1. Because it is sometimes impossible, by the largest doses of mercury, to excite it, when the exigences of the system render it most necessary.
2. Because it is not so quick in its operation, as to be proportioned to the rapid progress of the malignant state of fever.
3. Because it is at all times a disagreeable, and frequently a painful remedy, more especially where the teeth are decayed.
4. Because it cannot be proportioned in its duration, or in the quantity of fluid discharged by it, to the violence or changes in the fever.
Dr. Chisholm relied, for the cure of the Beullam fever at Grenada, chiefly upon this evacuation. I have mentioned the ratio of success which attended it.
V. Blisters are useful in depleting from those parts which are the seats of topical inflammation. The relief obtained by them in this way more than balances their stimulus upon the whole system need hardly say, that their effects in reducing the morbid and excessive action of the blood-vessels are very feeble. To depend upon them in cases of great inflammatory action, is as unwise as it would be to attempt to bale the water from a leaky and sinking ship by the hollow of the hand, instead of discharging it by two or three pumps.
VI. Abstemious diet has sometimes been prescribed as a remedy for fever. It acts directly by the abstraction of the stimulus of food from the stomach, and indirectly by lessening the quantity of blood. It can bear no proportion, in its effects, to the rapidity and violence of an inflammatory fever. In chronic fever, such as occurs in the pulmonary consumption, it has often been tried to no purpose. Long before it reduces the pulse, it often induces such a relaxation of the tone of the stomach and bowels as to accelerate death. To depend upon it therefore in the cure of inflammatory fever, whether acute or chronic, is like trusting to the rays of the sun to exhale the water of an overflowing tide, instead of draining it off immediately, by digging a hole in the ground. But there are cases in which the blood-vessels become so insolated, that they refuse to yield their morbid excitement to depletion from any outlet, except from themselves. I attended a sailor, in the Pennsylvania hospital, in 1799, who was affected with deafness, attended with a full and tense pulse. I prescribed for it, purging, blisters, and low diet, but without any effect. Perceiving no change in his pulse, nor in his disease, from those remedies, I ordered him to lose ten ounces of blood. The relief obtained by this evacuation induced me to repeat it. By means of six bleedings he was perfectly cured, without the aid of any other remedy.