610 PROFESSOR KELLAND ON GENERAL DIFFERENTIATION. 



^;=^ (^T^^-- U + -2^+■^)^«^(^ + «) + l2--^-4- 





1 





5 a 2^ 



0^ z 



12 6 ■ 



Which results being substituted in the general formula for the attraction, give 

 attraction = -^ j - 8 « R (a + R) log (« + R) 



+ 8(a' + 3aR + R0 (a + Rloga + R-2R) 



(a + R)/'^±5: logo + R-3R^-a-RR\ 



+ 24(^ logaTR-f R'-l g-^RB^- «-» • R| 



= ^|r(8a^ + 16aR + 8R0 (a + R)-8 (a + R^ "1 x log (a + R) 



-16R(«' + 3aR + R5)+24(a + R)(aR + 2R^) 

 _^R3_24aR^-8a^R I 



TT 



|-16a^R-48aR^-16R' + 24a^R 



4«^ 



R2 4- 24 « R.2 -^ 4S R.s 



3 



+ 48aR^ + 24aR^ + 48R'-5R'-24aR^-8a^R I 



=^{K3>1 



80> 



47rR^ 



d 



