300 BULLETIN OF THE UNIVERSITY OF WISCONSIN. 



made by this investigator of recognized ability. The theory at 

 once met with great opposition, notably in England, and it was 

 by no means received with open arms on the continent. But 

 the hypothesis inspired experimental investigation, and the re- 

 sults of this phenomenal activity (which at first centered in Ost- 

 wald's laboratory at Leipzig, but spread rapidly to other parte 

 of Germany, to various other countries of Europe and to Amer- 

 ica) soon silenced opposition in Germany and gradually dimin- 

 ished the opposition in England. It must not be supposed, 

 however, that this silence meant that all were convinced. The 

 silence seemed to result on the one hand because of a recognition 

 of the futility of the debate with the knowledge of existing 

 facts, and because of a recognition of, if not an admiration for, 

 the enthusiasm displayed by the adherents of the theory, — en- 

 thusiasm that bore fruitful results in experimental investiga- 

 tions of various physical, chemical, and physiological properties 

 of solutions, which results were ingeniously interpreted in the 

 light of the new theory. 



It was at first only in the case of aqueous solutions of the or- 

 dinary acids, salts, and bases that van't HofT's theory of solutions 

 met its difficulties ; and when Arrhenius pointed out that these 

 solutions are conductors of electricity, and assumed that the dis- 

 solved substances are electrolytically dissociated into free ions, 

 these solutions were on this basis shown to support the theory. 

 Arrhenius calculated the troublesome factor i (which van't Hoff 

 had found it necessary to introduce to make the behavior of the 

 above mentioned solutions conform to the gas equation) from 

 the electrical conductivity on the one hand and from molecular 

 weight determinations on the other, the resulting figures show- 

 ing an agreement to within 5 to 15 per cent., according to his 

 estimation. In view of the few experimental data at hand in 

 1887 and the fact that many of them had not been determined 

 with accuracy, the poor agreement of a goodly number of values 

 at least was readily overlooked in view of the generalities that 

 the theory sought to bring, generalities which were soon incor- 

 porated without proper qualifications into text-books. The 

 electrolytic solutions with which Arrhenius made his compari- 



