( 773 ) 



the method of least squares has been a j >; >licd directly to the indivi- 

 dual isotherms, iii order to obtain ;i formula which represents the 

 observations as accurately as possible. 



The number of points on each isotherm not being large enough 

 for all six coefficients to be determined ai once, definite values were 

 assumed for the last three values. Fa was put = 0, and values 

 were calculated for I)\ and Ea from the sets of coefficients VII.l *), 

 which was chosen instead of V of Comm. N°. 71. This assumption 

 means, that a definite course was prescribed for the isotherms at 

 higher densities, which corresponds as closely as possible to the 

 law of the corresponding states. The results of these calculations are 

 laid down in the subjoined table. Da and Ea are the values assumed 

 for the calculation according to the above. 



It appears from the table, that the coefficients of the same column 

 varv regularly with the temperature, except for — 135°. 71, for which 

 we may account by taking into consideration that the two piezo- 

 meter-determinations which had to be used for the calculation, lie 

 so close together, that a slight difference in their relative situation 

 already produces a large difference in B'a and C'a- 



By the aid of the coefficients the values of pvA were determined 

 anew according to formula (1). The divergencies for every isotherm 

 between the assumed values of pvA, Wi and the //„, calculated with 

 . I ' i, B'a and C'a Q>''a = 1 for and 760 mm.), where i indicates 

 the number of that observation in table XII, have been represented 

 in the subjoined table. 



) For Ihe calculation of Da and Ea the uncorrected reading of the hydrogen 

 thermometer was used {sec preceding note . 



