This saline belongs to the prodncts of the "German Potash Indus- 

 try" at Strassfurt. It contains from 15 to 16 per cent, of sulphate of 

 potassa, besides sulphate of lime (gvpsum), sulphate of magnesia, 

 and chloride of sodium (common salt), etc. A careful trial of the 

 article upon hill pastures as a top-dressing, in connection with fine- 

 ground bones, deserves attention. It sold at $14 per ton of 2,000 

 lbs., on board of car, Boston. 



285. I. DouV)le Sulphate of Potash and Magnesia, sent on for 

 examination. 



II, Double Sulphate of Potash and Magnesia, sent on from 

 Hatfield, Mass. 



Moisture at 100° C, 

 Potassium oxide, 

 Magnesium oxide, 

 Calcium oxide. 

 Sodium oxide, 

 Sulphuric acid, 

 Chlorine, 

 Insoluble matter, 



The samples represent, probably, the extremes in composition. 

 Large percentages of chlorides are, in many instances, considered 

 objectionable, in high-priced sulphates. The articles have been 

 offered at from $38 to |40 per ton. 



286. BONEBLACK WASTE. 



I, Sent on by Bolton Farmers' and Mechanics' Association, Bolton, 



Mass. 



II, Sent on for examination, from Concord, Mass. 



I II 



fotmds per hundred. 



Moisture at 100° C, 2.30 6.00 



Total phosphoric acid, 30.20 27.36 



Insoluble matter, 1.53 6.60 



Allowing four cents per pound of phosphoric acid, for boneblack 

 of a fine mechanical condition. Sample I represents a value of from 

 $23 to $24 ; and Sample II, of from $21 to $22, per ton of 2,000 lbs. 

 The valuation of these articles depends, somewhat, on their mechan- 

 ical condition. They furnish a superior material for the manufacture 

 of superphosphate of lime. 



