132 PLASTER BANDAGES. 



bandages. Modellers' dry plaster is rubbed into ordinary loosely 

 woven bandages which are then rolled up, care being taken that 

 as large a quantity as possible of the plaster is retained in the 

 material. Just before use they are saturated with water (preferably 

 containing a little dissolved alum, which hastens setting) ; they 

 are then gently squeezed and at once applied to the parts, which 

 have previously been padded as above described. The first folds 

 should be applied around the free extremity of the limb and ban- 

 daging continued upwards, care being taken not to use much pressure. 

 The piece of linen placed next the skin should extend beyond the 

 limits of the bandage so that when the latter is complete the edges 

 of the linen can be turned up after the manner of a cuff, enveloping 

 the wadding or other padding material. This gives the dressing a 

 rounded edge, and prevents any pressure on or rubbing of the skin. 

 After complete application the surface of the dressing may be 

 smoothed with the wet hands, or some thin plaster may be spread 

 over it and smoothed off. Depending on its thickness the bandage 

 sets in from fifteen to thirty minutes, during which time extension 

 or flexion of the limb must be prevented. Plaster of Paris, if long 

 kept or allowed to become damp, sometimes fails to set, but a 

 little care in storage will prevent this. If desired, setting may be 

 delayed by adding glycerine to the water used in mixing the plaster. 

 To further support the dressing thin pieces of wood or splints of 

 zinc or tinned iron may be inserted between the layers. 



Instead of pure plaster a mixture of one part cement to two or 

 three parts of plaster has been recommended. It appears to present 

 no special advantages. 



Tripolith, a grey powder the composition of which is unknown, is 

 sold commercially. It hardens in much less time than plaster, and 

 has the advantage of keeping well, even in open vessels. Dressings 

 made with it are lighter and cheaper than those made with plaster, 

 but as it hardens so very rapidly only one or two bandages should 

 be moistened at a time. 



All the above dressings can be made waterproof by varnish or 

 shellac solution, which also gives them greater durability. While 

 the plaster is setting it is absolutely necessary that the limb should 

 be retained in the proper position, as any movement breaks and 

 therefore usually entirely spoils the dressing. For this reason small 

 animals must be kept lying ; larger animals should be placed in 

 slings. 



These dressmgs, especially when of plaster, are often very difficult 

 to remove, especially if one wishes to remove the bandage in two 



