The Democratic advocate. [volume] (Westminster, Md.) 1865-1972, 1873-01-11
Gelatine.


horns, hoOfsand bones yield the same mate
rial. We give to this product the generic
name of gelatine, but know its impure and
coarser forms as glue, and the finest and
purest as isinglass. While glue is well-nigh
Indispensable for multitude of well-known
purposes, isinglass is mainly employed in
the preparation of jellies, creams, blanc
mango, and various table delicacies. Besides
this, gelatine is used for numerous other
purposes, such as the clarifying of liquors,
the dressing of silks and other goods, and
the forming ofdelicate pouches and capsules.
1t is also formed into thin, transparent
sheets for copyings drawings and preparing
artificial flowers. 1t is used, too, for taking
casts of complicated forms and, owing to
its property of contracting greatly upon
the application of alcohol impressions have
been taken upon thin films of it, which,
upon being reduced by this contraction
have been transferred to stone as mere
miniatures Of the original. This process
has also been reversed, and greatly enlarged
prints have been obtained by sleeping the
gelatlne film in water, and then transferring
the impression. But these are only minor
uses; its great utility, after the making
ofcements and glue, is an article of food.
1t is interesting, however, to notice that
it is upon this very substance which we
extract from the tissues of the animals $
skin to make our delicate jellies that we
also depend to make the leather for our
shoes. Though itselfso soluble, when mix
ed with tannin It forms an insoluble
compound. In the process of leather-mak-
ing the object is to have the tanic acid
contained in the bark seek out the little
particles of gelatine contained in all the
cells of the skin, and turn them into this
compound, which, from its insolubility,
makes the skin waterproof" After this
change We call the skin leather; and its
waterproof quality depends upon the
amount Of gelatine it contained, and the
thoroughness with which this has been
saturated with the tannic acid. There is
far more gelatine in the tissues of all young
animals than of older ones. Hence the
well tanned calfskin will turn water far
better than the same thickness shaved from
the cowhide.
There are various methods for prepar-
ing gelatine which is to be sold as an arti.
Gle Of food. For the best, the skin of
calves heads and thick pieces unfit for
leather, are used. All different processes
agree in thoroughly cleansing and reduc-
ing this to a pulp, which is afterwards par
tally dried, and cut into any convenient
form for handling; after which thorough
dessication, or drying, is secured. Ok
skins, bones, and other materials are some
times used for making gclatine, but they
produce an inferior article.
lsinglass is made from the air-bag or
swimming bladder of fishes. In different
parts Of the world it Is obtained from
different species of fish, and is, therefore,
of various qualities. That from Russia is
reckoned best, and is obtained from spe-
cies of sturgeon, found in the Black and
Caspian Seas and their tributaries. This
fish is large, sometimes attaining the
length of twenty-five feet. The membrane
Of its air-bladder is carefully cleansed, dried
and scraped to form leaf isinglass; or, fol-
ded into packages, it is called book isin-
glass; or, cut into strips and twisted into
various forms, it is known as long and short
staple. An inferior isinglass, prepared
without much care, is imported from Bra
I'll. 1t is little used for domestic purposes,
but quite largely in other ways, and to
adulterate the better kinds. In this coun-
try also isinglass is produced from some Of
the fish of our waters, especially the cod
and the common hake, but the quality Of
this article is not the best II is more
commonly used for purposes similar to the
Brazilian. All isinglass undergoes pro-
cess of refining before it is employed for
making table delicacies In this the leaf
is carefully picked over and all the discol-
orcd parts removed for other uses. The
assorted leaf is then rolled into thin rib
bons by passing through successive pairs
of rollers, and the ribbons afterward cut
into fine shreds. But this process favors
adulteration by allowing inferior sheet &c.
latine sometimes to be introduced between
two sheets of isinglass, and thus to be in,
corporated with it.
Isinglass being nearly pure gelatine, and
prepared without exposure to great heat
forms tougher and much frmer cement
than glue. Dissolved in water and alcohol
and carefully heated to the boiling poin
with few drops of essential oil to preserv,
it from moulding, it forms what is knowr
as the diamond cement" With gun
ammoniac introduced, some have used i
as cement for fastening precious stones
and nending porcelain. II also usually
forms the adhesive substance of court
plaster. Covered with transparent var
nish which cannot be penetrated by mois
air, it has also been used for the window
lights of vessels; aud hence the name isin
glass, by which it is known.
At one time it was held that not onl,
edibles made from isinglass, but ell prepa
rations from gelatine were exceedingl,
nutritious and healthful food, and they
were especially recommended for invalids
Arrangements were made in some cities :.
obtain the gelatine from bones in larg,