Quarterly Abstract of European Chemistry. 185 



Osmium and Iridium — means of obtaining them pure, by Fremy, 

 (Comp. Eend. Jan. 1844, p. 144.) — One hundred parts of the residue 

 of the platinum ore after the platinum has been entirely extracted, is 

 fused with 300 parts of nitre, and kept red hot for an hour ; after this 

 calcination it is poured upon a metallic plate, taking care to protect the 

 skin from the vapors of osmic acid. The mass is introduced into a 

 retort and treated with nitric acid, which disengages the osmic acid that 

 is to be condensed in a concentrated solution of potash ; that is after- 

 wards to be treated with a little alcohol, which causes the formation of 

 a salt, (osmite of potash,) and its subsequent deposition in the form of 

 a red crystalline powder ; the salt can be washed with alcohol. By 

 adding to the osmite a cold solution of sal ammoniac, it is first dissolv- 

 ed, and subsequently decomposed, giving rise to a yellow salt but 

 slightly soluble in water. It is from this that the pure osmium is ob- 

 tained by heating it in a current of hydrogen gas. To obtain the pure 

 iridium, the residue left in the retort, after driving off the osmic acid, 

 is first treated with water to wash away the nitre ; and the impure oxide 

 of iridium afterwards dissolved in hydrochloric acid. To this solution 

 sal ammoniac is added, which forms an insoluble double salt of iridium 

 and ammonia, as well as a little chloride of osmium and ammonia. 

 This impure salt is suspended in water, and a current of sulphurous 

 acid gas passed through ; this dechlorates the iridium salt, rendering it 

 very soluble in water, while the double salt of osmium and ammonia 

 is not altered. This soluble salt of iridium crystallizes in large prisms 

 of a brown color from a solution of sal ammoniac ; and by heating them 

 in a current of hydrogen, pure iridium is obtained. 



Hydride of Copper, by A. Wurtz, (Compt. Rend. April, 1844, p, 

 702.) — This is a combination of hydrogen and copper, formed by dis- 

 solving 1 part of hypophosphite of baryta in water, precipitating the 

 baryta by sulphuric acid, and adding to the filtered solution 0'8 parts 

 of the sulphate of copper in solution, (concentrated ;) the mixture is 

 then gently heated to a temperature not exceeding 70° C. (158'^ Fah.) 

 and not even that, if hydrogen escapes. It is a yellow powder, presenting 

 the appearance of kermes ; in washing it is necessary to do so with water 

 deprived of air, and in an atmosphere of carbonic acid. When dry, it 

 inflames in chlorine ; hydrochloric acid acts in a singular manner upon 

 it, decomposing it with the production of a lively efiervescence of hy- 

 drogen, and the dichloride of copper is formed. This is very remark- 

 able, as hydrochloric acid does not act on copper when alone, and one 

 would presume that it would be less apt to do so when hydrogen was 

 present ; but this is another instance of the remarkable decomposition 

 by contact, as in the case of the peroxide of hydrogen, &c. In the 



Vol. xLviii, No. 1.— Oct.-Dec. 1844. 24 



