214 ON THE EARLY STAGES OF INFLAMMATION 
for a very considerable period ; and if a piece of wet lint be suspended above 
such a specimen so as to prevent evaporation, the corpuscles will retain their 
adhesiveness for a long time (e.g. twenty-four days in one instance), until the 
water communicated to the mixture by the artificially damp atmosphere grad- 
ually renders them non-adhesive. These experiments were made in winter, 
when the low temperature prevents rapid decomposition ; but it appears unlikely 
that even at that period of the year a part of the human body should retain 
any vital properties after having been left three and a half weeks mixed with 
strong gum, which, it is to be observed, alters very much the form and appear- 
ance of the corpuscles. 
Both in man and in the frog the white corpuscles also are found aggregated 
together more or less in a drop of blood examined microscopically, and indeed 
they adhere much more closely than the red ones both to the glass and to one 
another ; but as they are not disc-shaped, but globular, they do not become 
grouped into rouleaux, but into irregular masses, which, in consequence of 
their colourless and transparent character, are apt to pass unnoticed, or to be 
mistaken for masses of coagulated fibrine. If a portion of blood be allowed 
to run in between two plates of glass nearly in contact with one another, the 
white corpuscles will be found sticking together near the edge of the glass at 
which the blood entered, the blood having been as it were filtered of white 
corpuscles as it passed on ; and this is not due to the greater size of the colourless 
corpuscles than the red, for I have seen it occur with frog’s blood when there 
was room enough between the plates for the red corpuscles to lie edgewise, their 
transverse dimensions being greater than the diameter of a white corpuscle. 
The red corpuscles also often adhere to the colourless ones. 
It will be seen hereafter that the corpuscles of blood within the vessels of 
the living body present great varieties of adhesiveness, according to the amount 
of irritation to which a part may be subjected; such variations are also met 
with in blood outside the body, in consequence of differences in the quality 
of the plasma. 
If a drop of very thick solution of gum-arabic, freshly prepared and free 
from acidity, be added to about four drops of blood, the red corpuscles of the 
mixture will be found to aggregate much more speedily and more closely than 
those of ordinary blood, a fact ascertained some years ago by Mr. Wharton 
Jones and some other observers.’ The result is the formation of dense orange 
masses with large colourless interspaces, but without much regular appearance 
of rouleaux. On closely examining such a specimen, the red discs are seen 
to be much diminished in breadth and increased in thickness, and exhibit an 
* Guy’s Hospital Reports, vol. viii, p. 73. 
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