by a Charged Metal Surface. 
439 
supposing a harmonic force acting in the normal direction re- 
sisting any motion of the corpuscles out of the charge layer. 
If we suppose the forces are periodic and vary as we 
have 
? mp 2 ’ 
eY 
V = 
mp 2 
and 
?=- 
mp 1 
a 1 
as far as the external forces are concerned, we shall therefore 
have a flux of ions 
e , etc. 
dt 
And the equations for the charge layer are 
dX _ n'te 2 y _ y fiN dM\ \ 
dt mp \dy dz ) 
dY 
dt 
mp 
nie 2 
mp 
dZ 
dt 
n ce 2 p 
mp 2 — a 2 
dy 
Y - W — _ — 
1 dz dx 
m _ sz 
dx dy 
Z= V 
} 
We have also the magnetic equation 
dU 
dt 
= — V curl E. 
If we suppose the forces vary as 
qi (lx+my+nz+pt) 
X { P ~‘mp) = V( - mN ~ nM) 
01 ^ P^\ 
X = V(nL -IN) 
we have 
(p- 
(p- 
mp) 
ne 2 
mp 2 - 
V ( IM — mL) 
•(i). 
and (L, M,N) = - ( mZ-nY , nX - IZ, lY-mX). 
We have therefore 
ZLl =0 
XLX = 0 
.( 2 ). 
