In the first place, no man should be bled who has lost a considerable quantity of blood, unless indeed he was known in his state of health to be very strong and robust; and that the fever sets on with such fury, that the system requires absolutely to be reduced; for the solids and fluids have such a strict dependance amongst themselves, that they keep each other in an equipoise. If therefore the blood is of an acrimonious nature, and at the same time impoverished by lessening its quantity, the coats of the arteries and veins will be the more stimulated; thence the fever will naturally encrease, and generate more acrimony; which at length will destroy the patient. I have been an eye witness more than once, that the fever has actually increased upon every repeated bleeding, till the whole supply of life was spent; and all my persuasions have not been listened to till too late. Nay, a fever is sometimes absolutely necessary; and proves to some constitutions a remedy on its own account, provided it is properly treated, and kept within due bounds. Secondly, If the constitution of the patient before the accident was but slender, and of a phlegmatic nature, bleeding should be very little or cautiously performed; for the blood of itself being but poor, must naturally be impoverished by being lessened; and whilst the tenseness of the fibres is lost, it is the more acted upon and rendered more acrimonious, and still unable to strengthen the tone of the irritated fibres; whence a relaxed body, together with a poor acrimonious blood, and all its evil tendencies must be the consequence. Let it once for all be observed, that all the benefit we can possibly hope and expect from bleeding, is to lessen the whole system, to reduce the quantity of the fluids, and to relax the solids. This lessening of the system I must own is very often highly necessary; But, let us not fall into the ridiculous notion to suppose that bleeding will draw off the bad blood, and leave the good behind; far otherwise; the quantity of the blood is soon replenished, but the quality becomes impoverished. The principle intention in fevers of whatever kind, should be to promote perspiration. This is the grand restorative of nature; and I cannot recommend it too much. Nature designed this evacuation in the formation of man; and by that, fevers were cured in time of yore, many ages before art contrived either lance or lancets. But here let me not forget another great caution; namely, not to mistake profuse sweating for perspiration; for this is an extreme into which many have erroneously fallen. Nature frequently produces a sweat without force or compulsion; and if so, it should be favoured, but never brought on by stimulants, or strong forcing medicines.