and dress the ulcer with equal parts of wine and honey, and apply a sponge dipt in wine and oil of roses, which things are incarning. A proper regimen however, as I have observed elsewhere, is more effectual for this purpose: that is, when the fever is removed, and the appetite restored, bathing now and then, daily but mild gestation, and such kinds of food and drink as are of the most nourishing nature. All which rules also hold with regard to an abscess, that has been broken by medicines. But because it is hardly possible to cure a large tumour without the knife, the mention of these has been reserved to this place. CHAP. IV. OF FISTULAS. With regard to fistulas, if they penetrate pretty deep, so that a collyrium cannot reach the bottom of them, if they are tortuous, or consist of several sinuses, operations are more useful than medicines; and those, that run in a transverse direction below the skin, give less trouble than such as go directly inward. Therefore, if the fistula be transverse under the skin, a probe ought to be introduced, and an incision made upon that. If it be tortuous, its windings are to be followed by the probe and knife. And the same course must be taken, if several of them appear like rivulets _uniting their streams_. When we have reached to the end of the fistula, all the callosity must be cut out, and fibulae applied to it with medicines to agglutinate. But if it points directly inward, when its direction is found by a probe, that sinus must be cut out: then a fibula put upon the lips of the skin, and agglutinating medicines laid over it; or if the ulcer be very foul (which sometimes happens from a carious bone) when that also is cured, medicines to promote a digestion. [Sidenote: _Of fistulas amongst the ribs._] It is common for fistulas to extend beneath the ribs. When this case occurs, the rib in that part must be cut through on both sides, and taken out, lest any thing corrupt be left within. It is usual for them also, when they have got through the ribs, to penetrate the transverse septum, that divides the intestines from the superior viscera. Which circumstance may be known, both from the situation, and from the violence of the pain, and because sometimes the air comes out with the matter, as it were bubbling, and particularly when the patient keeps in his breath. For this case there is no remedy. In the other kinds about the ribs, which are curable, greasy medicines are hurtful, and _therefore_ we should use such as are adapted to wounds: but the best application is dry lint, or if any thing requires to be cleansed, the same dipped in honey. [Sidenote: _Of fistulas in the belly._]