affection be observed.

"I have only to add that I am now fully satisfied of the efficacy
of the cow-pox in preventing the appearance of the smallpox, and
that it is a most happy and salutary substitute for it. I remain,
etc.,

"M. J. TIERNY."

Although the susceptibility of the virus of the cow-pox is, for
the most part, lost in those who have had the smallpox, yet in
some constitutions it is only partially destroyed, and in others
it does not appear to be in the least diminished.

By far the greater number on whom trials were made resisted it
entirely; yet I found some on whose arm the pustule from
inoculation was formed completely, but without producing the
common efflorescent blush around it, or any constitutional
illness, while others have had the disease in the most perfect
manner. A case of the latter kind having been presented to me by
Mr. Fewster, Surgeon, of Thornbury, I shall insert it:

"Three children were inoculated with the vaccine matter you
obligingly sent me. On calling to look at their arms three days
after I was told that John Hodges, one of the three, had been
inoculated with the smallpox when a year old, and that he had a
full burthen, of which his face produced plentiful marks, a
circumstance I was not before made acquainted with. On the sixth
day the arm of the boy appeared as if inoculated with variolous
matter, but the pustule was rather more elevated. On the ninth