AND GEOLOGY OF THE MALAY PENINSULA, 
105 
fine to coarse.* We have large specimens with the ore adhering to 
and partially invested with quartz. We are not aware that it lias 
ever been actually seen in the solid rock in the Peninsula, but in Ban¬ 
ka it is found associated with iron ore in veins in the granite. A 
Dutch writer also describes whole layers as occurring in some moun¬ 
tains which consist partly of granite, but in the centre principally 
* In most cases it appears to be properly stream ore i. c. the fragments 
and particles of disintegrated rock that have been born to lower levels by 
rain torrents and streams. We think however that there are both tin and 
gold pits in which the rock has been decomposed and disintegrated in situ, 
and a careful examination would probably prove that there are many such. 
Theclaysinour Peninsular vallies are not always alluvial, and in the higher 
part appear most often to mark the decomposition of the subjacent rock. In 
a recent excellent geological work by Professor Ansted (Geology , Introduc¬ 
tory, Descriptive and Practical vol ii. p. 281) it is erroneously stated that 
in Banka the ores of tin are entirely obtained by sifting the gravel and sand 
of rivers. In Banka and the Peninsula the beds of streams are seldom resorted 
to, save to obtain indications of the probable abundance of w tin sand” in the 
vicinity. One of the narrow vallies between the parallel ranges or branches 
of the low hills is selected, and, if tin be found, pits from 10 to 60 feet in depth 
are dug, and carried regularly up the valley, a new one being opened as soon 
as the last is exhausted. In this way the entire breadth of a valley is some¬ 
times excavated by successive pits throughout a length of two or three miles, 
if the tin sand be found continuous. 
In Malacca the tin sand is generally found at the bottom of a series of al¬ 
luvial layers. This is also the case in Cornwall, where it appears to be at¬ 
tributed to diluvial action. In the Malacca vallies there is no evidence of 
diluvial action. The accumulation of the tin ore in the bottom of the valley 
maybe explained, in some cases, by the decomposition of the rock and wash¬ 
ing away of the clayey and lighter siliceous particles,—the tin ore and as¬ 
sociated quartz remaining by their gravity. In other cases it may probably 
be explained by the consideration that in the earliest ages of the vallies 
the disintegration must have been more rapid and the fall of the vallies 
greater. The torrents in rains would have a considerable impetus, and car¬ 
ry forward the disintegrated fragments of the rugged and naked ravines. 
In the course of time these would he smoothed into gentle slopes covered 
with vegetation, and the slopes of the bottoms ol the vallies would gradually 
decrease as their mouths became choked with mud flats and sand banks, 
and the alluvial deposit spread back, raising the level of the vallies. 
We have dwelt at some length on Tin because it is the principal natural 
production of the Peninsula, which derives from the fact of its being the 
greatest stanniferous tract in the world an importance economically which 
has never been sufficiently appreciated. We are able to state confidently 
that the geological conditions which seem to be necessary for the produc¬ 
tion of tin in this part of the world are found in the Peninsula as fully deve¬ 
loped as in Banka. Both portions of the zone have been equally affected by, 
and have indeed originated in, one and the same igneous action, of which one 
of the phenomena has been the formation of tin ore. The existence of tin in 
Banka was unknown until 1709 when it was accidentally discovered. Now, 
its produce doubles that of the Peninsula, although the latter has a surface 
18 times larger. The reason is not a mineralogical one. ft is because in 
Banka the Chinese are stimulated, furthered and protected by a strong Go¬ 
vernment, which directly interests itself in their operations. 
