260 Proceedings of the Royal Physical Society. ^ 
same order as r^, and since <pT^ h^ is two dimensions in 
lower than -vl/r^, we must retain terms of the form '2{(pr^ /i^'"}, 
&C.5 to the fifth order in \ \ l^ . 
Also, since the particles of ether are symmetrically 
arranged, if fr be any function of r, m 2{/r h^ Tc'i V'} vanishes, 
unless p qr are all even, and then its value is the same in 
whatever manner p qrhQ interchanged. Hence from (7) 
and (10) we find 
d^u 
dy' 
Put K = ^ 2 I (pr^ 7^1* I 
Then it can be easily shown that 
And let ^ 2 -v^r, = &c =8. 
Then equation (11) becomes 
dx^ ^ dx 
-(m.s)S.(K.s)5.(B.s)Sm 
Similarly it may be shown that 
And ^t-. = <.VV^.OS = ^^£--(l^) 
Also by (8) and (9) 
t = t = « a^) 
