Intellisence and Miscellaneous Articles. 397 



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ceeded in isolating three : — 1, a rose-coloured crystalline salt; 2, an 

 amber-coloured substance, having the consistence of Venice tur- 

 pentine ; 3, a white pulverulent compound. All these compounds 

 contain potash, sulphuric acid, chlorine, and protoxide of iridium 

 in variable proportions. They are nearly insipid, and very slightly 

 soluble in water, disengage sulphurous acid when heated, and are 

 difficultly decomposed by calcination. 



Hydrochloric acid dissolves them readily, disengaging part of their 

 sulphurous acid, and converting them into other salts containing an 

 equivalent of chlorine. The aqueous solution gives a white floccu- 

 lent precipitate with chloride of barium, and the alkalies decompose 

 them with difficulty. They are but slowly oxidized by means of 

 aqua regia; and before conversion into chloride of iridium, they 

 assume a deep cherry-red colour. 



The author has analysed the rose-coloured salt, and finds the 

 composition to be represented by — 



(2K0, S02+2KCl)-f(2lrO J^^qi' j • 



The amber-coloured substance resembling turpentine M. Claus 

 lias also analysed, and gives as its rational formula — 



4KO,S02-f-2IrO+ {^^q }* 



The white salt of iridium, obtained only in small quantity, has 

 been described and analysed by the author ; its formula is. — 



3K0, SO"'+IrO^ S0"-i-5Aq. 



On treating this salt with hydrochloric acid, a yellow solution is 

 obtained, which by evaporation yields yellow prisms, considered by 

 M. Claus as a double salt, or sulphite of protoxide of iridium and 

 chloride of potassium, 3KC1 + Ir0% SO^. 



b. Compounds of Osmium. — The potassio-chloride of osmium 

 undergoes no modification by sulphurous acid at common tempera- 

 tures ; but when heated, sulphite of potash occasions a partial de- 

 composition, producing a pulverulent precipitate which is a double 

 sulphite of potash and osmium, represented by the formula 3KO, 

 SO'^ + OsOSS02-|-5Aq. On treating this salt with hydrochloric 

 acid, the double salt, 3K Cl + Os OS SO-, or chloride of potassium 

 and sulphite of osmium. 



c. Compounds of Platina. — The author describes in a few words 

 the preparation of potassio-chloride of platina, which, heated with 

 sulphite of potash, serves for the preparation of a white substance, 

 which the author from his analyses considers as a double sulphite of 

 potash and platina, 3K0, SO^ + Pt O^ S0^ + 2iAq.; it resembles 

 the salt of osmium, but is more insoluble, almost insipid, heavier, 

 and contains only half the quantity of water. With hydrochloric 

 acid it acts differently from the preceding salts ; for it loses all its 

 sulphurous acid, and is converted into potassio-chloride of platina. 



d. Compounds of Ruthenium. — Sulphurous acid acts but little 

 upon the potassio-sesquichloride of ruthenium at common tempera- 

 tures ; but a solution of the salt treated with sulphite of potash 



