The operation of applying a ligature on the vessel at a distance from the tumour, and thus intercepting or weakening the flow of blood into the cavity, so as to allow complete coagulation to take place, is of comparatively modern invention, and is the one now practised with almost invariable success. To John Hunter without doubt belongs the merit of proposing and putting it in practice; it has been claimed also for the celebrated Desault. This operation has been variously modified. Some have advocated the temporary application of a ligature, conceiving that the effects produced will be as complete and permanent when it has been allowed to remain only for a certain time, as when it is left undisturbed and ultimately separated by nature. Such a theory, however, has proved to be incorrect in most of the instances in which it has been reduced to practice on the human subject; and the operation is at best very uncertain, and not to be relied on. Others have employed a double ligature, and some of the Continental surgeons have applied a great many; some were tightened, others left loose, and looked upon as ligatures of reserve to be tightened, should hemorrhage take place, an occurrence likely enough to follow their clumsy and unsurgical proceedings. A thick broad ligature like tape has also been used, from an ill-grounded apprehension that all the coats of the artery would be cut completely through by the tight application of a thin and firm one. With the same view, a roll of linen or plaster has been interposed betwixt the noose and the vessel, and this practice has been advocated even by good surgeons—as Scarpa. Such complications can do no good, and may do much mischief. The artery must be greatly detached from its surrounding connections before the numerous and flat ligatures can be applied, in consequence of which its coats will be apt to slough or ulcerate, and hemorrhage occur. When, from any cause, the vessel has been detached to a greater extent than is sufficient for the passing of one ligature, two ought undoubtedly to be used, and one applied close to each extremity where it is attached to the surrounding parts. Again, it has been proposed, after the application of a double ligature, that the vessel should be cut through betwixt the two deligated points; it being supposed that in this way the closure of each extremity will be more rapid, the cut ends retracting, and being, in fact, in the same circumstances as the extremities of arteries which have been tied on the face of a stump. Mechanical contrivances have also been invented for the compression of the artery,—such as the serrenœud and presse artere; these, however, are clumsy, insufficient, and often injurious.