(Presented in the session of February 6, 1908.)[1]
7. Calculation of quantity H.
In order to express by the variables , we insert the value for from (6) into (13) and obtain
(15)
This partial differential equation assumes a simpler form, when the quantities are chosen instead of as independent variables. Namely, shall be the value of entropy again, when the system is adiabatically brought to rest; of course . Thus we think of as being expressed by entropy and volume; if for example
.
Then it is:
,
because according to (7), is changed by at adiabatic volume change. If we furthermore introduce the variable