PROCEEDINGS OF SOCIETIES. 141 
formed the subject of a special experimental inquiry, the re- 
sults of which are given in a supplement to the paper. It is 
there shown that the contraction of the arteries of the frog’s 
web are regulated by a part of the spinal cord, the irritation 
of which induces complete constriction of the vessels, while 
its destruction is followed by permanent dilatation. Neither 
stimulation nor removal of the nervous centre for the arteries 
produces any perceptible change in the quality of the blood, 
as respects adhesiveness of its corpuscles or otherwise. 
Section III. “On the Effects of Irritants upon the Circu- 
lation in the Frog’s Web,” commences with an account of 
some experiments performed with tepid water applied for a 
brief period to the foot. 
Subsequent experiments with a variety of other irritating 
agents showed that the corpuscles, both red and white, were 
obstructed in their progress through the irritated part m 
consequence of their tending to adhere in an abnormal degree 
to one another and to the walls of the vessels. The effects 
upon the blood were always similar, although the means em- 
ployed to produce irritation were exceedingly various, such 
as solutions of salts, mustard, essential oils, chloroform, heat, 
galvanic shock, mechanical violence, &c. 
The well-known adhesiveness of the white corpuscles within 
the vessels does not occur, according to the author, unless 
some degree of irritation is present, and never exceeds that 
which is always seen in blood outside the body. Hence the 
inference is drawn, that the tissues of a healthy part exert an 
influence on the blood in their vicinity, by means of which 
the corpuscles, both red and white, are preserved free from 
adhesiveness ; but that in an inflamed part this influence is 
more or less in abeyance. 
At the commencement of Section IV, “On the State of 
the Tissues in Inflammation,” it is stated that “ the conclu- 
sion arrived at in the latter part of the last section, that 
blood flowing through an inflamed part, behaves itself in the 
same way as when separated from the living body, naturally 
leads us to infer that the tissues of the inflamed part are in 
some degree approximated to the condition of dead matter, or; 
in other words, have suffered a diminution of power to dis- 
charge the offices peculiar to them as components of the 
healthy animal frame. This inference is strongly supported 
by considermg 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 disturbance of the circulation.” 
It is then pointed out that all these agents, though differing 
greatly in their nature, agree in their tendency to inflict a 
