the Analyses of M. Klaproth. 337 



Analysis of the Black Ore of Szekcremh in Transylvania. 



Besides the red ore of manganese found at Szekerenib, 

 which varies both in regard to its form and colour, and 

 sers'es as matrix to the auriferous ores of telkirium worked 

 there, there is one w hich exhibits the following characters : 



It has a mean colour between the brown and the black 

 of iron (ethiops). It is almost always compact, sometimes 

 veined with red ore of mangaiiesej or it forms alternate strata 

 with that ore. 



It has a semi -metallic state. 



Its fracture is unequal, of a small grain, and foliated in 

 even,r dh-ection. 



It splits into fragments irregularly angular, the edges of 

 which are not very obtuse. 



It is opake. 



When scratched the trace appears of the dark yellow co- 

 lour of brass, inclining much to green, and almost entirely 

 dull. It is of a mean hardness, and pretty smooth to the 

 touch. Its specific gravity is 3-950. This ore contains ♦ 

 Oxidulous manganese soluble in nitric acid 82 

 Carbonic acid ----- 5 



Sulphur - - - - - - 1 1 



98 



New Analysis of Cryolite by M. Klaproth. 

 Cryolite is one of the most interesting of the new disco- 

 \ieries in mineralogy. It was found in Grcejiland, and a 

 small quantity of it was some time ago received at Copeu- 

 liagen. Professor Abilgard, v.'ho was of great service to 

 the mineralogy of chemistry, undertook the analysis of it. 

 He found it \o be composed of fluoric acid and alumine; a 

 very unexpected combination, no instance of which had be- 

 fore been found. 



External Characters of Cryolite. 



External form as yet undetermined ; colour a bright 

 whitish gray; fracture, when longitudinal, brilliant; when 

 parallel to 'the axis, less brilliant. Both have a vitreous 

 splendour: its fractures are foliated, and intersect each other 

 at right angles ; in the other directions they are unequal. 

 Crymite breaks into cubic fragments: it is semi-tran-i- 

 parent, tender, and pretty soft to the touch ; exceedingly 

 fragile; and, according to Andrada, of the mean specific 

 gravity of 2-9G95, 4jr according to Haijy L"949. 



VoL.XVi. No. 04. Y Exposed 



