ON DEW, &c. 145 



upon fine shavings of wood, than upon a thick 

 piece of the same substance. It is chiefly for a 

 similar reason, I believe, that fine raw silk, fine 

 unwrought cotton, and flax, were found by me 

 to attract somewhat more dew, than the wool 

 I employed, the fibres of which were thicker, 

 than those of the other substances just men- 

 tioned. 



III. Bright metals, in consequence of some 

 circumstance in their constitution, attract dew 

 much less powerfully than other bodies ; all of 

 which, after allowance has been made for any 

 difference, which may exist in their mechanical 

 states, seem to attract dew in quantities not 

 very unequal, if they be similarly situated. 



Musschenbroek was the first, who distinctly 

 remarked this peculiarity of metals ; but Dufay *, 

 I believe, published it before him, referring, 

 at the same time, the discovery to its proper 

 author. Both Musschenbroek and Dufay, how- 

 ever, made too large an inference from their 

 experiments ; for they asserted, that dew never 

 appears on the upper surface of bright metals, 

 whereas the contrary has since been observed 

 by many persons, and I have myself known dew 

 to form on gold, silver, copper, tin, platina, 

 iron, steel, zinc, and lead. Dew, however, * 



* Mem. de 1'Acad. Fran. 1736. 



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