9»4 ANNWAi, REPORT OF THH ©ff. Dee. 



the quantities of valuable constituents the average materials now on 

 the market contain, the wholesale cost per pound of the valuable con- 

 stituents can be readily estimated. In the case of aramoniates, the 

 quotations are '"per unit of ammonia" in many cases. The term 

 "unit" is ecjuivalent to ''per cent.;" in goods sold by the ton of 2,000 

 lbs., the unit is equal to 20 lbs.; and 20 lt)s. of ammonia contain 16.47 

 lbs. of nitrogen. 



In the case of refuse bone-black, unacidulated, the mean, 28.25 per 

 cent, of phosphoric acid, is assumied to represent the average ma- 

 terial on the market. 



Phosphate rock is sold by the ton of 2,240 lbs.; this material is sold 

 on the basis of the bone-phosphate of lime it contains, with draw- 

 backs for injurious constituents. Since the bone phosphate of lime 

 contains 45,8 per cent, of phosphoric acid, each per cent, of bone 

 phosphate in a long ton of phosphate rock is equivalent to 22.4 lbs. 

 and contains 10.26 lbs. of phosphoric acid. 



In the wholesale trade, it is customary to sell dried blood, azotine, 

 horn and hoof meals, and concentrated tankage solely on the basis 

 of ammonia, to the entire disregard of the phosphoric acid contained. 



Likewise, the insoluble phosphoric acid in dissolved rock is omitted 

 from consideration, and contracts are based solely upon the "avail- 

 able" phosphoric acid; that is, the sum of the "soluble" and "revert- 

 ed" or "citrate soluble" phosphoric acid; nor in rock phosphates is 

 any claim made for the small quantities of nitrogen and potash they 

 always contain, nor in dissolved bone for the potash present. 



Under these conditions, the wholesale cost per pound in New York 

 of the valuable constituents of such materials as furnish but a single 

 fertilizing element, these materials being assumed to be in the stat^ 

 of preparation and in the package in which the manufacturer pur- 

 chased them, are given in the following table; also, a figure repre- 

 senting a fair retail price at the factory, the materials having under- 

 gone no change in treatment or packing, and the allowance for ex- 

 pense and profit in retailing being 20 per cent. 



