MIN ERA LOGIC A L DESCRIPTION OF TI1E ISLAND OF BANKA. 409 
der the soil, which was 2 feet deep, I remarked a mixture consisting; 
of small fragments of quartz deposited in a clayey substance of a 
white colour, which, where it had been exposed to the air, was chal¬ 
ky and adhered to and coloured the hands. The ore of tin was dis¬ 
persed through the whole of this stratum, commencing immediately 
under the soil, where it was not perceived by the eye, but became 
evident on exposing it to the process of washing; about 8 or 10 feet 
below the surface it became very evident by a black discoloration of 
the stratum, making a striking contrast with the particles of quartz. 
It was also plainly perceived by its weight when taken up, and 
some of the lower parts of the stratum were very rich. 
In the neighbourhood of this mine, which had been exposed by 
former works, I found the following substances : 
1. Quartz and felspar in a state of incipient decomposition: the 
crystals of the former were wedgeshaped, very brittle, easily separat¬ 
ed, if force was applied, when the decomposed felspar appeared as 
a white friable powder ; they were united into tables or slabs mostly 
with oblique surfaces. 
2. Quartz and felspar united into masses of nearly equal pro¬ 
portions of admixture, to a substance of a variegated fracture (as 
above described.) 
3. Amygdaloids consisting of the stone just mentioned united to 
small portions of the red Iron-stone by a clayey cement. 
4. Black shining sand combined with particles of quartz by 
means of a ferruginous cement. Besides the sandstone above des¬ 
cribed, and various combinations of clay and sand. 
The mines of Sunnie are situated near the northern boundary of 
the district of the mines above mentioned. They are of the large 
kind : the workmen had, at the time of my visit nearly arrived at 
the commencement of the stratum containing the ore, after having 
penetrated: 
1. A stratum of soil. 2 feet, 
2. White clay mixed with a small proportion of sand, 
eo-agulable to a solid mass by drying. 3 ,, 
3. Coarse sand, consisting chiefly of fragments of 
