The administration of these remedies requires but little particular attention; the doses of the saline waters must be regulated by their effects. They should be drunk till they produce a slight evacuation from the bowels; and, of course, the weaker impregnations are of little importance. If a pint, or from a pint to a pint and half daily, does not produce some sensible effect, the quantity of fluid will be more injurious as a load, than useful as a medicine. The chalybeate waters, if also saline, should produce some sensible effect in the same way; and, it is said, that the tonic power of the metal prevents their debilitating effects as cathartics. The sulphureous waters have, in general, their appropriate doses regulated by their other impregnations. Those wholly chalybeate must never be drunk in large quantities at once, or without some preparation.. The quantities of the Bath waters necessary for different diseases are taught on the spot: it is a sacred science which the uninitiated must not aspire to know: juvat integros accedere fontes, atque haurire. The others require no particular advice, except not to distend the stomach so far as to produce inconvenience. This caution is peculiarly necessary in the use of the acidulous waters. In general, it is better to begin with small quantities, and repeat them often. If sea water is too nauseous, or excites too much thirst, a portion of milk added to it will greatly diminish the inconveniences.

See Kirwan and Sanders on Mineral Waters, Monro on Mineral Waters, Falconer on Bath Waters, Mon-nett's Hydrologia, Annales de Chimie; Fourcroy's Connoissances Chimiques.

Aquae minerales artificiales. The preparation of artificial mineral waters has now almost become a science. Since the idea is in a great measure abandoned, that in the vast laboratory of nature they can be only with advantage prepared, many have attempted to imitate them by impregnating common water with their contents. We have just now admitted that the ingredients are of consequence as medicines, but have at the same time allowed that many of the effects are owing to a change of scene, of air, and of habits. We cannot therefore expect from these creatures of art what we find from the natural waters, assisted as they are by the other advantages; at the same time, it is of importance to consider the progress and state of this very useful art, which will supply in part the - advantages derived from visiting the springs. It has been common to attribute the invention to Dr. Priestley. In fact, we are indebted for it to a French physician of Montpelier, who, in 1755, presented to the Academy of Sciences an account of his method of imitating the Seltzer waters. Bergman, in 1774, followed these steps; and, in his successive dissertations, published in 1774, 1775,and 1778, taught us to prepare the waters of Seidchutz, Seltzer, Spa, and Pyrmont; the cold and warm hepatic waters. In this interval, Dr. Priestley gave us the form of preparing the acidulous waters; and Mr. Lane taught us that water thus impregnated was a menstruum of iron. In 1779, M. Duchanoy, a French chemist, reduced the scattered facts to a systematic form, but added little to them. He was followed by numerous other instructors, till M. Paul of Geneva, and M. Schweppe in this country, have rendered the art an almost perfect imitation of nature. Imitation! it is more, for all the noted waters are prepared with an ac-"curacy which prevents their being distinguished from those which nature offers in stronger or weaker states, and with additions adapted to the disease. M. Paul, it is said, has sold 40,000 bottles of artificial Seltzer water in one year. Of M. Schweppe's manufacture we have received no information, so that our account of this lis". must be collected from the report of the French academicians appointed to examine M. Paul's apparatus and management. The general doctrines we have anticipated in the article of mineral waters, and the impregnations are those which the most accurate analysis has detected in the natural mineral waters. When the acidulous waters are prepared by the separation of the carbonic acid gas from chalk or marble, some of the vitriolic acid escapes with the air, and gives a harshness not found in the natural acidulous waters. M. Paul prepares it with carbonic acid gas, separated by combustion, and all the airs are united to water by compression. His alkaline water is prepared with potash, in compliance with the directions of Mr. Home and others, who have recommended it in calculous cases. In the natural waters, however, the alkali is the soda; and this is the salt in the Vichy waters, and many of those of Puy de Dome, and Mont d'or. In many of his aerial waters, the quantity of air is greater than in the natural waters: experience must determine whether this is an advantage, for we know that we lose the peculiar qualities of a medicine by excess in the dose. It is evident, however, that the unavoidable loss in keeping, in uncorking, and pouring out the water, is thus compensated. The sulphureous waters contain half their bulk of pure hydrogenated gas, with 1/32, or, in the stronger kind, one-fourth of the sulphureous hydrogenated gas. According to Bergman, the proportion of the latter ingredient is larger. An alkali with an excess of carbone has been lately offered to sale, to prepare the aerial water extemporaneously. Air rapidly escapes in solution; but, to make the salt efficacious, it should be dissolved in a close vessel, or drunk during the solution.

The oxygenated water is a new remedy, yet it seems rather pressed into the water than united with it, and very readily escapes. It should certainly be drunk from a siphon, furnished with an accurately ground stop cock. Of this remedy we have no experience; yet, in the Bibliotheque Britannique, a work of character and credit, we find many facts in its favour. It seems from this work that the oxygenated water may supply the use of acids, and of various oxygenating remedies; but we would recommend its being used with caution, as oxygen in the stomach appears to be occasionally injurious. The oxygenated water has no taste, while the oxygenated wine, a quack medicine recommended in fevers, is slightly acid, and certainly consists only of wine with a small proportion of one of the mineral acids.