44S G. O. Squier — Electro-Chemical 



With nitric acid the liquid was finally made up, as follows : 



Distilled water 10 grams 



Hard gelatine 1 gram 



C. P, nitric acid (sp. gravity, T415), 0'533 grams 



The gelatine and water were allowed to stand until the 

 former had dissolved without the application of heat, when 

 the acid was added, and the whole thoroughly mixed. Too 

 strongly acidulated gelatine would not harden at all. 



In some cases, in order to protect the point from the begin- 

 ning, the electrodes, secured as usual at the ends of two small 

 glass tubes containing the connecting wires, were firmly 

 clamped in the proper position between the poles of the mag- 

 net, and the magnetic field put on before the cell was com- 

 pleted by pushing the beaker containing the solution up in 

 position around the electrodes. 



With this cell a series of parallel experiments were conducted 

 to obtain the variation of the effects with time, or the amount 

 of iron salts present ; the fluidity of the solution, and with 

 constant and variable magnetic fields. 



A. Behavior of the cell with time, in the Earth? s field. 



The cell was placed entirely outside the magnetic field, and 

 galvanometer readings taken at intervals of one minute for 

 three hours. The curve fig. 1 (I) shows these results. Posi- 

 tive ordinates indicate a current from the point to the disc, 

 and negative ordinates the reverse current. Other experiments 

 with fresh solutions, same electrodes, same exposed area, and 

 every condition as nearly as possible the same, gave curves of 

 practically the same character, and the one given is selected to 

 illustrate. 



The curve indicates that the original current was to the 

 point electrode, this gradually decreased due to polarization 

 until after an hour and five minutes it reversed slightly, but 

 again reversed thirty-five minutes later, and after a little more 

 than two hours the deflection became perfectly constant, re- 

 maining so indefinitely. 



The iron salts formed could not move with facility from the 

 exposed surfaces through the hardened gelatine, and were 

 easily outlined from their brown color, as the whole apparatus 

 was placed in a strong light. 



B. In a uniform magnetic field. 



The cell was next placed in the magnetic field which was 

 kept practically uniform (about 15,650 H) for three hours, 

 and galvanometer readings taken as before. 



