78 Intelligence and Miscellaneous Articles. 



BISILICATE OF IRON OR FERRUGINOUS PYROXENE. 



This new mineral is described in a memoir presented by M. Du- 

 fr^noy to the Academy in the name of M. Gruner, mining engineer, 

 and Professor in the School of Mines at St. Etienne. It corresponds 

 in composition to a pyroxene with a base of iron. 



M. Gruner states that this mineral resembles certain varieties of 

 asbestos, or more nearly fibrous amphibole. Its specific gravity is 

 3* 7 13, which exceeds that of the densest epidotes, amphiboles or 

 pyroxenes. By analysis M. Gruner obtained — 



Silica 43-9 



Protoxide of iron 52*2 



Lime '5 



Magnesia , . . . 1 ' 1 



Alumina 1*9 



99-6 

 Admitting that the greater portion of the foreign bases is derived 

 from a small quantity of the gangue, it will be seen that this mineral 

 is bisilicate of iron, or ferruginous pyroxene with one base only. — 

 Comptes Rendus, Mai 5, 1847. 



CHLOROSULPHURET OF SILICIUM. 



M. Isidore Pierre states that M'hen hydrosulplmric acid and chlo- 

 ride of silicium in vapour are passed through a porcelain tube heated 

 to redness, they react upon each other : much hydrochloric acid is 

 produced, which is disengaged with excess of hydrosulphuric acid 

 gas and a little chloride of silicium, which escapes the reaction. 



If the products of this reaction be passed into a U-shaped tube 

 immersed in cold water, a fuming liquor condenses, which has a 

 sharp foetid odour, resembling that of hydrosulphuric acid and chloride 

 of sulphur. The liquor thus obtained was slightly opake by sul- 

 phur suspended in it: this was deposited by being left forty-eight 

 hours in a well- stoppered bottle. There were also deposited on the 

 sides of the bottle, clear lemon-yellow crystals, which were sulphur 

 in the form of oblique rhombic prisms, without any modification. 



The condensed liquor has consequently the power of dissolving 

 sulphur, and of depositing it in crystals belonging to the same system 

 as those which are obtained in the dry way. The smallness of these 

 crystals prevented the author from determining their angles ; but he 

 reckons upon being able soon to do so. No sensible traces of sul- 

 phuret of silicium were found in the minute deposit produced in the 

 porcelain tube. 



The liquid condensed in this operation was distilled in an oil-bath 

 from a retort furnished with a thermometer : the more volatile por- 

 tions, which usually distil from 140° to 176° F,, were rejected. 

 They consist principally of chloride of silicium mixed with a small 

 quantity of chlorosulphuret. Afterwards there is obtained a limpid 

 colourless liquid which fumes in the air, and has an odour resembling 

 that of chloride of silicium and hydrosulphuric acid. 



