Modified Theory of Gravitation. 99 



media; such qualities, however, being without any bearing 

 on the problem, so long as on the whole there are no forces 

 tending to displace relatively to one another the positive and 

 the negative electrons which together make up the medium 

 under consideration. 



50. Let yLt l5 /jL 2 denote the masses of the positive and nega- 

 tive electrons respectively, contained in unit mass of matter ; 

 then 



^1 + ^2=1 (63)- 



Also let the total charge of the positive electrons in unit 

 mass of matter be e%, the total charge of the negative elec- 

 trons being accordingly — e% : where e is the quantity of 

 electricity required to liberate one gram of hydrogen elec- 

 trolytically, and x is a numeric. 



Further, in a held of gravity whose intensity is measured 

 by the acceleration / let 



gravitational attraction on mass ^ of positive electrons be fx Y y^f. 

 „ „ „ /jl 2 of 'negative electrons be /*2 72./- 



We then readily find, for a mass moving freely in the field/, 

 that the electrical condition is the same as if an electro- 

 static field were exerted, whose intensity, measured in the 

 same direction as f, is 



(-/*i + /*i7i)//e%=f/*2-^272)//e%; . . (64) 



this equivalent field-intensity being expressed in electro- 

 static or electromagnetic measure, according as e is in 

 electrostatic or electromagnetic measure. 



51. The (single) condition that this quasi-electromotive- 

 intensity should vanish is ry x = 1 = *y 2J in which case the 

 gravitational forces acting on masses fi Y , /jl 2 of positive and 

 negative electrons in a field of intensity/' arc respectively 

 yu-i/, fi 2 f ; that is to say, in the proportion of the masses. As 

 will be seen in Appendix B, the gravitation theory of this 

 paper appears almost certainly to demand that the condition 

 just referred to should be satisfied; but putting that theory for 

 the time being on one side, it is interesting to trace out some 

 consequences of a less restricted view as to the relative 

 behaviour of positive and negative electrons under the action 

 of gravity. 



52. When the body with which we have to deal is not 

 moving freely in a sensibly uniform gravitational field, the 

 corresponding results cannot be written down without making 

 some assumption as to the relative mobility of positive and 

 negative electrons in a conducting or dielectric mass. For 



H2 



