THEORY OF THE EYE. 295 
Leuwenhoeck, armed with his powerful microscopes, 
traced out, and gave figures of, the muscular fibres in 
all their ramifications in the crystalline of a fish. To 
awaken the attention of the scientific world, tired with 
these long debates, nothing less was necessary than the 
high renown of two new members of the Royal Society 
who entered the lists: one, a celebrated anatomist, the 
other the most eminent instrument-maker of whom Eng- 
land could boast. These jointly presented to the Royal 
Society a memoir, the fruit of their combined labours, 
intended to establish the complete unalterability of the 
form of the crystalline. ‘The scientific world was not 
prepared to admit that Sir Everard Home and Ramsden 
together, could possibly make inaccurate experiments, or 
be deceived in micrometical measurements. Young him- 
self could not believe it ; and in consequence he did not 
hesitate publicly to renounce his theory. 
This readiness to own himself vanquished, so rare in 
a young man of twenty-five, and especially on the occa- 
sion of a first publication, was in this instance an act of 
modesty without example. Young, however, had really 
nothing to retract. In 1800, after having withdrawn 
his former disavowal, our colleague developed anew the 
theory of the change of form of the crystalline in a me- _ 
moir against which, from that time, no serious objection 
has been brought. 
Nothing could be more simple than his line of argu- 
ment ; nothing more ingenious than his experiments. 
Young, in the first instance, got rid of the hypothesis 
of a change of curvature in the cornea by the aid of 
microscopic observations, which were of a kind to ren- 
der the most minute variations appreciable. We can 
say more ; he placed the eye in special conditions where 
changes of curvature in the cornea would have been 
