PROCEEDINGS OF THE FARMERS' CLUB. 321 



soil down into a stiff clay, especially if it contains iron. Some persons 

 also think they have subsoiled their land when they have only run the sub- 

 soil plow along' the bottom of a turned furrow, stirring- the earth a few 

 inches deeper. Wlien subsoiling is properly done, the share of the subsoil 

 plow runs 12 to 16 inches deeper than the furrow of the turning plow, 

 making a channel through the hard earth without disturbing the surface. 

 I have never seen any land that was not permanently benefited by such an 

 operation, though it often fails to show any improvement in the crops the 

 first year. 



How Farmers can Dissolve Bones. 



Mr. Henry Cope of Chester county, Pa., wants to know " whether the 

 water and acid should be mixed, and then the bones added, or the bones 

 first wet and left to soak the acid afterward. The bones are ground fine 

 without steaming or heating." 



Prof. Mapes replied that where bones have been neither boiled nor burned 

 the acid should be diluted with twenty pounds of water to one of acid, and 

 it matters very little whether the bones are put into the liquid or put into 

 a tub, and the acidulated water poured upon them. Of course the bones 

 are acted upon more readily when broken fine, and they are more completely 

 dissolved, when the acid is sufficiently diluted than when it is too strong. 

 If used too strong, the acid dissolves the outer coating of the bone, and 

 also appears to form a compound with the gelatin and oil, which prevents 

 the action of the acid upon the interior. Burnt bones may be treated with 

 acid diluted one to ten. 



Josiah Spalding, the old farmer alluded to above, gives the following as 

 his experience in dissolving bones: "I procured 150 pounds of sulphuric 

 acid, 500 pounds of bones, breaking them on a boulder in a box, with a 

 stone hammer, to a size less than my finger. I put the water into a half 

 hogshead tub, and added the acid, and then commenced putting in the 

 bones. This was an error, as the shoveling and weighing occupied some 

 minutes. The bones should have been in such a state of readiness that 

 they could have been added immediately after tlie mixture of the liquid, 

 that they might all have the benefit of the whole operation, because the 

 intense heat is the main power in dissolving the bones, as a few bones 

 added after the heat had abated were not affected. The bones dissolve 

 rapidly; in two hours, I think there were not 25 pounds not completely 

 dissolved, and those were mostl}'' teeth, the enamel of which had not been 

 broken. The heat was intense, boiling furiously, and in a few minutes the 

 tub, which was of oak, with staves an inch thick, was so hot I could hard- 

 ly hold my hand upon the outside, yet it was not injured for future use." 



Prof. Mapes. — He is mistaken in supposing the heat to be the main 

 cause of the quick dissolution of the bones. The mixture would have pro- 

 duced the same effect if allowed to become cool before adding the bones. 

 When the acid is used so strong as Mr. Spalding made it, the first bones 

 put in are affected quickly and take up the strength of the acid, as shown 

 by the result. It is more economical to use it in a more diluted form and 

 wait its slower action, unless time is very important. 



Mr. Solon Robinson said that he thought it a better plan to put the bones 

 [Am. Ins.] 21 



