TREATMENT AND CARE OF PEARLS 387
breaking
of the thread, and the precision with which forty, fifty, and even
sometimes several hundred knots are made on a single string, is a
pleasing operation to witness, and requires the greatest care and
nicety of touch. If knots are made frequently between the pearls, there
is less danger of losing them should the thread break, as only one or
two can fall off; sometimes, indeed, when the drill holes are very
small, the silk thread, waxed or unwaxed, fits so closely that the
pearl does not become detached even when the thread breaks.
The
thread used is invariably of silk of the highest standard of purity,
strength, and texture, undyed, and not containing any chemicals. Two
or three of these threads are held together, then with a knife the
edges are very carefully scraped till the combined material of the
three threads is less than the thickness of one. Some use a needle to
scrape or fray to a sharp point. Then this point is stiffened by means
of "white glue," the best material of this kind being pure gum arabic
dissolved in water. A little of this is rubbed on the pointed threads.
It stiffens in a moment, then the pearls are passed on, one after the
other. If the pearls to be strung are already on a necklace, this
process is simplified by the unknotting of the end of the necklace to
be re-strung ; two or three of the pearls are slid on to the new
string, the ends or points of the new necklace thread are twisted
together with the old ends and the pearls are simoly_trans-j ferred.
Frequently
the holes have been drilled so as to leave the rims rather sharp; in
this way the thread may be frayed out or even cut. This sharp edge can
easily be removed by careful reaming. Silk of pure quality is the best
material known for stringing pearls. A series of experiments were made
with every available fiber of sufficient durability from every quarter
of the globe,, but silk alone was found to possess the strength, the
flexibility, and the smoothness necessary to permit a very fine set of
threads to pass through an opening as small as the drill hole of a
pearl. In the case of a long chain or sautoire, more than three hundred
pearls will be strung on a single row, one of over eighty inches in
length containing over three hundred pearls, and it requires a degree
of neatness and patience that few possess to do this in exactly the
right way, so that the thread may not be cut, that the pearls may not
be too tightly strung, and that the ends shall be carefully attached at
the clasp, so that the necklace may hang well and there may be no
danger of the ends breaking loose.
According
to the frequency with which it is worn, a necklace should be re-strung
every three, six, or twelve months. The proper time for re-stringing
can generally be determined by the stretching of the thread so that it
can be seen either between the pearls or at either end,
