methods of cooking animal food. To explain the philosophy of these
simple culinary operations, we must advert to the effects that are
produced by heat on the principal constituents of flesh. When
finely-chopped mutton or beef is steeped for some time in a small
quantity of clean water, and then subjected to slight pressure, the
juice of the meat is extracted, and there is left a white tasteless
residue, consisting chiefly of muscular fibres. When this residue is
heated to between 158째 and 177째 Fahrenheit, the fibres shrink together,
and become hard and horny. The influence of an elevated temperature on
the soluble extract of flesh is not less remarkable. When the watery
infusion, which contains all the savoury constituents of the meat, is
gradually heated, it soon becomes turbid; and, when the temperature
reaches 133째, flakes of whitish matter separate. These flakes are
_albumen_, a substance precisely similar, in all its properties, to the
white of egg (see No. 101). When the temperature of the watery extract
is raised to 158째, the colouring matter of the blood coagulates, and the
liquid, which was originally tinged red by this substance, is left
perfectly clear, and almost colourless. When evaporated, even at a
gentle heat, this residual liquid gradually becomes brown, and acquires
the flavour of roast meat.