REVISIONS OF THE THEORY OF ELECTROLYSIS." 



By Henry S. Carhart, LL. D. 



No subject in the whole domain of theoretical electricity possesses 

 more interest to the electrochemist than the theory of the decompo- 

 sition of aqueous solutions of salts and acids through the agency of 

 an electric current. For more than a hundred years scientific atten- 

 tion has been converged on it, for it has presented problems both of 

 unusual interest and of unusual difficulty. Its development has not 

 been one of uninterrupted progress, but rather one of leaps and 

 bounds, alternating with seasons of suspended animation. Even 

 with the noteworthy additions of the past twenty years, it can not 

 be said that all difficulties have yet been resolved. We are in little 

 danger of so completely clearing up the entire field that nothing shall 

 be left for posterit}-. 



An historical review of this subject, biased it may be by perspec- 

 tive and distorted by the disproportionately large visual angle under 

 ^A■hich we view recent events, may yet give us more respect for the 

 achievements of the past and less unreserved satisfaction with the 

 advances of our own times. 



The earliest record of observed electrolysis dates back of the inven- 

 tion of Volta's dry pile and " crown of cups." The decomposition 

 of water by electrical means was described by van Troostwijk 

 and Deimann in 1789. It was accomplished by sending a series 

 of electric discharges through water in a narrow glass tube between 

 gold wires whose ends were an inch and a half apart. The tube was 

 placed vertically, and when the end of the upper wire became uncov- 

 ered the spark caused the explosive reunion of the mixed gases. 

 These experimenters concluded, contrary to the opinion of many of 

 their scientific contemporaries, that both the hydrogen and the 

 oxygen were obtained from the decomposition of w^ater and that 



<■■ Presidential address delivered at the seventh general meeting of the Ameri- 

 can Electrochemical Society, held at Boston, Mass., April 25, 1905. Here 

 reprinted from Transactions of the American Electrochemical Society, Vol. 

 Vll, Philadelphia, 1905. Copyright 1905 by the American Electrochemical 

 Society. 



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