The skin is liable to an almost innumerable class of diseases, some affecting also other organs, and even the whole system, accompanied with severe pain, violent fever and often delirium, ending unless speedily relieved, in death. Others are of a more chronic character, attended with but little, if any fever, oftentimes tedious in their cure, and generally far more annoying than dangerous. Among the former class we may mention, Scarlet Fever, Erysipelas, Measles, and Small-Pox.

Scarlet Fever, Measles, Chicken-Pox, and Small-Pox, are infectious, and generally prevail as epidemics. Very seldom is a person attacked with either of the above diseases more than once. The danger of infection is greatest after death. Infection seldom if ever takes place before the eruption appears, but from that time until the pustules have fairly dried up, or the eruption has in a great measure subsided, the infectious matter is being constantly thrown from the system.

For the sake of convenience, we shall divide eruptive diseases into two classes. 1. Eruptive Fever. 2. General Cutaneous Diseases.