of the Electrical Terms Intensity and Tension, 507 



in the other, there would be a greater number of points in the 

 large sphere for the reception of the charge. 



Let the surfaces, for example, be as 3 to 1 ; then where there 

 is one particle on a point of the large sphere, there will be three 

 on a point of the smaller sphere. Here, again, intensity, when 

 correctly interpreted, is nothing more nor less than the quantity 

 of electrical force at a given point. It by no means follows, 

 however, that in this case the agency in operation has a higher 

 amount of elastic power in the one case than in the other, or is 

 necessarily more or less dense : if it exhihits a greater degree of 

 energy in any given point of the one body than it exhibits in 

 any given point of the other, it may be because there is a greater 

 amount of mere force, in operation in that point. We really can- 

 not say, until we have a clear conception of the nature of elec- 

 trical force, whether it is susceptible of change in quality or con* 

 stitution or not ; and any inference, therefore, of a change in elec- 

 trical density or tension must be mere assumption. The idea of 

 a difference of density in the two cases of the small sphere and 

 the large one (figs. 4 & 5), supposing the electrical agency to 

 be material and subject to the laws of ordinary matter, is cer- 

 tainly in accordance with the deduction that, " where there is one 

 particle of force acting in a given point of the large sphere, there 

 are three particles in a given point of the small sphere." So far 

 this corresponds with the theory of density, or, as better ex- 

 pressed perhaps by the French philosophers, with " thickness of 

 stratum;" but, as already observed, since we have no know- 

 ledge whatever of the occult nature of the electrical agency, 

 we can scarcely venture to rely upon any hypothesis of this 

 kind, but must be content to consider electricity as mere 

 force, without assigning to it any specific elementary condition — 

 much in the same way as we accept gravity as a mere force, with- 

 out troubling ourselves as to its occult nature. 



6. It follows from this that there is no such element as inten- 

 sity independent of quantity, and that what we are to under- 

 stand by intensity is only the greater or less quantity of force 

 in a given point operating on the electrometer. We accord- 

 ingly find that what is called intensity, as indicated by the elec- 

 trometer, is subject to all the laws of quantity. It is in this 

 sense I propose the term intensity to be accepted — an accepta- 

 tion which frees it from all mysterious and hypothetical uncer- 

 tainty whatever. 



7. In considering the term intensity as applied to a charged 

 electrical jar, similar considerations present themselves. The 

 electrical jar is simply an electrical condenser upon VohVs prin- 

 ciple. We have here an insulated conductor (that is, the inner 

 coating) in close approximation to a similar conductor (the outer 



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