INFLAMMABLES. 78. Graphites. 237 



78. GRAPHITES. Confia'.ng principally of car^ 

 bon, with a little iron and generally a little filica 

 or alumina; when pure burns with a reddifl^ 

 flame, emitting beautiful fparks and a fmell of 

 fulphur, and leaving little refiduum : black, 

 opake, very foft, feels fomewhat greafy and 

 (lains the fingers, brittle, breaking jnto indeter- 

 minate fraorments. 



c>' 



^iumhago. Q( a metallic luftre, and l]aty ftrii61ure, 



Molybdsenum fubquamos. Syfi.nat. xii. 3.^, 121. n. I. a, b. 



Fcrrum corrofum. Wall. fist. 2. p, 249. n. 14, 



Plumbago. Scheele Jl^. Stockh. 1779. p- 23S. 



plumbago, ^irvjan miner. 2, p. 66. 



Black lead. Sc/jmeiJ/er mineral, i. /», 30U 



Plumbago. Thom/an chem ^. p. 16. 



Found in different parts of Great-Brifahi, particularly near 

 Dumfries in Zcbtland^ at Barronxdale, and Krfxvick in Cu7nher-> 

 land i in Greenland and various parts'cf the continent: colour 

 blackifli or iron-grey, blueifh-grey when cut, with a flight 

 metallic luftre : yields to the impreffion of the nail, and makes 

 a black mark on paper: texture compact, with a fine grain, 

 and rather a little flexible : it is chiefly ufed for making 

 black-lead pencils, for blackening floves, and when mixed 

 with a proper proportion of filica for crucibles : fpccific gra- 

 vity from 1,9^7. to 2,^89. contains when purCj carbon 90, 

 il'on 10. Sc/jeelg, 



Carls, Of a chonchoidal {l:ru6lure, breaking into indeterminate 

 fragments. 



Wiedenm. Berg. Jcurn* ^7^9' *• P 609. 



Klaproth chem. annal. i 790. i. /. 293. 



Found near Schemniz in Hungaryy imbedded in thin ftrata or 

 veins of black indurated alumina, near To^ariuem^a running 

 through a matrix of opal like a vein, in France and Noriuay: 

 when expofed to a white heat lofes all its carbon which is 90 

 per cent, leaving a refiduum of nearly equal parts of alumina 

 and oxydeof iron. 



Fi*lig(f* Deep black internally, making a deep black mark. 

 Habel. Schreb, berl. natitrf, 10. ^. 75, 

 Found near Dutfweiler in Naffouioy alternating in thin llrata 



with coals. It is probable that thefe three fpccies might with 



much propriety be reduced to one. 



