s were made with blood taken from a small vein in the
hand or foot of three or four different patients, whom I had at that time
under inoculation. They were selected from 160, as having the greatest
number of pustules. The part was washed with warm water before the blood
was taken, to prevent the possibility of any matter being mixed with it
from the surface."

Shall we conclude from hence, that the variolous matter never enters the
blood-vessels? but that the morbid motions of the vessels of the skin
around the insertion of it continue to increase in a larger and larger
circle for six or seven days; that then their quantity of morbid action
becomes great enough to produce a fever-fit, and to affect the stomach by
association of motions? and finally, that a second association of motions
is produced between the stomach and the other parts of the skin, inducing
them into morbid actions similar to those of the circle round the insertion
of the variolous matter? Many more experiments and observations are
required before this important question can be satisfactorily answered.

It may be adduced, that as the matter inserted into the skin of the arm
frequently swells the lymphatic in the axilla, that in that circumstance it
seems to be there arrested in its progress, and cannot be imagined to enter
the blood by that lymphatic gland till the swelling of it subsides. Some
other phaenomena of the disease are more easily reconcileable to this theory
of sympathetic motions than to that of absorption; as the time taken up
between the insertion of the matter, and the operation of it on the system,
as mentioned above. For the circle around the insertion is seen to
increase, and to inflame; and I believe, undergoes a kind of diurnal
paroxysm of torpor and paleness with a succeeding increase of action and
colour, like a topical fever-fit. Whereas if the matter is conceived to
circulate for six or seven days with the blood, without producing disorder,
it ought to be rendered milder, or the blood-vessels more familiarized to
its acrimony.

It is much easier to conceive from this doctrine of associated or
sympathetic motions of distant parts of the system, how it happens, that
the variolous infection can be received but once, as before explained; than
by supposing, that a change is effected in the mass of blood by any kind of
fermentative process.

The curious circumstance of the two contagions of small-pox and measles not
acting at the