and the Properties of Liquids. 



values of L we obtain 



t T /3T 2 



575 



Pi 



, /., al /3±* \ 



+ /o 3 = A;/3 c ( 1+ Y + Tj + " I 



where k is a numerical constant. If the terms containing 

 higher powers of T than the first be omitted, the equation 

 expresses what is known as Cailletet and Matbias 5 linear 

 diameter law. This law agrees well with the facts. The 

 nature of the constants in the equation, it may be pointed 

 out, are the same as would be obtained by applying the 

 equation to the critical and the absolute zero of temperature. 

 We have thus another simple equation lor the internal heat 

 of evaporation, viz., 



L=c- 2 ( / , 1 - P2 )(l+^)(^I>. 

 According to this equation — — — is proportional to 



(V^ 1/3 



for all liquids at corresponding states. That this is the case is 



shown by Table III., which contains the values of for 



J Pi-P* 



Table III. 





L. 



W?«, 



Pc 



L 



<£? {s v^yo7n. 



P1-P2 



Ether 



75-44 



39-87 

 81-73 

 92-85 



65-88 



27-84 

 27-30 

 26-76 

 18-92 

 31-72 



•2604 

 •5576 

 •3045 



•3489 

 •3654 



110-0 122-8 



27'9 27-6 



103-7 ! 1059 



1 

 1C0-3 1 92-2 



69-0 ! fi*7-3 



Carbon tetrachloride. 



Methyl formate 









2T 

 temperatures of ~ obtained from the values of L calculated 

 o 



by Mills*, and the values of (^™i)V' 2 ) multiplied by 5711. 



The agreement between the two sets of values is fairly good. 



* Journ. of Phys. Chem. vol. viii. p. 405 -(1904). 



