service
of a Farmer in the same village in the year 1782; but neither this
woman, nor any other of the patients who had gone through the Cow
Pox, received the variolous infection either from the arm or from
mixing in the society of the other patients who were inoculated at
the same time. This state of security proved a fortunate
circumstance, as many of the poor women were at the same time in a
state of pregnancy.

_CASE XIII._

One instance has occurred to me of the system being affected from the
matter issuing from the heels of horses, and of its remaining
afterwards unsusceptible of the variolous contagion; another, where
the Small Pox appeared obscurely; and a third, in which its complete
existence was positively ascertained.

First, THOMAS PEARCE, is the son of a Smith and Farrier near to this
place. He never had the Cow Pox; but, in consequence of dressing
horses with sore heels at his father's, when a lad, he had sores on
his fingers which suppurated, and which occasioned a pretty severe
indisposition. Six years afterwards I inserted variolous matter into
his arm repeatedly, without being able to produce any thing more than
slight inflammation, which appeared very soon after the matter was
applied, and afterwards I exposed him to the contagion of the Small
Pox with as little effect[1].

[Footnote 1: It is a remarkable fact, and well known to many, that we
are frequently foiled in our endeavours to communicate the Small Pox
by inoculation to blacksmiths, who in the country are farriers. They
often, as in the above instance, either resist the contagion
entirely, or have the disease anomalously. Shall we not be able now
to account for this on a rational principle?]

_CASE XIV._

Secondly, Mr. JAMES COLE, a Farmer in this parish, had a disease from
the same source as related in the preceding case, and some years
after was inoculated with variolous matter. He had a little pain in
the axilla, and felt a slight indisposition for three or four hours.
A few eruptions shewed themselves on the forehead, but they very soon
disappeared without advancing to maturation.

_CASE XV._

Although in the two former instances the system seemed to be secured,
or nearly so, from variolous infection, by the absorption of matter
from sores produced by the diseased heels of horses, yet the
following case decisively proves that this cannot be entirely relied
upon, until a disease has been generated by th