excited by Evaporation, 233 ; 



this treatment they were cleanfed from their fkins and other 

 foulnefles. 



9. In fix trials with unprepared mufele-fhells, the electro- 

 meter diverged P. three times, onceN.; once the gold-leaf 

 beat the fides of the bottle fo violently, that I could not de- 

 termine; and once it did not diverge at all. As thefe fhells 

 were in the fame Hate as the periwinklc-fbells were in the 

 firft feventeen trials with them, I therefore fuppofe the dif- 

 agreement to arife from the fame caufe. 



to. In nine trials with chalk, I could not find that there 

 was any electricity produced. 



11. In twelve trials with bones, I could not find that there 

 was any electricity produced. 



12. In eight trials with gravel-flones, the electrometer 

 |diverged N. fix times, and twice the gold-leaf beat the 

 fides of the bottle fo violently, that 1 could not determine 

 which ftate was produced. 



13. In five trials with clinkers, the electrometer diverged 

 N. very gradually every time. 



14. In eight trials with ihiall pieces of iron, the electro- 

 meter diverged N. fix times, and twice not at all. 



15. In fix trials with fome nifty nails (that had lain in the 

 earth till they were quite rufted through, and from which I 

 carefully wafhed the dirt, See), the electrometer diverged 

 N. four times, and twice it did not diverge at all. Seeing 

 this rufiy iron did not produce P., agreeably to Cavallo's 

 experiment, I fufpected that, notwithstanding all my care, 

 the nails were not free from foulnefs. I next procured fome 

 flakes of ruft which had fallen from an old anchor, which 

 lies in Perry's dock-yard at Blackwall; and fuppofing thefe 

 flakes to be pure ruft, I expected to find the electrometer 

 diverge P., but in feven trials it was N. every time. 



16. In eleven trials with pieces of fteel-flle, the'electro- 

 meter diverged N. eight times, once P.; once it did not di- 

 verge at all, and once it diverged and clofed again before I 

 could determine which ftate was produced. 



17. In two trials with pieces of china, the electrometer 

 diverged N. both times. 



18. In five trials with flate, the electrometer beat the fides 

 of the bottle violently, with N. every time. 



J 9. A piece of fullers-earth made the electrometer di- 

 verge N. 



20. In eight trials with a copper halfpenny, the electro- 

 meter diverged N. four times, and four times it did not di- 

 verge at all. And in eight trials with a penny piece, it di- 

 verged N. every time, 



Q 4 21. To 



