ents;
and as much of the blood was insinuated under the cuticle as I could
introduce by elevating the skin without drawing blood; and three or four
such punctures were made in each of their arms, and the blood was used in
its fluid state.

"As the appearances in all these patients, as well as in myself, were
similar, I shall only mention them in general terms. March 13. A slight
subcuticular discoloration, with rather a livid appearance, without
soreness or pain, was visible in them all, as well as in my own hand. 15.
The discoloration somewhat less, without pain or soreness. Some patients
inoculated on the same day with variolous matter have considerable
inflammation. 17. The discoloration is quite gone in them all, and from my
own hand, a dry mark only remaining. And they were all inoculated on the
18th, with variolous matter, which produced the disease in them all."

Mr. Power afterwards observes, that, as the patients from whom the blood
was taken had the disease mildly, it may be supposed, that though the
contagious matter might be mixed with the blood, it might still be in too
dilute a state to convey the infection; but adds at the same time, that he
has diluted recent matter with at least five times its quantity of water,
and which has still given the infection; though he has sometimes diluted it
so far as to fail.

The following experiments were instituted at my request by my friend Mr.
Hadley, surgeon in Derby, to ascertain whether the blood of a person in the
small-pox be capable of communicating the disease. "Experiment 1st. October
18th, 1793. I took some blood from a vein in the arm of a person who had
the small-pox, on the second day of the eruption, and introduced a small
quantity of it immediately with the point of a lancet between the scars and
true skin of the right arm of a boy nine years old in two or three
different places; the other arm was inoculated with variolous matter at the
same time.

"19th. The punctured parts of the right arm were surrounded with some
degree of subcuticular inflammation. 20th. The inflammation more
considerable, with a slight degree of itching, but no pain upon pressure.
21st. Upon examining the arm this day with a lens I found the inflammation
less extensive, and the redness changing to a deep yellow or orange-colour,
22d. Inflammation nearly gone. 23d. Nothing remained, except a slight
discoloration and a little scurfy appearance on the punctures. At the same
time th