” tf 
Pal 
* 
Prof. Faraday on Electric Conduction. 369 
the bodies in which it occurs; and it is considered as varying 
in degree (7. e. in facility) with the affinities of the constituents 
belonging to these bodies ; there are, however, other cireumstan- 
ces which evidently, and indeed very strongly, affect the readiness 
of transfer, such as temperature, the presence of extraneous mat- 
ters, &c. Conduction proper differs as to facility by degrees so 
far apart, that the quantity of electricity which could pass through 
a hundred miles of one substance, as copper, in an inappreciably 
small portion of time, would require ages to be transmitted 
through the like length of another substance, as shell-lac; and 
yet the copper with its similars offers resistance to conduction; 
and the lac, and its congeners, conduct. 
he progress and necessities of science have rendered it im- 
portant within the last three or four years, and especially at the 
present moment, that the question “ whether an electrolyte has 
any degree of conduction proper” should be closely considered, 
and the experiments which are fitted to probe the question have 
been carried to a very high degree of refinement. Buff,* by 
employing the electric machine, and Wollaston terminals, i. e. 
platinum wires sealed into glass tubes, and having the ends only 
exposed, has decomposed water by a quantity of electricity so 
small that it required four hours to collect gas enough to fil 
little cylinder only one-tenth of an inch in diameter, and the one- 
fth of an inch in length; yet the decomposition was electro- 
lytic and polar; and therefore the conduction was electrolytic 
‘80. When one pole only was in the water, and the other in 
the air over it, still the decomposition, and therefore the conduc- 
Hon, was electrolytic ; for one element appeared at the pole in 
the water, and the other in the air or gas over the water at the 
conduction proper. Many other philosophers have supported, 
ith more or less conviction, the same view, and believe that 
electrolytic conduction extends to, and includes cases, which for- 
merly were supposed to depend upon conduction proper. Sore 
scvances certain experimental results,+ but reserves his opinion 
from being absolute. Von Breda and Logeman adopt the more 
pam View unreservedly.t De la Rive, I think, rep a a 
ery little may perhaps pass by conduction proper, but that elec- 
trolytic edness is he pi fees of electrolytes.$ Matteucci 
has at one time admitted a little conduction proper, but at pr ’ 
I believe, denies that any degree exists. On the other hand, 
Despretz, | Leon Foucault, Masson,** and myself, have always 
admitted the possibility that electrolytes possess a certain amount 
* MS. letter. Annales de Chimie, xlii, 257. t Phil. Mag,, viii, 465. 
Ais de Genéye, ue 134, 144; xxvii, 177. : cone FE tescaed ag 
ee Comp. Rend, XXxvii, 580; ibl. de Geneve, xxiv, 263; xxv, 180; xx t 
** Prize Essay Ty i, 78. 
Sxconp Serizs, Vol. XXI, No. 63.—May, 1856. 47 
