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 ; 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 strontia, 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 
