218 
DK. E. KLEIN ON THE SMALLPOX OE SHEEP. 
Experiment 4. — On the 1st of April, 1874, lymph diluted with 15 to 20 times its 
volume of saline solution was used for infecting a healthy sheep ; thus 
(a) Several punctures (three) were made in each ear-lobe. 
(b) Four punctures in each mammary gland. 
(c) Three in the right groin. 
(d) About \ to 1 division of a Pravaz syringe was injected into the subcutaneous 
vein which runs between the mammary gland and the median line. 
The pocks on the mammary glands, groin, and ear-lobes were discernible on the 
evening of the 4th of April as small red circumscribed swellings. On the 6th of April 
they were very much enlarged. On the 7th of April, while still increasing in size, they 
already showed a differentiation between a central somewhat pale depressed part and a 
peripheral portion still red and thickened. 
On the evening of the same day (April 7) there appeared several small red swellings 
round the lips as the first indication of a general eruption. 
The number of secondary pocks increased rapidly until the Xlth of April, especially 
on the lips and nostrils ; there were several in the axillae, and a great number in the 
skin of the chest and hypochondrium. 
During the appearance of the later secondary pocks those (secondary pocks) which 
had made their appearance first (on the lips) had already commenced to form pustules 
and to dry up. 
It is important to state that the primary pocks, in this as in the former cases, were of 
a very much larger size than the secondary ones — many of the former reaching a diameter 
of ^ to 1 or l^r inch, whereas the diameter of most of the secondary ones did not reach 
a quarter of an inch. There were, however, amongst the secondary pocks, especially 
those that came out very late, e. g. on the chest and hypochondrium, some which 
had a diameter of J to inch, or even a little larger. 
Another point worth noticing is this: the primary pocks showed in nearly all 
instances, while increasing in diameter, a differentation between a central depressed and 
a peripheral thickened part ; whereas the secondary ones, except those that were of a 
large diameter, remained thickest in the centre, or at least did not become depressed. 
It will be seen subsequently that this difference is chiefly due to the differences in the 
changes of the epidermis. 
The course of the animal’s temperature was the following : — 
o o 
March 31 . , 
. . 39-1 C. 
April 7 
. . . 41-8 C. 
April 1 . , 
. . 39 
„ 8 
. . . 41-5 
„ 2 . , 
, . 39-1 
„ 9 
... 41 
„ 3 . . 
, . 39-3 
„ 10 
. . . 40-2 
„ 4 . . 
, . 39-8 
„ 11 
... 39 
„ 5. , , 
, . 40-8 
„ 12 
. . . 39-3 
„ 6 ,. , 
. . 41-8 
„ 13 
. . . 39-7 
