ANIMALS. 357 



instantly discharge. TLus the hand, if it be exposed to broad 

 day-light for some time, and then immediately snatched into a 

 dark room, will appear still luminous : and it will be some time 

 before it is totally darkened. It is thus with the eye ; which 

 cither by an instant gaze at the sun, or a steady continuance upon 

 some less brilliant object, has taken in too much light ; its humours 

 are, for a while, unfit for vision, until that be discharged, and 

 room made for rays of a milder nature." How dangerous the 

 looking upon bright and luminous objects is to the sight may 

 be easily seen, from such as live in countries covered for most 

 part of the year with snow, who become generally blind before their 

 time. Travellers who cross these countries are obliged to wear 

 a crape before their faces, to save their eyes, which would other- 

 wise be rendered totally unserviceable ; and it is equally danger- 

 ous in the sandy plains of Africa. The reflection of the light 

 is there so strong, that it is impossible to sustain the effect, with- 

 out incuiTing the danger of losing one's sight entirely. Such 

 persons, therefore, as read or write for any continuance, should 

 choose a moderate light, in order to save their eyes ; and all 

 though it may seem insufficient at first, the eye will accustom 

 itself to the shade, by degrees, and be less hurt by the want 

 of light than the excess. 



" It is, indeed, suqirising how far the eye can accommodate 

 itself to darkness, and make the best of a gloomy situation. 

 When first taken from the light, and brought into a dark room, 

 all things disappear ; or, if any thing is seen, it is only the re- 

 maining radiations that still continue in the eye. But, after a 

 very little time, when these are spent, the eye takes the advan 

 tiige of the smallest ray that happens to enter ; and this alone 

 would, in time, serve for many of the purposes of life. There 

 was a gentleman of great courage and understanding, who was a 

 major under King Charles I; this unfortunate man, sharing in 

 his master's misfortunes, and being forced abroad, ventured at 

 Madrid to do his king a signal service ; but uiduckily failed in 

 the attempt. In consequence of this, he was instantly ordered to 

 a dark and dismal dungeon, into which the light never entered, and 

 into which there was no opening but by a hole at the top, down 

 which the keeper put his jirovisions, and presently closed it again 

 on the other side. In this manner the unfortunate loyalist con- 

 finued for some weeks, distressed and disconsolate ; but ;it hist 



