When, instead of a puncture, an incision is made, the eruption appears both upon, and round about it; and brings on that inflammation, which is esteemed a sign that the infection has taken effect. But as this incision, and the treatment of it, prevent the variolous humor from shewing itself under a pustular appearance, inoculators have not sufficiently attended to the nature of this inflammation, or to the period of this local eruption.
The third period takes place from the beginning of the fever to the general eruption. Indeed, the first sensible effect of the venom upon the whole frame, is not commonly a fever, but a pain at the groin, axillæ or loins, and a heaviness in the head; but as these sometimes fail, are always slight, and are soon followed by the fever, which is the only constant symptom of the variolous ferment acting upon the whole animal system, the first appearance of this fever fixes the beginning; arid its cessation, when the eruption begins, the end of this period.
The fourth takes in the whole time of the general eruption to the falling off of the scabs.
This eruption once come out, the fever goes off, as do all the other symptoms of the foregoing period; those which now succeed are no longer the effect of the immediate action of the virus, which spent itself by the eruption, but are owing to the inflammation and suppuration of the pustules. Each of these is a