This pudding-stone is composed of gravel formed of the hardest parts
of the schistus and granite or porphyry mountains. That compound
parasitical stone has been also again cemented by heat and fusion; I
have a specimen in which there is a clear demonstration of that fact.
One of the water-worn stones which had been rounded by attrition, has in
this pudding-stone been broken and shifted, the one half slipping over
the other, three quarters of an inch, besides other smaller slips in
the same stone. But the two pieces are again cemented; or they had been
shifted when the stone was in that soft state, by which the two pieces
are made perfectly to cohere. Those shifts and veins, in this species of
stone, are extremely instructive, illustrating the mineral operations of
the globe.
In like manner to the north of the Grampians, along the south side of
Loch Ness, there are mountains formed of the debris of schistus and
granite mountains, first manufactured into sand and gravel, and then
consolidated into a pudding-stone, which is always formed upon the same
principle. The same is also found upon the south side of those mountains
in the shire of Angus.
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