On Material Molecules and the Etherial Medium. 265 

 Differentiating equations (23) we get 



d 2 u 4^ „ . "2at n , ,v 



-^g- = ^- v 2 a sin — (6; + my + nz - vt) 



4** 2 



x 2 

 i* 2 



d 2, io 



&c. &c. 



dt* ~ x' 



dht' 4cr 2 l/2 , 



dx 2 x' 2 

 &c. &c. 



Hence substituting in any of the equations (21) we 



naVe 2 2 



tftt = A(/ 2 + m 3 + n 2 ) + P^« - P^w' 

 + ~ (AT 2 + BW 2 + CV 2 ) u[ 



= { § (AT 2 + BV + CV 2 ) - P^ 2 } * • ■ (24) 



Similarly from equations (22) 



| ?/ 2 - (FT 2 + G'm' 2 + HV 2 ) - P'^ 2 } 



I ={? F - F £}« • • • • ^ 



Multiply the right and left hand sides respectively of (24) 

 and (25), and divide by uu\ and we have 



L* _ a — P~) | i/ 2 - (FT 2 + GW 2 + RW 2 )- P— | 



= - P'*l) | AT 2 + BV + C',,'' - | (20) 

 Let us neglect the terms containing X- and x" J , which are 



