The Tendencies of Chemistry 



of energy liberated varies with the temperature, 

 the pressure and the physical state of the reacting 

 bodies; hence the application of the principle 

 of maximum energy demands a greater number 

 of numerical data than are usually available. 

 But this is not a serious obstacle, as it is possible 

 to fill gaps of this nature. What, however, 

 is more momentous is that the principle itself 

 of maximum work is inaccurate. 



One might have suspected as much from the 

 simple fact that some chemical reactions are 

 accompanied by an absorption instead of a 

 release of heat. If, for example, we mix alcohol 

 and acetic acid and keep the temperature of 

 the mixture at 100 C., in a few hours' time a 

 perceptible portion of the mixture will have 

 been converted into acetic ether, while the 

 reaction, instead of releasing heat, will be 

 found to have absorbed it, that is like (to 

 take our original comparison), a stone which, 

 of its own accord, rolls uphill. Chemistry is 

 full of similar instances. However, the chemists 

 did not surrender ; this is a typical case, because 

 it illustrates the persistent and injurious tend- 

 ency of each science to separate from the other 



43 



