PRESENT PROBLEMS 299 



think that a more complete knowledge of these questions will at some 

 time be gained. This fuller knowledge will take account, too, of many 

 lines of work upon which I have no time to dwell, such as the question 

 of changing atomic volume to which Professors Richards and Traube 

 have directed our attention, and the knowledge of heats of combus- 

 tion, of molecular refraction and dispersion, of color, viscosity, 

 dielectric constants, and other physical properties. The future must 

 give to us a new theory, or a development of old ones, which shall 

 include all of these phenomena in one comprehensive view. 



SHORT PAPER 



PROFESSOR OSWALD SCHREINER, of the United States Department of Agricul- 

 ture, read a short paper on " A Study of the Sesquiterpene Class of Hydrocar- 

 bons." 



