888 
1 = 
3 Nn} (ur nite RT, 
by which the transition in question has been accomplished. In what 
follows u? will, however, always simply be written instead of (w,?),, 
with omission of the indices r and » and of the usual mean-value 
dash (the time-average is then denoted by w,*); the real mean 
velocity square wu’, if it should occur, being expressed by (w’). Hence 
we have: 
' 
oo Ce oe nt Be (ome Teel re) 
Starting from the relation (ef. equation (a) on p. 1189 loc. cit.) 
1 1 
ry Nm == Thee u + Nf(l—ao)’, 
in which 5 represents that distance from the centre of the moving 
molecule to that of the molecule supposed stationary, towards which 
it moves, at which the work of the attractive forces reaches its 
maximum value (hence at which the attraction changes into repul- 
sion) — we shall find, after multiplication by */,, for the real mean 
squares of velocity : 
1 1 3 
a Nm lu) == a Nm (u,°) + a N f(l—o)’. 
In this } Von (u,?) = FE represents the total Energy of the system 
(the atom-energies within the molecule being left out of considera- 
tion). Further */, Vm (u,?) = L, is the mean kinetic Energy at the 
neutral point halfway between the two molecules at rest (where 
the attractive forces neutralise each other), ?/, N f(/—o)?= A re- 
presenting the maximum work of the attractive forces. We have 
represented this last quantity by 4, in our first paper, but as this 
way of representation can easily give rise to misunderstanding, we 
shall substitute 4 for #, in what follows. We have therefore: 
Eli AE Ee el 
in which accordingly "DSE SNe te, =| Ne 
Hence in the joint neutral points # — L, + the total potential 
energy of the attractive forces; and in the joint points o in the 
immediate neighbourhood of the molecules, with which the moving 
molecule will impinge, / will be = L, + the total increment of 
the kinetic energy in consequence of the attractive forces. 
The quantity A, therefore, represents the fixed, invariable (poten- 
tial or kinetic) energy of the attractive forces, which rise or fall 
