modify the virus differently? Although the skin,
for example, adipose membrane, or mucous membranes are all capable of
producing the variolous virus by the stimulus given by the particles
originally deposited upon them, yet I am induced to conceive that
each of these parts is capable of producing some variation in the
qualities of the matter previous to its affecting the constitution.
What else can constitute the difference between the Small-pox when
communicated casually or in what has been termed the natural way, or
when brought on artificially through the medium of the skin? After
all, are the variolous particles, possessing their true specific and
contagious principles, ever taken up and conveyed by the lymphatics
unchanged into the blood vessels? I imagine not. Were this the case,
should we not find the blood sufficiently loaded with them in some
stages of the Small-pox to communicate the disease by inserting it
under the cuticle, or by spreading it on the surface of an ulcer? Yet
experiments have determined the impracticability of its being given
in this way; although it has been proved that variolous matter when
much diluted with water, and applied to the skin in the usual manner,
will produce the disease. But it would be digressing beyond a proper
boundary, to go minutely into this subject here.

At what period the Cow-pox was first noticed here is not upon record.
Our oldest farmers were not unacquainted with it in their earliest
days, when it appeared among their farms without any deviation from
the phaenomena which it now exhibits. Its connection with the
Small-pox seems to have been unknown to them. Probably the general
introduction of inoculation first occasioned the discovery.

Its rise in this country may not have been of very remote date, as
the practice of milking cows might formerly have been in the hands of
women only; which I believe is the case now in some other dairy
countries, and, consequently that the cows might not in former times
have been exposed to the contagious matter brought by the men
servants from the heels of horses[4]. Indeed a knowledge of the
source of the infection is new in the minds of most of the farmers in
this neighbourhood, but it has at length produced good consequences;
and it seems probable from the precautions they are now disposed to
adopt, that the appearance of the Cow-pox here may either be entirely
extinguished or become extremely rare.

Should it be asked whethe