EXPERIMENT STATIOjST. 21 



Potash signifies the substance known in chemistry as potassium 

 oxide, which is the valuable fertilizing ingredient of " potashes'* 

 and " potash salts." It is most costly in the form of sulphate, 

 and cheapest in the shape of muriate or chloride. 



The Valuation of a Fertilizer signifies estimating its worth in 

 money, or its trade-value ; a value which, it should be remem- 

 bered, is not necessarily proportional to its fertilizing effects in 

 any special case. 



Plaster, lime, stable manure and nearly all the less expensive 

 fertilizers have variable prices, which bear no close relation to 

 their chemical composition, but guanos, superphosphates and 

 other fertilizers, for which |30 to $80 per ton are paid, depend 

 chiefly for their trade-value on the three substances, nitrogen, 

 phosphoric acid and potash, which are compai-atively costly and 

 steady i« price. The money-value per pound of these ingredients 

 is easily estimated from the market prices of the standard articles 

 which furnish them to commerce. 



The average Trade-values, or cost in market per pound, of the 

 ordinarily occurring forms of nitrogen, phosphoric acid and pot- 

 ash, as found in the Connecticut and New York markets, and 

 employed by the Station during the last two years, have been as 

 follows : 



TBADE-VaLUES fob 1881 AND 1882. 1881. 1882. 



Cents per lb. 



Nitrogen in nitrates, 26 26 



" in ammonia salts, -- 22^ 29 



" in Peruvian Guano, fine steamed bone, dried and fine ground 



blood, meat and fisli, superphosphates and special 



manures, - - -- 20 24 



" in coarse or moist blood, meat or tankage, in cotton seed, 



linseed and Castor Pomace, — 16 18 



" in fine ground bone, horn and wool dust, 15 17 



" in fine medium bone, — - 14 15 



" in medium J)one, 13 14 



" in coarse medium bone, - -- 12 13 



" in coarse bone, horn shavings, hair and fish scrap, 11 11 



Phosphoric acid soluble in water, 12^ 12^ 



" " " reverted" and in Peruvian Guano, — 9 9 



" " insoluble, in fine bone, fish guano and superphosphates, 6 6 



" " " in fine medium bone, — 5| 5^ 



" " " in medium bone, 5 5 



" " " in coarse medium bone, 4-^ 4^ 



" " " in coarse bone, bone ash and bone black, 4 4 



" " " in fine ground rock phosphate, 3^ 3 



Potash in high grade sulphate, H '^ 



" in low grade sulphate and kainite, 5^ 5 



" in muriate or potassium chloride, 4^ 5 



