RICHARDS. CHANGING HEAT CAPACITY. 317 



6. The fact that in many reactions the change of heat capacity is 

 small and the concentration effect about balanced affords an explanation 

 for the frequent fulfilment of Berthelot's approximate " rule of maximum 

 work." 



7. A distinction is drawn between endothermic and pseudo-endothermic 

 reactions. 



8. If the change of total energy could be corrected for the heat energy 

 displaced by change of heat capacity, a measure of the total affinities 

 might be obtained, for into this heat the osmotic tendencies do not 

 enter. 



9. If the same contraction in volume as that exhibited on combining 

 could be produced on the uncombined factors in the reaction by outside 

 pressure under similar conditions, the work expended might serve as 

 another measure of the total affinity. 



10. In the absence of concentration-effect, the "attracting energy " of 

 a given reaction probably lies between the change of free energy and the 

 change of total energy. 



11. It is shown that the hypothesis of compressible atoms affords a 

 conceivable explanation of these facts, and that it is not inconsistent with 

 either of the two laws of energy. 



Cambridge, Mass. 

 June 2, 1902. 



