Vaccination was the successor of Inoculation (or, more precisely, Variolation), entering into a possession already acquired in the human mind. It had been observed from of old that some forms of disease rarely recur in the same person in a lifetime; and thus when scarlet fever, or measles, or smallpox broke out in a family, it was considered-prudent to let the dis ease have its course, and thereby obtain immunity from fear of future infection. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.