138 AMERICAN MANURES. 



profits. As to organic substances, such as blood, 

 fish scraps, horns, hair, etc., in these manures, 

 they have a value proportioned to the amount 

 of nitrogen or ammonia contained in them ; but 

 as they are usually mixed with a considerable 

 amount of water and other ingredients, of no 

 value, that costs the buyer as much as the 

 nitrogen or ammonia is worth, they may be left 

 out of the estimate ; thus leaving only phos- 

 phoric acid, ammonia and potash as a basis of 

 value. We shall examine them in the following 

 order : Phosphoric Acid insoluble and soluble ; 

 Ammonia actual and potential ; Potash 

 the Muriate and Sulphate. 



Insoluble Phosphoric Acid, or Bone Phos- 

 phate of Lime, enters largely into the composi- 

 tion of bones, as the following analysis of cattle 

 bones, in their natural dry state, will show. 



G elatin 30'58 Ibs. contain nitrogen 5'00 Ibs. 



Phosphate of Lime... 58-30 " " Phosphoric Acid 26-71 " 



Carbonate of Lime.... 7*07 " 



Fluoride of Calcium.. 1-96 " 



Phosphate of Mag.... 2-09 " " " 1-13" 



100-00 Ibs. Total Phosphoric Acid 27'84 Ibs. 



A ton of such bones contains 556 Ibs. of phos- 

 phoric acid, and 10 1) Ibs. of nitrogen. If this 

 insoluble phosphoric acid be estimated at 4 J cents 

 per lb. ? and the nitrogen at 15 cents, we have 

 $10.02 a the real value of these bones. Such 



