428 SCIENCE PROGRESS. 



may be calculated from the rate at which the solution 

 saponifies ethyl acetate. 



These equilibrium methods have now put us in a 

 position to give the order of affinity of both acids and bases 

 from the strongest to the weakest, and even for the weak- 

 est an approximation to the dissociation constant can be 

 calculated. 



With regard to other affinities, the study of electro- 

 motive force seems to promise excellent results in certain 

 directions, but the solution of the general problem is still 

 the task of the future. 



James Walker. 



