122 On the Ekctricity of Metallic Subs tances, 



Metals which acquire resinous Electricitj/, 



Platina. 



Gold. 



Tin. 



Antimony. 



Gvav Copper, stronc^. 



Sulphurated copper, vStrong. 



Pyritouo copper, strong. 



Sulphurated lead. 



Telluiium of Nac;yacr, strono', 

 « • • I -1 ° ° 



Antimonial silver. 



Sulphurated silver, strong. 



Nickel. 



Gray cobalt. 



Arsenical cobalt. 



Sulphurated antimony. 



Sulphurated iron. 



Oxydulous iron. 

 In proofs in regard to silver, copper, and other metals, 

 found in a native state, I operated on fragments which were 

 in that state, and on others arising from the fusion of these 

 metals. 



I repeated my experiments a great number of times, and 

 almost always obtained the same results; oxydulous iron 

 and oligist iron alone exhibited anomalies bv acquiiing, 

 imder certain circumstances^ an electricity different frem that 

 indicated in the table. 



Steel, which in general acquires vitreous electricity, gave 

 also some exceptions, arising in all probability from a dif- 

 ference in the quantity of carbon united to the iron, or 

 perhaps in the effect of the temper. Those habituated to 

 electric experiments know that the faculty of acquiring one 

 kind of electricity rather than another, by the help of fric- 

 tion, differs sometimes by such slight shades that they escape 

 the most attentive observer. 



If the two parts of the above table be compared, it will 

 be observed that metallic substances, which ha^-e the same 

 aspect, differ from each other iu the results of electrisation. 

 From these results one will be able to avoid confounding 

 tiilver with platina; !:he same kind of silver wilh antimo- 

 nial silver, native copper with pvritous copper, oligist iron 

 with gray copper, &c., all the fjrst substances giving signs 

 of vitreous electricity wheu they have been rubbed, while 

 a)' the second manifest the contrary clectricitv. 



There 



