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 em., 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? 
