16 LIMESTONE. 



These two specimens so clearly prove that the origi- 

 nal materials of their substance were derived from the 

 deep, that no further arguments need be advanced to 

 support this fact as to our limestone. The former is, 

 perhaps, the mountain limestone of Werner ; the latter 

 a variety of dolomite. Our other quarries, as well as 

 the lower strata of the above, present no such indica- 

 tions of animal formation, and they are probably sedi- 

 ment arising from a minute division of shelly bodies 

 now indurated by time and superincumbent pressure 

 and become a coarse-grained marble. Our limestone 

 thus appearing not to be contaminated with any great 

 portion of magnesian earth, it may be used for all agri- 

 cultural purposes with advantage. Many detached 

 blocks of limestone are found about us, having broken 

 shelly remains; and the joints of the encrinite, greatly 

 mutilated, embedded in them. Irregularly wandering 

 near the lime-ridge is a vein of impure sandy soil, cov- 

 ering a coarse-grained siliceous stone ; sand agglutin- 

 ated, and colored by oxide of iron, resisting heat, and 

 used in the construction of our lime-kilns : the laborers 

 call it " fire-stone." 



We occasionally, though sparingly, find, in a few 

 places on our downs, nodules of lead ore, which induced 

 persons in years past to seek for mineral riches ; but 

 the trial being soon abandoned, the result, I suppose, 

 afforded no reasonable ground for success. We like- 

 wise find thin veins of carbonate of strontian, but make 

 no use of it j nor is it noted by us different from com- 

 mon rubbish; nor do I know any purpose to which it is 

 peculiarly applicable, but in pyrotechnics. Spirit of 

 wine, in which nitrate of strontian has been mixed, 

 will burn with a beautiful bright red flame ; barytes, 

 which approaches near to stroritia, affords a fine green ; 

 nitrates of both, compounded with other- matters, are 

 used in theatrical representations. Strontian exists in 

 many places, and plentifully; some future wants or ex- 

 periments will probably bring it into notice, and indicate 

 the latent virtues of this mineral. 



Perhaps I may here mention an incident, that occur- 

 red a few years past at one of our lime-kilns, because it 



