226 G. HARKER. 



The admission of steam only raised the temperature from 

 103*2° to 103*6°. It immediately began to fall owing to 

 dilution of the solution. The bunsen flame was then 

 removed, and witli it the condenser, in order to prevent 

 too rapid dilution of the solution. The vapour arising from 

 the solution still remained well above the temperature of 

 100° 0. Its temperature gradually fell but that this was 

 due to the dilution of the solution was proved by shutting 

 off the steam, replacing the condenser, and boiling again 

 by the bunsen flame. In a few minutes the thermometers 

 A and B showed the same readings as were obtained just 

 before the steam was shut off. This experiment was of 

 interest, because it showed that the bunsen flame was not 

 causing superheating. 



The results obtained prove that the vapour arising from 

 a boiling solution has a higher temperature than the vapour 

 from the boiling pure solvent. Since in these experiments 

 the vapour was cooled after it left the solution, there can 

 be little room for doubt but that it leaves the solution at 

 the same temperature as the boiling solution itself. It is 

 therefore steam in ah unsaturated condition. 



