30 Miss D. Marshall on the Heats of Vaporization 



Table III. 



Benzene 



8 



10 



15 



25 min. 



0-416 gr. 

 0-180 



0-543 

 0-227 



0-698 



0-267 



0974 

 0-318 



Alcohol 





The loss of weight is thus seen to be considerable. In 

 order to find how this error affects the calculation of results, 

 it is necessary in each case to estimate the surface loss during 

 the average time of preliminary heating, and to subtract this 

 from the total loss. 



Table IV. shows this preliminary loss for four pairs of 



liquids ; and Table Y. gives the ratio A got directly from 



? 



the measured losses of weight (as given in Table IT.), and the 



ratio obtained by applying the correction. It will be seen' 

 that the alteration is within the limits of experimental error. 



Table IV. 





1 

 t. m. 



Benzene 



CH01 3 



Benzene 



C01 4 



C H.Br 



5 - 5 min. 0-449 gr. 

 5-5 „ 0-580 „ 

 5 „ 0-405 „ 



5 „ 0-523 „ 



1 

 5 „ 0-350 „ 



5 „ 0-535 „ 



1 



C 2 H-I 





§ 6. Two experiments were made to see whether an 

 absolute determination of L might not be obtained by prac- 

 tically the same method. All that was needed was to measure 

 the average strength of the current and the D. P. across the 

 ends of the platinum spiral during boiling. 



The D. P. was easily got on the bridge by comparison with 

 that of a suitable number of Clark cells. 



