GEOLOGICAL FEATURES OF SINGAPORE. 
85 
Adverting to the nature of these two last ingredients, the overlying 
soil of Bukit Timah most probably consists of about. 
Silex 56 
Alumina 51, 
Lime 1. 90 
Potash 10.20 
Iron 2. 90 
I do not include vegetable matter. The specimens of Bukit Timah 
granite are, 
1. Quartz and felspar in excess—-mica hardly discernible. 
2. Do. Do. Very quartzose. 
3. very light grey colored,—quartz and felspar redundant,— 
small specs of black mica. 
A, Still sjjghtcr coloured and with paucity of mica. 
5. Coarse grained and quartzose. 
6. Veins of a light coloured and hard quartzose rock, tinged 
yellowish red by oxide of iron. Brown iron films betwixt the 
cleavages,—these last being cross, that is across the vein. 
7. The stratum above and next to the rock, where examined, 
was angular quartzose gravel and red clay. 
8. Granite with pretty equal proportion of its three ingredients. 
On the right of the southern Biifeit Timah road, and close 
to it, just where it surmounts Scott’s Hill, stands or lies a detached 
block of dark, and rather compact*, granite resembling the darkest 
granite of Bukit Timah. 
This last hill is about 5 miles distant from Bukit Timah, and a long 
ancl almost level vallay stretches the whole way betwixt the latter 
and the rising ground on the fop of which the block lies. I could 
find no indication that this block is connected with any primary rock 
beneath,—all round, and apparently, below, being sandstones and 
days. If, therefore, it be quite isolated, but not in situ it may 
perhaps be a proof that the sandstone strata were formed, or, at 
least, that they were elevated to their present position, subsequently 
to the protrusion of the Bukit Timah granite through the crust of 
the earth. I did not trace, however, any appearance of diluvial 
action upon it. Some detached but smaller fragments of granite 
were lying on the rising ground close to the opposite side of the 
road on Scott’s Hill. 
