a OY 
stant on the temperature. Led by his relation ef equilibrium (equa- 
tion 11) he pronounced the supposition that for the velocity constant 
an equation would hold of the shape : 
dink A 
aan eA ey eaten apes EAN 
This equation has been repeatedly put to the test in later times, 
generally, however, for reactions in dilute solutions. First of all the 
question suggests itself whether the considerations which have led 
us to equation 6, may also be applied to dilute solutions. Though 
the velocity of 6 for dilute solutions cannot be rigorously proved, 
an application also for these reactions does not seem open to serious 
objections. We have, namely, tested our original equation, by reac- 
tions in dilute solutions in the cited paper; it proved to be able to 
account for the course of reaction, and the reasons which led us to 
the assumption of transitional states, hold unchanged also for reac- 
tions in solution. Accordingly the shape of equation 6 leads us to 
expect that this will be generally valid. Van ’r Horr’s equation 
(equation 11), moreover, holds also for equilibria in dilute solution, 
and it is therefore certainly natural to assume, that the splitting up 
of the value of energy will be essentially the same for all reactions. 
Van ’r Horr’s equation is generally not applied in the form as it is 
given by 14, but in the form which arises when either A or B is 
put zero in 14. The expression which arises by the introduction of 
zero for B has been later defended by Arruenius, and has appea- 
red to be compatible with a great part of the material of facts. If, 
however, one puts B equal to zero in 14, really equation 13 is 
obtained by integration, and all the reaction-velocities which satisfy 
ARRHENIUS’ expression, can therefore be represented with the aid of 
the two constants e7—e, and B of equation 13. Reversely equation 
13 furnishes us also with the possibility of pretty accurately calcu- 
lating the differences of energy, at least if they are not too small; 
the absolute value of the difference of entropy, however, remains 
unknown, because B among others cuntains the unknown constant, 
which accounts for the unity of concentration and time. The above 
considerations, however, suggest that besides the difference of 
entropy B will not contain any constants dependent on the nature 
of the substances. In perfect analogy with the conclusion of § 2 we 
conclude also here that measurement of reaction velocities, at least 
if they have not been very accurately executed cannot decide whether 
the difference of energy and of entropy depends on the temperature. 
I will apply the above considerations in my next paper to a 
series of experimental data from organic chemistry. 
