CHEMISTRY — RICHARDS. 157 



difference between the change of total energy and the change of free energy. 

 This result, while not enough to prove the relation in question, is at least 

 highly encouraging, and points to the advisability of continuing the research. 

 Even if the supposed relation should be found to be non-existent, the data 

 are interesting and valuable, and can not but be of use in the experimental 

 development of chemical thermodynamics. The work will soon be con- 

 tinued here. 



(8) The adiabatic combustion of organic substances and the heat of com- 

 plete combustion of benzol formed the subject of another research carried out 

 with the assistance of Dr. h. J. Henderson and H. L. Frevert. In this series 

 of experiments, the last to be reported here, a research begun with a subsidy 

 from the Rumford fund of the American Academy of Arts and Sciences was 

 continued under the auspices of the Carnegie Institution of Washington, 

 The object of the research was the exact determination of the heats of 

 combustion of a series of typical organic substances in order to discover a 

 possible relation between changes of internal energy and differences of 

 structure. The Berthelot-Atwater calorimetric bomb was used adiabati- 

 cally, according to the new method devised by the author, and various 

 precautions necessary to attain great accuracy were adopted. While the 

 results concerning benzol seem to be definitive, much remains to be done 

 with other substances ; hence this investigation is still in progress. 



The effort will be made to publish in full the details as soon as possible. 



