DB. E. KLEIN ON THE SMALLPOX OE SHEEP. 
219 
From the 14th of April the temperature was over 40° C. ; this may be easily accounted 
for by the fact that, from this date for the next four or five days, a number of secondary 
pocks had been cut out from different parts, whereby extensive suppuration was pro- 
duced in different places. 
Besides the characters of the primary and secondary pocks above mentioned, they 
had all the common character, that when excised, no matter whether it was twenty-four 
hours after their appearance, or whether they were in the stage of increase of size, or 
of the formation of the pustules, or in the stage of drying up, the subcutaneous loose 
tissue by which the skin is connected with the subjacent adipose or muscular tissue 
was always found in a state of oedema. This oedema was greatest in the stage of their 
increase in size and for a short time after. 
I have to tender my thanks to Mr. W. Duguid, Veterinary Surgeon at the Brown 
Institution, for assisting me in the experiments, and particularly for making and 
recording the observations on temperature. 
Section II.— ANATOMICAL METHOD. 
The pocks that were excised were all used for anatomical examination. The skin 
was invariably cleaned before the operation, and the pock was cut out with a surrounding 
small zone of healthy skin. 
Immediately after the pock was cut out, clean instruments always being used, it was 
pinned out on a cork like a tent, the pins being fixed in the surrounding healthy skin, 
and the object was then placed, cork upwards, either in J to ^ per cent, chromic acid 
solution or in methylated spirit. 
In some instances the pock was divided into two halves, and one half placed in each 
of the above-named reagents. After twenty-four hours the object was removed from 
the cork and returned to the hardening fluid. 
Four or five days are usually quite enough to bring the object to such a consistence 
that it can easily, when imbedded in a mixture of wax and oil, be cut into micro- 
scopical sections. 
Those pocks that were hardened in chromic acid were placed in spirit for several 
hours before they were imbedded. 
It was found that chromic acid was preferable to spirit for hardening the pocks ; for 
in those hardened in chromic acid the topography of the elements and their relation to 
each other was found to be unaltered and very clear and distinct ; whereas when 
hardened at once in spirit it was found that these relations became considerably altered, 
the reagent producing too much shrinking. 
As I shall afterwards mention, in all the pocks the corium was more or less cedema- 
tous; the hardening in spirit was found especially damaging in those pocks where there 
was only slight oedema of the corium. 
The contrast between the microscopical preparations of that half of a pock hardened 
