314 THE OCEAN, 



cates with a fifth and smaller, called the lake of Paria, neither of 

 which have any other exit. Of these, the Caspian, wh'ch is by 

 much the greatest, is reported to be somewhat less salt than the 

 ocean, The Lacus Asphaltites is so exceedingly salt, that its waters 

 seem fully saied, or scarcely capable to dissolve any more; whence 

 in suom:et*time its b*> ks are incrustated with great quantities of 

 dry salt, of somewhat a tnuio pungent nature than the marine, as 

 having a relish of sal ammoniac ; as I was informed by a curious 

 gentleman who was on th c p.ace. 



" The lake of Mexico, properly speaking, is two lakes, divided by 

 the causeways that lead to the city, which is built in islands in the 

 midst of the lake, undoubtedly for its security ; after the idea, pro- 

 bably, which its first founders borrowed from tiieir beavers, who 

 build their houses on dam> they make in the rivtrs after that man- 

 ner. Now that part of the lake which is to the northward of the 

 town and causeways, receives a river of a considerable magnitude, 

 which being somewhat higher than the other, does with a Muall fall 

 exonerate itself in the southern part, which is lower. Of these the 

 lox\er is found to be salt, but to what degree I cannot yet learn 

 though the upper be almost fresh. 



" And the lake of Titicaca, being nearly eighty leagues in circum. 

 ference, and receiving several considerable fresh rivers, has its waters, 

 by the testimony of Herrera and Acosla, so brackish as not to be 

 potable, though not fully so salt as that of the ocean ; and the like 

 they affirm of that of Paria, into which the lake of Titicaca does in 

 part exonerate itself, and which I doubt not will be found much 

 salter than it, if it were inquired into. 



*' Now I conceive that as all these lakes receive rivers, and have no 

 exit or discharge, so it will be necessary that their waters rise and 

 cover the land, until such time as their surfaces are sufficiently ex- 

 tended, so as to exhale in vapour that water which is poured in by 

 the rivers ; and consequently that lakes must be larger or smaller, 

 according to the quantity of the fresh they receive. But the va. 

 pours thus exhaled are perfectly fresh ; so that the saline particles 

 brought in by the rivers remain behind, while the fresh evaporates ; 

 and hence it is evident that the salt in the lakes will be continually 

 augmented, and the water grow salter and salter. But in lakes that 

 have an exit, as the lake of Genesaret, otherwise called that of Ti- 

 berias, and the upper lake of Mexico, and indeed in most others, 



