Sometimes also it happens, though rarely, that a collection of pus is inclosed in a covering of its own: the ancients called this a coat. Meges, because every coat is nervous, affirmed a nerve was not generated in a disorder, which destroyed the flesh, but that the pus being lodged below for a long time, was surrounded with a callosity. This however has not the least relation to the method of cure; because the same course, that ought to be pursued if it be a coat, is also necessary if it be a callosity. And though it should be a callosity, yet as it invelops something, there is no reason against calling it a coat. And then again, it is not uncommon for this to be found even before the suppuration is formed(3), and therefore what is below it cannot be extracted by a cupping vessel. But this is easily discovered, when the application of that instrument has made no change. Therefore, where-ever that happens, or when there is already a hardness, nothing is to be expected from this remedy: but as I have directed elsewhere, either the afflux of matter to the part must be diverted, or it must be discussed, or brought to a perfect suppuration. If either of the former has taken place, nothing further is necessary. If the pus has been maturated, in the armpits and groin an incision is rarely to be made: likewise where-ever the abscess is but small; also where-ever the malady is in the surface of the skin, or even in the flesh; unless the weakness of the patient obliges us to lose no time. And it is sufficient by cataplasms to assist the pus to make its own way. For the part, that has not been touched by an instrument, is generally free from a scar. If the malady lies deeper, it ought to be considered whether the part be nervous or not. For if it be nervous, it should be opened by the actual cautery; the reason of which is, that a small wound may keep open longer for evacuating the pus, and the cicatrix afterwards may be small. But if there be nerves near it, the actual cautery is improper, lest convulsions follow, which may debilitate(4) the limb; yet the assistance of the knife is necessary. The others may be opened before they be quite mature: but amongst tendons the utmost ripeness is to be waited for, that the skin may be thin, and the pus brought close to it, that it may be the sooner found. And some again require a wound(5) in a straight direction, as those in the flesh: but others render the skin extremely thin; and in such the whole surface of it above the pus must be cut away. Now in all cases where the knife is used, care must be taken, that the wounds be as small and as few in number as possible: with this caution, however, that we do all the case requires, both with regard to size and number: for larger cavities require broader incisions; sometimes even in two or three different directions. And we must endeavour that the deepest part of the sinus shall have a free discharge, lest any of the humour