e of the granite rock
was quite altered to a very considerable depth, not however to sand,
but to a fine, often reddish, clay, thus in quite a different way
from that on the coast of the Inland Sea of Japan. Here too one
could at many places follow completely the change of the hard
granite mass to a clay which still lay _in situ_, but without its
being possible to draw so sharp a boundary between the primitive
rock and the newly-formed loose earthy layers as at the first-named
place. We had opportunities of observing a similar crumbling down of
the hard granite at every road-section between Galle, Colombo, and
Ratnapoora, with the difference that the granite and gneiss here
crumbled down to a coarse sand, which was again bound together by
newly-formed hydrated peroxide of iron to a peculiar porous
sandstone, called by the natives _cabook_. This sandstone forms the
layer lying next the rock in nearly all the hills on that part of
the island which we visited. It evidently belongs to an earlier
geological period than the Quaternary, for it is older than the
recent formation of valleys and rivers. The _cabook_ often contains
large, rounded, unweathered granite blocks, quite resembling the
rolled-stone blocks in Sweden. In this way there arise at places
where the _cabook_ stratum has again been broken up and washed away
by currents of water, formations which are so bewilderingly like the
ridges (_osar_) and hills with erratic blocks in Sweden and Finland
that I was astonished when I saw them. I was compelled to resort to
the evidence of the palms to convince myself that it was not an
illusion which unrolled before me the well-known contours from the
downs of my native land. An accurate study of the sandy hills on the
Inland Sea of Japan, of the clay cliffs of Hong Kong, and the
_cabook_ of Ceylon would certainly yield very unexpected contributions
to an explanation of the way in which the sand and rolled-stone _osar_
of Scandinavia have first arisen. It would show that much which the
Swedish geologists still consider to be glacial gravel transported
by water and ice, is only the product of a process of weathering or,
more correctly, falling asunder, which has gone on in Sweden also on
an enormous scale. Even a portion of our Quaternary clays have
perhaps had a similar origin, and we find here a simple explanation
of the important circumstance, which is not sufficiently attended to
by our geologists, that often all the errati