The animal of this shell, although popularly called an oyster, is very
different in structure, bearing greater resemblance, in some parts of
its formation, to the mussel, particularly in possessing a _byssus_, or
beard; it is the shell in which the famous oriental pearls are found.
There are but two known species of the Meleagrina, which are chiefly
found in the Persian Gulf, and at Ceylon, or in some of the seas of
Australasia.
The cause of the formation of pearl in the shells of this and other
inhabitants of the water, has been the occasion of considerable
dispute, but it is now pretty well ascertained.
The inner portion of the shell of the Meleagrina is lined with a
pearly substance, which is called mother-of-pearl; this is formed by
an animal deposit, and is in thin layers. If, by any accident, the
inner surface of the shell is injured, so as to cause a fracture of the
mother-of-pearl, the deposit, in that place, becomes for the future
irregular, and a bump is gradually formed. Accidental circumstances
cause this bump to assume various shapes; sometimes it is oval,
sometimes globular, and at others pear-shaped. This kind of pearl is
always originally found attached to the shell by means of a small neck,
or footstalk, and the spot at which this neck was placed can always be
traced on the pearl itself.
[Illustration: _Meleagrina margaritifera._]
But pearls are at times found loose in the shell;—in this case, the
pearly matter is deposited on some extraneous substance, such, for
instance, as a grain of sand, and by dissolving the pearl in an acid,
this nucleus can be traced.
Some of these round pearls are supposed to be formed on a centre,
consisting of the remains of a diseased _ovum_, or egg, of the animal.
Every schoolboy knows the story of Cleopatra having dissolved a
valuable pearl in vinegar, and afterwards drunk it off, to show her
ridiculous disregard of expense. But the account may reasonably be
doubted; for had the acid been strong enough to dissolve the pearl, it
would have been impossible to drink it, and if it was weak enough to
drink, it would not have dissolved the pearl, at least not until the
lapse of a very considerable time.
At the island of Ceylon the fishery for pearls is a matter of great
moment. The following is an account of the mode in which it is
conducted.
The country round Aripo, on the north-western coast of the island of
Ceylon, is flat, sandy, and barren, presenting nothing to the eye
but low brushwood, chiefly of thorns and prickly pears (which are
the plants that nourish the cochineal insect[2]), and here and there
some straggling villages with a few cocoa-nut trees. But Condatchy,
three miles distant, where, in general, nothing is to be seen but a
few miserable huts, and a sandy desert, becomes, during the period of
the pearl-fishery, a populous town, several streets of which extend
upwards of a mile in length (though, as the houses are only intended
as a shelter from the sun and rain, they are very rudely constructed),
and the scene, altogether, resembles a crowded fair on the grandest
scale. The people most active in erecting huts and speculating in the
various branches of merchandise, are Mohammedans, Cingalese (natives
of Ceylon), and Hindoos from the opposite coast of the continent of
India. Apparently, however, from their natural timidity, none of the
Cingalese are divers, and scarcely any of them engage in the other
active parts of the fishery; they merely resort hither for the purpose
of supplying the markets.
About the end of October, in the year preceding a pearl-fishery,
when a short interval of fine weather prevails, an examination of
the banks takes place. A certain number of boats, under an English
superintendent, repair in a body to each bank, and having, by frequent
diving, ascertained its situation, they take from one to two thousand
oysters as a specimen. The shells are opened, and if the pearls
collected from a thousand oysters be worth three pounds sterling, a
good fishery may be expected. The “banks,” or beds of oysters, are
scattered over a space in the Gulf of Manaar, extending thirty miles
from north to south, and twenty-four from east to west. There are
fourteen beds (not all, however, productive), of which the largest is
ten miles long, and two broad. The depth of water is from three to
fifteen fathoms.
The pearl oysters in these banks are all of one species, and of the
same form: in shape not very unlike our common English oyster, but
considerably larger, being from eight to ten inches in circumference.
The body of the animal is white, fleshy, and glutinous: the inside
of the shell (the real “mother-of-pearl,”) is even brighter and more
beautiful than the pearl itself: the outside smooth and dark-coloured.
The pearls are most commonly contained in the thickest and most fleshy
part of the oyster. A single oyster will frequently contain several
pearls, and one is on record, as having produced one hundred and fifty.
Sometimes the English government of Ceylon fishes the banks entirely
at its own risk; sometimes, the boats are let to many speculators:
but, most frequently, the light of fishing is sold to one individual,
who sub-lets boats to others. The fishery for the season of the year
1804 was let by government to an individual for no less a sum than
120,000_l._
At the beginning of March, the fishery commenced, and upwards of two
hundred and fifty boats were employed in the fishery alone. These,
with their crews, and divers, and completely equipped with everything
necessary to conduct the business of the fishing, come from different
parts of the coast of Coromandel. After going through various ablutions
and incantations, and other superstitious ceremonies, the occupants of
these boats embark at midnight, guided by pilots, and as soon as they
reach the banks, they cast anchor, and wait the dawn of day.
At about seven in the morning, when the rays of the sun begin to
emit some degree of warmth, the diving commences. A kind of open
scaffolding, formed of oars and other pieces of wood, is projected from
each side of the boat, and from it the diving-tackle is suspended,
with three stones on one side, and two on the other. The diving-stone
hangs from an oar by a light rope and slip-knot, and descends about
five feet into the water. It is a stone of fifty-six pounds’ weight, of
a sugar-loaf shape. The rope passes through a hole in the top of the
stone, above which a strong loop is formed, resembling a stirrup-iron,
to receive the foot of the diver. The diver wears no clothes, except a
slip of calico round his loins,—swimming in the water, he takes hold
of the rope, and puts one foot into the loop or stirrup, on the top of
the stone.
