4GS 
ON THE MEDICAL TOPOGRAPHY OF SINGAPORE. 
feet with a base of clay which in the plains is met with from 10 to 
50 feet below the surface, or broken Sand-stone. The vallies are of 
course the richest in good soil from containing what is washed down 
from the hills, as well as that immense quantity of half decomposed 
vegetable matter, which successive generations of vegetable life fur¬ 
nish. From the general appearance of the valley of Singapore, from 
coral having been found in making excavations, with shells and that 
kind of black mud, a compound of decayed animal and vegetable 
matter, we would infer that this has been reclaimed from the sea by 
a process of elevation, which may to this day be going on, and that 
this elevation cannot be very ancient may be inferred from the fact 
of Mr. Thomson having found a piece of wood bored thiough at one 
end with the remains of a twisted rope, 40 feet below the surface, 
and £ a mile inland to high water mark (ante, p. 136). At the 
western entry of this valley the town of Singapore is built, facing 
the sea to the south, and having a range of hills about 100 feet high 
to landward. Through the centre of the town runs the Singapore 
river, the largest river on the southern aspect of the island. On the 
East forming the boundary in that quarter is the Kalang river. Be* 
twixt these rivers there is a third of some importance in Medical 
Police from having been converted into a canal in a part of its course ; 
it drains a large extent of ground, it is called the Rochor Canal and 
carries off the superabundance of water that would otherwise stagnate 
on a valley of some size through which the Bukit Tima road runs. 
The river of Singapore that divides the town in two, lias its channel 
near the mouth of great breadth, perhaps 150 yards, and at high wa¬ 
ter permits boats of 30 to 60 tons to enter, but at low water the 
insignificance of the stream is visible ; from its mouth about of a 
mile inland it receives an anastamosing branch, which in the shape of a 
canal joins it again higher up, having 5 to 6 feet of water at full tide, 
but diy at low water. A little above the bridge at Campong Ma¬ 
lacca, the river divides into numerous branches, one of which pro¬ 
ceeds as far as the Seapoy lines, others join to form islands covered 
with mangroves and dry at low water, until tracing its progress in¬ 
land through many turns and windings for about 2 to 3 miles, it is 
