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XXIX. — On the Solution of Bones in Sulphuric Acid for the 
purposes of Manure, By the Duke of Richmond. 
To PJi. Puseij, Esq. 
My dear Pusey, — I have not yet received the details of the ex- 
periments tried by the Morayshire Farmers' Club with sulphuric 
acid and bones, but I know that the result has been most satisfac- 
tory. On my own farm, which is light sandy soil, I tried one acre 
with it, another with guano, and a third with stable-yard dung. 
Early in November I had a quarter of an acre of each drawn and 
weighed : the heaviest crop was from the land manured with the 
sulphuric acid, though it did not cost me above lis. or lis. (jd. 
an acre. 
I understand also that the turnips came into rough leaf sooner 
on that acre than on any of the others. 
Believe me yours sincerely, 
Richmond. 
London, December 9, 1843. 
Note. 
The experiment contained in this letter bears out those of the 
Morayshire Farmers' Club, the details of which appeared in the 
last Journal, and affords good hope that this, the most important 
saving which was ever held out in the use of manure, will be 
found generally applicable. For those details I must refer to 
1 that paper, merely mentioning now, that in one trial a bushel of 
; bones to which sulphuric acid had been applied, exceeded in its 
effects six bushels used in the common way. As this is the first 
. instance, I believe, in which chemistry has assisted practical farm- 
ing, it may be interesting to Examine the theory on which this 
apj)lication is founded. Bones may be roughly stated to consist 
of fat, of jelly, and of an earthy matter, called phosphate of lime. 
When they were first employed as manure, it was doubtful of 
course to which of these substances they owed their beneficial 
effect, and many persons were unwilling to purchase bones which 
had been boilecl, and had consequently lost their grease. It was 
soon found, however, that boiled bones were as good manure as 
those that were unboiled. There still remained iu the boiled 
bones two substances, either of which might be their active prin- 
ciple. But Sprengel states that he found bones which had been 
not only boiled, but burnt, still act as manure ; and Mr. Hannam 
has tried the same experiment with the same result. Now as fire 
drives out of the bone the solid jelly which holds it together, there 
remains only the earthy matter behind, thus proved to be the ma- 
