Upon the propriety of removing the exciting causes, and the manner of doing so, very little requires to be said. If any acrid, or stimulating substance, has been applied to the skin, or any extraneous body been forced into it, these must be removed before the inflammation can be resolved; because, if they be allowed to remain, they will keep up the action so long, and to such a degree, that suppuration will be produced, or gangrene, if the part be very sensible, (as, for instance, the cutis) or if the exciting cause be very irritating. Acrid substances are to be removed by ablution with water, which is in general much better than the solutions which are proposed upon the principle of chemically combining with the acrid; because these generally are likewise acrid, or stimulating, and increase still more the inflammation which has taken place, before they can combine with the substance which was formerly applied, and become neutralised. This may be illustrated by the operations of acids and alkalis. If heat have been applied, so as to induce inflammation, we must remove the superabundant quantity of heat, but must not apply cold; because we then do mischief, as will be afterwards mentioned. When a substance is forced into the skin, so as to stimulate mechanically, we must endeavour to lay hold of it, and pull it out; but if it have penetrated so deep as to make this impracticable, we must then enlarge the wound, and remove it; because we thus may enable the wound to heal by the first intention. If, however, the injury done be great, if the part be much bruised, or the extraneous substances be numerous, we may be less anxious about the extraction of such as require much trouble; because the irritation which is thus given will tend to increase the degree of inflammation, and, very probably, its extent, at the same time, that, from the original injury, there is little prospect of adhesion being procured, or suppuration prevented. We are then chiefly to search after, and extract foreign bodies, when we apprehend that their removal may permit the inflammation to be resolved, and adhesion to take place, and when we expect that their presence will excite a greater action than our endeavours to extract them will do. This is a rule which ought to be carefully remembered by every surgeon, and especially by those whose situation makes them be daily called to take the management of gun-shot wounds. They are not brought to their patient to show how much they can do in the way of cutting and probing; it is their duty to administer relief, and act so as to prevent and abate the inflammatory action, which they will often do most effectually by letting their patient alone, and throwing aside their ball-screws and forceps.