WITH PHYSIOLOGICAL OBSERVATIONS. 
61 
rection outwards, the pupil, in passing the centre of the orbit, contracted a little, and, 
when approaching the outer canthus, expanded again to the size it held when the 
eye was in its usual inverted position. On looking from the temporal side into the 
pupil, a large portion of the opake capsule was observed in the posterior chamber. 
The interior of the eye-ball presented a brownish-black appearance. The patient 
had not the slightest perception of light with this eye ; it was perfectly amaurotic. 
The left eye presented in the conjunctiva, especially at the inner canthus, a number 
of varicose vessels, and in the scleiotica a fine vascularity around the outer half of 
the cornea; this latter membrane was regularly convex, clear, and perfectly pellucid 
The fibres of the iris were rather irregular; its brown colour not equally diffused. 
The pupil, w T hich was uncommonly large, was not round, but drawn angularly down- 
wards and inwards, neither altering in dimension with the movements of the eye, nor 
from the stimulus of light. On examining the eye by looking straight into it through 
the pupil, the anterior wall of the capsule was observed undestroyed, rendered opake 
in its whole extent, hypertrophied in several places, and of a colour and lustre like 
mother-of-pearl. On looking from the temporal side in an oblique direction into 
the pupil, there was visible in the anterior wall of the capsule a very small perpendi- 
cular cleft of about one line and a quarter in length. This cleft was situated so far 
from the centre of the pupil that it was entirely covered by the iris, and the inferior 
border being united to the uvea, it was kept a little open, so that the aqueous humour 
had free entrance into the cavity of the capsule. Except at the spot where the union 
of the capsule with the uvea took place (the cause of the angular form of the pupil), 
these two membranes were not in contact with each other. The patient only com- 
plained of an occasional sensation of pressure in the interior of the eye ; otherwise 
the organ was free from pain. With this eye he had a perception of light, and was 
even capable of perceiving colours of an intense and decided tone. He believed him- 
self moreover able to perceive about one third of a square inch of any bright object, 
if held at the distance of half an inch or an inch from the eye, and obliquely in such 
a direction as to reflect the light strongly towards the pupil. Cut. this I am con- 
vinced was a mere delusion ; for, from the state of the interior of the eye, as just de- 
scribed, it is evident that all rays of light falling in the direction of the optic axis in 
the pupil must be intercepted, and reflected by the opake capsule. By these rays, 
therefore, a perception of light indeed might be conveyed, but certainly no percep- 
tion of objects. On the other hand, it seems probable that the lateral cleft in the 
capsule permitted rays of light to pass into the interior of the eye. But as this small 
aperture was situated entirely behind the iris, those rays only would have permeated 
which came in a very oblique direction from the temporal side. Admitting then 
these rays of light to pass through the cleft, still on account of their obliquity they 
must fall at a place situated about midway between the ciliar ligament and the 
centre of the posterior hemisphere, where, from the laws of optics, they could produce 
but a very imperfect image ; and, owing to this imperfection of the image, it was im- 
