6 
Mr. Home's Lecture 
lens, as considerably to lessen their effect in fitting the eye for 
seeing near objects, and make this small increase of con- 
vexity inadequate to such an effect. 
Finding this to be the case, it became necessary to examine 
the eye with attention, to see in what way the full effect was 
most likely to be produced. For this purpose the following 
experiments were made upon the human eye, to determine 
whether the axis of vision could be elongated by any uniform 
pressure applied to its coats. 
The experiments were made in the following manner : an 
eye of a dead subject was carefully removed from the socket, 
before any change could be produced in consequence of death, 
and its different diameters were measured by a pair of calliper 
compasses. As soon as these were determined, a hole was 
made in the centre of the optic nerve, and a pipe fixed into 
it, through which air could be thrown into the cavity of the 
eye, so as to distend its coats. While distended in a mo- 
derate degree, by compressing with the hand a small bladder, 
containing air and quicksilver, attached to the pipe, the same 
diameters were measured again, and compared with those 
which were taken while in the natural state. 
These experiments were made by Mr. Muttlebury and 
Mr. Williams, two very intelligent and diligent students in 
surgery, who were filling situations that gave opportunity of 
making such experiments. They measured the diameters in 
these two states, and marked them on paper, without ascer- 
taining their difference, so that there could be no fallacy in 
the measurement from any preconceived opinion ; and I have 
every reason to believe there was none from inattention. 
