228 ON THE EARLY STAGES OF INFLAMMATION 
capillaries. The opacity of the mustard prevented the vessels beneath it from 
being observed, but at a short distance from its edge the artery measured I0° 
and the vein 14°. In a few minutes the capillaries seen beneath the extreme 
margin of the mustard, which was slightly transparent, were observed to be of 
crimson colour, in consequence of their containing closely crammed corpuscles, 
some of which were still moving, while others were motionless. On the applica- 
tion of a higher power, the continuations of these capillaries immediately exterior 
to the mustard showed, many of them, red corpuscles sticking to their walls, 
and more or less obstructing the progress of the blood through them. 
In the accompanying sketch of the 
vessels at one part, together with those 
corpuscles which were motionless in them, 
M represents the edge of the mustard, aa 
capillary partly overlaid by the mustard and 
crammed with stagnant corpuscles, ba capil- 
lary with red discs adhering to its internal 
surface, but still transmitting blood, while 
further from the mustard all the corpuscles 
were in motion, and consequently none 
appear in the drawing ; c was a rouleau of 
red corpuscles projecting from a stagnant 
mass into the vein V, through which the 
blood was flowing rapidly ; yet the rouleau, 
though its free end was moved to and fro 
by the current, was prevented by the mutual 
adhesiveness of its corpuscles from being 
broken up or detached. Thus it was evident 
\ that in the capillaries of the space covered 
by the mustard, the red corpuscles had an 
abnormal tendency to adhere both to the walls of the vessels and to one another, 
and were on this account accumulating and sticking within them, while almost 
immediately outside the mustard, the blood in the capillaries presented the 
same appearance as in other parts of the web. This effect was independent of 
changes in the calibre of the vessels, for any results of alteration in the size 
of the artery under the mustard must have been shared by the surrounding 
capillaries, which also derived their blood chiefly from it ; and that the vesse 
was dilated to the same degree there as elsewhere, was shown by the fact, that 
its branches continued throughout the experiment to transmit full streams of 
blood after emerging from beneath the opaque mass. I also measured some 
