134 Experiments and Obfervations 



a foil, a ftream from the Nile, which however would be in- 



difpenfibly neceflary to feed it, lince it ought not, and even 



could not be dug to the bottom, or to the level of the two 



fea?. 



There is however one important remark (till to be made, 

 which is, that the prefent trade of Egypt with Afia is carried 

 on merely by caravans, and by two different ways; one en- 

 tirely over land acrofs the ifthmus and fands for $o or 60 

 leagues, even to Syria ; and another by a defile among the 

 mountains of Upper Egypt, for 25 or 30 leagues only, from 

 Cophtos to Cofeir, which is a port of the Red Sea much 

 eafier, of accefs than Suez, becaufe the fea there is broader 

 and much lefs dangerous. But as this defile feems to be 

 favourable to a canal, which might be fed equally well and 

 with more eafe from the Upper Nile, and as that river is 

 navigable to Cophtos as well as to Grand Cairo, there is 

 every appearance that a canal in the latter fituation, planned 

 with the fame care, would be more fure as well as more ad- 

 vantageous to the nation that might have the fovereign pof- 

 fefiion of Upper as well as Lower Egypt, efpccially as it is 

 abfolutcly neceflary that it mould be fufficiently powerful to 

 fubdue the Bedouins, who infeft the whole country, and 

 who would foon render the canal of Cairo as impracticable. 

 as that of Cophtos, 



V. Obfervations on the Organs of Vifion in Bats, 

 ByM. Spallanzani 



■JL HESE obfervations are extracted from a fmall work 

 publiflied by tyl. Spallanzani a few years ago, under the 

 following title : " An account of fome fpecies of bats, which, 

 when deprived of fight, perform their movements in the 

 air as if they Mill faw ; a faculty not poflcfled by other birds 

 under the like circumflances," And the author fays that he 

 was led to them by fome experiments which he made on 



nigh* 



