EXPERIMENTS MADE ON SHEEP WITH THE INSECT^ &C. 113 
sheep, there kept for two full hours, and during that time made 
to run against each other, and thus to expose it as much as pos- 
sible to catching the infection in the natural way. After this 
time the sheep was put back into its own stall, which, of course, 
was perfectly clean. After the closest examination of the sheep 
for five weeks and a half, i. e. up to the 1st of December, not 
the slightest vestige of the disease was to be discovered, and it 
was therefore concluded that no infection had taken place. 
This sheep was afterwards the subject of another experiment 
(see the foregoing, No. 6). 
Experiment No. 10. 
Inoculation with the dry Scurf or Scabs . — (Sheep No. 5.) — 
On the 15th of October, the sheep marked No. 5 was treated 
in the following manner : After the wool was clear from the 
skin on the middle of the back, I placed a good deal of dry 
scurf, taken from a very scabby sheep, upon the naked surface : 
I then drew the wool around over this place, and fixed it there. 
This scurf was well examined with a lens, and was found to be 
free from insects ; moreover, no eggs could be discovered in 
it. — On the second day the scurf remained in its place, but not 
the slighest change was perceptible in the skin. — From the 3d 
to the 6th day. The scurf is now gone, but there is no appear- 
ance of change in the skin. — From the 7th to the 12th day. 
The part remains quite healthy. 
Experiment No. 11 ( repetition of the foregoing Experiment). 
As no change was produced from the last experiment for the 
space of twenty-one days, it appeared useless to wait any 
longer, and on the 5th November the same sheep was treated 
exactly in the same manner, the dry scurf having been taken 
from a sheep covered with the scab : the scurf was placed on 
the back between the wool. On the second day not the trace 
of any effect could be seen. From the 3d to the 11th day. 
Still no change could be seen on the skin. — From the 12th to 
the 21st. During this period nothing was to be seen, and the 
experiment may be considered to have failed in producing any 
effect. 
Experiments Nos. 12 8j 13 (third and fourth repetition of the 
above). 
On the 26th of November, the experiment was performed in 
the following manner : 10 grains of fresh and perfectly pure 
scurf from a scabby sheep was moistened with a small quan- 
tity of lukewarm water, and gently rubbed so as to make it into 
a solution : this solution was rubbed partly into the skin of the 
