If a quick reaction is desired a cold douche may be added to the steam, and the so-called _Russian vapour bath_ consists of a vapour bath of high temperature followed by a cold douche. _Air baths_ are baths from which we never escape except when we are taking a water bath, our bodies naturally being always surrounded by a layer of the atmosphere. _Cold-air baths_ are not much employed, although they have been recommended; and we have heard of persons who have sought to stimulate their skins and circulation by running naked in the open air. The _hot-air bath_ has always, at least since the days of ancient Rome, been a favourite luxury and means of treating disease; these baths, which are also called Russian or Turkish baths, consist really in a succession of processes, which, in the best establishments, are as follows: The bather is received at a barrier, where he is relieved of his boots and provided with check napkins in which to swathe himself while bathing. Passing the barrier he arrives at the tepidarium, a room of Eastern design, which attracts him by its coolness, quietness, and cleanliness. A marble basin, filled with water, into which a jet of water from a fountain falls with a soothing splash, occupies the centre, while all round are divans for reclining and conveniences for dressing and undressing. Through a Moorish arch at the end a glimpse is caught of the sudatorium, separated by a plate-glass partition from the tepidarium. Stripping himself naked and donning his checks, the bather passes into the sudatorium, an apartment with a domed roof, and having a marble floor and red-brick walls. The temperature of this room is about 120° or 150°, and here the bather sits, reading or otherwise amusing himself until perspiration is fully advanced. If perspiration is not free it may be encouraged by a draught of cool water, which will be tendered him by an attendant. If perspiration is slow in its advance, the heat of the room causes discomfort. Some burning of the skin, quickness of the heart’s action, and occasionally a throbbing tensive headache. A drink of water generally has the effect of causing the whole surface to bead with moisture, and then a sense of comfort succeeds to discomfort. Perspiration being fairly started it may be still further encouraged by removing into a still hotter apartment (of which there are three) varying in temperature from about 150° Fahr. to 210° Fahr. In these hot rooms (where it is necessary to wear thick list slippers to prevent the feet being scorched by the hot marble) the perspiration, in some persons, streams off the body, and when sufficient perspiratory action has been allowed, the bather returns to the body of the sudatorium, and, reclining on a marble slab, he is shampooed by an attendant. Next the whole surface is thoroughly washed with hot soap and water and the skin rubbed with a horse-hair glove; lastly, the process is finished by the application of cold water, which is done in one of two ways,