_Arnott’s Floating Bed._—In the hydrostatic or floating bed of Dr. Arnott, the patient floats on the surface of a trough of water, into which he sinks until he has displaced his own weight of water; his floating apparatus, or raft, so to speak, being a sheet of waterproofing, and a thin mattress or folded blanket, on which he lies. The bed consists of a trough running on large castors, about 8 feet long, 2 feet 8 inches wide, and 1 deep, with a tap at the bottom for letting out the water, and a spout in one corner to fill it by. Over the top a macintosh cloth is spread, its edges being firmly nailed to the margin of the trough, but the cloth is left slack enough to float easily on the surface of the water when the trough is partly filled. This slackness is requisite to allow the water displaced by the weight of the patient’s body to rise up around him without tightening the cloth, or the floating principle of the bed is not carried out, and the pressure of the patient’s weight not evenly distributed over his body (see fig. 93). Three or four blankets are laid evenly over the macintosh, and these again protected from the moisture of the patient by a macintosh under-sheet. If a mattress is used, it must be very thin, and supple enough to let the surface of the water adjust itself to the patient’s body and receive the pressure evenly. The water employed to fill the bath should be about 50°. [Illustration: Fig. 94.—Water-cushion.] _Water Cushions_ are flat cushions of stout macintosh cloth, half or two-thirds full of water, and laid on the mattress beneath the blanket and sheet (see fig. 94). They are more portable than the water-bed, but they are simply soft pillows, and do not counter-balance the weight of the patient in the manner of the floating bed. =The Stomach-Pump= is used for emptying the stomach, or for injecting fluid food when patients refuse to swallow. It consists of a brass syringe holding 4 ounces, of which the nozzle is connected with two tubes, one at the end, the other at the side. The passage through these is directed by a valve which is governed by a lever lying on the barrel (see fig. 95). When the lever is at rest, the current passes in and out of the syringe by the lateral tube; when depressed, by the direct tube. The elastic tubes with smooth nozzles, about 2 feet long, are fitted to the syringe. There is also a gag of hard wood, having a hole in the middle, through which the tube passes on its way to the stomach, to protect it from the patient’s teeth. [Illustration: Fig. 95.—The stomach-pump.]