230 Intelligence and Miscellaneous Articles. 



added, which throws down fluoride of calcium if a fluoride of 

 any metal be present. Care should be taken to prevent ac- 

 cess of air as much as possible, otherwise carbonate of lime 

 would also be thrown down. The whole is then to be filtered, 

 and the precipitate gently heated with strong sulphuric acid 

 in a platinum crucible covered with a glass plate, having a 

 thin coating of wax with a few letters or words etched on the 

 wax, so as to leave the glass bare at a few points. The pre- 

 cipitate can thus be proved beyond doubt to be fluoride of 

 calcium, by the glass being attacked by the evolved hydro- 

 fluoric acid. 

 Dublin, August 1^. 



ON THE NEW METAL RUTHENIUM. 



M. Claus states, that after an uninterrupted labour of two years' 

 duration, he has succeeded in obtaining the above metal, which he 

 had previously discovered, in a state of purity and by a simple pro- 

 cess from the residues of platina. 



This metal has, however, as yet been obtained only in the state of 

 a gray powder, which is much lighter than iridium ; and its simple 

 and double chlorides strongly resemble those of this metal. The 

 chloride of potassium and iridium so strongly resembles that of po- 

 tassium and ruthenium, that M. Berzelius, to whom M. Claus sent 

 a portion, stated it to be the salt of iridium ; but some days after he 

 withdrew this opinion, and considered this salt as that of a metal 

 which was unknown to him. 



The characters of this metal are so distinct, that no doubt can be 

 entertained as to its being different from all previously known. Its 

 highest chloride has a fine orange colour ; and when ammonia is 

 added to its aqueous solution, a black oxide is precipitated, whereas 

 the solutions of the other platina metals are not precipitated at all 

 by ammonia at common temperatures. The solution of the chloride 

 is not altered by hydrosulphuric acid (H-S) till the action has been 

 long continued, and then a brown precipitate is at first obtained, 

 virhich afterwards becomes a black sulphuret, and the solution as- 

 sumes a magnificent azure-blue colour. These changes depend upon 

 the precipitation of a small portion of metallic sulphuret and the 

 conversion of the chloride into a higher one, which has a blue colour, 

 and which is not decomposed by the hydrosulphuric acid. If a 

 plate of zinc be put into the solution of the orange chloride, acidified 

 by a little hydrochloric acid, a black metallic powder is precipitated 

 after some time, and the solution becomes of a deep indigo-blue co- 

 lour ; eventually the whole of the metal is precipitated, and the so- 

 lution becomes colourless. 



The metal thus obtained, and all its combinations, when mixed 

 with a large quantity of nitre and heated strongly to redness, give a 

 blackish-green mass, which, when dissolved in water, yields a solu- 

 tion of a fine orange- red colour. This solution of the potash salt of 



