Earths. 175 



acids that alkalies do: they have the same at- 

 traction for the acids, and the same affinities. 



The compound of lime, and an acid after sa- 

 turation, has no acrimony or acid taste : it pro- 

 duces no effect on vegetable infusions. Lime is 

 found purest in limestone, marble, and chalk, 

 which only differ in their degree of purity, or in 

 the manner of their aggregation admitting more 

 or less polish. The coarser limestones contain 

 other substances besides the calcareous earth. 

 The different coloured veins in marble are pro- 

 duced by the admixture of other substances, un- 

 equally distributed through the mass. 



Freestone may be mentioned as another kind 

 of matter, which contains a considerable quantity 

 of lime. The principal ingredients of freestones 

 are sand or gritty particles cemented by some 

 other substance, which is most frequently lime ; 

 these are often found in extensive strata in the 

 bowels of the earth. 



2. Lime is often found in the veins of rocks 

 and crevices of mountains, combined with fluoric 

 acid, and in this state it is called spar, or, more 

 properly, fluor spar, to distinguish it from others. 

 The English lead-mines are full of spars. 



3. It appears in the form of vegetable and 

 animal substances petrified into stone, by being 

 exposed to petrifying waters. These fill up the 

 pores of the substances with lime, commonly in 

 a state of combination, as carbonat of lime, and 

 incrust them. Hence we may conclude that this 