He remains in this upright position for a little while, supporting
himself by the motion of one arm. Then a basket, formed of a wooden
hoop and net-work, suspended by a rope, is thrown into the water to
him, and in it he places his other foot. Both the ropes of the stone
and the basket he holds for a little while in one hand. When he feels
himself properly prepared and ready to go down, he grasps his nostrils
with one hand, to prevent the water from rushing in; with the other
gives a sudden pull to the running-knot suspending the stone, and
instantly descends: the remainder of the rope fixed to the basket is
thrown into the water after him, at the same moment: the rope attached
to the stone is in such a position as to follow him of itself. As soon
as he touches the bottom, he disentangles his foot from the stone,
which is immediately drawn up, and suspended again to the projecting
oar in the same manner as before, to be in readiness for the next
diver. The diver, arrived at the bottom of the sea, throws himself as
much as possible upon his face, and collects everything he can get
hold of into the basket. When he is ready to ascend, he gives a jerk
to the rope, and the persons in the boat, who hold the other end of
it, haul it up as speedily as possible. The diver, at the same time,
free of every incumbrance, warps up by the rope, and always gets above
water a considerable time before the basket. He generally comes up at a
distance from the boat, and swims about, or takes hold of an oar or a
rope, until his turn comes to descend again; but he seldom comes into
the boat, until the labour of the day is over. When a young diver is
training to the business, he descends in the arms of a man completely
experienced in the art, who takes great care of him, and shows him the
manner of proceeding, and the pupil at first brings up in his hand a
single oyster, a stone, or a little sand, merely to show that he has
reached the bottom. The length of time during which the divers remain
under water, is rarely much more than a minute and a half; yet, in
this short period, in a ground richly clothed with oysters, an expert
man will often put as many as one hundred and fifty into his basket.
There are two divers attached to each stone, so that they go down
alternately. The men, after diving, generally find a small quantity
of blood issue from their nose and ears, which they consider as a
favourable symptom, and perform the operation with greater comfort
after the bleeding has commenced. They seem to enjoy the labour as a
pleasant pastime, and never murmur or complain, unless when the banks
contain a scarcity of oysters, though their labours are continued for
six hours.
When the day is sufficiently advanced, the head pilot makes a signal,
and the fleet set sail for the shore. All descriptions of people hasten
to the water’s edge to welcome their return, and the crowd, stir, and
noise, are then immense. Every boat comes to its own station, and the
oysters are carried into certain paved enclosures on the sea-shore,
where they are allowed to remain in heaps (of course, well guarded) for
ten days, that time being necessary to render them putrid. When the
oysters are sufficiently decayed, they are thrown into a large vessel,
filled with salt water, and left there for twelve hours to soften their
putrid substance. The oysters are then taken up, one by one, the shells
broken from one another, and washed in the water. Those shells, which
have pearls adhering to them, are thrown on one side, and afterwards
handed to clippers, whose business it is to disengage the pearls from
the shells, with pincers.
When all the shells are thrown out, the slimy substance of the oysters
remains, mixed with sand and broken fragments of shells, at the bottom
of the vessel. The dirty water is lifted out in buckets, and poured
into a sack, made like a jelly-bag, so that no pearls can be lost.
Fresh water being then added from time to time, and the whole substance
in the vessel continually agitated, the sand and pearls together, are
by degrees allowed to sink to the bottom.
As soon as the sand is dry it is sifted; the large pearls, being
conspicuous, are easily gathered; but the separating the small
and diminutive (“seed pearls,” as they are called,) is a work of
considerable labour. When once separated from the sand, washed with
salt water, dried, and rendered perfectly clean, they are sorted into
classes, according to their sizes, by being passed through sieves.
After this, a hole is drilled through each pearl; they are then
arranged on strings, and are fit for the market.
Pearls have been considered as valuable ornaments from the earliest
times: they are mentioned in the book of Job (xxviii. 18,) and are
often alluded to by the classical writers. There have been various
attempts made to imitate them successfully, one of the most singular
of which,—known to have been practised early in the Christian era,
on the banks of the Red Sea,—is still carried on in China. A hole is
bored in the shell of the pearl oyster, a piece of iron-wire inserted,
and the oyster restored to its place: the animal, wounded by the point
of the wire, deposits a coat of pearly matter round it: this gradually
hardens, successive layers are added, till a pearl of the requisite
size is formed, and the shell is once more brought to land.
A plan, somewhat similar to this, was employed by Linnæus, who pierced
the shells of the fresh-water mussel, causing thereby a pearl to be
formed at the punctured spot; and the Swedish government actually
established artificial pearleries,—but these were abandoned after
a few years; for, although pearls were formed, they were seldom of
sufficient size to be of much value.
False pearls are made of hollow glass globules, the inside of which is
covered with a liquid, called pearl-essence, and then filled with white
wax. This liquid is composed of the silver-coloured particles which
adhere to the scales of the bleak, (_ablette_,) and was first applied
to this purpose, early in the last century, by a Frenchman of the name
of Jacquin[3].