THE EYE AND THE MICROSCOPE. 



Oculus ad vitam nihil facit, ad vitam beatam nihil rnagis. 



SENECA. 



The eye, no servitor of duty, 

 But minister of all life's beauty. 



The vignette represents an ideal section through the little camera - 

 obscura, which is called the eye-ball. The arrow and the dotted 

 lines indicate the manner in which the picture is brought on to the 

 retina (the receiving plate of the apparatus) . 



