These and the Mud-baths to be presently described, are becoming very fashionable in Germany. From every inch of surface in the peat bog around Franzensbad, carbonic acid gas is constantly issuing forth in such quantities that its extrication is audible and visible, wherever there is water on the ground. To have a reservoir of this gas, it is only necessary to build a house, and prevent the carbonic acid from being dispersed in the air. It is there collected, and baths and douches are constructed for its ready application to the body generally, or to any particular part thereof. The Gas-bath or building at Franzensbad, stands within thirty or forty yards of the Franzensquelle, and from the ground of this house, which is of very moderate extent, there issues 5760 cubic _feet_ of gas every twenty-four hours!! There is little doubt that the extrication of carbonic acid is equally plentiful in any and every part of the bog in which the town is situated. I should think that to go to sleep on the ground, in a calm Summer’s night, would be inevitable death. As it is, the good people of Franzensbad, inhabitants and visitors, must be perpetually inhaling an atmosphere well impregnated with this gas. I do not suppose, however, that this is productive of any injurious effects. The gas is conveyed into the bath through a cock at the bottom, and the patient, being either dressed or undressed, sits down on a little stool, while a wooden lid or cover, with a hole that fits tolerably close to the neck, is placed over the body, the head being in the open air. They have small tubes through which they can apply the gas to the eyes, ears, or any part of the body, in a stream, the velocity of which can be augmented or diminished at pleasure. They can also diminish the intensity of the gas by applying a piece of muslin or taffeta over the pipe, or over the eyes or ears that are subjected to the stream. I did not try the gas baths here, but at Marienbad I used them generally and locally, accompanied by my kind friend Dr. Herzig of that place. Standing in the bath, the cock was turned without my being aware of it, and, in a few seconds, I felt a sense of heat ascending quickly along my legs towards the body. Without thinking of the gas I stooped, and put my head down towards the aperture of the tube, by which I inhaled as much of the carbonic acid as caused a sudden faintness. Dr. H. and the bathman quickly extricated me from my perilous situation, and I went on with the bath, while my head was in the open air. I found that the following representation of the sensible, and physiological effects of the bath, as given by Baron Aimé, is sufficiently correct. 1. The gas excites and even irritates the skin, producing a pricking, and soon afterwards a strong itching on the surface, accompanied by heat, and ultimately perspiration. 2. The gas stimulates the nerves of all parts to which it is applied. I had a stream directed on my eyes, which caused a most profuse flow