The waters of Carlsbad were formerly used almost entirely as baths—but now it is just the reverse—they are chiefly taken internally. In former times the bathers passed eight or ten hours in the baths, as they now do at Leuk, Baden, and Pfeffers. My friend De Carro thinks that, formerly, cutaneous complaints were more rife—and now, that liver and stomach affections are the prevailing maladies—hence the change from bathing to drinking at this celebrated spa. There may be some truth in this. The taste of these waters very much resembles that of weak chicken-broth, with a flat and alkaline savour. It has been seen that SODA, combined with sulphuric, muriatic, and carbonic acids, is the chief agent in the Carlsbad waters. Soda uncombined with acids, either out of or in the body, has rather a deleterious effect on the organs of circulation and digestion. “But the Carlsbad water (says Chev. De Carro) though used for a long time, reanimates, vivifies, excites the appetite, and promotes digestion—thus with proper regimen, restoring the patient to health.” Doubtless the efficacy of the waters is augmented by the admixture, however small in quantity, of other elements, as the oxide of iron, the carbonic acid, the iodine, and materials yet unknown, diffused in extreme solution, through a fluid of a very high temperature, which enables the component parts of the spring to permeate the minutest vessels of the body. The Carlsbad salts are found in the renal secretion, as well as in the cutaneous transpiration, after being taken internally. These waters act by exciting the stomach, bowels, kidneys, liver, and abdominal organs generally, augmenting the secretions and excretions—especially those of the intestines, sometimes it is said even to purgation, when they are taken in considerable quantity. This effect, however, must be rather unfrequent, for I found no one, including myself, who experienced it. “They excite the circulation, so as frequently to produce palpitation of the heart, and determination of blood to the head. This water augments the activity of the absorbents; but it is not till after its other operations, that it acts as a direct TONIC.” Purgation is not considered by the Carlsbad doctors as essential to its beneficial agency, which is often produced without any action on the bowels, but only on the various secretions already mentioned. In all cases, however, it is necessary to guard against constipation, by adding some Carlsbad salts to the water, or exhibiting some other aperient. Although these waters contain no sulphuretted hydrogen gas, or extremely little, they produce fætid eructations from the stomach when drunk—but they have not a corresponding effect on the alvine evacuations. “The operation of the Carlsbad waters, in fact, is what is called ‘_alterative_,’ or ‘_deobstruent_;’ and as such they are applicable to a long list of maladies arising from congestion or obstruction in the abdominal organs, particularly