546 
Proceedings of Poyal Society of Edinburgh. [sess. 
and this is seen to be the product of two determinants which both 
vanish, viz., the determinants 
1 
1 
0 
Pi 
PiK 
.PiV 
*1 
\ 2 
0 
and 
P 2 
P2^2 
V 
V 
0 
0 
0 
0 
so that to say that the persymmetric determinant of the s’s 
vanishes is the same as to say that 
1 1 0 2 
\ \ 2 0 
V V o 
PiP* 
= 0. 
