it is rather a poetic fancy than a scientific fact. We have latterly been especially indebted to the German naturalist, Theodore von Hessling, for a very circumstantial and thoroughly exhaustive memoir on the natural history of the pearl oysters and their pearls,[90] in which the learned author seeks to establish that the enveloping matter of the germ of the pearl is identical with the covering of the animal, and that in the process of growth two influences are at work, an external and an internal. The first is called into play by the property peculiar to the hinge system that unites the double shell, of gaping wide open, in consequence of which extraneous substances rush in with the current of water, such as minute fragments of quartz, molecules of plants, &c., which, being detained either circling in the cavity, or eddying round the hinges, are seized on in the course of their revolutions, and entangled in the parenchyma of the various organs, which is specially secreted from the mantle, till it becomes enveloped by layers of solid shell. On the other hand, the internal development is closely allied to the conditions of deposition and subsequent growth of the shell-matter. Molecules, either a single grain or congeries of grains, varying from 9.01 to 0.05 of a line (¾ of an inch down to the 1⁄240th of an inch), enclosed in the epidermis of the shell, constitute usually the nuclei of the pearls, which, to a certain extent, may be considered as nothing but a portion of the epidermis not applied to the formation of shell. The pearls also are simply independent concretions growing in the creature, and consisting of the substance of the shell, which are with difficulty discriminated from the various descriptions of growths which constitute the inner surface of the shell.
[90] Die Perlen-Muschel, und ihre Perlen, Naturwissenschaftlich und Geschichtlich mit Berücksichtigung der Perlen-gewässer Bayerns, beschrieben von Theodor von Hessling, Leipzig, 1859.
The great importance of the pearl as an article of luxury and commerce, has naturally led to numerous attempts to manufacture them by artificial means, in the course of which extraneous bodies have been introduced between the mouth and shell of the animal, sometimes with, sometimes without injury to it. The Chinese especially are adepts at placing certain small bodies, specially prepared, in the shells of the pearl oyster, which, after a short time, becomes coated with mother-of-pearl, or nacre. This manufacture of artificial pearls is carried on on a large scale in the neighbourhood of Hong-Chow-Foo. During our stay at Hong-Kong and Shanghai respectively, we ourselves saw several mussel-shells, in which a mother-of-pearl covering had formed over small neatly carved figures, mostly sitting figures of Buddha,[91] the singular appearance of which would, at the first glance tend to make the observer suspect that the pearl had been fastened to the mussel by some adhesive substance. But we had so frequently an opportunity of satisfying ourselves by actually witnessing the entire process, that we could no longer doubt that the carved figures are with the utmost care introduced into the animal, and, after remaining a few days in the water, become attached to the mussel by a distinct membrane. This, their membrane, afterwards becomes interpermeated by the calcareous matter, till, finally, layers of mother-of-pearl are deposited all around the nucleus, the whole formation corresponding with the chalk-like concretions occurring in other creatures.
[91] The antiquity of this experiment is proved by the fact that the Topographia of Ischikiang speaks of a pearl, which had been sent to the Imperial Palace at Pekin, 490 b. c., which resembled Buddha, and apparently must have been produced by this same method; although likewise the priests of Buddha, at that early epoch, might not have objected, in the interests of their religion, to make capital out of such a specimen of artistic skill.
Besides the pearl-shells, the northern shores of Ceylon, especially between the Island of Manaar and Karativoe, are especially rich in beds of a volute mussel (Turbinella rapa, or soluta gravis), which are exported in great numbers to India, where the Hindoo women saw them into rings of all sizes, to be worn as ornaments on the arms, legs, fingers and toes. The chank-shell is likewise a chief instrument of the Buddhists, who, amongst other devout customs, blow three times a day on this sacred shell, to summon believers to worship.[92] It is also used as a festive ornament of the Indian temples, as well as a donation to the dead, which, inspired by a religious feeling, the survivors place in the grave alongside of the corpse of their illustrious departed.
[92] According to the most ancient annals of the Cingalese, the chank-shell is sounded in one of the superior heavens of the demigods (similar to the conk-blowing Tritons of Grecian mythology), in honour of Buddha, as often as the latter wanders abroad on the earth.
