MINE HA LOGICAL DR6CIUFTION OF THE ISLAND OF BANKA. 785 
it is therefore covered with cellulosities. The colour in general is 
white ; some portions are enclosed by a coating of regularly formed 
transparent rock crystals, while others are variegated with lines and 
spots of a dull milky white, in many places the surface is reticu¬ 
lated. 
In the component parts of this rock we meet again the substances 
most abounding in the primitive portions of the island : the white 
intersecting lines exhibit quartz and felspar, and the blueish sub¬ 
stance forming the body of the stone is also of a siliceous nature. 
On the further course to the westward, several hundred yards 
from this rock, an extensive vein of sand-stone stretches across the 
low plain ; it is of a white colour and close grain. Numerous large 
fragments of siliceous stone, resembling those found at the aqueducts, 
were collected in one place near a rivulet; but none of the persons 
who accompanied me was able to inform me with certainty whether 
or not a mine had been formerly worked on this spot. In the ri¬ 
ver of Sungie Pait as well as in the other rivulets which pass through 
the plain on the foot of the alluvial ridges, the loose fragments are 
mostly of a siliceous nature and derived from the decomposed pri¬ 
mitive rocks of the Manumbing and its appendages. 
Between the river Sungie Pait and Sungie Bara the road passes 
near the shore at the foot of the alluvial ridge, which is very steep 
and being completely covered by vegetation and concealed by a thick 
vegetable mould, afforded no opportunities for observations. 
On my first route from Penjalin-Belo to Minto, my attention 
was attracted at this village by a peculiar kind of Breccias greatly 
different in their general aspect from all that I had hitherto observ¬ 
ed : I had no opportunity at this time of comparing them with 
others : after my return to Minto I devoted some time to their ex¬ 
amination. The space which these Breccias occupy, is, as far as I 
could determine, confined between the rivers of Sungie-Baru and 
Teluk Robeya, but on account of their tabular form they are carried 
in all directions through the neighbourhood for various domestic 
purposes, for building, tombstones &c. In the tract just mention¬ 
ed, they are found, both in fixed situations on the sides of the al¬ 
luvial ridge, and in detached masses in the low plain, to the boun¬ 
dary of the ocean. At the extremity of one of the smaller ridges 
terminating abruptly near the shore, they cover an extensive sur¬ 
face ; I here took the opportunity to examine their form and com¬ 
position. 
