EXPERIMENT STATION. 59 



various other matters. The double sulphate of potash and magj- 

 nesia contains 46 to 4Y per cent, of potassium sulphate, 33 to 34 

 per cent, of magnesium sulphate, 5 per cent, of water and 15 per 

 cent, of sulphates of soda and lime, and other matters. Kainit 

 contains about 85 per cent, of sulphates and chlorides of potas- 

 sium, sodium and magnesium and 15 per cent, water. 



Saltpeter Refuse. 



853. From stock of S. J. Archer, 194 Duane street, New York. 

 Sampled and sent by S. S. Green, New Milford, Ct. 



Analysis. 



*Nitric acid (N2O5), 4.44 



Chlorine, - 54.41 



Potash, - 4.27 



Soda, - ■ 48.21 



Insoluble matters, ^ -- -- .88 



112.21 

 Deduct oxyp;en equivalent to chlorine, 12.26 



99.95 

 * Nitrogen 1.15. 



The compounds probably existing in this refuse are : 



Potassium nitrate (saltpeter), — 8.31 



Potassium chloride, .61 



Sodium chloride (salt), 90.20 



Insoluble mattgr, .88 



100.00 



It is a mixture of nine parts of salt and less than one part of 

 saltpeter and is probably a waste product from some manufactur- 

 ing process. Its cost is llO per ton on cars in New York. Allow- 

 ing i^ cents per lb. for the potash and 20 cents per pound for the 

 nitrogen, its estimated value would be $8.23. It could be safely 

 used only in moderate quantity since for every pound of saltpeter 

 applied, 10 pounds of salt would also be applied. [If the price 

 were lower, those who salt their meadows would find this an'ex- 

 cellent material for the purpose.] 



