l^ 



MENACANE, AND ITS ORES. 



obtained at the same time with the gold, and comes to lis 

 intermixed with grains of rtitilc, oriental garnet, native iron, 

 cyaaite, and comiiioa sand ; -which renders it extremely 

 probable, that this tbssil, also, is a native of the primitive 

 mountains. 



Species IV. 

 Menacane. 



FOURTH SPECIES. 

 MENACANE. 



Menachanite of Kirwan. 

 Menacan of Werner. 



ETteriirtl cha- 

 racters. 



Observations 

 on menacane. 



Physical and 

 chemical cha- 

 racters. 



EXTERNAL CHARACTERS. 



Is of a greyish colour, inclining somewhat to iron blaclc. 

 Only met with in very small, flattish, angular grains, which 

 have a rough glimmering surface. Internally, moderately 

 glistening, with adamantine lustre, passing into the semi- 

 metallic. The fracture is perfectly foliated, approaching to 

 the slaty. The fragments are indeterminately angular, and 

 sharp-edged. Perfectly opaque. Is soft. Brittle. Retains 

 its colour in. the streak. Easily frangible. Heavy, in a 

 moderate degree (^^All). 



OBSERVATIONS. 



This fossil has been said, but erroneously, to have much 

 resemblance to iron sand, from which it may be easily 

 distinguished by the fracture, lustre, and inferior specific 

 gravity. 



PHYSICAL AND CHEMICAL CHARACTERS. 



Menacane is attractable by the magnet, but much more 

 weakly than iron sand, or magnetical iron ore ; it is infu- 

 sible by the common blow-pipe, or heat of a porcelain 

 furnace, exposed in a coal crucible, but melts, when ia 

 contact with a clay one ; it also melts quickly to a black 

 bead, before a blow-pipe animated by pure air. The menae 

 contents may be easily extracted by digestion with acid of 

 sugar. Klaproth and Lampadius, about the same time, have 

 shewn, that it consists of nearly equal parts menac and iron 



wlces. 



GEO. 



