Hysteric and hypochondriac persons, and such as are subject to an habitual diarrhœa or dysentery, or to frequent and violent attacks of epilepsy, or who are afflicted with the scrofula or the scurvy, ought to be cautious in the use of mercury. Where any one of these disorders prevails it ought either, if possible, to be cured, or at least palliated, before the patient enters upon a course of mercury. When this cannot be done, the mercury must be administered in smaller doses, and at longer intervals than usual. The most proper seasons for entering upon a course of mercury, are the spring and autumn, when the air is of a moderate warmth. If the circumstances of the case, however, will not admit of delay, we must not defer the cure on account of the season, but must administer the mercury; taking care, at the same time, to keep the patient’s chamber warmer or cooler according as the season of the year requires. The next thing to be considered is the preparation necessary to be observed before we proceed to administer a course of mercury. Some lay great stress upon this circumstance, observing that by previously relaxing the vessels, and correcting any disorder which may happen to prevail in the blood, not only the mercury will be disposed to act more kindly, but many other inconveniencies will be prevented. We have already recommended bleeding and gentle purges, previous to the administration of mercury, and shall only now add, that these are always to be repeated according to the age, strength, constitution, and other circumstances of the patient. Afterwards, if it can be conveniently done, the patient ought to bathe once or twice a day, for a few days, in lukewarm water. His diet, in the meantime, must be light, moist, and cooling. Wine and all heating liquors, also violent bodily exercise, and all great exertions of the mind, are carefully to be avoided. A proper regimen is likewise to be observed by such as are under a course of mercury. Inattention to this not only endangers the patient’s life, but often also disappoints him of a cure. A much smaller quantity of mercury will be sufficient for the cure of a person who lives low, keeps warm, and avoids all manner of excess, than of one who cannot endure to put the smallest restraint upon his appetites; indeed, it but rarely happens that such are thoroughly cured.