790 MINERALOGICAL DESCRIPTION OF THE ISLAND OF BANKA. 
At the eastern side of the river I collected on the beach, and from 
th e layer of sand and clay which terminates the stratum, the follow¬ 
ing specimens: 
1. Granite containing fascieulae of schorl, resembling the rocks 
of the mountain Manurabing. 
2. Granite in a state of separation of its particles similar to that 
at the mines of Rangam. 
3. A nodule consisting of small crystals of quartz united to a 
fragment of Red-Iron-stone. 
4. Fragments of sand stone of various kinds. 
5. Granite with the fragments of felspar in a state of decompo¬ 
sition appearing as a white powder on the fracture. 
The western side of the river is likewise bounded by a deep layer 
of clay and sand, resembling those usually found at the mines and 
containing masses of Poudingue (different from the dark coloured 
ferruginous Poudingues of the neighbourhood) and small fragments 
of granite and quartz. 
The tract bounding the course of this river to its rise from the 
Manumbing has been very productive in Tin, and a large establish¬ 
ment of Chinese existed here formerly who have in a great degree 
exhausted the strata of ore. 
Between the plain of Black-Iron-stoue near the river Teluk-Ru- 
biya and the discharge of the river Minto-tawar, 1 found, at the bor¬ 
ders of the sen, no traces of the large depository of Iron ore, but it 
appears again on Minto hill. On the highest part of the alluvial 
ridge above the central part of the town of Minto and near the banks 
of the river, an establishment has lately been formed, on behalf of 
government, consisting of accommodations for the Resident and offi¬ 
cers of the Garrison, barracks for the troops, and other public build¬ 
ings, In the environs of this establishment, 1 concluded my miner- 
alogical remarks on the Island. I shall mention, in the first place, the 
indications of the large depository of ore. The most common form in 
which it appeared was as Red-Iron-stone, but in many cases it partook 
more of the nature of Bog-Iron-ore, or it passed into the Argillaceous 
ore or into the Black-Iron-stone. These varieties occured in extensive 
veins or continued senes of rocks projecting beyond the surface or 
slightly covered with soil and sand. Their constitution will appear 
in some measure from the specimens here collected, viz. 
1. Blavk-Irons tone, the fracture uncommonly dark, manypor- 
