PHYSIOLOGICAL ACTION OP ATROPINE. 
103 
the third pair of nerves, which are supposed to supply the 
circular fibres, but to the excitation of the filaments of the 
sympathetic supplying the radiating fibres of the iris, the 
author proceeds to express a wish that the question “ might 
be brought to the test of direct experiment by some one 
accustomed to such inquiries.” 
I happened, during last winter, to have made, at the sug- 
gestion of Professor Garrod, some experiments exactly analo- 
gous to those recommended in the same paragraph by Mr. 
Bell, and considering that the question might be fraught with 
a certain amount of interest, especially as it would seem to 
have excited some discussion at a recent meeting of the 
Medical and Chirurgical Society, I. beg to lay before your 
readers the mode of proceeding, and the results obtained 
from the experiments. 
In the early part of last year. Professor Sharpey made an 
experiment, in order to ascertain if atropine, when directly 
applied to the cervical s}unpathetic, w r ould cause dilatation 
of the pupil ; and, in the beginning of this year, Professor 
Sharpey and I repeated the experiment upon a cat, in the 
following manner : 
Experiment 1. — The left cervical sympathetic nerve was 
carefully dissected out from the neighbouring tissues, for 
nearly two inches in extent, and afterwards divided ; the 
pupil of the eye, on the same side, immediately, or at least 
in a few seconds, became contracted, and permanently 
remained so. The upper end of the cut nerve was next sus- 
pended in a strong solution of atropine, and, notwithstanding 
that it was retained in the liquid during at least twenty-five 
minutes, no dilatation of the pupil occurred either then or 
throughout the day. This experiment I have again repeated 
with an exactly similar result, and I believe the same thing 
occurred in Professor Sharpey’s first experiment. Atropine 
thus certainly appears to have no direct simulating effect 
upon the sympathetic nerve in the neck ; for had it stimu- 
lated as galvanism does, the application of it to the nervous 
substance of the cervical sympathetic would have been 
followed by dilatation of the pupil. 
Experiment 2. — On another occasion, while performing an 
analogous experiment upon a cat, a drop or two of the atro- 
pine solution accidentally fell upon the exposed muscles of 
the neck, and in a short time after absorption had taken 
place, the pupils of both eyes became dilated, although in 
different degrees. The dilatation of the pupil in the sound 
