290 E. L. Nichols and W. S. Franklin — Electromotive 



Art. XXIV. — The Electromotive Force of Magnetization;* by 

 Edward L. jNTichols and William S. Franklin. 



At the Ann Arbor meeting of the American Association for 

 the Advancement of Science, we described some singular mod- 

 ifications in the relation of iron to acids which occur when the 

 reaction takes place wit nm the magnetic field. The present 

 paper deals with the behavior of iron when that metal acts as 

 one electrode in a voltaic circuit, and is at the same time sub- 

 jected to magnetization. 



A galvanometer placed in a circuit consisting of two elec- 

 trodes of iron, metallically connected on the one hand, and 

 dipping, on the other, into a cell containing any liquid capable 

 of dissolving them, will indicate the existence of a current 

 whenever the reaction between the metal and the liquid dif- 

 fers in character or rapidity at the two terminals. There are 

 always at work a number of causes of such inequality of ac- 

 tion, and the electro-motive force between iron poles in any 

 liquid which attacks them freely is not inconsiderable. It 

 amounts as a rule to several thousandths of a volt and even 

 when special precautions have been taken to secure homogen- 

 eity in the elements of the circuit, a sensitive galvanometer 

 will not fail to show the .existence of a current. If one of the 

 terminals be placed within a magnetic field, new differences 

 of potential will be developed, both from the magnetization 

 of the iron and from the change in the chemical relations be- 

 tween the metal within the field and the liquid. This electro- 

 motive force we have proposed to call the electro-motive force 

 of magnetization. 



With the exception of two papers by Dr. Theodor Grossf 

 of Berlin, which came to our notice too late to enable us to 

 take advantage of their valuable contents in our investigation, 

 we know of no observations of the effect of magnetization 

 upon the voltaic behavior of iron. Dr Gross's research deals 

 chiefly with the electro-motive force due to the magnetization 

 of the iron, and touches only incidentally upon the nature of 

 the currents -produced when one of a pair of iron electrodes 

 has its electro-chemical relations to the solution modified by 

 being placed within the magnetic field. It is with the lat- 

 ter phase of the subject, principally, that our experiments 

 have to do. 



* Paper read at the New York meeting of the American Association for the 

 Advancement of Science, August 11, 1887. 



f Th. Gross; Ueber eine neue Kntstehungsweise galvanischer Strome durch 

 Magnetismus: Sitzungsberichte der Wiener Academie, vol. xcii, 1885. 



