i 491 ] 



tlie fuperior (trata of the atmofphere under which the fouthern 

 air is introduced, not being fupported by air as denfe as that 

 which fubfifted under them before their introdudion, ne- 

 ceflarily defcend and. mix , with the inferior fouthern air ; by 

 this intermixture they are warmed, and deprive the clouds 

 already formed and in its vicinity of part of their eledlron, or' 

 perhaps in conformity to the eleventh principle, they are them- 

 felves deprived of part of their eledlron by thofe clouds, and the 

 vapours they contain are thus converted into clouds ; in cither 

 way clouds differently elecHirified mult be formed. Hence 

 proceeds their gradual attradion to each; other which terminates 

 in thofe gentle fhowers that ufually accompany this wind. North- 

 erly and eaflerly winds on the contrary, proceeding from colder 

 countries are lefs highly eledrified than the foil of the countries 

 they invade ; and hence from the oppofite reafons to thofe juft 

 mentioned they introduce ferene weather and a difpofition ad- 

 verfe to nubification. 



The reafons hitherto adduced to explain the different effeds 

 of thefe different wine's, evidently arofe from an ignorance of 

 the origin and" progrefs of thefe winds. It was imagined that 

 foutherly winds, flowing into colder countries were fuddenly 

 cooled by an intermixture with the colder air of thofe countries,, 

 and that thus their vapours were condenfed into rain, yet, even 

 foj this intermixture could only produce clouds and not rain,. 



but 



