, and from the Cow to the Human Subject.

Morbid matter of various kinds, when absorbed into the system, may
produce effects in some degree similar; but what renders the Cow-pox
virus so extremely singular, is, that the person who has been thus
affected is for ever after secure from the infection of the Small
Pox; neither exposure to the variolous effluvia, nor the insertion of
the matter into the skin, producing this distemper.

In support of so extraordinary a fact, I shall lay before my Reader a
great number of instances[3].

[Footnote 1: The late Mr. John Hunter proved, by experiments, that
the Dog is the Wolf in a degenerated state.]

[Footnote 2: They who attend sick cattle in this country find a
speedy remedy for stopping the progress of this complaint in those
applications which act chemically upon the morbid matter, such as the
solutions of the Vitriolum Zinci, the Vitriolum Cupri, &c.]

[Footnote 3: It is necessary to observe, that pustulous sores
frequently appear spontaneously on the nipples of Cows, and instances
have occurred, though very rarely, of the hands of the servants
employed in milking being affected with sores in consequence, and
even of their feeling an indisposition from absorption. These
pustules are of a much milder nature than those which arise from that
contagion which constitutes the true Cow Pox. They are always free
from the bluish or livid tint so conspicuous in the pustules in that
disease. No erysipelas attends them, nor do they shew any phagedenic
disposition as in the other case, but quickly terminate in a scab
without creating any apparent disorder in the Cow. This complaint
appears at various seasons of the year, but most commonly in the
Spring, when the Cows are first taken from their winter food and fed
with grass. It is very apt to appear also when they are suckling
their young. But this disease is not to be considered as similar in
any respect to that of which I am treating, as it is incapable of
producing any specific effects on the human Constitution. However, it
is of the greatest consequence to point it out here, lest the want of
discrimination should occasion an idea of security from the infection
of the Small Pox, which might prove delusive.]

_CASE I._

JOSEPH MERRET, now an Under Gardener to the Earl of Berkeley, lived
as a Servant with a Farmer near this place in the year 1770, and
occasionally assisted in milking his master's cows. Several horses
bel