On Metallic Minerals. 389 



Ten- soft and unctions feci, both in substance and powder 

 — specific gravity, 2 2-3. 



In powder it is partially soluble, without effervescence 

 in the mineral acids, and their diluted solutions. When 

 tested with Prussian alkali, or tincture of galls, the presence 

 of a proportion of iron, which the low specific gravity, and 

 pale colour of the mineral in question would not lead one 

 to suspect the presence of, is indicated. By evaporation 

 salts of a white colour, acicular form, and the flavour of 

 copperas, are obtained from its solution in sulphuric acid ; 

 sometimes a slight acidulous taste like alum is noticed, but 

 never the nauceous bitter of epsom salts. Its powder in 

 water conununicates a blue colour to test paper. Its solu- 

 tion in muriatic acid does not redden flame.* 



In the mattrass, if not |>erfectly dry, it decrepitates 

 violently, and giving out its moisture it turns black. — 

 Befure the blow-pipe, if moist, it decrepitates violently, 

 otherwii.e not, and turns black, but not magnetic. A small 

 thin fibre-shaped particle fuses in the interior flame, into 

 a dull white enamel, but slowly and with difliculty. A 

 larger essay is impossible. With borax it forms slowly, a 

 colourless transparent glass. It phosphoresces a little on a 

 shovel heated below redness. 



Fronj its geological position, and some of its other char- 

 acters, I was induced at first to consider this mineral to be 



h;i>i-iio flaTor by wliirli llicy can bo distinKlli^lle(l from cliiilk, and tlip fact 

 tliat tlie clmrueU-r uC lluvoris entirely oniittcd hy iiiinpralu^isls Ju d(•^c^illille 

 thoi- "iibbtiiiRi-n, inuki V it appear that that (ipiiiuin is generally enliilaiiied 

 by I hem. With due MibmiMiiun, huMever, tu mkIi hi);h uiilhurity, it iiecma 

 t<j mi' lo b<- an iin|Miilaijt churaetrr uinitted, us I am ahuoNi eertuin thut I 

 eonid delect tliesc mineials iu a iit4te ufptirity, by thi.i churucter alone. 



* See Sillinian's Journal, vol. 18, No. U,^" Ou the rcJ colour of Jlume," 



