[ 48i ] 



ceiyers, with one by a metallic and with the other by a glafs 

 adopter, more pafTcd through the latter than through the former. 

 It is probable that Du Fay, who made thefe experiments, would 

 give this explanation if he had purfued this inquiry. Thus the 

 brtatii is immediately evaporated from poliflied fteel, but is re- 

 tained by poliftied glafs. 



MuscHENBROECK alfo obfervcs that this different power of cpl- 

 leding dew is in fome meafure local, for that it does not take 

 place at Leyden though it does at Utre£l, Hefs and Paris, which ap- 

 pears to me to be occafioned by the unequal ele(ftrization of the 

 vapours; thofe from the vicinity of Paris and Utredt being coUeded 

 from a drier foil are more highly eledrified than thofe of Leyden, 

 the foil of which is fo moift that they can have no cellars, whereas 

 they carv and have at Utred. He alfo tells us, fogs, univerfally, 

 equally moiften all bodies, which {hews they contain much lefs 

 eledron than defcending vapors. 



Hence dew is nothing more than the condenfed vapours elevated; 

 durina; the day from the foil over which the air that depofits it 

 is incumbent, and hence its noxious qualities when elevated 

 from ftagnating marflies, and the various impregnations it has 

 been found to contain. 



Section 



