MINERALS. 
Under this head are classed all those materials 
which form the basis of our globe, and are hidden 
within the bowels of the earth. We have hitherto 
considered only those objects which present them- 
selves to our notice on the surface, and which, like 
us, depend for their existence on a proper supply of 
air : but we are now to leave the animated part of 
the creation, and descend to the interior of the 
globe, in order to investigate some of those curiosi- 
ties which nothing but persevering industry could 
ever have brought to light. 
The different parts of the mineral kingdom have 
been arranged under four heads ; viz. earths and 
stones , salts , combustible matters , and metals. These 
various substances are met with in different states ; 
sometimes they appear under the form of rude 
masses, of no determinate shape, sometimes in beds 
composed of layers running either in a horizontal 
or oblique direction ; and this last disposition by 
beds is observed to be by far the most frequent. 
