NATURAL THEOLOGY. 



53 



Securities of the Eye. 



T. In a telescope it is necessary the glasses 

 should be preserved from the least scratch, dust, or 

 injury ; how is this managed in the] eye ? 



A. The principal security is the eye-lid. This 

 active little shutter seems almost animated with a 

 sense of the important office assigned it. It closes 

 immediately, as if of its own accord, whenever any 

 thing approaches very near the eye. Every person 

 is sensible how hard it is to keep from winking in 

 such a case, even though challenged to do it if he 

 can. It seems to be one of the natural securities 

 provided originally by the all-wise Architect ; for we 

 discover the same in infants. It is not, therefore, the 

 result of habit or experience. It is a further mark of 

 design, that the shutter shoald be made in two parts ; 

 the eye, of course, is sooner covered by dividing the 

 duty between them ; nor is this the only advantage. 

 The middle of the ball, being the spot where the 

 light enters, by having two shutters, the one above 

 and the other below, we are enabled to see, and to 

 cover our eyes at the same time : that is, to cover 

 them, all but a little space ; whereas with a single 

 lid, one half of the front must always have been open 

 and exposed, to enable us to see at all. 



B. What perfect mechanism ! How admirable 

 the whole art of divine wisdjm in the formation of 

 this fine organ ! 



T. Very perfect for a shutter ; but still a delicate 

 place for a shutter to be employed. You may judge 



