756 
MEMORANDA RESPECTING SUMATRAN COAL, 
shale interspersed, and the fracture of the coal is occasionally shaly. 
The Sul an it seems gave no account of the width of the seam or of 
its dip. It seems to he an outcrop in the river. There is no appear¬ 
ance of wood fibre in this coal. But we should recollect that the 
Sultan would only produce the best specimens. 
This coal does not ignite in the flame of a candle like the Tanjong 
Katong, Tanjong Bumbong and Pulo Tiga coals, owing to its being 
less bituminous than these are, and it consequently takes a longer 
time to ignite in the fire than they do. When fairly ignited it burns 
rapidly with a whitish yellow flame, this last proceeding chiefly from 
the bitumenj for the coal itself, unless Under great heat, continues 
almost black until the bitumen has been consumed. 
The bitumen does not spurt out as in these other coals, but is 
gradually evolved over the whole surface. It burns without any 
particular smell of sulphur, and I cannot perceive any but faint 
traces of snlphuret of iron, although as will be noticed afterwards it 
contains iron in considerable quantity. It has from this deficiency 
of sulphur one advantage over these other coals, and thus also, it 
does not decrepitate while consuming. 
The residuum, after being burned under the action of the behoves, 
was found by me to be a hard black substance, in grains, not coak, 
and consisting of iron (I suppose, a protoxide) and earthy matter, 
the coal losing by the combustion about two-thirds at least of its 
weight. This ferruginous matter is strongly attracted by the mag¬ 
net, and it forms about one-fifth part perhaps of the residuum, which 
last is black and very hard. The piece of coal thus burned by me 
did not contain any of the transparent resinous looking substance 
before noticed. 
This last substance looks, indeed, as Captain Congalton remarks, 
very like rosin, but I think it is amber. It is interspersed in small 
portions through the coal and it lies in larger layers betwixt the lay¬ 
ers of the coal and conformably to it. In my specimens these lay¬ 
ers do not exceed ^ of an inch'in width and they consist of numer¬ 
ous films of from one-sixteenth to one-eighth of an inch in thick¬ 
ness. They are brittle, and break into small irregular fragments 
approaching the rhomboidal. It is insoluble in water ; when pow¬ 
dered and thrown on the fire it flashes like rosin. 
I submitted this resinous looking substance to heat iri contact 
with the air. It does not readily ignite in the flame of a candle, but 
when placed in an earthen vessel over a brisk fire it melted and then 
