506 
Proceedings of the Pioyal Society 
Hence, putting A for a in the integrated result above, we have 
for the potential at cr 
27ra ( aTA_ -aTA\ 
TAV / ° ' 
That this may be constant, = 27 -aY suppose, so long as Tcr'v: a , 
we must have 
(TA)V = yjp £(Tc~ + a)F(Tc~ + a) - (Tc~ - a)F(a - Td~) J ; 
which gives at once 
V = constant = 2, suppose, 
and 
the gravitation law r , 
Fa;= - 
X 
And as the operator becomes, for a, by expansion 
_ __ i 
1.2.3 1.2.3.4.5 j 
2a I 1 - AA, + “ 4A4 
while 
1 
T 
= 0 
<T~ 
we have for the external potential the usual expression 
47T« 2 
5. An Experimental Research on the Antagonism between 
the Actions of Physostigma and Atropia.. By Dr Thomas 
R. Fraser. (With a diagram.) 
(Abstract.') 
In a Preliminary Note, read before this Society on the 31st of 
May 1869 (see Proceedings ), a number of experiments were de¬ 
scribed, which proved that the lethal action of certain doses of 
physostigma can be prevented by the administration of atropia.* 
* June 1871.— While this Abstract is passing through the press, the author 
has received a paper by M. Bourneville, in which the above result is satisfac¬ 
torily coufirmed by experiments on guinea-pigs. 
