Chapter VIII

Sand and gravel of the boulder--What they suggested--Their
consideration leads us among the more mechanical operations
of Nature--An endless succession of mutations in the
economy of the universe--Exhibited in plants In animals--In
the action of winds and oceanic currents--Beautifully
shown by the ceaseless passage of water from land to
sea, and sea to land--This interchange not an isolated
phenomenon--How aided in its effects by a universal process
of decay going on wherever a land surface is exposed to
the air--Complex mode of Nature's operations--Interlacing
of different causes in the production of an apparently
single and simple effect--Decay of rocks--Chemical
changes--Underground and surface decomposition--Carbonated
springs--The Spar Cave--Action of rain-water--Decay of
granite--Scene in Skye--Trap-dykes--Weathered cliffs of
sandstone--Of conglomerate--Of shale--Of limestone--Caverns
of Raasay--Incident--Causes of this waste of calcareous
rocks--Tombstones,

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