flesh undergoes very considerable changes. For instance, when the animal
is young, the fluids which the tissues of the muscles contain, possess a
large proportion of what is called _albumen_. This albumen, which is
also the chief component of the white of eggs, possesses the peculiarity
of coagulating or hardening at a certain temperature, like the white of
a boiled egg, into a soft, white fluid, no longer soluble, or capable of
being dissolved in water. As animals grow older, this peculiar animal
matter gradually decreases, in proportion to the other constituents of
the juice of the flesh. Thus, the reason why veal, lamb, and young pork
are _white, and without gravy_ when cooked, is, that the large quantity
of albumen they contain hardens, or becomes coagulated. On the other
hand, the reason why beef and mutton are _brown, and have gravy_, is,
that the proportion of albumen they contain, is small, in comparison
with their greater quantity of fluid which is soluble, and not
coagulable.