ON THE SPARE Y SIAGES OF INFLAMMATION 247 
tongue speedily produces numbness there, and a piece of mustard lying on 
the finger for an hour or two dulls the sensibility of the skin. Chloroform, too, 
while it very readily induces stagnation followed by vesication in the frog’s 
web, is an agent which appears likely to benumb the vital energies. If a small 
frog be put into a bottle of water highly charged with carbonic acid, and removed 
from it some time after all motion of the limbs has ceased, it will be found that, 
though the heart is still beating, the blood-vessels of the webs are loaded with 
stagnant corpuscles. After a while, however, resolution will take place, and 
some time later the animal will regain its consciousness. Here it appears pro- 
bable that the carbonic acid, poisoning the web as well as the brain, paralyses 
for a time the functional activity of both ; and that the return of the circulation, 
like the recovery of the cerebral functions, depends on a restoration of the 
dormant faculties of the affected tissues. 
Perhaps the most instructive case is that of the galvanic shock, which the 
following circumstances first showed me to be capable of causing inflammatory 
congestion. Being desirous of ascertaining the effects of galvanism upon the 
cutaneous pigmentary system, I applied the poles of a battery in rather powerful 
action to the skin of the head of a frog, when, the shock affecting the brain, 
the animal was stunned and lay perfectly motionless. This state of things 
being favourable for pursuing my inquiry by aid of the microscope, I drew 
down one of the passive limbs, and having placed the foot under the instrument, 
arranged the fine platinum-wire extremities of the poles at a short distance 
from one another at opposite sides of one of the webs, so that the current might 
pass through a part in the field of view, the circulation meanwhile remaining 
healthy. I now completed the circuit of the battery, when the leg became 
instantly drawn up by reflex action ; yet on re-examination of the web, I found 
that, momentary as the shock had been, the part through which it had passed 
had become affected with intense inflammatory congestion, gradually shading 
off towards the healthy condition, which existed at a little distance. After 
about a quarter of an hour resolution of the confused mass of stagnant corpuscles 
occurred, and shortly after this the creature regained the power of voluntary 
motion. I afterwards repeated the experiment, both upon the same animal 
and upon another specimen, and always with the same results ; and I particu- 
larly observed in one case that the white corpuscles were affected with great 
adhesiveness in the congested region. 
With regard to the manner in which the abnormal condition of the blood 
was brought about in these cases, it has been already mentioned in Section I 
that the galvanic current produces no increase of the adhesiveness of the red 
corpuscles of blood outside the body ; but after what has been stated in the 
