SOURCES OF PLANT-FOOD 



deceit that served no purpose with many cus- 

 tomers, and have placed acid phosphate and mixed 

 goods upon the market without the intimation 

 that the phosphoric acid was derived from animal 

 bone. 



The demand for bone makes prices high for the 

 very limited amount upon the market, when avail- 

 ability is taken into account, and the advice that 

 such goods be used would be valueless if it had 

 any general acceptance. Prices would go higher, 

 and the amount in the world would remain wholly 

 inadequate. 



Raw Bone. Stable manure lasts several years 

 in the soil because decay is slow. Raw bone has 

 appealed to many because its action is likewise 

 necessarily slow. The fat in it prevents fine 

 grinding and protects the coarse particles from 

 decay. It is known as bone-meal or coarse 

 ground-bone. A good quality of raw bone may 

 contain 4 per cent of nitrogen, while the phos- 

 phoric-acid content is 20 to 25 per cent. The 

 bones of old animals is less rich in nitrogen. 

 The age of the animals, and the sorting for 

 manufactures of various kinds, cause variation 

 in quality, and the purchase of raw bone should 

 be made on guaranteed analysis just as surely 

 * [177] 



