666 Mr. W. H. Gibson on Influence of Volume Change 



and 70° C. should agree with the fluidities calculated from 

 the formula 



100 vF = m i v l F 1 + ?>i 2 v 2 F 2 . 



The following table compares Thorpe and Rodger's results 

 with the calculated values: — 



Temp. 



°C. 



Mixture I. 



7763 CC1 4 . 



F 

 found calc. 



Mixture II. 

 5621 C01 4 . 



found calc. 



Mixture III. 



32-29 0C1 4 . 



F 

 found calc. 



10 



100 



1033 



110-2 



1137 



120-2 



122-8 



20 



1176 



120-6 



1290 



133-0 



141-5 



143-6 



30 



1363 



1390 



149-0 



1532 



163-5 



165-5 



40 



1560 



158-7 



171-5 



175-0 



186-6 



189-0 



50 



176-7 



178-9 



1950 



197-2 



211-5 



2130 



60 



199-0 



200-4 



219-5 



220-9 



237-0 



238-3 



70 







243-5 



245-5 



2640 



265-2 ! 



It can be seen that the agreement is fairly good. 



For the same pair of liquids Ramsay and Aston * found 

 that surface tension followed the mixture rule ; and J. von 

 Zawidski f found only a slight deviation of the vapour- 

 pressure curve from the mixture rule, this deviation being- 

 later ascribed to slight association of carbon tetrachloride by 

 Dolezalek { . 



It may be pointed out here, that of the liquid mixtures 

 which give straight-line vapour-pressure curves investigated 

 hj J. von Zawidski, benzene and ethylene dichloride, the only 

 pair for which the Batschinski equation of each liquid is 

 known, have the ^same ratio of v to w, and from that 

 standpoint would be expected to behave normally. 



A second pair of liquids fully investigated by Thorpe and 

 Rodger was methyl iodide and carbon bisulphide. 



Batschinski's formula for methyl iodide is 



v _0-3804 = 0-000284F, 

 and for carbon bisulphide # 



v _0-6642 = 0-000471F. 



* Zeit. Phys. Chem. xv. p. 92 (1894). 

 t Zeit. Phys. Chem. xxxv. p. 129 (1900). 

 X Zeit. Phys. Chem. lxiv. p. 727 (1908). 



