218 



G. HABKER. 



THE TEMPERATURE OP THE VAPOUR ARISING^ 

 FROM BOILING SALINE SOLUTIONS. 



By George Harker, d.sc. 



[Read before the Royal Society of N. 8. Wales, December 1, 1920.'] 



The temperature of the vapour arising from a boiling 

 solution lias been the subject of much dispute, and even 

 now different opinions appear to be held. Some think that 

 the temperature is substantially the same as that of the 

 solution, others that it is the same as that of the vapour 

 from pure water boiling under the same pressure. 



Sakurai in his paper "Determination of the Temperature 

 of Steam arising from Boiling Salt Solutions," 1 has given 

 a brief historical summary of the views held and the 

 experimental work carried out up to that time. From this 

 it appears that Faraday was the first in 1822 to publish a 

 paper bearing on the question. He found that when the 

 bulb of a thermometer was sprinkled over with a salt and 

 then introduced into steam coming from boiling water, the 

 thermometer showed a higher temperature than 100°. From 

 these experiments Faraday concluded that since a salt 

 solution was heated up to its boiling point by the action of 

 steam at 100° (a fact which was evidently known at that 

 time) the steam generated from a boiling salt solution had 

 only the temperature of 100°. Gay-Lussac on theoretical 

 grounds disagreed with this view as he considered that the 

 vapour must have the same temperature as the liquid with 

 which it is in contact. Faraday then published another 

 paper in which he stated that he had proved Gay-Lussac's 

 assertion to be correct, but that in order to do so he had 



1 Journ. Chem. Soc, 1892, 61, 495. 



