TRANSACTIONS OF THE SECTIONS. 25 
periments with light wheels, and suspended gold leaf, in which this 
appears to be a fact. He adverts to other experimenta crucis, all con- 
curring in his opinion to establish the theory of a single electric fluid, 
- as the movement of a line of water, or saline solution, from the positive 
or vitreous to the negative or resinous pole, as found by Mr. Porret 
and M. de la Rive; and appeals to ordinary experiments in which 
cards are perforated by electrical discharge in confirmation of the same 
view. The theory of a single electric fluid is capable of assuming two 
forms, in which material idio-repulsion is entirely discarded. The one 
form is that of an original theory adopted by Mr. Kennedy in the year 
1825. It was deduced froma rather complicated fluxionary calculation, 
by which a beautifully simple result was obtained. An exponential 
fluxionary equation, involving all the possible powers and simple func- 
tions of the electric force, was employed. The result of the calculation 
was surprisingly simple, namely, that electrical action varies in the 
inverse ratio of the electric quantity ; or, A OC Pv Ices At represent the 
: i 
attraction of a material corpuscle for electricity, in any given electrical 
condition, suppose the neutral state, and g the quantity of electricity 
which that corpuscle then contains. The tendeucy of two material 
corpuscles ¢ ce’ towards each other, may be denoted by T, and is = 2 A'g 
=A'xq+tA!'xq. Now, if the electrical quantities of ¢ and ec! be- 
come each = 2, the attraction of each of these corpuscles for electricity 
! I ! 
will become = ae and T’ will become = “-% x & + dg qg 
x @ 
as before ; that is, the joint tendency of the two corpuscles to mutual 
approach remains unaltered, so long as their electrical quantities are 
equal to each other, whatever each of these electrical quantities may 
be, whether a large quantity or a small. Suppose next, that the elec- 
trical quantity of ec becomes = 2, and that of c' = y, then their re- 
t 
Ag #4; and T will be 
spective attractions for electricity will be and 
t f ! ! 
yi xyt a a or Bray + Alga Now this must be greater 
ra 4g “ yi 
_ than 2 A’ gq, in every case in which z is unequal to y; for if x is un- 
! 
~ equal to y—because A! and q are constant quantities— A'@ ust be 
x 
; F : 
unequal to re *. If abe greater than y, sie! must be greater than 
Z y 
! 
ely, Now 44, Aa" FAB hen Whence,* 1 Y + “eu 
are oN than “ A' q; that is, the least possible value of Tis2 Al q3 
-—in common language, the tendency of the two corpuscles to mutual 
* Kuclid’s Elements, Book v. prop. xxv. 
