PHENOMENA OF DEW. 295 



C. The fame happens when the armour is at a diftance ; but on the glafs if 

 then if the humidity be depofited on the warm fide, it is not j! 1 ^™ 001 bc 

 on the armour, but it accumulates oppofite to it upon the 

 glafs. 



II. When the partition is armed in contact with the cold Armour on thc J 

 r cold face repels 

 Iace# moifture on 



A. If humidity be depofited on this face, it is not on the both fides, 



armour. 



B. And if humidity be depofited on the oppofite face, that 

 is to fay, the warm face, there is none on the correfpondent 

 place of the armour. 



C. The fame happens when the armour is at a diftance on if at a diftance. 

 the cold face. But then if the humidity be depofited on this 



face, there is not only a want of it on the armour, but there is 

 none on that furface of glafs oppofite the armour. 



III. A. In order that the phenomena fhould ceafe to take Glafs or varnim 

 place, it is fufficient that the armours of contaa, or the face of ^of'the^-" 

 the armours of diftance oppofite the glafs, mould be covered mour. 



with glafs or varnilh. Nothing remarkable then happens. 



B. If this glafs or varnilh be again covered with metal, the Alterations of 

 . . glafs or metal. 



phenomena again occur. 



C. They ceafe if this metal be again covered with glafs, 



D. They begin, &c. 



IV. One tingle propofition will include almoft the whole of 

 thefe fads. v 



When glafs feparates two majfes of air of unequal temperatures, General propofi- 

 the armour gives it (orfeems to give it) the property ofaccumu-^. 

 fating or repelling humidity, according as it is applied either on 

 the warm or cold face, and this influence extends through the glafs 

 and through other fubjlances, to the diflances offeveral centimetres. 



V. Or (till more limply. 



Glafs which feparates two maffes of air of unequal temperatures, Simple general 

 accumulates (ftems to accumulate) or repells humidity, according 1 ™ oi tft0 * e 

 as it is aj-med on the warm or cold face. 



EXPLANATION. 



I imagined for a long time, fays the author, that thefe phe- 

 nomena depended on electricity, but they may be explained 

 very naturally by the elective attractions which are exercifed at 

 a diftance, and by the well known property of the metals of 

 feeing good conductors of caloric. 



BASES 



