AND GEOLOGY OE THE MALAY PENINSULA. 
135 
is divided by an island into two channels, of which the northern has a 
breadth of about 150 yards and a depth of 4 fathoms at high water. 
Above this the river is about a mile broad. 
Of the other considerable rivers of the eastern side of the Pe¬ 
ninsula, the Tingeran, Tringanu, Klantan &c. we know even less. 
The islands off the eastern coast are in general rocky. The sides 
exposed to the N. E. monsoon are particularly steep, rugged and 
full of deep fissures and caves. Where small sandy coves occur, we 
observed in Pulo Tingi large pebbles of greenstone rolled to some 
distance beyond high water mark of the season of our visit, the close 
of the S. W. monsoon. Many were spheroidal, perfectly polished, 
and three and four feet in diameter, a size that would not be remark¬ 
able in stormier latitudes, but which is interesting as a measure of 
the force of the waves on the eastern coast of Johore compared with 
those on the western, where we never saw pebbles one twentieth of 
the bulk driven up in heaps on the beach. 
The matter of which the alluvial tracts of the Peninsula are form¬ 
ed consists principally of clays, whitish, greyish, yellowish, bluish and 
blackish, with a varying proportion of silex. The clays of the Sin¬ 
gapore plain appear to be less siliceous than those of Malacca and 
Province Wellesley. This may arise from the more felspathic cha¬ 
racter of the Singapore plutonic rocks. But it may be also due, in 
some measure, to the smallness of its streams, and the consequent 
slighter deposit of infusorial silex, which, considering the great num¬ 
ber of streams and creeks in which the waters of the Peninsula meet 
those of the sea, must have furnished a large portion of the matter 
of the plains.* 
* As a very considerable proportion of the matter of the alluvial plains 
and islands on both sides of the Straits of Malacca, must have been derived 
from infusoriae, we subjoin an extract from a paper by Prof. Ehrenberg on 
the subject shewing some of his results : — 
1, The minute microscopic animals of the sea extend up the bed of the 
Elbe, (and this is probably the case, also, in all rivers directly connected 
with the ocean,) as far as the ebb and flood of the tide are perceptible. 
2. The flood-tide in the upper district of the river, even where the salt 
taste is no longer perceptible, as above Hamburgh, does not consist merely 
of an accumulation of the river waters occasioned by checking its outflow, 
but is now proved to be due to the direct introduction ofthe sea water, pro¬ 
bably under the river water, and extending, very distinctly, as far as eighty 
English miles above the mouth of the river. 
