82 Galvanism, from Galvani to Ohm. 



enable them to act upon each other. It appears, therefore, 

 that heat possesses the property of augmenting the polarity of 

 these bodies." 



Berzelius accounted for Volta's electromotive series by 

 assuming the electrification at one pole of an atom to be some- 

 what more or somewhat less than what would be required to 

 neutralize the charge at the other pole. Thus each atom would 

 possess a certain net or residual charge, which might be of 

 either sign ; and the order of the elements in Volta's series 

 could be interpreted simply as the order in which they would 

 stand when ranged according to the magnitude of this residual 

 charge. As we shall see, this conception was afterwards 

 overthrown by Faraday. 



Berzelius permitted himself to publish some speculations on 

 the nature of heat and electricity, which bring vividly before 

 us the outlook of an able thinker in the first quarter of the 

 nineteenth century. The great question, he says, is whether 

 v the electricities and caloric are matter or merely phenomena. 

 If the title of matter is to be granted only to such things as 

 are ponderable, then these problematic entities are certainly 

 not matter ; but thus to narrow the application of the term is, 

 he believes, a mistake; and he inclines to the opinion that 

 caloric is truly matter, possessing chemical affinities without 

 obeying the law of gravitation, and that light and all radiations 

 consist in modes of propagating such matter. This conclusion 

 makes it easier to decide regarding electricity. " From 

 the relation which exists between caloric and the electricities," 

 he remarks, "it is clear that what may be true with regard 

 to the materiality of one of them must also be true with 

 regard to that of the other. There are, however, a quantity 

 of phenomena produced by electricity which do not admit of 

 explanation without admitting at the same time that electricity 

 is matter. Electricity, for instance, very often detaches 

 everything which covers the surface of those bodies which 

 conduct it. It, indeed, passes through conductors without 

 leaving any trace of its passage ; but it penetrates non-con- 



