262 Mr Wilson, On the Hall Effect in Oases 



But i = Xne (k x + h) 



ra HX 

 Therefore / = aeX {h + k 2 ) e A e ^ ' dz 



Jo 



2(3aee A , ~"cfc,+W« ,, 



Hence J. = log ^ ; 



2/Sae {e 2/3 - 1} 



i -ff^Y ,. , s , IH 

 ■•• lo g « = "So (^ + k) z + lo g " — ffx - • 



2/3 ae {€ w * — 1} 



Thus as we move across the tube log n increases uniformly 

 with z. If n Y is the value of n at z x and n. 2 at z 2 , then 



logJ = C(^-^), 



where = --^ (k x + k 2 ). 



Thus if Wj and w 2 denote the values of % at £ and .£" respec- 



tively we see that log— 1 increases proportionally to H. If there- 



n% 



fore there were an appreciable charge on E or E' due to the 

 negative ions diffusing more rapidly than the positive ions, as 

 explained above, then the Hall effect could not have been found 

 proportional to the magnetic field. 



Substituting the values of Z and X found experimentally in 

 the formula 



Z=\HX{h-h), 



„ 00248# . ^ nAn , 

 we get, since Z = and X = 349 yp, 



2Z 



k 2 -k 1 = jtv = 1-42 x lO- 3 ^- 1 " 5 . 



This must be multiplied by 10 8 to get k 2 — k x in cms. per 

 second, so that finally 



k i -k l = V4& x 10 5 _p- 15 . 



