( 220 ) 



The temperature corrections have been borrowed from the graphical 

 representation derived in Comm. N°. 68 from Amagat's determina- 

 tions. The uncertainty which still prevails with respect to the 

 correct course of the isotherms in the neighbourhood of the critical 

 state is, of course, also found in these corrections. 



The rather rapid process of the heating from 28° to 35° prevents 

 further that the whole apparatus has already assumed the temperature 

 of the waterbalh, so that also the observed differences of temperature 

 themselves are not quite Certain. 



In the following series of determinations we proceeded in the 

 same way till the 12 th opening (the 6 th at constant temperature). 

 It was put off for 3 hours. When the cock was opened the course 

 of the deviations of the galvanometer appeared to be the same as 

 in the preceding series; the remaining temperature corrections, 

 however, were somewhat smaller than in the 1 st series, which we 

 ascribe to this that all parts of the apparatus have had time to 

 assume the temperature of the waterbath. An increase of pressure 

 in the lower reservoir, which should have been found when e. g. 

 in this lower reservoir molecules were dissociated during these three 

 hours (see § 1, p. 216 footnote 2), and which should have given rise 

 to a greater galvanometer deviation when the cock was opened for 

 the last time, could not be traced. We found : 



SERIES II. 



In virtue of what the preceding determinations had taught us 

 as to the reaching of equilibrium of temperature and pressure the 

 cock was opened 12 times 12 seconds in a following determination, 

 and finally two more determinations were made in which the cock 

 was opened 12 times 4 seconds and at last once five minutes. We 

 found : 



