43. In former times a kind of splints was in use, which were made by securing bundles of straw round sticks proportioned in length to the length of the limb to which they were to be applied. But as these, from being of a round or cylindrical form, touched the limb with but a narrow surface, they did not retain the fracture with sufficient firmness. They were, therefore, very properly exchanged for flat and strong wooden splints, (such as Desault used) which retain the fracture much better, in consequence of presenting to the limb a broad surface, and thereby rendering it in some measure immoveable. 44. The bolsters for filling up interstices, being less intended to prevent displacement, (in which respect they are, notwithstanding useful) than to guard the limb from the immediate pressure of the splints, usually consist of several folds of old linen; this is the form adopted at the Hotel-Dieu; but to these Desault preferred small pallets or bags filled with chaff, which, fashioned according to the form and disposition of the limb, may, at the pleasure of the surgeon, be made thicker or thinner, to suit the inequalities of the surface, in consequence of the ease with which the chaff may be moved from one part of the bag to another. 45. From the foregoing examination of the action of bandages and splints, it appears, that the common apparatus, formed by their union, but not calculated to effect a permanent extension, may perhaps answer in cases of transverse fractures, which indeed but rarely occur, but are always insufficient when the division is oblique, because they cannot fulfil the double indication of drawing the inferior fragment down, and retaining the superior one up (38). § VIII. OF PERMANENT EXTENSION, AND THE MEANS OF EFFECTING IT. 46. By what means then can this indication be effectually fulfilled? By that which will perpetuate, throughout the whole treatment, the action of those means by which reduction was effected; by that which, to the ever active power of the muscles, will oppose a resistance constant in its action; by that which, forming on the exterior of the thigh a kind of artificial muscle, may become an antagonist to the natural muscles of the part, and neutralize their efforts, by acting in a contrary direction, and which, by pushing up the pelvis and retaining it there, may prevent it from being pushed downward by the weight of the trunk (14). But what other mean than that of permanent extension, unites these advantages? Whatever form of apparatus may be employed to obtain it, it is permanent extension alone that can prevent the displacement, because it alone is founded on principles calculated to meet and obviate the causes by which displacement is produced.