39. If to these indications we compare the mode of action of the different pieces that unite in composing our common forms of apparatus which do not make permanent extension, such as common bandages, splints, compresses, bolsters, &c. we will perceive that they are but ill calculated to fulfil them: and first of bandages. Whether the common roller, or the eighteen-tailed bandage be employed, their mode of operation is the same: their only action is, to add a second exterior and artificial covering to the natural cutaneous and aponeurotic covering of the thigh; to press against the fragments the muscles which form for them a kind of natural case intended to keep them in apposition; and to augment, by this pressure, the lateral resistance of the soft parts. By this contrivance, lateral displacements will, in part, be well guarded against, and, in this respect, these bandages are useful in transverse fractures. But what is there in them to prevent the two inclined plains of an oblique fracture from sliding on each other? What provision is there in them to secure the limb from the effects of motions and shocks which may be accidentally impressed on it from without? Will the pelvis be kept steady by them? or will muscular action be sufficiently checked and kept under by them? The force of the muscles will indeed be slightly diminished by means of compression; and to make this compression is the principal use of these bandages in oblique fractures. But will mere compression be sufficient to prevent a displacement in the longitudinal direction of the bone, particularly if the rollers be slack, as certain practitioners recommend, on the ground of the fallacious theory of Duhamel, who conceived, that a constriction too tight, would injure the action of the periosteum, which, according to him, is the sole agent in the formation of callus? So much, then, for bandages, whose only use is to prevent, by compression, the swelling of the limb, and to diminish, in some degree, the contraction of the muscles, which they press against the fractured bone. 40. These remarks apply equally well to the use of compresses; which make but a very feeble resistance against a powerful cause, and cannot be considered as any obstacle whatever to displacement. What can be said of those surgeons who, from servile attachment to a particular form of apparatus, do not consider a fracture as reduced, unless a certain quantity of compress secured by a given quantity of roller, be applied on the limb. Servile imitators in an art which calls for genius in its votaries, they are only capable of following, without reflection or judgment, the steps of their predecessors.