1 38 Mr. Faraday on Electric Conduction 



part of it, cannot conduqt, because a non-conducting body 

 (a resin) intervenes and separates them one from another, like 

 the supposed space in the lac. 



Next take the case of a metal, platinum or potassium, con- 

 stituted, according to the atomic theory, in the same manner. 

 The metal is a conductor ; but how can this be, except space be 

 a conductor? for it is the only continuous part of the metal, 

 and the atoms not only do not touch (by the theory), but as we 

 shall see presently, must be assumed to be a considerable way 

 apart. Space therefore must be a conductor, or else the 

 metals could not conduct, but would be in the situation of the 

 black sealing-wax referred to a little while ago. 



But if space be a conductor, how then can shell-lac, sulphur, 

 &c. insulate? for space permeates them in every direction. 

 Or if space be an insulator, how can a metal or other similar 

 body conduct? 



It would seem, therefore, that in accepting the ordinary 

 atomic theory, space may be proved to be a non-conductor in 

 non-conducting bodies, and a conductor in conducting bodies, 

 but the reasoning ends in this, a subversion of that theory alto- 

 gether ; for if space be an insulator it cannot exist in conduct- 

 ing bodies, and if it be a conductor it cannot exist in insula- 

 ting bodies. Any ground of reasoning which tends to such 

 conclusions as these must in itself be false. 



In connexion with such conclusions we may consider 

 shortly what are the probabilities that present themselves to 

 the mind, if the extension of the atomic theory which chemists 

 have imagined, be applied in conjunction with the conducting 

 powers of metals. If the specific gravity of the metals be di- 

 vided by the atomic numbers, it gives us the number of atoms, 

 upon the hypothesis, in equal bulks of the metals. In the fol- 

 lowing table the first column of figures expresses nearly the 

 number of atoms in, and the second column of figures the 

 conducting power of, equal volumes of the metals named. 

 Atoms. Conducting power. 



1-00 gold 6-00 



1-00 silver 4-66 



1-12 lead 0-52 



1-30 tin 1-00 



2-20 platinum ... 1*04 



2-27 zinc 1*80 



2-87 copper 6'33 



2-90 iron 100 



So here iron, which contains the greatest number of atoms 

 in a given bulk, is the worst conductor excepting one. Gold, 

 which contains the fewest, is nearly the best conductor; not 



