158 Intelligence and Miscellaneous Articles, 



is doubled, the increase of brightness of each line is, at the most, 

 equal to that which would be produced by doubling the thickness 

 of the flame, and is almost always inferior to it. We have to re- 

 mark that the quantity of free metal in the flame is not necessarily 

 proportional to the quantity of salt which it contains ; it seems to 

 follow from the comparison just made that it increases less quickly. 

 I purpose to return to this point when I have finished the study of 

 certain anomalies presented by these experiments. — Comptes Bendus 

 de V Academic des Sciences, July 9, 1877, tome Ixxxv. pp. 70-72. 



ON A NEW METAL, DAVYUM. BY SERGE KERN. 



At the end of last month I succeeded in isolating a new metal 

 belonging to the platinum group ; I have named it davyum, in 

 honour of Sir Humphry Davy the eminent English chemist. 



The platiniferous sand treated had the following composition : — 



Platinum 80'03 



Iridium 9*15 



E^hodium 0*61 



Osmium 1'35 



Palladium 1-20 



Iron 6*45 



Euthenium 0*28 



Copper 1*02 



100-09 



For the separation of the metals, the ores (600 grammes) were 

 treated by the analytical method of Professor Bun sen. The mother- 

 liquors obtained after the separation of rhodium and iridium were 

 heated with an excess of chloride and nitrate of ammonium. A 

 deep -red precipitate was obtained ; after calcination at a red heat 

 it gave a greyish mass resembling platinum sponge. This, fused 

 at the oxyhydrogen blow^pipe, furnished a metallic ingot of a silver 

 colour, and weighing 0-27 gramme. The density of davyum is 

 9*385 at 25° 0. ; the metal is hard, but malleable at a red-heat. 



Davyum is readily attacked by aqua regia, and very slightly by 

 boiling sulphuric acid. Caustic potash (KHO) produces a yellow 

 precipitate. Sulphuretted hydrogen, passed through a dilute solu- 

 tion of chloride of davyum, produces a brown precipitate, which, 

 after desiccation, takes a black colour. Sulphocyanide of potassium 

 (KCyS), with a dilute solution of chloride of davyiun, becomes red. 

 This reaction is identical with that given by the salts of peroxide 

 of iron. If the solutions of davyum and KGyS are concentrated, 

 a red precipitate is obtained. 



I think that, in the classification of the elements proposed by 

 M. Mendeleeff, davyum is the hypothetical element placed between 

 the metals molybdenum (Mo) and ruthenium (Eu). In that case 

 the equivalent of davyum should be 100. 



