70 Trans. Acad. Sci. of St. Louis. 



The phenomena which have been discussed in this and 

 the former paper have suggested the idea, that the 

 amount of electricity that can be pumped out of a body 

 in normal condition and at zero potential is not neces- 

 sarily equal to the amount that can be forced into or 

 upon it. This statement may perhaps correspond to the 

 statement that when a boiler is full of water, more water 

 can be pumped out of it, than can be forced into it. 



A large attracted disk electrometer was constructed of 

 sheet copper. The guard-plate which had a diameter of 

 nearly two meters was hung from the ceiling on four silk 

 cords, and faced a grounded plate of equal diameter. 

 The attracted disk had a diameter of about 20 cm., and 

 was hung on silk cords from a long and light balance 

 beam of wood turning on two needle points. The appar- 

 atus was surrounded by a grounded screen of galvanized 

 wire netting. The scale-pan carrying the weights was 

 just outside of the screen. When the negative terminal 

 of the influence machine was grounded, and the positive 

 terminal was connected with the attracted disk, the 

 attraction was about 20 per cent, greater than when the 

 reverse connections were made. The results of this paper 

 and of the previous one seem to make it doubtful whether 

 this is to be accounted for as due to unsymmetric leakage 

 through the ionized air between the large plates. It 

 seems probable that this difference in the conditions ex- 

 isting in the two cases tends to diminish the observed 

 effect. Apparatus of greater precision is being pre- 

 pared for a further examination of this effect. 



Again assume two equal spheres to be charged to 

 potentials +V and — V. Surround them by concentric 

 spherical shells which are insulated. If shell and sphere 

 are in each case put into contact, we have been accus- 

 tomed to say that the charges on the two spheres go to 

 the shells. If the one-fluid theory is to be adopted, we 

 must suppose that Franklin's fluid flows from the shell 

 to the positively charged sphere which it surrounds. May 

 we not properly expect a dissymmetry in these two cases? 



