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 In 1800, after having withdrawn 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 



