6 ELK.MKNTAUY PKIXU 1'LKs ()F MICKOSCOPICAL OPTICS 



Let n> m.w supp<e thiil in fig. '2 tin- ray is travelling in the op- 

 posite direct inn. (I F in the denser medium will n>\v lc the incident 

 ray. :ind F E in tin- r.-in-r nifdiuin will ! the rcfrnc-ted ray. Xo\v. 

 if the ;in^lr |; K <i In- inriviiM-d. the nii^le A F E will also lie in- 



!' 1 1.. :J. -The phenomenon of total reflexion. (Promt i E Nature,' 



published by Miifinill 



rrease.l in a greater proportion, and the ray I-' K \\ ill a|>| oai-h t he 

 surface F D. 



Wlu-ii F E coincides with F D, O F is .sai.l to !>.- ineid..!!! at the 

 '/// iml (inijlc of the medium. When this critical an-le is reached. 

 none )C the incident light will pass nut of the denser medium, Imt it 



