2 28 TRAVELS IN UPPER 



times a da}', in order to moderate (he heat, and to 

 cool the air which was respired. When earth, 

 violently heated, is moistened so plentifully, it 

 sends up a great quantity of nitrous and inflam- 

 matory vapours, which cannot fail to impair and 

 injure the sight : but it is impossible to include the 

 custom of the inhabitants, to sleep in the open 

 air, among tlie many circumstances which make 

 ophthalmy and blindness so common in Egypt, its 

 many persons have supposed and w rittcn. Indeed, 

 although the natives of Upper Egypt, where the- 

 heat of the sun by day occasions them to sigh for 

 the cooling breezes of the evening, have no other 

 •bed than the terrace of their huts, yet they have 

 nothing to fear from that habit, for they wrap up 

 the whole body so carefully, and particularly the 

 head, that you must be an Egyptian to escape 

 stifling under the folds ot cloth with which they 

 cover and shut up their (ace, so as even to inter- 

 cept respiration. Besides, it is well known that 

 the people of ancient Egypt did not in general 

 sleep so much exposed, and nevertheless they 

 were equally subject to blindness and the dph- 

 thalmy. 



It was now, as I have before observed, the time 

 of the swelling of the Nile. The goulte^ that mi- 

 raculous dew, which, according to the belief of the 

 Egyptians, purifies the atmosphere, and preserves 

 ^ from 



