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ILLUSTRATIONS OF 
advantages of this kind of stratification upon healthy 
says — The only principles on which the strata of 
any district lying beneath the soil and superficial beds 
of clay and gravel, appear capable of exerting an 
influence over the health of its inhabitants, are — as 
those strata absorb water more or less readily and 
completely, thereby affecting the hygrometrical state 
of the atmosphere ; and as they furnish, by springs 
and rivers, water more or less impregnated with 
foreign ingredients, and therefore less or more fit for 
the use of man. Under the first view, the red sand- 
stone is well adapted, by the avidity with which it 
imbibes water, to moderate the evils of a rainy 
climate like that of Lancashire. Under the second 
aspect, this rock furnishes an abundant supply of 
beautifully clear water, agreeable to the palate, but 
holding, in solution, much carbonate of lime, and a 
little sulphate of that earth, both of which are de- 
posited on boiling. There is no reason to suppose 
that these impregnations have any effect unfavourable 
to health. They can have no tendency to produce 
calculous diseases, which were once imputed to 
them, but which have been shewn to be produced 
by causes quite independent of the qualities of 
water, and to depend on morbid operations of the 
animal economy. The almost universal freedom of 
the red sandstone from noxious metals (lead and 
copper being rarely found in it,) adapts it for the 
purpose of an excellent natural filter. By its sponta- 
neous decomposition, also, this sandstone is known 
to furnish an excellent sandy loam, one of the most 
