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PEARL,
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188
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reign,
belonging to Sir Thomas Gresham, which was valued at £15,000, and which
he is said to have treated after the fashion of Cleopatra; for he
powdered it and drank it in a glass of wine to the health of the Queen,
in order to astonish the ambassador of Spain, with whom he had laid a
wagor that he would give a more costly dinner than could the Spaniards.
During
the occupation of Britain by the Romans this country became famous for
its pearls, which were found in the fresh water mussel of our rivers.
Generally the pearls of these molluscs are small, badly coloured, and
often valueless ; but occasionally they occur of such beauty as to
rival those of the pearl oyster. Some years ago, in the Scotch rivers,
the search for pearls was prosecuted vigorously, especially by a
merchant named Unger, of Edinburgh, who had brought Scotch pearls into
great repute. He collected specimens ranging, as was stated, from £5 to
£90 each and formed a necklace said to be worth £350. In Scotch pearls
of the highest quality, there is a pleasing pinkish tint, which is very
permanent. The fishing for pearl mussels is by no means so dangerous or
troublesome as for pearl oysters; usually they are found in the beds of
streams, shallow enough to wade in, and so clear that they can seethe
bottom. If too deep to remove with the hand, they are easily captured
by putting a stick between their gaping shells, which instantly close
upon it, and can be drawn out with it. So profitable did this pursuit
become, that a great many persons engaged in it.
Very
fine river pearls, known on the continent as Bohemian pearls, are found
in the rivers Moldau and Wottawa. There is also a fresh-water pearl
fishery in Bavaria,where the river Iltz yields at times very fine
specimens. Even the most inferior pearls can ouly be properly polished
with pearl dust, and the inferior pearls are powdered for the purpose
of polishing and rounding the finer ones.
False
pearls are very admirable imitations, made by blowing very thin beads
or bulbs of glass, and pouring into them a mixture of liquid ammonia,
and the white matter from the scales of the Bleak and sometimes of the
IJoach and Dace. The proper way to prepare the pearl-matter is first to
remove the scale of the lower part of the fish; these must then be very
carefully washed, after which they are put to soak iu water, when the
pearly film falls off and forms a sediment at the bottom of the vessel,
which is removed and placed in liquid ammonia for future use. This
pearl mixture, when of the best quality, is very costly, being as much
as £4 or £5 per ounce, For use, it is diluted with ammonia, and
injected into the glass beads, so as to thinly coat them inside;
afterwards the better kinds have melted white wax poured iu, which
renders them more durable. The French and Germans produce in this way
imitations of the finest oriental pearls of such beauty, that the most
practised eye can hardly detect the difference. The bleak is procured
iu considerable quantities for this purpose from the Thames and other
rivers in England.
The
invention of artificial pearls is due to a Frenchman, named Jaquin, in
the time of Catherine di"Medici, and the manufacture is now chiefly
carried on in the department of the Seine, where great improvements
have lately been made, especially in the art of giving the irregular
forms of large pearls to the glass-bulbs, and thus increasing the
resemblance, and in removing the glassy appearance caused by the
exterior glass coating, by exposing it for a short period to the action
of the vapour of hydrofluoric acid, Mucilage of fine gum-arabic is also
used instead of wax, which increases the trausluoeney, gives greater
weight, and is not liable to melt with the heat of the wearer's body—a
defect to which those filled with wax are very liable.
Roman
pearls differ from other artificial pearls, by having the coating of
pearly matter on the outside, to which it is attached by an adhesive
substance. The art of making these was derived from the Chinese.
MoTiiFJt-or-PEABL, the sliells of the large bivalve mollusc, Meleagriitu „uir-(ffiii/i'ia, which
also produces the precious pearls.* These shells are collected in vast
niiinbi'i's m the tropical seas, chiefly on the coast of Ceylon,
Manila, Cuba, Panama, and the South Sea Islands. Those from Panama are
small and thick, and aro known in commerce as " bullock " shells ;
those from Manila arc rine'-t in quality, often as much as a foot in
diameter, round and flat. There are two varieties—the white or silver
lipped and the black lipped. So enormous is the trade in these shells,
that the imports of this country alone amounted to 3,000 tons
* This is a curious error. Mother-o'-pearl is procured chiefly from large shells of quite a different species.—Ed.
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