will endeavour to give a short account of the mines from which diamonds principally come, their chemical characteristics and properties, and the relative value of the different sizes. The ancients give us but little information on the subject of diamond mines. Pliny mentions the Acesines or Jenaub, and the Ganges, as gemproducing rivers; and Ammian says that the land of the Agathyrsi, beyond the Sea of Azof, where certain spurious diamonds, whose use is strictly forbidden by the Russian Government, are still found, abounded with them in his day. Oriental writers indulge us with many marvellous stories of an inaccessible valley of diamonds' on Mount Zulmeah, or Sarendip; a translation of some of them may be consulted in the Journal of the Bengal Asiatic Society for 1832. It is therein related that when Alexander of Macedon visited the mysterious valley, he ordered raw flesh to be thrown down into it, with which the eagles and vultures who resort to it to feed on snakes, flew away, dropping the precious stones in their course on more accessible places. Marco Polo in the thirteenth century assures us that this trick was a very common one amongst the natives of India. The first real authority on this subject is Jean Baptiste Tavernier, born in 1605. The son of an old Antwerp map-maker who had settled in Paris, young Tavernier caught from the geographical conversation of his father's customers, a violent passion for travel and adventure. At the age of twenty-two, having learnt the trade of a jeweller, he determined to gratify his longing for travel, and at the same time continue his traffic in precious stones. Passing first through France, England, the Low Countries, Germany, and Italy, he travelled for no less than forty years all over Turkey, Persia, India, and the far East, and realized a considerable fortune. On his return in 1664, he was, although a Protestant, ennobled by Louis XIV. as Baron d'Aubonne, near Geneva, where he retired to end his days, as he hoped, amongst his fellow Calvinists. But the mismanagement of a nephew to whom he had confided his business, soon broke up his long-coveted repose. Jewels to the amount of several hundred thousand livres, on which a profit of a million should have been realized, were so carelessly disposed of, that the loss nearly ruined him. At the age of eighty-four he was compelled to sell his estate, and start again for the East, hoping that his experience and tact would enable him to found a fresh fortune. But anxiety and the fatigues of the journey were too much for him, and he died, en route, at Moscow, 1689. His works, edited by two of his friends, were published at Paris in three volumes, ten years before his death, besides many interesting details of his travels; they contain special descriptions of three celebrated mines, that of Coloor in the Circars, now British territory; that of Sumelpoor or Guel, on the south-western frontier of Bengal; and the well-known mines of Golconda. From these latter most of the diamonds in the European market originally came; they were discovered by a shepherd who bartered the first specimen for a little rice; it must have been of enormous value, for we are told he actually stumbled over it. The passing traveller into whose hands it had thus passed from the poor ignorant and nearly starving shepherd, sold it for a good sum to a native jeweller, who never rested till he discovered the mine itself; and when Methold, an English traveller, visited it in 1622, he found 30,000 labourers at work. The mine was then farmed to a jewel merchant, named Marcander, for £37,500; the king claiming all stones above two carats weight, a usual stipulation, which accounts for the fabulous wealth in precious stones of Eastern Princes, one sovereign after a reign of forty years having collected four hundredweight of jewels. The slaves, however, manage to secrete the larger specimens at times, either by swallowing them, or by throwing them away when found, and going back to look for them by night. One of the most singular portions of Tavernier's narrative is his account of the boy-traders of Golconda. A company of boys, whose age varies from ten to sixteen years, assemble under a large tree in the public square, each with a bag for diamonds, and a purse sometimes containing £100 or £150 by way of a bank. These lads act as middlemen' between the finders of the gems and the 'administration,' as our Gallic friends would have it, of the mine. When a diamond is brought to them, it is silently examined by each in turn; the captain of the firm then makes a bid, rising by slow degrees if necessary. When the bargain is struck, if the firm think he has paid too much, he is obliged to keep the diamond and run all risks himself; but if they are content, he is paid a certain proportion by each. The stone is then taken to the authorities, who buy it at a small advance on the boy's payment, and the profits are then divided, the captain receiving one-fourth per cent. more than the So accurate is their judgment, that if the captain after having a diamond thrown on his hands, is willing to lose his commission of onefourth per cent., the others will almost always relieve him of it. These mines, once so productive, employing, as Tavernier tells us, more than 60,000 men, are now entirely deserted, the great supply coming from Brazil, which since 1727 has supplied more than two tons weight. rest. That the diamond is simply carbon is now undisputed, but the manner of its formation is still a mystery; as also are the flaws which sometimes disfigure it, and the varieties of its colour, white, yellow, orange, red, pink, brown, green, blue, black, and opalescent.* Liebig imagines that the flaws arise from the presence of uncrystalized vegetable matter; Harry Emanuel, that the imperfect crystalization of the carbon is the real cause; but on the subject there is great obscurity. Diamonds are combustible under tremendous heat; Francis of Austria exposed some with a few rubies in an assayer's furnace for twenty-four hours, and found on opening it that the rubies were unhurt, while the diamonds had vanished. Lavoisier, after burning a fine diamond in oxygen, obtained the same result as from burning carbon, viz. carbonic acid. Diamonds having *Harry Emanuel, The Diamond,' &c. been thus proved to be after all a most simple material, produced, it is true, in a most subtile manner by the chemistry of nature; many and many an experimentalist has devoted his time, health, and fortune to endeavouring to manufacture them; a vain attempt, worthy to be classed with those medieval fallacies, the elixir vitæ, and the philosopher's stone. The Romans believed that this gem possessed a superior magnetic power to the loadstone, and that if placed together the power of the latter was neutralized-an idea