246 ON THE EARLY STAGES OF INFLAMMATION 
which render it fit for transmission through the vessels, and assuming those 
which it exhibits when removed from the body and placed in contact with 
ordinary solid matter. The first indication of this disorder of the vital fluid is, 
that its corpuscles, both red and white, acquire some degree of adhesiveness, 
which makes them prone to stick to one another and to the vascular parietes, 
and, lagging behind the liquor sanguinis, to accumulate in abnormal numbers 
in the minute vessels. This adhesiveness may exist, in proportion to the severity 
of the affection, in any degree, from that which merely gives rise to a very slight 
preponderance of the corpuscular elements of the blood in the part, up to that 
which induces complete obstruction of the capillaries ; and when the irritation 
has been very severe, the liquor sanguinis also shows signs of participation in 
the lesion by a tendency to solidification of the fibrine. 
SECTION WY 
On the Effects of Irritants upon the Tissues. 
The object of the present section is to inquire into the nature of that primary 
change which we have seen to be produced in the tissues by the direct action 
of irritants upon them. 
The conclusion already arrived at, that blood flowing through an irritated 
part approaches more and more nearly, in proportion to the intensity of the 
affection, the condition which it assumes when separated from the living body, 
naturally leads us to infer that the tissues concerned are in some degree approxi- 
mated to the state of ordinary matter, or, in other words, have suffered a diminu- 
tion of power to discharge the offices peculiar to them as components of the 
healthy animal frame. 
This inference is strongly supported by considering what common effect is 
likely to be produced upon the tissues of the frog’s web by all the various agents 
known to cause inflammatory congestion. To take first the case of mechanical 
violence. A forcible pinch of the delicate web seems likely, a priori, to impair 
its powers ; for if the lesion be sufficiently severe, complete death of the part 
will result. An elevated temperature proves equally destructive if carried far 
enough ; and its operation to a degree just short of this, while it produces con- 
gestion, can hardly fail to cause diminished vigour in the tissues. So also 
powerful chemical agents, if used cautiously, give rise to inflammation; but 
if otherwise, kill the part they act on. Even the pungent irritants which do 
not exert much chemical action, seem to benumb the energies of the spot to 
which they are applied. Thus a morsel of capsicum placed on the tip of the 
