MIN ERA LOGICAL DESCRIPTION OF THE ISLAND OF BANKA. 723 
right-lines crossing and intersecting each other mostly at oblique 
angles : these lines being of a substance more hard and compact 
than the rock appear slightly elevated on the surface where the 
stone has been exposed to the weather. The fracture is white, va¬ 
rying to light red and grey, and presents the lines observed on the 
surface in a manner similar to the rocks of Kampak ; they appear 
as a pure white siliceous substance and are very narrow. 
The grain of these rocks is line and their texture compact; their 
range is probably extensive and the fragments of sand-stone found 
at many of the mines of Mar&w&ng and Pangkal-pmang, are proba¬ 
bly derived from them : beyond these rocks I observed a large vein 
of Red-Iron-stone projecting from the surface, and about 3 miles 
further I crossed the river of Mara wan g. On the further route to¬ 
wards the vicinity of Dshuruk, very few remarks offered themselves ; 
t^e tract is, on the whole, low. In one place only I observed a fix¬ 
ed vein of Red-Iron-stone, and in another I found loose fragments 
on the road: they are both similar in their fracture to the more 
compact Iled-Iron-stones found in other parts of the Island. 
Several miles east of the village of Dshuruk an extensive district 
is partially inundated, and the passage through it is as usual over 
fallen trees and long slender bridges: this swamp it formed by the 
heads of the river of Dshuruk not yet united into a common stream. 
That extensive track which stretches in the central parts of the is¬ 
land towards the mountain Harass and towards the south-east di¬ 
vision of the island is of a similar constitution and gives rise to se¬ 
veral rivers, discharging themselves towards the east and west, which 
are laid down on the Geographical Map. Vegetation in all these 
central districts is highly profuse and the soil black and fertile. 
About half a mile to the east and almost in sight of the village of 
Dshuruk I found on the hill called Bukit Pungong-ake by the na¬ 
tives, a mineralogical product that I had before not noticed on Ban- 
k&. In ascending this hill a stone of a peculiar kind caught my at¬ 
tention, it was different in form and colour from all the substances 
hitherto enumerated and presenting where it was not concealed re¬ 
gular sides and angles: after removing the soil it became evident 
that it consisted of many separate portions, and on applying the 
hammer the larger fragments separated into cubes, parallelograms, 
rhombs &c, while the same disposition to separate into regular frag¬ 
ments shewed itself in the minutest portions. The whole rock was 
intersected by numerous lines which indicated the point of separa*. 
