® 
100 On the Generation of Statical Electricity. 
gen; nitrogen, and carbonic acid gases, when thoroughly dry (and 
a vacuum) produced nearly the same amount of electrical action, 
when the same oxidizable or non-oxidizable rubbers were em- 
ployed; hence this result coincides with that obtained by others.* 
The conclusion is therefore adopted, that the electrical machine 
produces its effect entirely by friction. 
The second branch of the subject will now be examined, viz. 
to ascertain what substance is most effective, in generating elec- 
tricity by friction. In the endeavor to attain this point, numer- 
ous experiments were made with various substances: a list of 
some of them is given, arranged according to their effective ac- 
tions. 
1. Bisulphuret of Tin and amal-20. Bismuth. 
- ‘gam. 21. Galena. 
2. Common Amalgan. 22. Talc. 
3. Pure Mercury. 23. Chromate of Iron. 
A. Bisulphuret of Tin. 24. Protoxide of Copper. 
5. Tin foil. 25. Protosulphuret of Mercury. 
6. Zine filings, (fine.) 26. Chromate of Lead. 
‘iP a filings, (fine. ) 27. Protoxide of Bismuth. 
8. Silv 28. Peroxide of Manganese. 
9: Gola. * 29. Peroxide of Mercury. 
10. Platina. /30. Protoxide of Zinc. 
11. Lead. 31. Protoxide of Mercury. 
12. Caoutchouc. 32. Protoxide of 'Tin. 
13. Silk. : 33. Shellac, 
14, Paper. 34, Wax, (no action.) 
15. Leather, (soft.) 35. Tallow, “ 
16. Woolen. (36. Lard, . 
17, Plumbago. 37. Bishfphures of Mercury with 
18. Iron filings. lime, gives negative elec- 
19. Antimony. tricity. 
From the preceding, it appears that bisulphuret of tin rubbed 
over a surface of amalgam, containing but little mercury, is the 
most efficient of all substances employed ; it is, however, inferior 
in value to the common amalgam, on account of its transient ac- 
* Dans la production de l’éléctricité par frottement, l’action de l’air sur les en- 
~ . ou moins enna des frottoi sig “it oe exercer aucune influence sur 
les 4 $s mr 
+S teas. 
