Indian Coal. 
281 
1831 .] 
100 grains were first dried on a sand bath to expel the water: (this operation 
was imperfect, inasmuch as it is always uncertain whether the loss on drying 
should be esteemed mere hygrometric moisture, or whether a pai t may not bv. 
derived from a partial decomposition of the coal : in most cases two trials were 
made, and the agreement between them was very good, unless the heat was carried 
so high as to commence the expulsion of smoke.) After being weighed, they weie 
charred in a well closed crucible of silver or platina, and the loss asceitained. 
The coke was then incinerated by exposure to free air under a muffle at a tem- 
perature of about 1800°, and the ashy residuum was lastly submitted to the balance. 
The Coals under examination may he divided into four varieties : 
1. Cannel Coal. Comprising the Burdwan, the Soliagpur and the Hosliangabad 
coal: also specimens from Silhet, Ava, and Manipfir- 
The distinctive characters of this coal as it occurs in India, are as follows 
specific gravity above 1.3, and under 1.4 ; massive, colour jet black , resinous lustie, 
fracture even, fragments trapezoidal : does not soil : burns with blight flame 
cakes slightly on coking and assumes metallic lustre 1 : leaves much lai = ei asn 
than good English sea coal, and gives out more gaseous matter. It is therefore 
less suitable for coking, and for close furnaces, though well adapted for blaze nres. 
It occurs in seams from 1 to 9 feet in depth, and generally under shales and coals 
of inferior quality. The coal from Palamu differs considerably in quality from that 
of Burdwan, but will be found perhaps to assimilate more closely to it, w hen the 
lower seams are thrown open : of two samples obtained from Captain Sa^e, ex. 
off. at Dinapoor, one had partially a glossy surface, the other was dull and of 
slaty fracture : much gas was given out, but with little or no flame. A specimen 
from Sohagpfir, contributed by Capt. Franklin, has a higher lustje, and lescinbles 
more closely the Burdwan coal : it is accompanied as usual by seams of slate coal. 
The Silhet or Laour coal, on the contrary, appears more bituminous than that 
of Burdwan; and disengages jets of flame, becoming soft and adhesive like com- 
mon English pit-coal : it is of a browner colour, foliated texture, and resinous 
lustre; one species is friable readily between the fingers, dull brown -black colour, 
amorphous, and leaves a brown streak on paper : they both burn fiercely in t le 
forge : some very hard slate coal or bituminous shale accompanies the Silhet 
specimens. The Ava coal is of very good quality ; I am however doubtful of its 
locality, some specimens being labelled, Tank-kiouk , and others Kuenduen river, 
lu the latter case it should perhaps be classed with the lignites. 
2- Anthracite, or Slate-coal, comprehending specimens from Baghelpur, Chanda 
(near the confluence of the Warda and Nerbada), Sohagpfir, &c. It generally 
accompanies the other coal, and in fact every variety from true coal to meie 
shale or slate may be met with in the same locality'. Sometimes one, some- 
times the other predominates. This species abounds in vegetable impressions ; 
specific gravity above 1.4 ; — fracture slaty ; — cross fracture conchoidal ; colour 
8 re y black; no lustre : — soils the fingers ; inflames readily, gives little heat, and 
kavesa slaty white ash, varying in weight from 20 to 50 per cent, of the coal. It 
| s of little use as a fuel, but might perhaps be turned to profit for the gas which 
11 gives out in great abundance. 
3 - Lignite, from tlie Derail Dun valley, in the Himmalaya, and from themoun- 
tain passes between Manipur and Ava : — also in the shape of fossil almon 
Apparently from the formation of a thin coat of plumbago on the surface . in 
Soine cases the platina crucible was entirely lined with thin scales of this substauc* 
"ifich were at first supposed to he ferruginous until tried by the blowpipe. 
