This form of the " German Potash Salts " has thus far proved a 

 very reliable source of potassa for general agricultural purposes ; an 

 extensive application has caused of late some advance of its cost, 

 as compared with previous years. 



47. Potash Magnesia Sulijhate, of Bowker Fertilizer Co. Col- 



The above compound belongs to a series of salines which some 

 ten years ago, under the name of "German Potash Salts" or "Stass- 

 furt Salines," were introduced into our agricultural industry for 

 manurial purposes. Its peculiarity consists in the combination of a 

 large amount of potassium sulphate, from 46 to 47 per cent., with a 

 remarkable quantity of magnesium sulphate, from 33 to 34 per cent. 



The magnesium sulphate stands foremost among substances noted 

 for their quality to counteract the well known great retentive power 

 of most soils for potassa. This circumstance renders the Potash- 

 Magnesia sulphate a very valuable material for the cultivation of 

 deep rooting plants, in case of an exhaustion of potassa in the sub- 

 soil. 



The Potash-Magnesia Sulphate, as well as the " Douglass Muriate 

 of Potash," occupy a peculiar position among our recently intro- 

 duced potash resources for manurial purposes. The former has 

 proved the preferable compound where the presence of large quanti- 

 ties of chlorides is known to affect seriously the quality of the vege- 

 table growth, as in the case of tobacco, etc. ; whilst the latter rec- 

 ommends itself, on account of from 70 to 75 per cent, of muriate of 

 potash, in presence of from 15 to 20 per cent, of sulphate of magnesia, 

 for deep-rooting forage plants. 



A detailed discussion of the character and special fitness of the 

 various brands of German Potash Salts for agricultural purposes, 

 can be found in the annual report of the Secretary of the Mass. 

 State Board of Agriculture for 1874. 



