THE OPAL.                                  257
	Towards the close of his painstaking and steadily-progressive career the aforesaid Master—in the last edition of his leading work, 1833—gave the most ex­pressive evidence of his belief in the virtue of attenuations, by saying that he could scarcely name one disease which during the past year he, and his assistants, had not treated with the most happy results, solely by means of " olfaction," (or the practice of smelling the highly subtilized medicinal substances) ; and he added that a patient, even when destitute of the sense of smell, may expect an equally perfect action, and cure, from the medicine, through the act of olfaction, or smelling thereat; but only one such medicine may be used (in this way) at a time. As a striking illustration of such exquisitively refined, yet absolutely sure potency for cure, which external means, mineral or metal, when correctly chosen serve to exert, we would refer our readers to the instance of the Bloodstone, as given fully at a following page. Well authenticated cases will be found related of severe chronic bleedings becoming arrested solely by the patient's outward use of such a stone ; and remaining arrested (in one instance) only so long as this stone was retained in wear. The raison d'etre for these curative effects may be sufficiently accounted for by the recognisable presence within the substance of the Bloodstone of Iron Oxide, in red specks, or streaks ; this Iron being of long, standing repute with doctors as an active, and effective astringent of bleedings. And similarly with respect to the Mineral Silica, (Flint),—which proves quite insoluble, as hitherto supposed, and medicinally inert,—this substance, under skilful trituration, has been converted into a most useful medicament for cures. When applied to 17