OF ETHER FROM OILS. 



275 



Chart V. shows the effect of increased surface on the rate of 

 evaporation. One oil only was selected to show the principle, which 

 is : the rate of evaporation bears a direct ratio to the surface exposed. 



These experiments were made in glass, hence they do not dis- 

 close all the factors in the conduct of such mixtures in contact with 

 the walls of the colon, for there the principles of osmosis and dif- 

 fusion are involved. But these observations demonstrated several 

 striking- facts : 



Chart III. 



1. While ether boils at 34.6° C, it does not escape violently 

 from an oil-ether mixture, as from an aqueous mixture when the 

 mixture is heated higher, namely, to the body temperature of 37° C. 



2. The rate of separation of ether from the oil quickly acquires 

 a definite and fairly fixed speed. 



