MR. J. J. WALKER ON THE DIAMETERS OF A PLANE CUBIC. 161 



and if in \fi for xyz are substituted respectively 



30 30 ,30 30 30 ,30 



n =* m - / 5^ n - m ~ - I , 



dy cte d* dc dc . / 



the result may be thrown, if L = Ix -+- rny -j- &z, into the form 





L r r /a^ a^_ / ^_\\ / af a^ ^ a^ \ / a^ a-> a 2 ^ a 2 ^ \ i 

 r o> - 1)- Ll W <>* taw / W^^ ^3^ a^" S^y" h ^S a y a 2 ~a/ a*ar/ " j 



The proof of this theorem depends on the identities 



\fs 



y2 - 



with similar values for 



But (28) 



MDCXXLXXXVin. A. 



