Intelligence arid Miscellaneous Articles. 391 



phur, to one-eighteenth. Chlorine by compression gives a weak violet- 

 coloured light. 



M. CoUadou has also ascertained by means of an instrument which 

 he invented ; first. That the alteration of temperature is not exactly 

 proportional to the change of volume which gases suffer : secondly, That 

 when the volume of the gas is inconsiderable, the increase of tem- 

 perature indicates the diminution of volume : thirdly, That a dilated 

 gas is more heated by compression than one which is compressed. — 

 Ibid. 



METAL OF ALUMINA. 

 M. Oei"sted is stated to have obtained the metal of alumina by em- 

 ploying the chloride of that earth. Pure alumina is heated to redness, 

 and then intimately mixed with powdered charcoal : the mixture is 

 introduced into a porcelain tube ; and after heating to redness, dry 

 chlorine gas is passed over it. The charcoal reduces the alumina, the 

 metal combines with the chlorine, and oxide of carbonis also formed. The 

 chloride of aluminum is soft, crystalline, and evaporates at a little above 

 the temperature of boiling water j it readily attracts moisture from the 

 air, and becomes hot when water is added to it. By mixing with an 

 amalgam of potassium, containing much of the latter, and immediately 

 heating the mixture, chloride of potassium is formed, and the metal of 

 the alumina combines with the mercury. The amalgam quickly 

 oxidizes by exposure to the air. Being subjected to distillation out 

 of tiie contact of air, the mercury is volatilized, and a metallic button 

 is left, which has the colour and splendour of tin. M. Oersted has 

 ascertained many properties belonging to the new metal and its amal- 

 gam, which he promises to publish speedily. — Ibid. 



NKW METALS IN THE URALIAN PLATINA. 



The discovery of these metals by Professor Osann of Dorpat is 

 announced as follows, in Hensman's Repertoire de Chimie for Sep- 

 tember last. 



" I have discovered in the platina of the Uralian mountains three 

 metals, the properties of which are different from those of every other 

 known metal. One of thern occurs in the residuum left by the solu- 

 tion of the platina in aqua-regia, which is sold at the Mint in Peters- 

 burgh. I have as yet found it only in one specimen of the metal. 



"The oxide crystallizes in long prisms from the nitro-muriatic .solu- 

 tion of the platina : these crystals sublime without undergoing any 

 change, but at a higher temperature than required for the sublima- 

 tion of oxide of osmium. Subjected to the blowpipe a portion of the 

 salt sublimes, while another is reduced to a globule of metal. Sul- 

 phuret of ammonia converts the reduced metal to a gray sulphuret, 

 which readily fuses, and burning in the air, it is converted into oxide. 



" The .second metal is found in the nitro-muriatic solution of 

 the same platina ; it possesses the following properties. The 

 solution yields white acicular crystals, which soften in the heat of 

 melting glass, and are reduced to the metallic state. Hydrogen re- 

 duces it to a metal of a gray colour witli a tint of red : this metal did 

 not melt, but retained the crystalline form of the oxide, Aqua-regia 



readily 



