220 



Prof. G. F. Fitzgerald. Clausius's Formula [Mar. 31, 



Pressure. 



2362 



60,000 





0-409 



0-383 





1-417 



1 -3925 





1-008 



1-0095 





At 200° C.— 



Pressure. 



22,434. 



60,000. 





1-003 



0-858 





1-793 



1-720 





0-793 



0-862 





At 240° C— 



Pressure. 



47,500. 



60,000. 





2-166 

 2-468 



1- 641 



2- 169 





0-298 



0-528 





From this it is evident that x diminishes with increased temperature, 

 and increases with increased pressure. 



Notwithstanding this, that Clausius's formula does not at all 

 accurately represent the state of the liquid, there is no doubt that 

 it gives a wonderfully accurate general representation of the more 

 important features of the change of state. In this respect it is of 

 enormously higher value than the formulas that only give the relations 

 connecting the temperature and pressure of saturated vapours. In 

 addition to this, which it certainly gives in a rather complicated way, 

 it gives the state of the liquid and gas before and after as well as 

 during evaporation, and enables us to calculate points on the theoretical 

 continuous isothermal connecting the liquid and gaseous states. I 

 have calculated enough of these points to roughly sketch in these 

 curves that cannot be made the subjects of experimental investigation 



