Another quarry presents, likewise, unquestionable evidence of an animal origin, veins of it being composed of shattered parts of shells, and marine substances, greatly consumed and imperfect, embedded in a coarse, gray, sparry compound; an ocean deposit, not a fabrication, and consequently has more impurities in its substance than that of insect formation: it contains about Carbonate of lime 73 Magnesia 11 Clay 14 Silex 2 ——— 100 These two specimens so clearly prove that the original 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 indications of animal formation, and they are probably sediment 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 agricultural 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, covering a coarse-grained siliceous stone; sand agglutinated, 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 likewise find thin veins of carbonate of strontian, but make no use of it; nor is it noted by us different from common 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 experiments will probably bring it into notice, and indicate the latent virtues of this mineral.