which, though it must have been exploded at the first trial, still survives in the French word 'diamant,' or Pierre d'Aimant, as it originally stood, used indifferently for the loadstone or the diamond. It is, however, electric, attracting light objects when heated with friction, and alone among gems has the power of becoming phosphorescent in the dark after long exposure to the sun. Between the specific gravity of the pure white and yellow, or other coloured varieties of the diamond, there is some little difference, as well as between those of Golconda and of Brazil. The Indian again is octahedral, the Brazilian doxecahedral in its crystals. The diamond reflects light falling on its posterior angles at an angle of 24°13'. It does not polarize light, though Sir D. Brewster thought light changed slightly in passing through it; its power of refraction is enormous. All diamonds scratch glass, but only those with a certain acuteness of angle will cut it truly, these are worth £10 per carat, (a weight used in oriental nations, derived from the Indian word kerua, Greek form Kepátiov, a small seed weighing three grains.) The following table of values, taken from the most practical work on the diamond which we have, that of Harry Emanuel, must be considered as referring only to the purest and best white brilliants, other varieties varying according to the mania of the day, an influence which no precious stone of any kind is totally exempt from. £ S. After which size they are so difficult to value, that one may say 'they are worth what they will fetch,' ten to fifty thousand pounds having been stumbled over it. The passing traveller into whose hands it had thus passed from the poor ignorant and nearly starving shepherd, sold it for a good sum to a native jeweller, who never rested till he discovered the mine itself; and when Methold, an English traveller, visited it in 1622, he found 30,000 labourers at work. The mine was then farmed to a jewel merchant, named Marcander, for £37,500; the king claiming all stones above two carats weight, a usual stipulation, which accounts for the fabulous wealth in precious stones of Eastern Princes, one sovereign after a reign of forty years having collected four hundredweight of jewels. The slaves, however, manage to secrete the larger specimens at times, either by swallowing them, or by throwing them away when found, and going back to look for them by night. One of the most singular portions of Tavernier's narrative is his account of the boy-traders of Golconda. A company of boys, whose age varies from ten to sixteen years, assemble under a large tree in the public square, each with a bag for diamonds, and a purse sometimes containing £100 or £150 by way of a bank. These lads act as middlemen' between the finders of the gems and the 'administration,' as our Gallic friends would have it, of the mine. When a diamond is brought to them, it is silently examined by each in turn; the captain of the firm then makes a bid, rising by slow degrees if necessary. When the bargain is struck, if the firm think he has paid too much, he is obliged to keep the diamond and run all risks himself; but if they are content, he is paid a certain proportion by each. The stone is then taken to the authorities, who buy it at a small advance on the boy's payment, and the profits are then divided, the captain receiving one-fourth per cent. more than the rest. So accurate is their judgment, that if the captain after having a diamond thrown on his hands, is willing to lose his commission of onefourth per cent., the others will almost always relieve him of it. These mines, once so productive, employing, as Tavernier tells us, more than 60,000 men, are now entirely deserted, the great supply coming from Brazil, which since 1727 has supplied more than two tons weight. That the diamond is simply carbon is now undisputed, but the manner of its formation is still a mystery; as also are the flaws which sometimes disfigure it, and the varieties of its colour, white, yellow, orange, red, pink, brown, green, blue, black, and opalescent.* Liebig imagines that the flaws arise from the presence of uncrystalized vegetable matter; Harry Emanuel, that the imperfect crystalization of the carbon is the real cause; but on the subject there is great obscurity. Diamonds are combustible under tremendous heat; Francis of Austria exposed some with a few rubies in an assayer's furnace for twenty-four hours, and found on opening it that the rubies were unhurt, while the diamonds had vanished. Lavoisier, after burning a fine diamond in oxygen, obtained the same result as from burning carbon, viz. carbonic acid. Diamonds having *Harry Emanuel, The Diamond,' &c. been thus proved to be after all a most simple material, produced, it is true, in a most subtile manner by the chemistry of nature; many and many an experimentalist has devoted his time, health, and fortune to endeavouring to manufacture them; a vain attempt, worthy to be classed with those medieval fallacies, the elixir vitæ, and the philosopher's stone. The Romans believed that this gem possessed a superior magnetic power to the loadstone, and that if placed together the power of the latter was neutralized-an idea which, though it must have been exploded at the first trial, still survives in the French word 'diamant,' or Pierre d'Aimant, as it originally stood, used indifferently for the loadstone or the diamond. It is, however, electric, attracting light objects when heated with friction, and alone among gems has the power of becoming phosphorescent in the dark after long exposure to the sun. Between the specific gravity of the pure white and yellow, or other coloured varieties of the diamond, there is some little difference, as well as between those of Golconda and of Brazil. The Indian again is octahedral, the Brazilian doxecahedral in its crystals. The diamond reflects light falling on its posterior angles at an angle of 24°13'. It does not polarize light, though Sir D. Brewster thought light changed slightly in passing through it; its power of refraction is enormous. All diamonds scratch glass, but only those with a certain acuteness of angle will cut it truly, these are worth £10 per carat, (a weight used in oriental nations, derived from the Indian word kerua, Greek form Kepátiov, a small seed weighing three grains.) The following table of values, taken from the most practical work on the diamond which we have, that of Harry Emanuel, must be considered as referring only to the purest and best white brilliants, other varieties varying according to the mania of the day, an influence which no precious stone of any kind is totally exempt from. After which size they are so difficult to value, that one may say 'they are worth what they will fetch,' ten to fifty thousand pounds having been |