130 



anew from latitude 22° 52' to 18° 45'. In these 

 regions, in the twenty-fourth and thirtieth de- 

 grees of longitude, a large stripe of the ocean is 

 less salt than the rest. 



The muriat of soda amounts to 0*028 from the 

 parallel of 18° 8' to that of 12° 34', between the 

 thirtieth and fifty-fourth degrees of longitude. 

 It seemed to me, that, in the part of the Atlantic 

 comprised between the coasts of Portugal and 

 Cumana, the water is a little Salter to the south 

 of the tropic of Cancer, than under the tempe- 

 rate zone ; and I should be induced to general- 

 ize this fact, if the experiments made during 

 Cook's last voyage did not .peremptorily prove, 

 that this difference does not exist in every me- 

 ridian. Horizontal currents, which cross the 

 ocean at it's surface ; and oblique currents 

 which mingle the strata of water, placed at dif- 

 ferent depths ; modify the saltness of the seas ; 

 and supposing even, that the absolute quantity 

 of the muriats dissolved in the ocean has not 

 been augmented by the action of submarine 

 volcanoes, but has remained the same for thou- 

 sands of years, it is not the less probable, that 

 the distribution of this salt in different parts 

 of the Globe, undergoes, from time to time, con- 

 siderable changes. 



