coulombe’s results further investigated. 
439 
as to reduce the quantity contained on it to one half, and bring it to equality with the 
fixed disc, on the supposition that the plate had abstracted from the sphere one half 
the charge. The new distance of the index from zero was again observed, and the 
two discs again brought into contact, so as to equalize more completely the distri- 
bution between the discs, should any difference exist. Little difference, however, 
was apparent ; hence the assumption that the plate had abstracted one half the elec- 
tricity, was to a certain extent confirmed. Finally, the electrical reactions were ob- 
served at the original distance of 48°. 
This process was repeated in substituting a similar sphere for the circular plate, 
and also a solid sphere of the same diameter. The following results were obtained : 
fxfifz designate the reactions above mentioned, the electrical reaction at the original 
distance of 48° being denoted by f 3 . 
Table VII. 
Reactive force of the instrument T - ir ’ w . 
Reaction at 
48° distance 
before contact. 
Reactions after 
contact of plate. 
Reactions after 
contact of sphere. 
Reactions after 
contact of solid 
sphere. 
fi- 
f* 
/«• 
/l- 
fi- 
fz- 
,/i- 
fz- 
fz- 
o 
48 
39 
22’5 
12 
38 
23 
12 + 
39 
23 
12 
N. 
a 
b 
M 
a ' 
V 
M' 
a u 
b " 
M" 
2 7. It may be observed in this Table, that under whatever corresponding cir- 
cumstances we compare the results after contact with the plate and spheres, whether 
previously to equalizing the electrical state of the discs, as in f l3 or subsequently, as 
in f 2 , or otherwise after the equalization, as at/ 3 , the result is very nearly the same. 
I repeated these inquiries with the electrometer represented in fig. 18*, and found by 
the attractive force of a unit of charge on the suspended neutral plane, that whether 
an electrified sphere was subjected to the contact of a circular plate of equal area, or 
otherwise to the contact of a similar sphere, hollow or solid, the subsequent attractive 
forces were equal, and the quantities abstracted precisely one half the original quan- 
tity with which the first sphere was charged, or very nearly so, taking the square roots 
of the forces to represent the respective quantities. I found also in connecting the 
plate and sphere successively in any point with the fixed ball of the balance, and 
communicating to each the same quantity of electricity by means of a transfer plate, 
charged to a given intensity, that the electrical reactions were the same, as already 
shown (by another method of experiment) in my former paper-f. 
28. Experiment K. — This kind of experiment I further extended to cylinders, hex- 
agonal and other prisms, and bodies of other forms ; and find, as in the cases given 
* Philosophical Transactions for 1834, p. 215. 
f Ibid. pp. 218, 232. 
