5S On the TJfc of Calcareous Stones 



cide with a jufl: preference upon that quahty nioft proper fot 

 the culture of his grounds. I found chalk to contain car- 

 bonic acid and water -- - 3 7 "3 

 Silex and a minute portion of clay - i'045 

 Lime _ - . 6t'655 



100 parts. 

 Trifli white lime-ftone. — ^This beautiful calcareous rtone is. 

 found in various places ou the coaft of Ireland. It greatly 

 refembles chalk, and diflers only from it in its hardncfs, 

 which it derives from a greater quantity of water of cn,'ftal- 

 lifation ; it abounds with fine fpecimens of dog teeth and 

 coxcomb cryftals ; contains a confiderable quantity of flint 

 in rounded and ovular forms, with very perfeft fpecimens of 

 belenmites. I found this lime-ftone to contain water ot 

 cryftallifation and carbonic acid - 44'5 



Silex and a minute portion of clay - 3-7 



Lime - - - 5i"8 



100 parts. 

 Irifti blue lime-ftone from Learn. — This ftone is of a dark 

 blue colour, fmooth frafture, and ftudded with fmall ftiining 

 fpiculas; it contains no mixture, or form foreign to itfelf. It 

 contains water of cryftallifation and carbonic acid 37*14 

 Silex - - - 9-43 



Lime ... 53-43 



ICO parts. 

 Arran lir>ie-ftone, from the Ifland of Arran. — This is a 

 reddifti-coloured lime-ftone, abounding with fuch an im- 

 menfe quantity of ftiells, that the whole ftratum, which 

 meafures 60 feet in thicknefs, appears to have been formed 

 of ftiells connefted bv means of a calcareous cement much 

 lefs pure ; thde are all univalve, uncommonly large, fome of 

 them 6 or 8 inches in diameter, and form the pureft lime. 

 In calcination this ftone lofes its colour, and becomes as 

 white as fnow ; perhaps a fmall portion of iron diflblved in 



the 



