218 Prof. G. F. Fitzgerald. Clausiuss Formula [Mar. 31, 



n c = 5- w c = w c = 2 7 . 



I have assumed as the result of observation that T c = 516*5 and 

 P c = 49,000 mm. This latter value is probably a little too large, but, 

 as there seems some uncertainty as to its value from the experiments, 

 from which it is very difficult to approximate accurately to the actual 

 position of the critical point, I have thought this value sufficiently 

 accurate. I have calculated the result of making changes in this 

 value, and any variation within limits allowable by the experiments 

 does not materially affect my results. 



The values of these constants for alcohol as determined from the 

 observations are — 



1351-35 

 516-5 

 49,000 



1-780 

 3-560 



0-07023 



0-1664 



0- 9118 



1- 3462 



I have found that constant values for « and ft do not satisfy the 

 observations accurately, and that a varies from 1*087 at 0° C. to 

 0*184 at 240° C, as I explain further on. I calculated b and n so as 

 to make the saturated vapour- tensions correct at 0° C. and 100° C. 

 The process of calculation I adopted was to calculate 11/11, at 0°C.and 

 100° C, and then from Clausius's tables obtain the corresponding 

 values of 0/9 c . This gave two equations, to determine b and n by 

 means of c /0 = (1 + 6)(T C /T) W — b. The equation for n being— 



This was solved by trial and error and then b calculated. Having 

 determined b and n, the value of 0/0 c for any temperature may be 

 easily calculated, and thence the corresponding values of Il/lTc, W/W c , 



W c — w c 



T c 



: ry : 

 : 2 7 : 

 1_ 

 87 



8 

 27 7 



b 



n — 



