Injuries of nerves and their consequences - Reflex Sympathetic ...

174 INJURIES OF NERVES.
method of such examinations may not be out of place.
our hospital we used the thermometer, held in succession
on the skin of two parts anatomically symmetrical, and
which had been subjected for half an hour to the same
At
external conditions. More satisfactory results Avere obtained
by the use of the thermo-electric disks of Becquerel
and the galvanometer; but of late I have employed a
small thermometer, the bulb of which is covered on onehalf
of its circumference by a piece of cork, which extends
a half-inch on eitlier side beyond and also below the bulb.
By this arrangement the heat is conlined, and the time
needed for the observation is shortened. Some weeks or
months after complete division of a large nerve, it will be
found that the affected parts are colder than those which
are not influenced by the injury. The range in my cases
was from two to fifteen degrees Fahrenheit lower than
that of the sound tissues. ISIr. Hutchinson's cases were
six to ten degrees colder in the parts palsied, and Mr.
Erichsen had a like result.*
Where a nerve trunk had been merely injured and not
thoroughly divided, we commonly found that the temperature
of the affected tissues was lowered in most cases
from half a degree to two or three degrees but when
;
there was some irritative lesion, with consequent causalgia
and glossy skin, the temperature was either normal,
or, as happened in the majority of such cases, slightly
above that of the neighboring tissues.
At the U. S. A. Hospital for Diseases and Injuries of
Nerves the records were unfortunately only comparative,
owing to the galvanometer being the instrument used,
* See, also, Earle, Med.-Chir. Trans., vol. vii. 1816, p. 173, for observations
on the low temperature of traumatic palsy, and on the effect of
electricity in raising it Also, Yellovvby, same journal, vol. iii. Also,
W. B. "Woodman, in Sydenham Soc. Translation of Wunderlich on Temperature
in Disease, p. 152.