50" 



300 c 



100° 150° 200° 250' 



Diagram 10. 

 Ordiuates give internal heat of vaporization in calories. % 



30° show beyond question that the line for water should al 

 curve perceptibly before that temperature is reached. 



2. The curves are all concave towards the temperat 

 axis. Hexameth}^lene, di-isobutyl, brom-benzene, and iod 

 benzene would not always be concave if the observations w 

 exactly followed. But the diagrams themselves add strong 

 to evidence already pointed out (p. 147, etc.) in indicating thj 

 these values need further study. 



3. Except in the case of acetic acid, the int 

 heat always decreases with the temperature. 



4. Several attempts to find a simple empirical formu 

 connecting- the internal latent heat and the temperat 

 failed. The investigation was not pushed. 



