142 



between two neighbouring' basins have presented 

 themselves under every zone to the imagination 

 of the vulgar, as well as to that of natural 

 philosophers ; for the latter, without confessing 

 1% sometimes repeat popular opinions in scien- 

 tific language. We hear of subterranean gulfs 

 and outlets in the New World, as on the shores 

 of the Caspian sea, though the lake of Taca- 

 rigua, is two hundred and twenty-two toises 

 higher, and the Caspian sea fifty-four toises 

 lower, than the ocean ; and though it is well 

 known, that fluids find the same level, when they 

 communicate by a lateral channel. 



The changes, which the destruction of forests, 

 the clearing of plains, and the cultivation of 

 indigo, have produced within half a centu ry in 

 the quantity of water flowing in on the one 

 hand ; and on the other the evaporation of the 

 soil, and the dryness of the atmosphere, present 

 causes sufficiently powerful to explain the suc- 

 cessive diminution of the lake of Valencia. I 

 am not of the opinion of a traveller, who has 

 visited these countries since me*, that " to set 



* Mr. Depons {Voyage a la Terre Ferme, vol. i, p. 139) 

 adds : " The small extent of the surface of the lake" (it 

 amounts however to 106,500,000 square toises " renders 

 impossible the supposition, that evaporation alone, however 

 considerable under the tropics, could remove as much water, 

 as the rivers furnish." In the sequel, the author himself 

 seems to abandon " this occult cause, the hypothesis of an 

 aperture." 



