Sfxt» III.] Tliconj and Practice of Phi^sic. So7 



tinned more and niorc^ to pre\'ail, and to become 

 the settled iiabit of all that ])oiiion of society who 

 were placed in easy circnmstanees, and possessed 

 the better degrees of intelligence. The advantages, 

 however, of this practice, notuithstaiuling all its 

 benefits to the individuals who employed it, were 

 supposed by many, on a general calculation of 

 human life, to be extremely problematical. Bv' 

 carrying the disease more fre(|uenlly and univer- 

 sally through cities and countries, it was i'ound that 

 the poorer classes of people, which constitute the 

 great mass of every nation, were much oftener exr 

 posed to casual infection; and that, on the whole, 

 the mortality of mankind from this disease was 

 thereby much augmented. 



But such doubts and difficulties as these arising 

 in the mind of the philanthropist, and much of the 

 importance of the inoculation of the small-pox, 

 even to those who employed it, were removed by 

 the discovery of the inocidation of the Vaccine Dis- 

 ease, in the year 1798. This may perhaps l)e justly 

 considered as the most memorable imi)rovemenl 

 ever made in the practice of physic. By substi- 

 tuting a disease so much milder that it cannot fail 

 of being universally preferred, and one w liich at 

 the same time affords eifectual security against the 

 small-pox, the prospect is presented of speedily 

 exterminating the latter disease, and thereby closing 

 a great outlet of human life. 



To Dr. Jenner, of Great Britain, the worl.i i^ 

 indebted for this incomparable discovery, lor al- 

 though there has existed, perhajis from time im- 

 memorial, some popular knowledge of the vaccine 

 disease, and of the fact of its rendering the hunum 



