Intelligence and Miscellaneous Articles, 391 



2. That the parts of the liquid having most influence upon its con- 

 ducting-power are those nearest to the straight line joining the centres 

 of the electrodes. 



3. That beyond certain dimensions relatively to certain distances 

 between the electrodes, the cross section of the liquid has no further 

 influence ; and that the portion of liquid traversed by the current 

 increases with the distance interposed between the electrodes. 



4. That the resistance offered by the liquid, as shown by experi- 

 ment, does not agree with that calculated according to the law of 

 the resistance of circuits relatively to the length and cross section of 

 the conductor, supposing the conductor to be represented by the 

 liquid prism having the electrodes as bases; and the discrepancy- 

 becomes greater as the length of the liquid increases for a given cross 

 section. 



From these experiments it follows that when an electric current 

 travels through a liquid whose cross section is much greater than the 

 surface of the electrodes, it tends to diffuse itself laterally. It would 

 be interesting to examine if this happens also when only a section of 

 the liquid is narrowed — if when a diaphragm pierced with a small 

 aperture is interposed, the current diffuses itself in the liquid on 

 either side of it. Dr. Macaluso's experiments show not only that 

 the diffusion takes place, but also that the narrowing of the passage 

 by a diaphragm has comparatively little influence on the resistance, 

 as, by reducing the width of the passage from 14 inches to an inap- 

 preciable interval (that remaining between the edges of two plates 

 of glass ground together), the liquid resistance was [not quite qua- 

 drupled, the resistances in the two cases being as 100 to 378, not- 

 withstanding the very great reduction of the area through which the 

 current had to pass. The experiments showed further that when 

 the conducting liquid was equal in section to the surface of the elec- 

 trodes, and was made to take the shape of concentric cylindrical 

 shells, its resistance followed the ordinary law of transmission 

 through metallic circuits. 



After describing these experiments, Dr. Macaluso, by a theoretical 

 investigation based upon the known law of the resistance of solid 

 and liquid circuits (viz. that such resistance varies inversely with 

 the cross section when, in the case of liquids, the section is equal 

 to the surface of the electrodes), and upon the fact that the resist- 

 ance diminishes when the cross section of the liquid is made greater 

 for a given surface of the electrodes, comes to the conclusion that 

 two currents travelling side by side in the same liquid exercise an 

 influence upon each other which weakens them both ; and gives 

 the following experiments relative to this inquiry : — The electrodes 

 were formed of a series of copper points immersed in the conducting 

 solution ; these points could be made to approach or recede from 

 each other at will, remaining always in the same plane, perpendi- 

 cular to the direction of the current in the liquid, so that the dis- 

 tance between the pair of electrodes remained constant. It was 

 found that upon successively separating the points forming each 

 electrode to a greater distance from each other (that is, upon in- 