The gems found on the island are distinguished, less for their intrinsic value than for the great variety of precious stones which are present. They are, with few exceptions, found to have been disengaged from the primitive rocks, and washed into the alluvial soil, especially in the outskirts of the mountainous districts, where they are rolled along the beds of the streams together with other pebbles, or are washed out of the alluvial deposits. Hitherto, they have only been searched for for purposes of trade, and then only in the most desultory and thriftless way, no one having as yet examined the rocks themselves, by the disintegration of which the valuable stones are disengaged. There was, indeed, no detailed information as to the wealth in precious stones of the island, until the researches of the English mineralogist, Dr. Gygax, who has very lately published on this subject many interesting observations and remarks. The locality in which precious stones are most abundant is, so far as present experience goes, the district of Saffragam, the capital of which in consequence takes the name of Ratnapoora, or Anarhadnaporra, "the city of rubies." They are also found at various other parts of the island; in the plains on the West coast, between Adams' Peak and the sea, at Nuwera Ellia, Kandy, Matelle, and Ruanwelli, near Colombo, as also in Matura, and the river courses on the eastern side, towards the ancient Mahagam. The geologist of the Expedition visited some mines of precious stones near Ratnapoora. These are situated on the Kaluga-Sella, a small tributary of the Kalu-Gunga, and lie, some in the very bed of the river, some on the steep bank. They are about thirty feet deep, but having been some time disused, they are full of water. The uppermost stratum of these pits or mines is a rich fertile yellow loam, exactly resembling our diluvial loams. This is succeeded, according to the report of the proprietor of the mines, by a slimy black clay, and clayey sand, beneath which again is a bituminous clay, holding numerous organic remains, such as leaves, trunks of trees converted into a substance resembling lignite, and not infrequently elephants' tusks and bones of animals; thereafter sand, and lastly a bank of rolled gravel, forming a species of conglomerate with red, yellow, and occasionally blue clay—being, in fact, what is known as stone-gravel. This bank of pebbles is the layer in which the precious stones occur, and these are most commonly found between the larger masses of agglutinated matter, that are always found especially to abound in gems, whenever they are superposed upon what is called malave, which appears to be a sort of greenish-coloured talc-like half-decomposed mica. The most valuable stones that are obtained from these mines are rubies and sapphires. In the Kalu-Gunga, also, precious stones are occasionally washed down, and as the geologist of the Novara Expedition was descending the river in a boat, from Ratnapoora to Caltura, he perceived at several places, more particularly at the various rapids, men standing in the water, provided with flat pan-shaped baskets, in which they sifted the sand and pebbles.
The gems found on the island are rubies, sapphires topazes, amethysts, garnets, cinnamon-stone, and tourmaline. On the other hand, all the diamonds, emeralds, carnelians, agates, opals, and turquoises, which the natives offer for sale, are imported from India. One precious stone, on which the Cingalese set an exceedingly high value, because they erroneously believe that it is peculiar to the island of Ceylon, whereas it is also found on the southern shores of Hindostan, is the "Cat's-eye," a greenish transparent quartz, which, when polished in its natural shape, or "en cabochon," exhibits in its interior a varying reflected light, undoubtedly arising from the presence of fibres of asbestos, and which, in fact, bears some resemblance to the eye of a cat. The natives, as a rule, estimate the value and symmetry of this stone by the brilliancy and tenuity of the beam which it emits, and the clear olive-coloured ground upon which it shines in relief.
A vast number of men give themselves up to the exciting but most uncertain occupation of searching for precious stones, and barter what they have found, chiefly to Mahometan merchants, for clothes and salt. As, however, the natives themselves set a high value on jewels, in consequence of their small bulk admitting of their being readily concealed and easily carried about, the finer descriptions are readily disposed of at a good price, and, singular to say, it has frequently happened, as we ourselves found by personal experience, that precious stones are dearer in Colombo and Galle than in the European markets! The explanation of this paradox is probably that the steady copious influx into the London and Paris markets of precious stones from all parts of the earth where jewels are found, admits of by no means such excessive fluctuations in value as at Ceylon, where the supply actually on hand is so varying, and where the value of the article almost always depends upon the rank and wealth of the Indian purchaser. The foreign traveller very often cannot restrain a feeling of surprise at seeing the fingers of the stately Mahometan jewellers adorned with rings of costly gems, which are only offered for sale to himself at an exorbitant sum.
The value of the precious stones of all sorts found in Ceylon in the course of a year is estimated by Sir Emerson Tennent at about £10,000, one-fourth, at least, of the entire quantity finding a market on the island, a full half being sent to the jewel-polishers of India, so that only the remaining fourth is exported to Europe.