Scientific Intelligence. — Hydrography. 201 



hardness is occasioned by intermixed quartz. Streak dull, co- 

 lour not changed, but the powder soils. Specific gravity = 4.5 

 —4.7. Chemical Characters. — Before the blowpipe on char- 

 coal, gives out white vapours of arsenious acid ; deposits on it 

 a yellow crust, during which the ore becomes of a brown colour. 

 When well roasted before the blowpipe, and then mixed with 

 glass of borax and melted, it communicates to it a smalt blue 

 colour. If some small pieces of the ore are exposed to a low red 

 heat in a glass tube it affords a considerable quantity of arsenious 



acid. Constiticent Parts. — Arsenic 77.9602; cobalt 9.8866; 



iron 4.7695; bismuth 3.8866 ; copper 1,3030 ; nickel 1.1063; 

 sulphur 1.0160 = 99.9282. The characteristic ingredients of 

 this ore are arsenic-cobalt and arsenic-bismuth, a combination of 

 these metals hitherto not met with in the mineral kingdom. 

 Geographic^ Situation. — Has hitherto been found only at Shnee- 

 berg in Saxony. — We owe our knowledge of this minei al to Mr 

 Kersten of Gottingen. 



22. Selenium in Red Copper Ore. — Kersten of Gottingen, 

 on exposing the capillary red copper ore of Rheinbreitenbach to 

 the blowpipe, perceived a seleniferous smell, which, on farther 

 examination, he found to be owing to the presence of selenium 

 in that ore. The capillary red copper ore of the Bannet he did 

 not find to contain any selenium. 



HYDROGRAPHY. 



23. Discovery of a New Substance in Sea Water. — M. Ballard 

 of Montpellier, has discovered a peculiar substance in sea-water, 

 which he names Brome, and considers it intermediate between 

 iodine and chlorine. It has a disagreeable smell ; hence its name, 

 from /3g<w^o$ (foetor) *. It occurs, in very small quantity, in sea-wa- 

 ter : even the mother water of salt water contains but very little- 



• Brome is fluid at the average temperature of the atmosphere, and even 

 at 18* below 0° centig. In quantity its colour is reddish-brown ; in small 

 quantity it is hyacinth-red ; colour of its vapour exactly similar to that 

 of nitrous acid. It is very volatile, and is converted into vapour at 47* centig. 

 Smell very strong, resembling that of chlorine ; its density about 3. It de- 

 stroys colour, as chlorine does, and is soluble in water, alcohol, and ether. 

 Weight of its atom 9,328, that of oxygen being 1. It forma interesting com- 

 pounds with diOerent substances, and is an active poison. 



