440 K. Tsuruta on some Thermal Properties of 



pressure p, and q denotes the difference of mercury-levels in 

 the manometer and the tuhe containing the mixture. Vj was 

 not given by Andrews, so that I must proceed in the inverse 

 manner to deduce V, horn p according to the above formula. 

 q/760 is an unknown factor ; but inasmuch as Andrews 

 mentions in his first Bakerian Lecture that the difference 

 rarely exceeded 200 mm., a correction arising from this is so 

 small that it can be safely neglected. For example, since 



Vj_l at- q 



V ~>" + > + 760xp 2, 



taking the greatest possible value, 200 mm., for q, and the 

 least possible value, 40 atmospheres, for p, we have 



0*000164. 



760 xf 



Thus I get the values of V l5 which w 7 ill not perhaps much 

 differ from the directly observed ones. 



We are now able to calculate the corrections for the mano- 

 metric readings by applying the Clausius' form of cha- 

 racteristic equation for hydrogen with the values of the 

 constants determined by Sarrau * based on the data supplied 

 by Amagat's classical research — 



11=0-003665, K = 0-0551, a=0'000889, 



£= -0-00043. 



I have myself found that these values are very good, not only 

 in the few instances given by Sarrau, but also throughout. 



Although I was satisfied so far, yet I was anxious to extend 

 the verification to the temperatures of our manometer, 7°'2, 

 7°-4, 12°-0, 12°- 8, the temperature-range in Am agates in- 

 vestigation being from 30° to 100°. Wroblewski's post- 

 humous paper f on the compressibility of hydrogen was the 

 only one available for me. I give below so much as is 

 thought sufficient of my results of comparison : — 



* Comptes Rendus, xciv. (1882). 



t "Wiener Sitzungsbericht, Bd.'xcvii. (1888). 



