240 DISSERTATION on the 



Sthfy, Now, the bodies I have enumerated, are all in the 

 clafs of imperfect ideo-eleclrics, and have likewife the common 

 property of attracting moifture, fo that they can never be per- 

 fectly dry ; but water is, after the metals, the moft perfect 

 conductor of the electric fluid, or the lead of an ideo-electric, 

 I fay, after the metals ; for I think 1 have obferved, and pro- 

 bably others have done the fame, that water does not conduct 

 quite fo well as they do. But let that be as it may, thefe bo- 

 dies cannot certainly imbibe water without becoming lefs of an 

 ideo-electric, in proportion as they do fo, and, of courfe, the 

 more they dry again, the more they recover their natural quality. 

 The refult upon the whole then mull be, That during our 

 fevere cold, the bodies of which I fpeak become fpontaneouily 

 much better ideo- electrics here, than they ever are in any other 

 feafon or climate ; therefore thefe bodies have an extraordinary 

 difpofition to become eafily and ftrongly electric. 



It cannot have efcaped your penetration, Sir, that in all I 

 have faid ; I have advanced only known and generally received 

 facts, without admixture of hypothefes or conjecture of my own; 

 fo that the explanation I have given of the phenomena, (alluded 

 to in your paper, and which I was called upon to illuftrate) 

 arifes naturally and necefTarily from thofe facts, in fuch a man- 

 ner, that it may pafs, in my opinion, for a demonstration, 

 fuch as is to be given in Natural Philofophy. 



It appears to me then, Sir, that we are not obliged to have 

 recourfe to the conjectures of Meffrs Saussure, Bergman, 

 Wilke, &.c. to explain the above phenomena, as you appear to 

 have been difpofed to do, in the paiTage alluded to, with a mode- 

 ration that does honour to your mode of philofophifing ; nay, if 

 we were even inclined to employ them, I do not fee how they 

 would anfwer our purpofe, being only hazarded opinions ; but 

 could they be verified, (which I doubt much) they would even 

 then be of very little ufe, as they could contribute nothing to 

 the perfection of the theory of electricity. 



You 



