DR TRAILL ON THE TORBANEHILL MINERAL. 11 



One person insisted, that, as the mineral contained carbon, was inflammable, 

 and occurred in a coal formation, it must be considered as a coal. To this I would 

 reply, Must we consider as coals — Naphtha, Petroleum, Asphalt, Amber, Mellite, 

 or the rarer minerals, Piauzite, Ixolite, Schererite, Hartine, Walchowite, Middle- 

 tonite, Retinite, Hartite, Ozokerite, &c, all which are inflammables, contain car- 

 bon, and occur in the coal formation ? 



On these grounds I consider the Torbanehill mineral not to be a coal, but a 

 mineral not hitherto described in our systems of mineralogy, and for which I have 

 proposed the name of 



Bitumenite ; 

 and which has the following mineralogical characters. 



a. Colour passing from blackish-brown (108, Syme) to liver-brown (104), and 

 often spotted with hair-brown (105). 



b. It occurs massive. 



c. It is dull in every direction. 



d. Fracture — principal fracture flat, conchoidal, inclining to splintery ; cross 

 fracture uneven, slaty. 



e. Fragments are indeterminately angular, with sharp edges. 



/. Examined by a strong light, the sharp edges are feebly translucent, admit- 

 ting a dark reddish-brown light- 

 er. It yields to the hammer in the direction of the bed, but resists blows at 

 right angles to that direction, and is rather difficult to break, exhibiting a consi- 

 derable degree of elasticity, and causing the hammer to rebound smartly. 

 h. It is, however, soft and sectile. 



i. Its streak is quite dull, and has a pale ochre-yellow hue. 

 k. Its specific gravity = 1-284. 



Chemical Characters. 



a. It is very inflammable, readily catching fire without melting, burning with 

 a dense white flame, and much smoke. When ignited at a lamp, it continues to 

 burn a considerable time. Some bituminous shales will also thus burn for a 

 shorter time, but they leave their edges more or less white ; but with Bitumenite, 

 when the flame expires, the form of the fragment is unchanged, and it is wholly 

 covered with a black carbonaceous matter, derived from the dense smoke of its 

 flame. 



b. When exposed to a strong red-heat in a platinum crucible for 2£ hours, it 

 left behind a white matter, retaining the shape of the original fragments, but 

 readily crumbling on pressure into a grayish-white powder ; but no part of it was 

 converted into a slag. 



c. When distilled in a small iron retort, it afforded an abundant dense inflam- 

 mable gas, and some paraffine, with a few drops of water. 



VOL. XXI. PART I. D 



