J 3 J- SAKURAT: DETERMINATION OF THE TEMPERATURE 



solution is not sufficient to overcome the coolino* effect of the walls 

 will best be seen from the following numbers. These refer to a 

 solution of calcium chloride experimented upon in exactly the same 

 manner as before, but witliout introduction of steam from an external 

 source. The acetic acid was also more rapidly distilled. 



In spite of the fact that the solution was boiling briskly with a 

 free and uninterrupted evolution of steam, and in spite of the additional 

 fact that the temperature of the boiling solution rose from 111*9° to 

 125-2°, the temperature of the steam only rose from 103° to 105*1°, and 

 never above that of the acetic acid A'apour in the jacket. The rise 

 that did occur is evidently due to the heating effect of the acetic acid 

 vapour ; for, in this case, the outer surface of the steam-chamber was 

 constantly wet, owing to the condensation of the acetic acid va])our 

 upon it. Acetic acid vapour, Jind not steain, was then acting as the 

 heater. 



This result was so remarkable and apparently so conclusive, that 

 I was for some time induced to believe that the temperature of the 

 steam escaping from a solution of calcium cldoride boiling at the 

 temperature of even 125° is lower than 105^ and probably only 100°. 



