558 Intelligence and Miscellaneous Articles. 



perty distinct from conductibility ; but yet it is easy to see that the 

 assumption of this new property may be dispensed with, if it be 

 assumed that at least one of the dielectrics offers a certain hetero- 

 geneity of composition or of structure. If we conceive, on the one 

 part, a homogeneous dielectric endowed with a feebly, and on the 

 other hand a dielectric composed of a perfectly insulating mass, in 

 the midst of which are fragments of another perfectly conducting 

 substance, it is easy to see that the second dielectric might exceed 

 the first when the duration of the charges was sufficiently small, and 

 that, on the contrary, the homogeneous dielectric might preponderate 

 when the charges are sufficiently prolonged. 



This influence of heterogeneity I have been able to demonstrate by 

 means of two cakes of flour of sulphur of the same size, one contain- 

 ing a small quantity of water, and the other a somewhat larger one 

 of olive oil. Compared in the same manner as solid discs, I found 

 that the disc containing water gave a charge almost double that of 

 the other when the duration was only a fraction of a second, but 

 that when the duration was some minutes, the cake impregnated with 

 oil gave the greater charge. 



Is it now possible to attribute to sulphur such a heterogeneous 

 structure as I describe ? The researches of MM. Regnault, Ch. De- 

 ville, and Berthelot have shown us that this body may undergo 

 various modifications ; and it appears natural to assume that its elec- 

 trical properties may vary at the same time as its other properties. 

 With specimens of amorphous sulphur and of octahedral sulphur I 

 constructed pulverulent cakes which I investigated in the usual man- 

 ner, and I found that the quantity accumulated by the octahedral 

 sulphur- condenser increases with the duration of the charge, and for 

 even very small durations is greater than the quantity accumulated 

 by an air- condenser of the same dimensions. The charge of a con- 

 denser constructed of amorphous sulphur does not vary with the time, 

 and is exactly equal to the charge of an air-condenser of the same 

 dimensions. 



In short, all my investigations on these subjects lead me to believe 

 that they would all be affected in the same way by electrical influ- 

 ence if they could be completely deprived of their conductibility. 

 Hence I think Mr. Faraday's theory must be modified in one point. 

 According to the views of this illustrious physicist, induction and 

 conduction are only the two extreme terms of the same mode of pro- 

 pagation, which in all cases is effected by the intervention of the ma- 

 terial molecules. But it seemed to me quite established by my pre- 

 ceding researches, that the mathematical laws of transmission are the 

 same in the cases of induction and of conduction ; but it does not 

 therefore follow that these two modes of propagation take place in 

 the same medium. It appears probable, on the contrary, that elec- 

 tricity, like heat, may be propagated by the intervention of the aether 

 as well as by the intervention of ponderable matter ; and I am led to 

 believe that influence or induction takes place by the first of these 

 two ways, while conduction employs the second. — Comptes Rendus, 

 April 20, 1863. 



