Scientific Intelligence, Sfc. 473 



tricathig any gas, in consequence of the elements of the nitric acid 

 combining with the nascent hydrogen. Nascent hydrogen also de- 

 oxidates copper. To remove the hydrogen, he constructed the 

 constant battery; which consists of a copper cylindrical vessel, con- 

 taining in its axis, a membranous tube formed of the oesophagus of 

 an ox, in which is suspended a rod of zinc. Dilute acid is poured 

 into the membranous tube, by means of a funnel ; and passes off by 

 a syphon, communicating with the bottom. The space between the 

 animal tube and the sides of the copper cylinder, is filled with a 

 solution of sulphate of copper, and pieces of this salt, to keep the 

 solution saturated. By this arrangement, the oxide deposited is 

 removed as it is formed, by the syphon tube ; and the hydrogen 

 evolved from the surface of the copper, is absorbed. For, on com- 

 pleting the circuit, the electric current passes freely through the 

 blue vitriol solution, and no hydrogen appears on the conductor; 

 but the latter is covered with a coating of pure copper. The ad- 

 vantages of this battery are obvious ; it may be kept for hours in 

 action, with the same power, and is economical. 



VII. — Pharmacy, §c 



1. Quassin. — Winckler has succeeded in obtaining the bitter 

 principle of the quassia ainara in its pure crystalline state. He 

 prepares it by digesting 3 ounces of pulverised quassia wood in 2 lbs. 

 spirit of wine of 80 per cent, evaporating the tincture in a water 

 bath, dissolving the remainder in water, filtering the solution; he 

 then evaporates it in the water bath to the consistence of a thick 

 extract, and treats it with water and spirit of 80 per cent., with small 

 portions of absolute alcohol as long as they take up a bitter taste. 

 The spirituous tincture is then filtered, evaporated in a water bath, 

 the dry residue treated with hot water, when a small quantity of 

 dark brown matter remains. The filtered solution possesses a yellow- 

 wine colour; it should be decolourized by animal charcoal, and 

 evaporated at a gentle heat ; the quassin separates in fine white 

 prisms. From the watery extract no crystals can be obtained, but 

 merely a yellow-deliquescent mass. Quassin is soluble in water, 

 more so in spirit, very little in ether. By diluting the alcoholic solu- 

 tion the quassin is obtained in the form of a woody mass. The 

 aqueous solution is precipitated white by tannin and corrosive 

 sublimate. — Central blatt, Jan., 1836, 69. 



2. Chinese Rhubarb.— For the discovery of the true plant which 

 supplies this drug, (usually called Indian), the Russian government 

 have for several years offered a reward of 30,000 roubles. M. 

 Paravey, among some Chinese works which he has examined at 

 Pans, found two figures of the plant with violet and white flowers, 

 shewing that the source of this medicine is not confined to the 

 Rheum palmatum R. and R. uudulatum. — L' Inst Hut., 150. 



3. Rapid mode of preparing Mercurial Ointment.— According 

 to Van Mons mercury can be rapidly killed by adding some drops 

 of Balsamum mlphuris terebinthinatwnu —Buchncr's Repcr- 

 torium, iv. 272. 



