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

NEURO-PHYSIOLOGY. 55
responds to volitional or electrical irritations ;
and all tlie
sensitive parts to which it is distributed become devoid of
feeling. As the nerve thaws again, all of its functions
gradually return. Altered vascular conditions also occur.
At first the cold contracts the vessels, and almost instantly,
as the part thaws, they dilate, and the part becomes the
seat of a more or less intense congestion,
— a circumstance
of which I have made use in studying the congestions ot
nerves and ganglionic centres.
The best clinical study of the influence of cold on
nerves was made by Dr. A. "Waller,* in 1862. I shall
have occasion to refer to it again.
* Proc. Royal Soc. London, vol. ii. 1860-62, p. 89 et seq.