The use of this second roller is, to supply the place of the hand of the assistant, in pressing the arm against the side of the thorax; its effect evidently is to draw the upper extremity of the arm outwards, and, as it is already directed backwards, to retain it in that position. The compression of the circular turns on the arm, being thus gradually augmented, becomes, on the one hand, more efficacious, because it acts on a greater surface, and on the other, less troublesome, because, being more divided, it is less felt at the lower extremity of the arm, where it bears with most force.

38. A third indication remains still to be fulfilled, namely, to retain the shoulder in its elevated position, and, by that means, to assist in the extension of the fragments, which already has some effect in preventing a depression.

To fulfil this indication, an assistant sustains the elbow in its elevated position, with one hand, and, with the other, supports the patient’s hand before his breast, while the surgeon fills with lint the hollow spaces around the clavicle. He then applies on the clavicle, at the place where it is fractured, the two long compresses, wet with vegeto-mineral water, or some other cooling liquid. Taking now the last roller, he fixes the end of it under the sound shoulder; from thence he brings it obliquely across the breast, over the long compresses, and carries it down behind the shoulder along the posterior part of the arm, till it passes under the elbow. From this point, he again carries it obliquely upwards across the breast to the arm-pit, then across the back, over the compresses, and brings it down again before the shoulder, along the front of the humerus till it again reaches the elbow. From thence the roller again ascends obliquely behind the thorax, passing under the arm-pit, where the first cast of the roller is covered, and from whence it again starts, to run the same course we have just described. This constitutes a second round, which covers in part the first, and forms a kind of double triangle (e, f, d), situated before the breast, and over the circular turns of the other rollers (c. c. [Fig. 4]). The remaining part of the roller, brought from behind forward, is employed in circular turns over the arm, and round the thorax, for the purpose of preventing the displacement of the first part. To make it the more secure, it is fastened with pins at its different places of crossing.

The sling (Fig. 4) is next passed under the hand, and fastened above to the ascending turns (d), and not to the circular (c c), which the weight of the hand would be likely to draw downward.

39. It is only necessary to examine the course of this third roller, to see, that, united to the sling, it is well calculated to support the external fragment, which the weight of the shoulder has a tendency to depress, on a level with the internal one. It supplies the place of the assistant, who raises the elbow and supports the hand of the patient, in like manner as the second roller performs the office of the assistant, who presses the lower part of the humerus against the side of the thorax.

On the other hand, the circular turns, by which the application of the third roller is finished, being directed from before backward, push in the same direction the arm and shoulder, which have been already carried that way, by the process of reduction, and thus retain them in their proper places.

Hence may be inferred the truth of the proposition, which we have been endeavouring to demonstrate; namely, that the bandage of Desault, constructed according to the general principle formerly established (20), for fractures of the body of the clavicle, is calculated to retain the external extremity of the humeral fragment upward, outward, and backward.

40. The casts of the rollers, thus surrounding the thorax, however well they may be secured, are yet liable to be displaced, particularly when the patient is in bed. This inconvenience may be avoided, by surrounding the whole with a piece of linen, leaving nothing uncovered, but the sound arm, which is at liberty to perform its usual motions.

The arm of the diseased side, being thus fixed in such a manner, as to constitute a whole or entire body with the thorax, follows its movements, without producing any displacement. It is thus, that by the apparatus for a continued extension of the thigh, the fragments of the os femoris, forming an immoveable whole with the pelvis, cannot change their situation, even in following the motions of the trunk.