This dressing has almost supplanted the jacket poultice in the treatment of pneumonia in children, because it is more readily applied, is much lighter and consequently interferes less with the respiratory movements of the chest wall, maintains a more uniform temperature, requires changing less frequently, thereby avoiding fatigue and exposure, and is capable of gradual removal by thinning the cotton from time to time.

A muslin waist or a merino undershirt forms the frame of the cotton jacket. If a shirt be used it must have the sleeves cut off, be opened all the way down in front, and so arranged that when put on it may be closed by tapes. A waist should reach well up in front and behind, and down to the base of the chest, and be fastened over the shoulders and in front by tapes. To the inside of either frame, a thick layer of cotton must be basted, and to the outside a complete covering of oiled silk. Such a jacket need not be changed oftener than once in twenty-four hours, and may be worn much longer if the cotton does not become too saturated with perspiration or rolled into hard balls by the restless movements of the patient.