392 Litelligence and MiscellaJieous Articles. 



readily dissolves it, and sulphuret of ammonia precipitates it of a 

 brown colour : the precipitate being roasted in contact with air, be- 

 comes ot a blackish-brown colour. These two metals are found in 

 very small quantity in the Uralian platina, the latter in greater pro- 

 portion than the former. 



" The third metal is also found in the nitro-muriatic solution of pla- 

 tina : this metal possesses the singular property of forming an alloy 

 with iron, which is not decomposable by nitric acid. By fusing this 

 alloy with caustic potash and nitrate of potash, the iron is sufficiently 

 separated to be taken up by nitric acid ; the residuum after this sepa- 

 ration is a dark green coloured powder, and is the oxide of the metal. 

 When put upon a piece of platina and heated to whiteness, the pow- 

 der is blackened but not reduced ; but when exposed to the flame of 

 the blowpipe, it becomes a metallic mass of considerable lustre. 

 The metal thus obtained has the following properties : It is insoluble 

 in nitro-muriatic acid, even when heated ; when fused with caustic 

 potash and nitre, it yields a brownish coloured mass, which softened 

 by water deposits a gray powder still retaining some lustre ; the 

 alkali dissolves nothing, and the powder is merely the metal in a 

 divided state, in which aqua-regia attacks it slowly, and converts it 

 eventually into green oxide. By directing a current of hydrogen gas 

 upon the heated oxide, combustion resembling that of gunpowder 

 ensues J and a blackish powder is formed, which by the long re-action 

 of the hydrogen is completely reduced. The metal thus reduced has 

 a gray colour, nearly resembling recently formed spongy platina. 

 When heated in contact with the air it becomes black, and continues 

 so even at a white heat : it differs in this respect from rhodium, which 

 is oxidated by heat, and at a higher temperature is again reduced." 



NEW ALKALI IN HEMLOCK. 



Professor Ficinus of Dresden has discovered a new alkali in the 

 JEthusa Cynapiurn (Linn.) to which he has given the name of 

 Cynopia. It is crystallizable, and soluble in water and alcohol, but 

 not in aether. The crystals are in the form of a rhombic prism, 

 which is also that of the crystals of the sulphate. — Hensman's Reper- 

 toire. 



HEAT EVOLVED BY COMPRESSING WATER. 



M. Despretz has ascertained that when water is compressed by a 

 force equal to 20 atmospheres, that one sixty-sixth part of a degree 

 of heat is evolved. — Royal Institution Journal, Oct. 1827. 



lODOUS ACID. 



According to M.,Wohler, the iodous acid of M.Semcntini is nothing- 

 more than a mixture of chloride of iodine and iodine. When saturated 

 with carbonate of soda, the iodine in solution is precipitated, and on 

 evaporating to dryness and heating it strongly the residue fuses, and 

 by proper tests is found to be a mixture of chloride and iodide of 

 sodium. 



These statements apply only to the iodous acid : as to the oxide of 

 iodine, no source of chlorine exists in the process last described by 

 M. Sementini. — IbiiJi. jiANCiNESic 



