Step 2. The surgeon carefully greases the limb wherever the plaster will reach, and rolls a Welsh flannel roller round it for about 3 inches at the point where the plaster roller will cease. This protects the skin from the rough edge of the plaster splint when the apparatus is set and hard. Indeed, if the whole of the surface to be covered with plaster be enveloped in a flannel roller, the apparatus is more comfortable to the patient, and in this case the grease may be dispensed with. When the limb is prepared the surgeon intrusts it to assistants, who will maintain reduction while he lays on the plaster rollers, wetting them freely as they are laid on, with a sponge at hand in a basin of cold water. Usually two layers of roller give sufficient rigidity to the apparatus; but if the limb is heavy, the case should be strengthened, by smearing over it a coating of plaster, prepared by shaking the powder into a basin of water kept constantly stirred, till it has the consistence of cream. The surgeon must watch that the fractured bones are kept in position till the plaster is set, a process sufficiently advanced in five minutes, when the bandage, supported by sand-bags, may be left to dry. When the plaster is quite set the bone is immoveable and may be carried about without risk of displacement. In deciding what joints should be included in the bandage, the same rules obtain in this as for the starch bandage; no more joints should be rendered immoveable than are necessary to obtain command of the broken bone; when the fracture is near a joint, that must be confined to prevent the bones being moved with the movements of the joint; when the fracture is far away from it, sufficient control can be exercised over the bone to prevent the broken ends moving, and the joint may remain free. If the plaster apparatus is applied over a wound, the latter should be covered with greased lint, and its position noted before the rollers are applied; when the apparatus is set, the plaster must be dissolved around the wound by touching it with strong nitro-hydrochloric acid; when this is carried completely round, the isolated fragment of plaster may be removed, and the wound exposed. For removal, the roller can be unwound again readily, or it can be softened by acid along a line, and slit up with scissors, when the apparatus comes off in a piece. Should bandages of loose texture not be at hand, _common rollers_ can be made to answer the purpose tolerably well in the following way.