147 



TAB. CLXXVII. 



CALX carbon ata. 

 Carbonate of Lime. 



Div. 1. Crystallized. 



The hills of Pentland, near Edinburgh, are famous for 

 Petunse*, and much variety in Mineralogy; also for Agates 

 and other Pebbles. I am obliged to Mr, Jackson, who was 

 botanizing in that neighbourhood, for this specimen; for, 

 although he does not study mineralogy, he was struck by 

 the singular appearance of this stone when he picked it up, 

 and the regular formation of the Carbonate of Lime placed 

 so distinctly within the hollow is certainly worthy of no- 

 tice; for we know of no theory which satisfactorily accounts 

 for such a formation. The surrounding pinky Quartz, in 

 bundles of little eighteen- sided crystals, lines the cavity, and 

 the jasperine Quartz (if I may so call the red coat) seems 

 to terminate the whole pebble as it were, which is sur- 

 rounded by part of the rock of a brown hue, called trap, 

 in which there are smaller or larger pebbles sometimes in- 

 cluded, and sometimes hollows where others have been 

 entrapped. These hollows are sometimes coated with a 

 green or blue earthy substance called by some the Green 

 Earth of Verau, probably owing to an uncertain mixture of 

 Iron: this occasionally coats also the stones included. The 



* An interesting substance used in porcelain, 

 VOL. II. N 



