206 



BONES. 



to from 20 to 25 ; and in the fourth, to from 10 to 

 15. When coarsely powdered, the percentage is of 

 course diminished, since the operation is extended 

 over a longer series of years. As respects the kind 

 of crop^ bone-dust has been found just as good a 

 dressing for straw and oil-bearing produce as for po- 

 tatoes, etc. 



In addition to the greater or less pulverization, 

 various circumstances connected with the nature of 

 the soil and the weather exercise a very marked in- 

 fluence upon the action of bones, as will be dis- 

 cussed in the course of the following section. 



2. Application of Bones. 



1. Bone-dust. Here it must be held as a first 

 principle, that such sorts only as are finely comminuted 

 and powdered are to be employed. Hence the farmer 

 places himself in a better position by paying 9g?. or 

 Is. more for a finely pulverized article, than by pur- 

 chasing a coarsely broken sort at a lower price. If 

 bones are introduced in the latter state into the 

 earth, the small and exposed portions of gelatine 

 upon their outer surfaces pass, it is true, into putre- 

 faction, in so far as air and water can operate upon 

 them ; not so, however, the gelatine situated in their 

 interior, because, from its being surrounded with 

 bone-earth, which is nearly insoluble in water, it is 

 protected against the penetration of moisture, and 

 cannot, consequently, take on the putrefactive pro- 

 cess. Ten, twenty, and more years may pass away 



