118 G. E. Lineharger — Apparatus for the Rapid 



_ a'hs{l+l3s') 

 "'~ h's'(l+l3s)' 

 he obtained therefrom on putting 



h's' ~ ' , 



As 

 a = C 



l+/3s ' 

 and substituting for specific gravity =s, the specific volume 



= V = — , he finally obtained 



h 



a = C 



V+/3' 



an equation used throughout his work in transforming his 

 results. 



It is hardly necessary to mention that the degree of accuracy 

 which can be attributed to an indirect method of measuring a 

 physical constant of Nature depends upon the accuracy of the 

 results obtained by direct methods ; hence, the importance of 

 choosing the most exact directly determined data for the cali- 

 bration of an indirect method. Ramsay and Shields * have 

 elaborated the method of measuring the heights to which 

 liquids rise in capillary tubes, and have carried out series of 

 determinations of the capillary constants of various liquids in 

 contact only with their own vapor and glass, which are justly 

 regarded as of the greatest trustworthiness, and may be confi- 

 dently taken as standards. 



If Jager's equation, 



a(l ■i-/3s) _ hs 



be correct, it ought to be possible to obtain the same value of 

 fi, when the data for a and a\ s and s^, and A and A' are taken 

 for any pair of liquids. On carrying out the calculations, how- 

 ever, I found that the values of $ varied considerably for 

 different pairs of liquids, when the data given by Ramsay and 

 Shields (loc. cit.) were taken for the specific gravities and 

 capillary contents, and the readings of my apparatus for the 

 differences of level between the extremities of the two capil- 

 lary tubes. Furthermore, it was found that, if and c be 

 calculated for any two liquids, and then from the equation 



As 

 a = c zz- 



* Zeitschr. f. phys. Chem., xii, p. 433, 1893. 



