750 BLtfCIIER out into a plate over 40 inches long and about 3 inches wide. Prof. Henry St. Claire Deville of Paris has considerably modified Dr. Roberts's method of melting platinum, and performs the operation in lime crucibles. Messrs. Johnson and Matheys of London have fused some pounds of platinum and iridium in Deville's furnace. A compound blowpipe is conveniently made by placing one tube one eighth of an inch in diam- eter inside another of one half inch diameter. Illuminating gas is admitted at the side of the outer tube and lighted at one end, while the other end is made gas-tight. A current of air is blown by bellows through the inner tube, which at once changes the yellow gas flame to the intense blue blowpipe flame ; the combus- tion is more complete and the flame hotter as the mixture of gas and air is more perfect. This piece of apparatus is called Bunsen's blast lamp; it is used in all chemical laboratories which have gas, and is also used by glass blow- ers in the manufacture of nice chemical and philosophical apparatus. By this method the effect of a furnace is obtained by chemists for melting the contents of small crucibles in ana- lytical operations. If either or both gases be passed through heated pipes, a still higher de- gree of heat may be obtained. By substitut- ing oxygen for the atmospheric air, globules of platinum may be instantly melted upon charcoal. This mixture may be conveniently and economically used instead of hydrogen and oxygen for the production of the Drummond light. The so-called Bohemian glass blowers seem still to prefer the old-fashioned blowpipe, consisting of two gas burners about 10 inches apart, with air jets blowing directly toward each other, by which means the two opposite sides _of the glass are heated at the same time. Itl.M HIM:. Gebhard Lcberecht Ton, prince of Wahlstadt, Prussian field marshal, born at Rostock, in Mecklenburg-Schwerin, Dec. 16, 1742, died at Krieblowitz, in Silesia, Sept. 12, 1819. He was sent, while a boy, to the island of Riigen, and there, in 1756, secretly enlisted in a regiment of Swedish hussars as ensign, to serve against Frederick II. of Prussia. Made prisoner in the campaign of 1760, he was, after a year's captivity, and after he had ob- tained his dismissal from the Swedish service, prevailed upon to enter the Prussian army. In 1771 he was appointed senior captain of cavalry. In 1778 Oapt. Von Jagersfeld, a natural son of the margrave ofSchwedt, being appointed in his stead to the vacant post of major, Blucher wrote to Frederick : " Sire, Jagersfeld, who possesses no merit but that of being the son of the mar- grave of Schwedt, has been preferred to me. I beg your majesty to grant my discharge." In reply Frederick ordered him to be shut up in prison until he would retract his request ; but as he remained obstinate for nearly a year, the king complied with his petition in a note to this effect : " Capt. Von Blucher may go to the devil." He now retired to Silesia, married, became a farmer, acquired a small estate in Pomerania, and, after the death of Frederick II., retntered his former regiment as major, on the express condition of his appointment being dated back to 1779. Some montbs later his wife died. Having participated in the blood- less invasion of Holland, he was appointed lieu- tenant colonel in 1788, and in 1700 colonel. In 1793 he distinguished himself during the campaign in the Palatinate against republican France as a leader of light cavalry, and in May, 1794, after the victorious affair of Kirrweiler, was promoted to the rank of major general. While incessantly alarming the French by bold coups de main and successful enterprises, he never neglected keeping the headquarters sup- plied with the best information as to the hos- tile movements. His diary, written during this campaign, and published in 1796 by Count Goltz, his adjutant, is considered, despite its illiterate style, a classical work on vanguard service. After the peace of Basel he married again. Frederick William III. appointed him in 1801 lieutenant general, in which quality he occupied, and administered as governor, Erfurt, Muhlhausen, and Munster. In 1805 a small corps of observation was collected under him at Bayreuth. In 1806 he led the Prussian van- guard at the battle of Auerstadt (Oct. 14). His charge was, however, broken by the terrible fire of Davoust's artillery, and his proposal to renew it with fresh forces and the whole of the cavalry was rejected by the king of Prussia. After the double defeat at Anerstiidt and Jena, he retired down the Elbe, picking up the rem- nants of different corps, which swelled his army to about 25,000 men. His retreat to Lu- beck, before the united forces- of Soult, Berna- dotte, and Murat, forms one of the few honor- able episodes in that epoch of German war- fare. Since Lubeck was a neutral territory, his making the streets of that open town the thea- tre of a desperate fight, which exposed it to a three days' sack on the part of the French soldiery, afforded the subject of passionate cen- sure ; but under existing circumstances the im- portant thing was to give the German people one example, at least, of stanch resistance. Thrown out of Lubeck, he had to capitu- late in the plain of Ratkow, Nov. 7, on the express condition that the cause of his surren- der should be stated in writing to be " want of ammunition and provisions." Liberated on his word of honor, he repaired to Ham- burg, there, in company with his sons, to kill time by card-playing, smoking, and drinking. Being exchanged for Gen. Victor, he was ap- pointed governor general of Pomerania; but one of the secret articles of the alliance con- cluded, Feb. 24, 1812, by Prussia with Napo- leon, stipulated for Blucher's discharge from service, like that of Scharnhorst and other dis- tinguished Prussian patriots. To soothe this official disgrace, the king secretly bestowed upon him the handsome estate of Kunzendorf in Silesia. During the period of transition be- tween the peace of Tilsit and the German war
