54 MR. DANIELL ON VOLTAIC COMBINATIONS. 



a force of the nature of a radiant force, be probably explained by the interference of 

 the rays at points where their directions cross each other. 



Let A B C D represent the sphere and a and h two active points within ; the force 

 radiates from « to c and A and d, and from Z> to e and f and C without interrup- 

 tion. But the rays proceeding from aX,o g and from h to g, encounter one another, 

 and the force would appear to be directed in the diagonal of the two, or from g to 

 B, and in a direction parallel to a c and h c. 



A rod may obviously be considered as a succession of such balls or radiant points, 

 and hence the force would be propagated in a direction at right angles to its axis 

 towards a circumscribing sphere or cylinder. 



Let ah c d represent the radiant points, then will the rays a g and h g interfere 

 at g and pass on to i, iy*and cf to B, and c e, d e to I. Or the same letters may re- 

 present radiant points in a plate A C, the rays of which will thus pass in a parallel 

 direction to the opposite points of a conducting plate D E. 



Without attaching, however, any importance to the geometrical diagrams, I would 

 merely suggest that the resultants of all the radiant points acting from a to d 

 towards D E may be parallel, and that such an hypothesis would account for the 

 phenomena. The demonstration of this, if possible, would go far beyond my power 

 in mathematical science. 



The rays thus supposed to pass between two equal plates become parallel, and 

 hence the decrease of the force will be directly as the distance, as Mr. Snow Harris 

 found it by direct experiment. 



Now nearly the whole of the preceding experiments, except those of the zinc sphere, 

 had been made before I had the pleasure of reading the Eleventh of your Series of 

 Experimental Researches on Electric Induction* ; and 1 had been led to the supposi- 

 tion, which I believe I mentioned to you, that the force which is developed by voltaic 

 combinations might be subject to the law of radiant forces ; but I had been utterly 

 at a loss to understand how, upon this hypothesis, it could extend its influence to the 

 side of a plate opposite to that to which it was directed in right lines ; how, in short 

 (to make use of a term which you have happily employed to describe, what I now 

 believe to be, a perfectly analogous phenomenon), it could ^^ turn a corner''' Since 

 the perusal of that paper, however, everything seems to me to fall in so naturally 

 with the general views which you have therein explained, that I almost feel as if I 

 were intruding upon ground which is properly your own in venturing to apply the laws 

 which you have established of the " Essential and Fundamental Principle of Induc- 

 tion"-}- to the explanation of some of the foregoing results. Supposing my views to be 

 correct, you must have been led to them in the natural course of your investigations ; 

 and nothing in my own opinion could justify my interference in a work which must 

 have been more completely performed by you, but the circumstance that I was led to 

 it by the obvious direction of my own previous inquiries into voltaic combinations. 



* Philosophical Transactions, 1838, p. 1. f Ibid. p. 2. 



