236 ON THE EARLY STAGES OF INFLAMMATION 
webs, found that their characters were precisely similar.1. These are examples 
of what very numerous observations have tended to establish, namely, that 
on the one hand the red corpuscles in the vessels of a perfectly healthy part 
are free from adhesiveness ; and on the other hand, the adhesiveness which they 
acquire in inflammatory congestion, though varying in proportion to the degree 
of irritation, is never greater than occurs in the blood of a healthy part when 
withdrawn from the body. 
These conclusions, if correct, represent cardinal truths, both in physiology 
and pathology, implying relations of the tissues to the blood both in health 
and in disease, such as have never before been demonstrated, or, I believe, even 
suspected. I was therefore anxious to submit them to further test, particularly 
as it is by no means easy to estimate the precise degree of adhesiveness possessed 
by the red corpuscles within the vessels ; and it occurred to me that one means 
of doing this would be to compare specimens of blood shed from inflamed and 
healthy parts of the same individual; for if my deductions were sound, the 
adhesiveness of the red corpuscles ought to be neither more nor less in the one 
case than in the other. 
With this view I made the following experiments. Having carefully 
examined the blood of a large frog, drawn from a subcutaneous vein of the 
abdomen, so as to become quite familar with the appearance of its corpuscles, 
I applied mustard to the whole surface of one foot till inflammatory congestion 
had been fully developed in it, and then, amputating both feet at the ankle- 
joint, squeezed out blood from each upon a glass plate, and carefully examined 
both specimens, without being able to detect the slightest difference between 
them. The other experiments with this object were performed on the human 
subject. In one of these I applied a portion of moistened mustard to the dorsal 
aspect of the last phalanx of one of my fingers, and retained it there for five 
hours, with the exception of occasional removal for the purpose of drawing 
blood for examination. By the conclusion of the time mentioned, the skin on 
which the mustard had been placed was in a very decided state of inflammation, 
being red, swollen, and painful, and the redness at one spot disappearing imper- 
fectly on pressure, and returning languidly after its removal. A very minute 
drop of blood drawn with a fine needle from the surface of the most inflamed 
part was then compared with a drop of similar size from another finger, but no 
difference could be detected between them, nor had any been observed in pre- 
* In performing experiments upon a foot in which the circulation has been arrested, it is important 
to guard against a deception apt to arise from the direct action of an irritant upon the blood in the vessels. 
Thus, if a drop of chloroform of considerable size be applied to a web under those circumstances, it will 
soak in and produce its chemical effects upon the blood, the earliest of which is complete abolition of 
adhesiveness in the corpuscles. 
