this constitutes “nitro-muriatic acid,” the _Aqua regia_ of the older chemists. A bath acidulated with an acid of this kind has been recommended by Dr. Scott, as a powerful remedy for diseases of the liver in particular, and as a substitute for mercury in general. On the possible influence of this bath, I would beg to make one observation,—that the extensive application of a dilute acid to the surface of the body, is, under certain circumstances, capable of affecting the bowels. I have witnessed such an effect from sponging with vinegar and water. In this way the acidulated bath may occasionally produce benefit, but it is extremely difficult to conceive how it can be indebted for its utility to any other mode of operation. (See _Journal of Science and the Arts_, No. 2.) FORMS OF EXHIBITION. Muriatic acid should be administered in some bland fluid, as barley water, gruel, &c. (_Formula 145._) I have uniformly exhibited it with success in the most malignant cases of typhus and scarlatina, during several years extensive practice in the Westminster Hospital. See _page 157_. We should be careful not to apportion its dose in a leaden or pewter spoon. The antiseptic properties of this acid have been long known; Sir Wm. Fordyce relates that a “dry-salter” acquired a large fortune from possessing a secret that had enabled him to send out provisions to India in a better state of preservation than any others of the trade; his secret consisted in adding a small quantity of muriatic acid to the contents of each cask. After a copious evacuation of the bowels, it is in my experience the most efficacious remedy for preventing the generation of worms; for which purpose the infusion of quassia, stronger than that of the Pharmacopœia, is the best vehicle. DOSE, ♏︎v-xx, frequently repeated. It may be here observed that where the permanent influence of an acid is required, a mineral one should be always preferred, as such bodies appear to be beyond the control of the digestive process,[351] and are incapable of being decomposed by it; see _Form. 158_, whereas on the contrary it seems probable that the organs of assimilation have command over those of a vegetable nature, and generally decompose them. Dr. Marcet has very judiciously noticed this fact in his luminous work on the treatment of calculi, and I have ventured to offer some farther observations upon this subject, which may be of practical value, under the consideration of _Lithonthryptics_, page 123. ADULTERATIONS. _Sulphuric acid_ is detected by diluting the acid with six parts of distilled water, and adding a few drops of the muriate of baryta, which occasions a white precipitate if any be present. _Iron_, by saturating a diluted portion with pure carbonate of soda, and adding prussiate of potass, which will indicate its presence by a blue precipitate; or by a solution of ammonia, which, when added slightly in excess, throws down the peroxide of iron of a reddish yellow colour. _Copper_, by the