for obtaining animal fat in its greatest state of purity.

I have had occasion during the last two or three years to make many
experiments on the rendering and purification of animal fat, and at the
same time have been brought into communication with manufacturers of
oleomargarine on the large scale; the result of which experience has
been that I have lost faith in the efficacy of the Pharmacopeia process.
I have found that in the method now generally adopted by manufacturers
of oleomargarine, which is produced in immense quantities, the use of
water, for washing the fat before melting it, is not only omitted but
specially avoided. The parts of the process to which most importance is
attached are: First, the selection of fresh and perfectly sweet natural
fat, which is hung up and freely exposed to air and light. It thus
becomes dried and freed from an odor which is present in the freshly
slaughtered carcass. It is then carefully examined, and adhering
portions of flesh or membrane as far as possible removed; after which it
is cut up and passed through a machine in which it is mashed so as to
completely break up the membraneous vesicles in which the fat is
inclosed. The magma thus produced is put into a deep jacketed pan heated
by warm water, and the fat is melted at a temperature not exceeding
130°F.

If the flare has been very effectually mashed, the fat may be easily
melted away from the membraneous matter at 120°F., or even below that,
and no further continuance of the heat is required beyond what is
necessary for effecting a separation of the melted fat from the
membraneous or other suspended matter. Complete separation of all
suspended matter is obviously important, and therefore nitration seems
desirable, where practicable; which however is not on the large scale.