Modified Theory of Gravitation. 101 



gravity on a freely falling body ; and this expression agrees 

 with (64) which was obtained independently of any assump- 

 tion regarding the respective mobilities of positive and 

 negative electrons. 



54. On the other hand, if we were to assume that, while 

 currents of conduction were carried exclusively by the nega- 

 tive electrons, it was the positive electrons alone which were 

 acted upon by gravitational attraction, we should be led to 

 the conclusion that bodies at rest relatively to (say) the earth 

 would acquire no electrical charges through the action of 

 gravity. 



55. Reverting now to the illustrative assumption of § 52, 

 we may attempt to form some idea of the magnitude of the 

 electromotive effects to be expected when the negative elec- 

 trons are supposed to be not only the exclusive carriers of 

 currents of conduction, but also the only objects influenced 

 by gravity. A further assumption is needed as to the total 

 of positive or of negative charges carried by the electrons in 

 unit mass of matter. Let it be assumed, for example, that 

 %=1 (see § 50), so that the negative electrons comprised in 

 one gram of hydrogen (or of other substance) will have an 

 aggregate charge equal to e, the quantity of electricity 

 required to liberate one gram of hydrogen by electrolysis. 

 The expression (66) for the downwardly-directed quasi- 

 electromotive intensity resulting from the direct action of 

 gravity becomes — /x 2 7 2 <v/e, where i^^/ig is the downward 

 force exerted in the earth's gravitational field upon the mass 

 ft 2 of negative electrons comprised in one gram of matter. 

 But under our present assumptions this latter force is simply 

 the weight of one gram of matter, and is equivalent to g ; 

 so that finally the downwardly-directed quasi-electromotive 

 intensity is measured by — g/e. Now e is roughly 10 4 e.m. 

 units of quantity per gram, and g may be taken as about 

 980 cm./sec. 2 ; consequently, for the quasi - electromotive 

 intensity affecting stationary bodies at the earth's surface 

 the estimate obtained is 980 X 10~~ 4 e. m. units of potential 

 per cm., or 9*8 x 10 ~ 10 volt per cm. 



56. On applying the axiom that gravity cannot bo made 

 to furnish an unlimited supply of energy, it is evident that 

 the total gravitational electromotive force round any closed 

 circuit of conducting bodies must vanish, however small may 

 be the conductivity of those bodies ; so that any attempt to 

 detect such electromotive effects galvanometrically must fail. 

 The only methods conceivably available would be those de- 

 pending upon the convection of electric charges by insulated 



