largely impregnated with the peculiar ingredients of the formation, the famous medicinal springs of the Strath have their rise. They contain, as shown by chemical analysis, the sulphates of soda, of lime, of magnesia, common salt, and, above all, sulphuretted hydrogen gas--elements which masses of sea-mud, charged with animal matter, would yield as readily to the chemist as the medicinal springs of Strathpeffer. Is it not a curious reflection, that the commercial greatness of Britain, in the present day, should be closely connected with the towering and thickly spread forests of arboraceous ferns and gigantic reeds--vegetables of strange form and uncouth names--which flourished and decayed on its surface, age after age, during the vastly extended term of the carboniferous period, ere the mountains were yet upheaved, and when there was as yet no man to till the ground? Is it not a reflection equally curious, that the invalids of the present summer should be drinking health, amid the recesses of Strathpeffer, from the still more ancient mineral and animal debris of the lower ocean of the Old Red Sandstone, strangely elaborated for vast but unreckoned periods in the bowels of the earth? The fact may remind us of one of the specifics of a now obsolete school of medicine, which flourished in this country about two centuries ago, and which included in its _materia medica_ portions of the human frame. Among these was the flesh of Egyptian mummies, impregnated with the embalming drugs--the dried muscles and sinews of human creatures who had walked in the streets of Thebes or of Luxor three thousand years ago. [Footnote AV: "In the slaty schists of Seefeld, in the Tyrol," say Messrs. Sedgwick and Murchison, "there is such an abundance of a similar bitumen, that it is largely extracted for medicinal purposes."--(_Geol. Trans. for 1829_, p. 134.)]