It is of very great consequence to know when to bleed, and when not: for if the patient has too little blood or is weak, or has a low weak languid pulse, bleeding is dangerous. But sometimes a loss of strength or a low pulse may be owing to too much blood, and then the pulse will rise as soon as the blood begins to flow. Bleeding is generally necessary in the beginning of acute, continual, or inflammatory fevers, when the pulse is strong or hard; in particular kinds of epidemic fevers it is doubtful, and the height of the pulse is most commonly the rule. Bleeding is dangerous in the fit of an ague, in hysteric fits, and in fits of the falling sickness; in a suppression of the menses, it will be best to bleed in the soot. In disea-ses of the head, neck, or eyes, it will be properest in the jugular vein, or under the tongue. When the patient is full of blood and strong, he may loose twelve ounces at once. But it must be sparing in excessive bleedings of any kind, and in spitting of blood. In general it serves for three purposes; evacuation, revulsion, and derivation.