In the preceding pages I have described the usual progress of the small-pox from the inoculation. There are, however, deviations from this course, and indeed not a few; some of the most material of which, as they may embarrass the inexperienced, and create a real difficulty, as well as apprehensions of danger, it seems necessary to describe, and to point out the means that experience has suggested to remove these symptoms, or the doubts respecting the event. The first I shall take notice of, and which, though it very rarely happens, sometimes gives much trouble, is great sickness, accompanied with vomiting, coming on during the eruptive state of the distemper. For this complaint it is always necessary in the first place to clear the stomach; which may be effected, either by ordering the patient to drink plentifully of warm liquids to promote vomiting; or, perhaps more properly, by given one grain of emetic tartar to an adult, mixed with ten grains of compound powder of crabs claws; taking care to lessen the dose for very young and weak subjects. This usually throws off some bilious matter by vomit, sometimes procures stools, or occasions a moderate sweat, and generally administers relief. If, however, no stools should follow from this medicine, and the sickness should remain, a gentle laxative almost certainly procures a respite, and the appearance of the eruption removes the complaint intirely. Another deviation, of still more consequence, which sometimes happens towards the time of the eruption, and is often, though not always, accompanied with great sickness, is an erysipelatous efflorescence. This, if it shews itself on the skin partially, and here and there in patches, is not very alarming, and soon wears off. But sometimes the whole surface of the skin is covered with a rash intimately mixed with the variolous eruption, and so much resembling the most malignant kind of confluent small-pox, as scarcely to be distinguished from it: and indeed some cases of this sort have happened, where, being accompanied with petechiæ and livid spots, I have been much alarmed; not being able, by inspection only, though assisted by glasses, to determine whether what I saw was an inoffensive rash, or tokens of the greatest malignity. Very strict attention, however, has enabled me to distinguish the difference clearly; and the following observations will, I hope, tend to relieve others from the anxiety they would feel upon such an appearance.