Chap. 4 .] [ 473 ] 



CHAP. IV. 



OF THE OCEAN. 



Sahnefs of the Ocean. Different Opinions as tt the Caufe. Probable 

 Reafcns 'why the Sea has been always fait, Temperature of the Sea 

 at different Depths. Modes of rendering Sea-nvaterfrejh* 



TH E greateft quantities of water with which we 

 are acquainted are by no means pure, but 

 united with faline matter. The ocean is fait in all' 

 parts of the world ; but the degree of faltnefs differs 

 much in different climates, and is almoft univerfally 

 found to be greater in proportion as the water is taken 

 up nearer the equator, where the heat of the fun is 

 greateft, and the evaporation of the watery particles 

 confequently more confiderable. When treating of 

 fea fait, the refult of various obiervations relating to 

 this fubject were detailed. 



The caufe of the faltnefs of the ocean has been a 

 fubjecl: of inveftigation among philofophers in almoft 

 all ages, but it ftill remains in great obfcurity. There 

 can be little doubt, that a large quantity of faline 

 matter exifted in this globe from the creation -, and, at 

 this day, we find immenfe beds of fal gem, or common 

 fait, buried in the earth, particularly near Cracow ; 

 but whether thefe collections have been derived from 

 the ocean, and depofited in confequence of the eva- 

 poration of its waters in certain circumftances, or 

 whether the ocean was itfelf originally frefh, and re- 

 ceived its fait from collections of faline matter fituated at 

 its bottom, or from that brought by the influx of rivers, 

 cannot now be afcertajned.. ^No accurate obfervations 



on 



