Watertown republican. [volume] (Watertown, Wis.) 1860-1906, 1876-03-01
ARTIFICIAL PEARLS.
They Are Made from a Fish's Scales-The
Process of Manufacture.

They Are Made from Fish's scales-The
Process of Manufacture.
From M. Menieres (Angers) Journal of Applied
Science
1t was about the seventeenth century
that 1T was tried with more or less
success to initiate real pearls, and the
most successful means to which re-
course was had was with the aid of the
" Oriental essence" or pearly-white
solution from the scales of the bleak,
called guanine. In giving to this pro-
duct the name "Oriental essence" it
was with the intention Of keeping the
substance secret. In Anjou, although
this industry that is to say the bleak
fishery to obtain the "Oriental es-
sence, y is little known, it is no less GER
tain that the fishermen Of Ecoufflans
and Ponts-de-Ce largely aid the manu-
facture of imitation pearls, and that
they still use this name, or that Of
bleak white. The scale Of the bleak is
fabricated by mucus which was for a
long time considered albuminous, but
1t is not So This essence is very album
dant, and is difficult to mix with water,
1t coagulates by heat to thick, white
deposit, and becomes black in time if
proper remedy be applied to prevent it's
deterioration, especially during the
time of intense heat, during which pc
Rod fishing is at it's height in the
Loire and the Mayenne. If the scales
Of the bleak be examined under the
microscope, 1.-the smallest are found to
be nearly round; and if the surface
of one of the larger ones is slightly
pressed, this "Oriental essence" under
the form of small pearly drop, issues
from one of the canals and sticks to
the fingers. In this mucilage an infinite
number of small rudimental pearly
scales can be seen. The largest scales
are square, nearly rectangular, four
times as long as they are wide; each
scale has three colorless cylindrical
veins. 1t is to M. Joaquin that this in
vention is due, all the more fortunate
as it remedied the difficulties and bad
effects of the pearls made of quick
silver placed in a glass bulb. In Aniou,
In order to obtain this " Oriental es-
sence," they only fish for the bleak;
however, the scales of the dace furnish
it also. The bleak (Leuciscus a1baumos)
is the only river fish which is not used
for food; it is a white fish, we'll known
IN the running streams and on the flat,
sandy coasts of France, where the water
is not deep; it is also found in the
Seine, Marine, Moselle, Escaut, ETC.,
never descending into the Black Sea,
being principally found at the mouth
of rivers. In Anjou they spawn on
the sand in the months of May and
June. For its propagation in certain
parts Of France, artificial spawning
places are made by the aid of heaps of
sand where they multiply. In Anjou,
recourse is not had to any artificial
means; they breed, under the shelter of
the fiat, sandy coast, thus avoiding be-
coming the prey of other fishes.
The fishermen use a mesh net, and
catch the bleak by thousands as they
travel in shoals in the current, taking
care not to let them get entangled in
the meshes, or wound themselves, or
lose a part Of their large scales; but
above all not to stain themselves with
blood. The following is the process of
extracting the "Oriental essence;" Men
and children, provided with blunt
knives, take the fish one after the other
and scrape them over shallow tub,
containing a little fresh water Care is
taken not to scale the black or dorsal
part, as these scales are yellow, while
the white scales are very valuable
The whole is received in a horse hair
sieve. The first water, mixed with a
little blood, is thrown away. The scales
are then washed and pressed; the es-
sence settles at the bottom Of the tub,
and it is then that we have a very bril-
liant, blue-white, oily mass. Warm
water must not be used for the washing,
as it would promote fermentation. It
takes 10000 bleaks to furnish two
pounds of essence. The fishermen puts
this guanine in tin boxes, which they
fill up with ammonia the box is then
closed and sent to Paris. Others prefer
to put it in large-mouthed bottles. If
drop of the essence is taken up by a
straw and let fall upon the water, the
guanine floats, giving forth the most
brilliant colors. The intestines Of the
bleak are thrown away. They are,
however covered with this mucus.
There is here great negligence, and, in
spite of all the advice given on the
subject, the fishermen lose large part
of the produce. This guanine is insolu
BILE in water, in ammonia, and in acetic
acid, but combines with sui phuric and
other acids. We know that the pan
creas also furnishes this substance.
There is no doubt that they are wrong
to neglect that which covers the intes-
tines. Although the yield would be
small for each fish, it is none the less
true that large quantities could be SO
obtained.