Mr. Murray mentioned a beautiful gem of two hundred and fifteen karats, called the Round Brilliant of Portugal, and estimated its value at £388,290. Mr. Mawe describes another a little less in size, and also two nearly perfect octahedrons of one hundred and thirty-four and one hundred and twenty karats each. The state waistcoat of Joseph I. had twenty buttons, each button being composed of a solitaire diamond of the value of $20,000, and the rest of its ornaments were corresponding in beauty and value. This garment is said to have been the richest ever seen in Europe, with the exception of the recent grand illumination by the Shah of Persia. It has also been stated that the golden cane of John VI. had in its top a splendid brilliant of the value of a million of francs. The largest of the Brazilian diamonds was discovered as late as 1852, by a negress working in the mines of Begagem. Like most of the large diamonds, its form was not symmetrical, and its shape was much modified from the regular crystalline forms. In 1856 it was brought to France and exhibited to the members of the Academy of Sciences. The gem then weighed in its rough state 254¹⁄₂ karats, and appeared perfectly transparent and without tint. It was placed in the hands of Coster, of Amsterdam, for cutting, and reduced in weight to 127 karats. The form given it was the brilliant; but the gem was cut too thin to exhibit its full beauty. The spread of its table will be found, on comparison, to be much greater than that of the Regent diamond, which weighs 136 karats, or almost 10 karats more; therefore Babinet properly exclaims against the taste which adopted an imperfect brilliant, at a great reduction of weight, when the form of the brilliolette, like that of one of the Sancys, would have preserved three fourths of its weight and given it a more splendid lustre. It would then have been the second diamond in weight and beauty in Europe. This gem is known as the Star of the South, but is sometimes called the Halphen diamond, from the name of the gentleman who bought it on its arrival in Europe. The gem treasures of the Elector of Saxony are among the most valuable and unique in Europe. The commencement of their collection dates from an early period. The famous silver mines, prior to the discovery of America, placed the Saxon princes among the richest sovereigns of Europe; and they took pride in exhibiting their magnificence, in expending vast sums of money in the purchase of gems, jewels, and works of art.