride, when removed from the mines. Well 

 established experimental observations regarding the injurious influ- 

 ence of the latter compound on the healthy growth of roots, renders 

 its presence objectionable, and consequently its removal as far as 

 practicable, desirable whenever Kieserit shall be used for agricultural 

 purposes. The removal of any objectionable percentage of magnesi- 

 um chloride is usually accomplished by subjecting the crude material 

 to a moderate calcination ; the moisture present decomposes at a 

 high temperature largely the magnesium chloride into hydrochloric 

 acid, which escapes, and into magnesium oxide, which remains be- 

 hind. We find for this reason the calcined and the uncalcined 

 Kieserit in our markets. The former contains for obvious reasons a 

 larger per cent, of magnesia, than the latter ; yet is usually less sol- 

 uble in water. Both kinds ought to be well ground to render a pro- 

 per distribution possible. The Kieserit, on account of a greater 

 solubility in water, exceeds in efHciency the sulphate of lime or 

 gypsum as an absorber of ammonia in manure cellars, in stables and 

 upon the compost heap. Its well known beneficial influence on a 

 speedy diifusion of potash compounds throughout a deeper layer of 

 soil, as well as its reputed favorable action on leaf and stem growth 

 are of suflflcient importance to encourage experiments on the part of 

 farmers engaged in the raising of industrial crops and in particular 

 of gardeners and of fruit growers, to test its influence. The promi- 

 nence of the magnesia — among the mineral constituents of many of 

 our grain crops and fruits — leaves scarcely a doubt about its importance 

 in the vegetable economy of many of our cultivated plants. 



