296 E. L. Nichols and W. S. FranMin — Electromotive 



tected. Measurements were made in fields varying in intensity 

 between 2000 H., and 20,000 H. The results are given in the 

 following table. They show the manner in which the effect in 

 question increases with the strength of the field. 



Table. 



Influence of the Strength of Field upon the Electro -motive Force 



of Magnetization. 



Strength of field. E. M. F. in volts. 



2000 H -0008 volts. 



3600 .0045 



5040 -0208 



7770 -0386 



8400 -0424 



12750 -0487 



16300 -0510 



19700 . -0680 



We had noticed in the course of our experiments that a 

 layer of the more or less magnetic solution of the salts of iron, 

 produced by the reaction, always gathered around the induced 

 poles of the electrode within the field. In this way a two- 

 fluid battery was formed between the iron within the field and 

 that outside, whenever the surface nearest the poles of the 

 magnetized electrode was exposed. The terminal within the 

 field was thus surrounded by a concentrated solution of its 

 own salts, and was in a measure protected against the direct 

 attack of the acid. In the case however in which a neutral por- 

 tion of the electrode within the field was exposed, the products 

 of the reaction were continually withdrawn by magnetic attrac- 

 tion towards the pole-pieces, and the surface was left more 

 oj>en to attack than the opposing electrode outside of the field. 



For the purpose of ascertaining whether this arrangement 

 of the solution in the field would tend to produce the effects 

 which have been described, measurements were made of a 

 variety of batteries in which iron formed one electrode. The 

 results were such as to make it evident that the 'influence of 

 the magnet could, in part at least, be thus explained. An iron- 

 carbon cell, the liquid being nitric acid diluted with one part 

 of water, was found to have an E. M. F. of *88 volts. When 

 the acid was placed in a porous cup, containing the carbon pole, 

 and the iron was submerged in weak sulphuric acid (1 : 10), 

 the E. M. F. rose to 1*33 volts. The same metals in dilute 

 sulphuric acid containing potassium bichromate gave 1*05 volts 

 which was increased to 1*32 by placing the carbon and bichro- 

 mate solution in a porous cup and the iron in dilute sulphuric 

 acid. A cell with iron and platinum, in a solution consisting 

 of 200 cc of strong hydrochloric acid, 200 cc of water and 20 s ™ s 

 of potassium chlorate, gave 1*17 volts. When converted into 



