.>3(J ANALYSIS OF NEEDLE-ORE. ^ 



ftr yanolite, or yonojite, given by Delametherie to the oM 

 violet sclioevl. 

 ^t probably From the primitive form of the dichroit it is to be pre- 



Xr^'hi 7-^ ^ svitned, that it possesses the property of producing- a double 

 "* 'iuiaf^e; but this I couUJ not ascertain, for want of crystals 

 sufficiently tran»ipareut. The verification of this conjecture 

 however would be the more interesting, as the phenomenon 

 of doable refraction could take place only in a direction 

 oblique to the axis of the piista; of which I have satisfied 

 myself by exjjeriment, and which the pheoomena of the 

 emerald siutticiently confirm. Hence we see, that, on the 

 hypothesis of u double refraction, there would be such a 

 relation between this phenomenon and that of the double 

 colour, that the ei ystals would doable images in the direc- 

 tion in which the colours appear mingled, while we should 

 see a simple image by looking in that directioo, in which 

 fych colour becomes exclusive. 



Analysis of the Nadehftz of Liberia: hj Mi. ZoVkVi*^ 



^acirk^iz ?n it HE necdle-ore has been considered in Russia as au 



^iS^'jr&^sfiiuth. auriferous ore of nickel. In the work of Ret^ss, and in the 

 Ephemerides of b^ron Moll, it is classed among the ores of 

 chrome : but the analysis of Mr. John, given in Gehien'si, 

 journal, shows, that it is an ore of bismuth. 



The following are its external characters according to 

 Karsten. 



iHta^ternai ^^^ colour is steel gray, sometimes a pale copper red, oi 



^ra,cters. covered with a green and yellow coatingir. 



* Journal des Mines, vol. xxiv, p. 227. 



-)• The yellow coating is so slight, Mr John could only exjiQine it by 

 ^■wiping it off with cotton moistened with nitric acid, washing the cotton 

 ia water, and evaporating the water and excess of acid. It then appeared 

 to hio), from such experiments as he could make^to be oxide of uranium., 

 'i'he green coating, covering both the crystals and the quarts gangue, is 

 t^iicker and more abundant. From his analysis it consisted of carbonate 

 9/"?opprr, carbon-''*'". '"''■"■ ■■ --■' bl'^nuth. 



Colo-- 



