If it continues to spread, it is improper to amputate, for several reasons. In the first place, because the whole habit is in a bad state, and there must be a fever and general inflammation, which would be greatly increased by an operation which, of itself, is sufficient to bring on the death of the healthiest man. In the second place, amputation cannot be performed on the sound part, in the manner as is generally imagined, as the infection is very often more deeply seated than it appears to be: We may judge of this by observing what happens very frequently in whitlows of a bad kind, where the matter quickly insinuates itself along the arm, and is pent up there, inflaming sometimes even the axillary glands; as an inflammation of the toes, in a short time, brings on that of the glands in the groin: Thus the disease having taken root in the place where the operation is performed, would of course be increased by the ligatures, which are indispensably necessary in this operation, unless we would suffer the patient to perish by an hemorrhage. In such a case then, amputation is not a dubious remedy, but it is no remedy at all[16]; and if the patient sometimes does escape, it must be acknowledged that nature has effected the cure; that she has got the better both of the disease and of the bad treatment, and has thus overcome a double enemy. It is evident, from what I have said, that while the mortification gains ground, the method I have proposed, § VII. XVI. should be followed. When its progress is stopt, it must be considered whether the limb can be preserved or not. We may entertain hopes[17] of its preservation, if all the corrupted parts cast off, and the sound parts, and even the bones, begin to produce granulations of new flesh. I cannot here omit remarking, that Mr. Haller's late experiments, which prove to the satisfaction of many eminent anatomists, the insensibility of the periosteum, render the sign of a mortification derived from such insensibility very doubtful. My experiments on this subject agree with his, excepting in this, that I always found the pericranium extremely sensible[18]. Whatever weight may be laid on these experiments, this consequence may at least be deduced from them, that we ought not immediately to conclude that the bones and periosteum are affected, because we prick, cut or tear the periosteum without giving pain; nor, in like manner, from this symptom, ought we to neglect the medicines indicated § VII. XVI.