night is required to detect the critical
moment. With the less delicate skins this bran bath is not necessary.
Lime and acid solutions accomplish the same purpose. When the gelatine
matter is all removed the skins are ready for the actual curative
process.
Oil dressing or Indian dressing--which merely differ in application,
but are founded upon the same principle--is the most simple method of
curing skins. The principle of each is the soaking of the gelatine
fibers of the skin with oil, the union of the latter and the gelatine
appearing in the form of oxide, and resulting in the insoluble,
undecomposable, pliant, and tough material known to the commercial
world as leather. The first step in the oil dressing, after the skins
have been duly soaked to render them porous and absorptive, is to
cover them with fish oil and place them in the stocks or fulling
machines--huge wooden hammers with notched faces working in iron
cases--where they are beaten and turned, and subjected to a uniform
pressure until the oil is gradually absorbed. After taking them out,
hanging them up, and stretching them, the oil and fulling process is
repeated according to the thickness of the skin, and until every part
of it is full of oil. After this the skins are dried in a mild heat
that causes the oxidization of the oil. This being completed, all the
superfluous oil is removed by putting the skins in an alkali bath.
Then the curing process is complete.
With the preparation of kid leather alum is the astringent curative
agent. Its operation is accompanied by that of others whose purpose is
to secure elasticity and pliability, and mainly to preserve that
beautiful texture which makes kid leather superior to all others.
These assistants in the process are eggs, flour, and salt. They are
combined into what is called a custard. A proper quantity of the
custard and a number of skins having been put together in a dash
wheel, where they are thrown about for some time, the open pores of
the skin absorb the custard freely, and become swelled by the chemical
union of the custard and the skin. In trade parlance this swelling is
known as "plumping." This having progressed satisfactorily, the skins
are folded together with the fleshy side outward, and are dried by a
gentle heat.
They are now cured, but they are yet hard and rough. Another
objectionable feature is that they are of unequal thickness. Breaking
and staking, as they are called, are now resort
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