188 



Prof. W. Ramsay and Miss E. Aston. [June 14, 



II. Benzene and Carbon Tetrachloride. 



(a.) 1C 8 H 6 to 1CC1 4 . 



Similar experiments were made with the above mixture ; the 

 densities of the mixture were determined experimentally, and a com- 

 parison is given at each temperature of the numbers found, with the 

 mean density of the mixture, calculated from the found densities of 

 the components. The loss of weight on sealing showed that 4"5 per 

 cent, of the mixture had evaporated ; but here, too, the boiling points 

 of benzene and of carbon tetrachloride are so near that it is probable 

 that no important change in composition occurred. 



1C 6 H 6 to 1CCU. 



The calculated values of Ji are the means of the heights of benzene 

 and carbon tetrachloride at the respective temperatures. It is to 

 be noticed that the observed heights are widely different. But, 

 owing to the different densities of the two liquids, the calculated 

 values of 7, the surface-tensions, are nearly the means of those of each 

 taken singly ; and the agreement of the found and calculated molecu- 

 lar surface-energy, <y(Mv) il , is also a close one. The value of Jc 

 exaggerates the error of experiment, yet, on the whole, the agree- 

 ment is satisfactory. It would also appear that the operation of 

 mixing does not affect the density of either liquid appreciably. 



(I) and (c). The tables which follow show the effect of varying 

 the relative proportions : 



(6.) 10C 6 H 6 to 17CC1 4 . 



