seems as if the system were reluctant to admit the operation of a second morbid action, while a former one exists. Where, however, vaccination is successful, its influence in retarding the appearance of other cutaneous affections appears very transient, for we find them appearing just as usual, within a few weeks after the cow-pox. And with respect to many of these cutaneous eruptions, it did not escape the medical sages of yore (and every day's experience confirms the fact), that it is often fraught with the greatest hazard to attempt their hasty suppression. Hippocrates himself was not ignorant of the efficacy of counter-irritation, for he asserts in his observations on epilepsy, that in infants, if ulcers appear on the head, round the ears, and on the face, or even in other parts of the body, the epileptic symptoms are removed. It is true, indeed, at every period of life, that the most alarming diseases are kept in a state of abeyance by perpetuating the influence of counter irritation, for medical men are willing to take a lesson from nature herself in this respect, and learn to imitate the superficial irritation she is wont to set up; and it is equally true, that where such irritation (be it natural or artificial) has long existed, it can seldom be interfered with, but at the risk of superinducing, sooner or later, some more dangerous morbid process. Every practitioner has met with cases of this kind, where the periodical recurrence of certain cutaneous eruptions, has been the means of preserving to the individual an uninterrupted enjoyment of health. For the same reason, ulcerations that have existed for a series of years, cannot always be treated with impunity. Nay, the drying up of an issue or
