ON THE BARLY STAGES OF INFLAMMATION 235 
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seems by no means improbable, this could only lead to encrusting of the lining 
membrane of such a vein with adhering corpuscles, and not to the occupation 
of its whole calibre by them, as took place in these cases, unless the corpuscles 
were themselves also abnormally adhesive. 
Another important fact which was brought out by this class of experiments 
is, that mere quiescence of the blood in the vessels of a healthy part fails to 
induce aggregation of the red corpuscles, such as occurs in blood outside the 
body. In the parts which had not been subjected to irritation, the corpuscles 
exhibited no trace of adhesiveness ; and though completely at rest, they were 
nowhere to be seen grouped together, surface to surface, although in the larger 
vessels there was abundant space for the occurrence of this phenomenon, which 
invariably presents itself in freshly drawn frog’s blood examined between plates 
of glass in a sufficiently thick film. On one occasion, when examining the tissues 
of the web of a frog under chloroform, the limb being kept steady by a string 
tied tightly round the thigh, so as completely to arrest the circulation, I was 
particularly struck with the total absence of adhesiveness in the red corpuscles ; 
so much so, that, as the foot had been kept moist without circulation for about 
three hours, I suspected that it must have imbibed water, which, when mixed 
with blood outside the body, destroys altogether the adhesiveness of the red 
corpuscles. This, however, proved to be a mistake; for, having occasion 
to administer more chloroform, I applied it on a piece of lint of considerable 
size without taking the usual precaution of protecting the foot from the vapour, 
and left it so for about a quarter of an hour. On re-examination of the web, the 
red corpuscles were found to possess much mutual adhesiveness, and in the larger 
vessels were grouped together into masses, with considerable spaces of clear 
liquor sanguinis, just as in the best-marked forms of aggregation in frog’s blood 
outside the body. One of these masses was drawn by camera lucida, and is 
represented in the sketch at page 213, along with the outline of the vessel in 
which it lay. I afterwards purposely induced a similar change in the blood 
within the vessels of an amputated limb by means of mustard.!. Having ascer- 
tained that the red corpuscles, though they had been long at rest, were perfectly 
free from the slightest tendency to aggregation, I suspended, at a little distance 
from the web, a piece of lint smeared with freshly prepared mustard, so that 
the pungent vapour of the volatile oil might play upon it; and left it so for 
about a quarter of an hour, when I found the red discs aggregated, as usually 
seen in frog’s blood outside the body. I then shed some blood from the other 
leg between two plates of glass, and on carefully sketching and comparing the 
groups of corpuscles in this specimen and those within the vessels of the irritated 
1 This experiment was performed subsequently to the reading of the paper. 
