Metallic Bodies by Voltaic Electricity. 

 ''\ TABLE IV. 



219 



It may be observed, by reference to the above Table, that 

 the smallest copper- wire, No. 4, as compared with the largest, 

 No. 1, indicated a conducting power in the ratio of its diameter. 

 The same is observable on comparing No. 2. and No. 3. together, 

 whilst the conducting power, indicated with the copper-wires, 

 No. 1. and No. 2, seemed for the particular charge employed to 

 be the same ; hence these wires transmitted the force in action 

 equally well, the differences in the respective quantities of metal, 

 therefore, did not become apparent. On the contrary, the wires 

 of the less perfect conductors, platinum and lead, Nos. 1, 2, and 

 3, indicated a conducting power exactly in the ratio of their dia- 

 meters, or very nearly so, whilst the indications with the smallest 

 wires of these metals, No. 4, were inconsiderable. 



18. (k) The deductions arrived at, on examining in this way 

 the conducting power of various metals, were as follows : 



1st, That, for certain and given small forces, the differences 

 in the conducting powers vanish, each metal being equally effi- 

 cient ; a result quite consistent with that already arrived at in 

 the preceding section (17), with the copper wires, Nos. 1. and 2. 



2rf, The differences in the conducting powers become more 

 apparent, within a certain limit, as the force of the battery in- 

 creases, the exact proportions in which the differences increase 

 with the increased power, I could not correctly ascertain. 



