FERTILIZERS. 61 



By Dr. Nichols's method, our available phosphoric acid 

 from bone-black will have cost us about as follows : 



380 pounds bone-black, at $22.50 per ton, or 1J cents per pound, $4 27 

 170 " oil of vitriol, at If cents per pound . . . 2 38 

 80 " water. 



630 

 63 one-tenth deducted for waste, steam, and evaporation. 



567 pounds, costing $6 65 



Cost per ton for home-made phosphoric acid, where bone- 

 black, or "char," is used . . . . . . .2340 



Price in the market per ton 30 00 



Cost of available phosphoric acid per pound, the average being 



17 per cent nearly 07 



Now, let us see what it would cost to make soluble the 

 phosphoric acid, or, in other words, to make a superphos- 

 phate, when 100 pounds of bones are used. 



52 pounds sulphuric acid, at 1 T ^ cents . . . $0 92 

 100 " fine bone, at If cents . . . . 1 75 

 25 " water. 



177 

 17 loss in steam, gas, and waste. 



160 pounds, costing . . ..' . $2 67 



The superphosphate in a ton of bones would weigh 

 160 X 20 = 3,200 pounds ; and the cost, at the same rate, 

 would be, $2.67 X 20 = $53.40, which would be, for a 

 ton by weight, $33.37. The average price at which it is 

 sold in the market is $38. Difference in cost between the 

 home-made and purchased is $4.63. 



To determine the profits of this operation, we must 

 deduct from the $4.63 the extra freight of the acid and 



