ounds weight of starch. As to old
hard fibre, we are not in a position to say whether or not it possesses
any nutrimental value worth taking into account. The estimation of the
value of the flesh-forming materials is far more difficult than that of
sugar, starch, pectine compounds, and fat. The nitrogenous constituents
of food must be in a highly elaborated state before they are capable
of being assimilated. In seeds--in which vegetable substances attain
their highest degree of development--they probably exist in the most
digestible form, whilst much of the nitrogen found in the stems and
leaves of succulent plants, is either in a purely mineral state, or in
so low a degree of elaboration as to be unavailable for the purpose of
nutrition. But even plastic materials, in a high degree of organisation,
present many points of difference, which greatly affect their relative
alimental value; for example, many of them are naturally associated with
substances possessing a disagreeable flavor: and as their separation
from these substances is often practically impossible, the animal that
consumes both will not assimilate the plastic matters so well as if
they were endowed with a pleasant flavor. In seeds and other perfectly
matured vegetable structures, the flesh-formers may exist in different
degrees of availability. The nitrogen of the _testa_, or covering of
the seeds, will hardly be so assimilable as that which exists in their
cotyledons. The solubility of the flesh-formers--provided they be
highly elaborated--is a very good criterion of their nutritive power.
In linseed the muscle-forming substances are more soluble than in
linseed-cake--the heat which is generally employed in the extraction of
oil from linseed rendering the plastic materials of the resultant _cake_
less soluble, and diminishing thereby their digestibility, as practice
has proved.

From the considerations which I have now entered into, it is obvious
that the chemical analysis of food substances as generally performed,
though of great utility, does not afford strictly accurate information
as to their commercial value, and still less reliable in relation to
their nutritive power. At the same time, they as clearly establish
the feasibility of analyses being _made_ whereby the money value of
feeding-stuffs may be estimated with tolerable exactitude. Let the
chemist determine the presence and relative amounts of the ingredients
of food-substances, and--if it be p