108 PRACTICAL FARM CHEMISTRY. 



bones, in the course of three or six months, or a 

 year, have become soft and can easily be broken in 

 small fragments. 



The fourth way is that by acid treatment. I 

 do not commend it to the average farmer, when any 

 other way is open. The farmer is not a chemist, 

 and handling such corrosive substances as sulphuric 

 acid is hardly his province. There is always an ele- 

 ment of danger in this business, and the inexperi- 

 enced had better not seek too intimate acquaintance 

 with it. On the other hand, if you are bound to try 

 it, there is no great difficulty connected with learn- 

 ing all that is needed about it. Only use the utmost 

 care, and be sure you know what you are doing. 

 Put on old clothes when working with acids, and 

 keep within easy reach a little baking soda (bi-car- 

 boate of soda), unleached wood ashes or some other 

 alkali, and rub some of this on at once should a 

 drop of acid spatter on clothes, boots, or flesh. 



For a vessel in which to dissolve the bones, make 

 a large tank, box or vat of sound plank. If lined 

 with lead, all the better. Break up the bones as 

 finely as possible; heap them up in the bottom of 

 the tank, and thoroughly wet them with water. 

 Then gradually, carefully, add the sulphuric acid 

 (oil of vitriol). Some commotion and considerable 

 heat will be the result of the contact of the acid and 

 the bones. The mass is to be shoveled over repeat- 

 edly, and more acid added, until fifty pounds of the 

 latter have been used to every one hundred pounds 

 of bones. The acid, or oil of vitriol, can be bought 

 in "carboys" of one hundred and sixty pounds 

 each, costing about $2.25 or $2.50. The heap is 

 again shoveled over a few times, and after a while 

 will be reduced to a pasty mass. This must be 



