298 



Mr. S. R. Milner on the Beats of 

 Water. 



t. 



v. 



v'. 



U 



b. 



a. 







1-000 



210600 



575-7 



0-838 



7-76 xlO 9 



25 



1-003 



43960 



556-0 



•822 



7-71 



50 



1-012 



12050 



536-0 



•813 



7-66 



75 



1-026 



4102 



5163 



•803 



7-57 



100 



1-043 



1650 



496-5 



•799 



766 



125 



1-062 



755*5 



4770 



•794 



7-72 





Benzene, C 6 H 6 . 



Mol. wt 



. 77-84. 





t. 



V. 



v'. 



u 



b. 



a. 



0-2 



11113 



8141 



100-10 



0-8852 



1-66 xlO 9 



173 



1-1341 



3523 



9696 



•8864 



1-605 



32-0 



1-1544 



1874 



9430 



•8862 



1-614 



484 



1-1784 



1001 



91-32 



•8862 



1-628 



67-0 



1-2070 



538-0 



8001 



•8854 



1-640 



86-4 



1-2382 



304-7 



84-57 



•88% 



1-654 



95-6 



1-2541 



238-3 



82-94 



•8830 



1-666 



110-4 



1-2812 



164-2 



80-39 



•8837 



1-682 



121-6 



1-3037 



126-7 



78-55 



•8848 



1-697 



The latent heats have been calculated from the empirical 

 formulae 



Water . . L,= 606*5 -0'70* - PW~ V ) . 



Benzene' 



L,= 107-05-0-158*- 



pW-v) 



It will be seen that these cases, the only two in which the 

 latent heats have been measured experimentally, give opposite 

 results as regards the constancy of the numbers b and a. In 

 water, while b shows a gradual decrease of about 5 per cent, 

 in 125°, a remains fairly constant; in benzene b seems to 

 remain constant, while a increases. The regularity of the 

 variation of the numbers (such as the fall to a minimum with 

 subsequent increase in a in water) is due to the fact that Lj 

 has been calculated from an empirical formula the constants 

 of which may not be quite accurate. The increase at high 

 temperatures in the value of b for benzene is also due to 

 extrapolating the empirical formula for L t too far. The mea- 

 surements of Griffiths and Marshall extended only up to 40°, 

 so that the constancy of b at higher temperatures may be con- 

 sidered doubtful, since the linear form of their equation may 

 * Griffiths and Marshall, Phil. Mag. January 1896. 



