between Electrostatic Tubes and Insulators. 13T 



a rheostat of 900 ohms. The movement towards each other 

 persists and differs little from that on open circuit. The 

 repulsive electromagnetic action exists, but does not manifest 

 itself owing to the feebleness of the current (0"11 amp.). 

 There is only one probable explanation. The electrostatic 

 tubes join the two loops in the same way as in the statical 

 case, and the mechanical effect remains nearly the same, 

 because on the one hand through the small fall of potential 

 the tubes have nearly the same strength, and on the other 

 the electromagnetic repulsion is very small. 



In the statical condition the difference of potential be- 

 tween the two ends of each tube is the same and the system 

 o£ tubes is in equilibrium. In the dynamical condition the 

 differences of potential diminish from 100 volts to zero, and 

 the equilibrium of the tubes is disturbed. The transversal 

 pressures diminish gradually, and the tubes are displaced 

 perpendicularly to their axes, sliding along the conductors 

 and sweeping through the dielectric medium. The fall of 

 potential along the circuit shows that each tube, after an 

 infinitely small displacement, will have a less difference of 

 potential between its ends, an effect which may be set down 

 to the destructive discharge of the end-cellules in the body of 

 the conductors. We see that the experiment leads to results 

 exactly agreeing with the theory of Professor Poynting, and 

 that it confirms that theory. When the inserted resistance 

 is diminished to 200 ohms the attraction changes to electro- 

 magnetic repulsion. As the electrostatic action is inversely 

 proportional to the squares of the distances, and the electro- 

 magnetic action is inversely proportional to the distances, we 

 can make either prevail by varying the distance. 



Third Experiment. — In naphtha the attraction increases, 

 Fourth Experiment. — Cutting out the rheostat and im- 

 mersing the loops in distilled water the attraction becomes 

 very powerful and is manifested at a distance of 4 or 5 cm. 

 To get rid of the small liquid currents, and to be sure of the 

 electric character of the attraction, the author put on an 

 alternating current from a transformer and observed the 

 attraction while he dissolved larger and larger quantities of 

 some salt : the current and the electrolysis went on gradually 

 increasing, but the difference of potential between the loops 

 decreased, and at the same time the attraction decreased 

 down to zero. In this experiment the electrostatic tubes are 

 propagated in the water transversely to the conducting loop ; 

 they are destroyed in the liquid itself by means of an inter- 

 molecular discharge (by the aid of ions), and the lines of 

 current are directed along the electrostatic tubes. As the 

 tensions of these tubes are, before destruction, several times 



