52 
Action and Practical Application of Bones 
matter of bone is a fertilizer, and not that it has the chief and 
first effect ; for it is very well known in practice that 20 stones of 
horse-hair or other animal matter (which at 40 per cent, is about 
the weight of the organic part of 16 bushels of bones) applied to 
the soil under the most favourable circumstances will not have 
anything like the effect that an ordinary dressing of burnt bones 
has. The principal effect must, therefore, arise from the action 
of the earthy part. On the other hand the evidence which we 
have of the nearly equal effect arising from burnt and unburnt 
bones does not prove, as Sprengel holds, that the 40 per cent, 
animal matter which bones contain is of little or no value (a con- 
clusion which the practical use of the oil, &c. alone would falsify),, 
but that the earthy part acts more readily and efficiently when 
separated from the animal matter. In the case alluded to, there- 
fore, we may conclude that all the 60 parts of phosphates, &c. 
come into full action when burnt bones are used, and that when 
fresh bones are employed the 40 parts of animal matter first 
exercise their influence, and then a portion of the phosphates ; in 
which case it is easy to account for the equal results arising from 
the two applications, without asserting, what every day facts dis- 
prove, that the organic part is worthless ; the fact being that the 
union of the animal oil with the earthy elements prevents the 
operation of the latter in as great a degree, in cases where those 
earthy matters are required, as the oil itself does good. This 
theory, then, which the writer has already advocated, is in con- 
sonance with all the facts which have been elicited by his own 
investigations, or by the advocates of other theories, and reconciles 
what has too often been set forth as the groundworks of opposite 
conclusions. 
Thus, on the data produced by the supporters of the theories 
already discussed, it is clearly shown, on the one side, that the 
animal part, and on the other that the earthy portion, of the 
manure is of value ; both, therefore, may undoubtedly be con- 
sidered fertilizers. 
Again, it is also shown that in ordinary cases the animaKpart 
disappears before the earthy can act, and hence, in such cases, it 
must be considered to have the first effect upon the crop ; it has, 
however, also been proved that, in cases where this matter was 
removed, as in burnt bones, or even boiled ones, when water was 
absorbed, the effects of the earthy portion were equally immediate 
and potent throughout. It may, therefore, be as safely concluded 
that the earthy part is only secondary in its immediate action when 
prevented by the manner in which it is applied from being acces- 
sible to the young plant. The facts that Ijones which have been 
buried are found to lose their animal oil first (vide Analysis, 
Johnston's Lectures, p. 657) — that boiled and burnt bones are 
