The German physicians appear to be convinced that mineral springs are not merely waters impregnated with various mineral and gaseous matters, with or without increase of temperature; but that they are possessed of _vitality_—living beings, in fact, whose life is transfused into the human organism, thereby communicating energy to the solids and purity to the fluids of our bodies—in other words, correcting and expelling disease and restoring health! Even the venerable ALIBERT was smitten with this German transcendentalism, and he observes of the Aix waters—“these springs, under the empire of Nature, most undoubtedly enjoy a species of _vitality_ (une sorte de vitalité) in common with other living bodies on this globe. They are _animated_ by a multitude of principles, which will long, perhaps for ever, elude the most laborious researches of chemistry. The waters of Aix-la-Chapelle, whether used internally or in baths, act as potent restorers of vital energies. Their constituents are powerfully aided in efficacy by the high temperature and the impregnation of divers gases. Taken internally they excite the action of the abdominal viscera—detach mucosities and other morbid secretions, and evacuate them by the bowels, kidneys, and skin. The inhalation of the vapour rising from these waters has been very serviceable in many cases of pulmonary affections.” This _vitality_ hypothesis did not escape the notice of my friend Dr. Granville, who appears, however, to have thought it rather too large for John Bull to swallow, without some qualification. He therefore substituted “caloricity” for “vitality,” in order that so good an idea might not be lost—and that some _mysterious_ agency might aid the natural operation of the German spas. This mode of explaining the _ignotum_ by the _ignotius_ is, no doubt, very ingenious; but, for my own part, I shall at once acknowledge my ignorance, not only of the manner in which mineral waters are formed in the bowels of the earth, but of their _specific_ action (if any) on the human frame. The spa doctors candidly allow that the waters of Aix, “if taken too hot and in quantities too large, may produce irritation, and even purgation. But the latter is not a very common effect of these waters. In small doses they are favourable to digestion; and, taken in moderation, they are not calculated to weaken.” As baths, these waters act on the surface, and, by sympathy, on the internal organs, exciting the nervous, secreting, and circulating organs. The temperature of the blood (98°) is considered the best for the bath. “If taken at a higher degree, or too often, they are dangerous.” Let us now advert to the bill of fare which Alibert, Monheim, Zillerland, Dordonville, Reumont, and others, have spread before the invalids resorting to Aix-la-Chapelle. I shall endeavour, here and elsewhere, to form some scale or estimate of the probable, doubtful, and dangerous agency of the waters and baths.