17. The figure of 8 bandage, so generally in use, and all the various modifications, under which it has been revived, without being improved, fix the clavicle in the very direction most favourable to a displacement, and even do it in the very manner in which that accident is sometimes brought about; as maybe seen in the history of the case of the porter (6). This bandage does not, under any of its modifications, prevent the motions of the shoulder, because it does not restrain those of the arm, which remains free and unencumbered. Far from constituting an antagonist power to, it even co-operates with, that which has produced the displacement. (For further light on this subject, see what has been already said on the fracture of the clavicle, pages 22 and 25.) Bell, in condemning the figure of 8 bandage, not so much because of its action being insufficient, as because of its obstructing respiration, proposes, as a substitute for it, a kind of machine analogous to the iron cross of Heister, which, being fixed by straps passing under the arm-pit, and round the neck and body, is intended to retain the parts firm and immoveable. But the motions of the arm not being restrained, nor the action of the muscles of the shoulder opposed by an antagonizing power, places this piece of apparatus in the same class with those, which, from not being devised and constructed on a proper view and conception of the causes of displacement, have no affinity to rational practice. 18. The apparatus for a continued extension, invented by Desault, for fractures of the clavicle, fulfil here all those indications in which the others fail. By this, 1st. The aim, being firmly fixed against the side, by means of the roller (_c c_ Fig. 3), can communicate no motion either to the shoulder, or the clavicle. 2dly. The shoulder itself, being forcibly drawn outward, with the upper extremity of the humerus, by the action of the kind of lever into which this bone is converted, and to which the bolster (_a b_ Fig. 1) serves as a fulcrum, cannot, by its movements, derange the luxated bone. 3dly. The sternal extremity, being drawn both by the muscles which tend to displace it inwardly, and by the bandage which acts on it in an opposite direction, remains fixed between those two antagonizing forces, which thus destroy each other. Hence the apparatus of Desault, when accurately applied, offers to both of these powers of displacement, a resistance perfectly calculated to combat them. 20. We must, however, admit that this apparatus partakes of one inconvenience, common indeed to all bandages, but which is perhaps more particularly applicable to this in consequence of the numerous casts of the rollers that form it, namely, the great facility with which it becomes relaxed. Hence one cause of displacement, which the most exact and scrupulous attention cannot at all times prevent.