4-70 NATURAL HISTORY. 



air hath a little light, proportionable to the visual 

 spirits of those creatures. 



Experiments in consort touching the eyes and sight. 



867. The eyes do move one and the same way ; 

 for when one eye moveth to the nostril, the other 

 moveth from the nostril. The cause is motion of 

 consent, which in the spirits and parts spiritual 

 is strong. But yet use will induce the contrary ; 

 for some can squint when they will : and the 

 common tradition is, that if children be set upon 

 a table with a candle behind them, both eyes will 

 move outwards, as affecting to see the light, and so 

 induce squinting. 



868. We see more exquisitely with one eye shut, 

 than with both open. The cause is, for that the 

 spirits visual unite themselves more, and so become 

 stronger. For you may see, by looking in a glass, 

 that when you shut one eye, the pupil of the other 

 eye that is open dilateth. 



869. The eyes, if the sight meet not in one angle, 

 see things double. The cause is, for that seeing 

 two things, and seeing one thing twice, worketh the 

 same effect: and therefore a little pellet held between 

 two fingers laid across, seemeth double. 



870. Pore-blind men see best in the dimmer 

 lights : and likewise have their sight stronger near 

 hand, than those that are not pore-blind ; and can 

 read and write smaller letters. The cause is, for 

 that the spirits visual in those that are pore-blind, 

 are thinner and rarer than in others ; arid therefore 



