366 Original Faccine Institution. 
could have been prevented by any known circumstances of 
moculation. On examination it was admitted that no such 
circumstances were known, and of the reality of the sub- 
eo eccurrence of the small-pox there was the most 
convincing evidence. 
The next question for consideration was, the proportion 
f persons who might be still susceptible of the siall-pox 
fter vaccination, but who had not been yet infected, either 
pieaite they had not been exposed, or, if exposed, because 
their constitutions were not at that time susceptible, 
It was proposed to defer the attempt at an estimate till 
subsequent occurrences should furnish data, except that it 
might be admitted that at least not more than one balf had 
been infected with the small- -pox, who were susceptible ; 
so that at the fewest nuinber, according to the prac- 
tice of this institution, was one out of fe hundred, who 
might be considered as susceptible of the small-pox after 
vaccination. These results, it was remarked, had induced 
the institution not to warrant any person as secure without 
the test of a second inoculation. 
In the fourth ‘place, inquiry was made, What might haye 
been the probable proportion in the same region of prac~ 
tice in. other hands than those of. this establi$hment ?- 
This could not be accurately stated for want of documents 3 
but there was no reason to believe that it was less than above 
mentioned, in all probability it was greater, if confidential 
communications were to be depended upon. : 
In the fifth place, the question was proposed, What 
might be the proportion of failures elsew here than in Lon- 
dene in our own country ? 
It was observed, that in all probability the proportion of 
failures of persons duly vaccinated was muci smaller in 
other parts of the imperial kingdom than in London, for 
which two'reasons might be assigned. 
dst. Because fice was 4 less chanié te of exposure to in- ? 
fection. 
ad. Because there had probably not been any epidemic ~ 
prevalence’ of small-pox as there had been in London. 
Hénce, if even one person out of a hundred was left sus- 
e ceptible 
. 
: 
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