1071 
To find the mean persistence the above expressions for the number 
of collisions have to be multiplied each by the corresponding mean 
persistence, separately for a> and a< bd, then to be integrated 
with respect to 6 between O and oo, further with respect to x, 
in the former case between 1 and oo and in the latter between O 
and 1, and finally to be divided by the total number of collisions : 
A x (m, Jm, ) 
2n,n, O° é 
3 hm. im, 
The result of this somewhat lengthy calculation which need not 
be detailed any further was given above. A corresponding expression 
is found for the 77,-molecules viz. 
ma, 1 m,” V(m, +m. 1) a Vim, 
v, ze Ee + en log EE 
2 (m, — m,) 4 m,'l2 (m,+m, )*/2 Vm, Gi Adel Vin, 
The formulae given before for the coefficient of diffusion are now 
somewhat modified. Qualitatively there is no change, but the com- 
pensation at the limits referred to above is not so complete as 
before. 
For D the same expression holds as before viz. : 
I , 
= ae (as ulder de nu, lbf), 
where /, and /, keep their oe viz 
== . ;: pee m, +m, ia 
W2n, ze, 1 Bie 57 rn + 1,16 ee 1 + = 
Ave 5 
i Sa Me Wan (1 ps 7 ae naal eA mm, 
; nt C . ; oen mm, Ex 
ed BS | Vn (1) 1.x0.406-n,20°| ea Sime ‚| 
and 
, — 5 C k ; m ETR GC 
besl ë | 1-Wen,ns, (14.55 )x0.400—1 20 ye = EE DAAR 
For n,=0O and n, =O we now obtain: 
5 0) g (ea om, ; ie Gs; 1 
Bee 3nzo' hm, (m, 4m.) re 273 16) 
and 
