(173) 
I must, however, point out that this thesis is not of the same 
nature as that proved by Prof. van peR WAALS for the function 
Aer 
p(r) = In this case namely we must be able to find the 
potential in the point in question by a simple multiplication of the 
potential function with a coéfficient, depending on the radius of the 
shell. This is not the case with the general function. 
Every term of the function g(r) must be multiplied with the 
corresponding coefficient, to get the total potential. So it remains a 
superposition of different potentials. 
The problem which I have treated: what must be the form of 
the potential function, by which a spherical shell acts on exterior 
points, as if (leaving a coefficient out of account), the mass was con- 
centrated in the centre, was not discussed. 
The second problem which I have tried to solve, is this. Is there 
a potential function which possesses the property just mentioned, 
while it is constant for a point inside the shell. 
For the potential of a sperical shell at an exterior point we 
have found: 
rt R 
1M 
ae al pp (p) dp p = potential function. 
ZR 
r—R 
For an interior point we should have got : 
itr 
eee (p) d 
ee NS op (4 4 
: mj ro p 
R—r 
If we put {reo dr = w(r), we get 
ve 
2 Rr 
REN. 
The general form for the potential function, fulfilling the first 
condition was: 
Aevr Ber 
+. 
p(r) = gre ts 
r 
A, B, C and g are arbitrary constants. The mass-coefficient depends 
