320 On Vaccination. 



nicates no casual infection, and, while it is a protection to 

 the individual, it is not prejudicial to the public. 



III. The College of Phj'sicians, in reporting iheir ob- 

 servations and opinions on the evidence adduced in support 

 of vaccination, feel themselves authorized to slate, that a 

 body of evidence so large, so temperate, and so consistent, 

 was perhaps never before collected upon any medical ques- 

 tion. A discovery so novel, and to which there was nothing 

 analogous known in nature, though resting on the experi- 

 mental observations of the inventor, was at first received 

 with diffidence : it was not, however, difficult for others to 

 repeat his experiments, by which (he truth of his observa- 

 tions was confiriTied, and the doubts of the cautious were 

 gradually dispelled by extensive experience. At the com- 

 mencement of the practice, almost all that were vaccinated 

 were afterwards submitted to the inoculation of the small- 

 pox ; many underwent this operation a second, and even a 

 third time, and the uniform success of these trials quickly 

 bred confidence in the new discovery. But the evidence of 

 the security derived from vaccination against the small-pox 

 does not rest alone upon those who afterwards underwent 

 variolous inoculation, although amounting to many thou- 

 sands; for it appears, from numerous observations commu- 

 nicated to the college, that those who have been vaccinated 

 are equallv secure against the contagion of epidemic small- 

 pox. Towns indeed, and districts of the country, in which 

 vaccination had been general, have afterwards had the small- 

 pox prevalent on all sides of them without suffering from 

 the contagion. There are also in the evidence a few exam- 

 ples of epidemic small-pox having been subdued by a ge- 

 neral vaccination. It will not, therefore, appear extraordi- 

 nary, that many who have communicated their obseivations 

 should state, that though at first they thought unfavourably 

 of the practice, experience had now removed all their doubts. 



It has been already mentioned that the evidence is not 

 universally favourable, although it is in truth nearly so ; for 

 there are a few who entertain sentinionts diff"cring widely 

 from those of the great majority of their brethren. The 



college. 



