CHEMISTRY. 395 



be supposed to be coincideut with the Aus. a line (A=:ilG.5). (Nature, 

 xxxiv,51), 1886.) 



Germanium^ a neic Element, by Clemens Winkler. — In the summer of 

 1885 a rich silver ore of uncommon ai^pearance was found in the Him- 

 melfuerst mine near Freiberg. It was recognized as a new mineral 

 species by Prof, A. Weisbach, and named by him " argyrodite." Th. 

 Richter subjected the mineral to a jireliminary examination with the 

 blow-pipe, and found it to consist essentially of silver and sulphur. In 

 addition to these, he also detected the presence of a small quantity of 

 mercury, which is remarkable and interesting from the fact that this 

 metal had never before been found in the Freiberg ores. 



In the analyses made, Winkler found that the mercury did not amount 

 to more than 0.21 per cent. According to the purity of the material the 

 silver varied from 73 to 75 per cent., and the sulphur from 17 to 18 per 

 cent. Small quantities of iron and traces of arsenic were also found. 

 Though the analysis was often and carefully repeated there was always 

 a loss of 6 to 7 per cent, without it being jwssible by the ordinary 

 methods of qualitative analysis to discover the missing body. 



After several weeks of tedious search Winkler found that argyrodite 

 contains a new element, very similar to antimony, but still very distinct 

 from the same, which he named Germanium. The detection of this ele- 

 ment was very diflBcult, because the argyrodite was accompanied by 

 minerals containing arsenic and antimony, which, on account of their 

 similar behavior, and a total lack of a sharp method for separation, 

 caused much difficulty. 



Argyrodite, when heated with exclusion of air, preferably in a current 

 of hydrogen, gives a black, crystalline, quite volatile, readily fusible 

 sublimate, which melts to reddish-brown drops. In addition to mercury- 

 sulphite it consists essentially of germanium sulphide. Germanium sul- 

 phide is a sulpho-acid ; it is readily soluble in ammonium sulphide, and 

 when reprecipitated by hydrochloric acid, in a perfectly pure plate, it 

 forms a snow-white precipitate, which is instantly soluble in ammonium 

 hydrate. In the presence of antimony or arsenic the precipitate is 

 always tinged more or less yellow. 



On heating in a current of air or in nitric acid, germanium sulphide 

 is converted into a white oxide, which is not volatile at a red heat. It 

 is soluble in potassium hydrate, and the alkaline solution, when acidified 

 with sulphuretted hydrogen, gives the characteristic white precipitate. 

 Too great dilution prevents or retards the precipitation. 



The oxide, like the sulphide, is reduced by hydrogen, the latter with 

 greater difficulty on account of its volatility. The element has a gray 

 color, and perfect metallic luster. It melts at a point somewhat below 

 silver, say about 900°, and crystallizes in octahedra, which are very 

 brittle. Its specific gravity is 5,469 at 20o.4. It is insoluble in hydro- 

 chloric acid, readily dissolved by aqua-regia, is converted into a whit« 



