as a Manure for Turnips. 
53 
found to beffin their action more immediately than the uaburnt — 
that oil prevents the access of the water and organic acids in the 
soil from acting upon the earthy portion of the bone — and that 
finely pulverized bones are more immediate in their influence 
than bones imperfectly ground, are incontrovertible proofs that it is 
owing to their union with the animal oil that the j)hosphates and 
other earthy constituents of bone can ever be said to be secondary 
in their influence upon the crop. It is true, indeed, as Professor 
Johnston states, that there may be soils that do not require this 
earthy part of the bone ; so far, however, turni])s have very gene- 
rally exhibited a decided liking for such food upon most soils. It 
is, however (allowing the position assumed to be correct), equally 
probable that other soils may require no further supply of the 
organic food which is given in the animal matter of the bones. 
In the next "place, as to the relative value of the organic and 
inorganic matters, it is shown by the foregoing arguments that 
the animal part can only be the most valuable when the other 
cannot act, but that the latter is really and intrinsically the main 
fertilizer. No other proofs need be recapitulated, but the one 
well known, that the earthy constituents of 16 bushels of bones 
have a much greater effect than the same weight of any animal oil 
and gelatine. The general preference awarded by turnip-growers 
to dry bones, and the trials alluded to, in which burnt bones con- 
taining 60 parts of inorganic matter have shown themselves equal 
to fresh bones containing the same 60 parts of inorganic matter (in an 
unfavourable state for action) , with 40 parts of organic food also, 
are further illustrations that the earthy part of the bone, if pro- 
perly applied, is equal in amount of effect to all the animal matter 
and some of the earthy (for when fresh bones are applied plants 
obtain some portion of the earthy matter), consequently it must 
be the more valuable constituent. 
This, then, is the theory of the action of the manure which the 
facts already brought to bear on the subject, in the writer's 
opinion, sanction. In a case, however, where so much difference 
of opinion exists, and especially upon a question of such import- 
ance to practical agriculture, fresh facts cannot, as we asserted, 
but be valuable in order to enable us to agree in those first 
principles which, it is evident, are vet matters of doubt and 
dispute. 
The necessity for experimental inquiry on this subject is, how- 
ever, as obvious on the part of practice as of theory ; for, as it has 
been well observed, " skilful practice is applied science :" if, there- 
fore, the principles which explain the why and the wherefore of the 
action of the manure, and which consequently ought to direct its 
application, be not laid down and clearly defined, how is it pos- 
sible that its ])roper ecouojiiy can be understood or observed ? On 
