230 Dr. 0. Lodge on the Electrostatic Force between 



the above numbers are the amounts of permanent deflexion 

 produced at the end of three minutes. The bar was wiped 

 dry after each experiment, and no error was produced by 

 oxidation ; and as a large bulk of the liquid was employed, 

 the diminution of amount of fixed deflexion was not due to 

 exhaustion of the solution. The diminished electromotive 

 force indicated a spontaneous molecular change going on in 

 the amalgam during the first few days. 



In order to find whether the amalgam altered in volume by 

 repeated fusion, the specific gravity of a freshly made piece 

 was taken after the 1st and 6th fusion. The substance was 

 melted under water, and no loss of weight, or oxidation 

 occurred during the process. 



After the 1st fusion the spec. grav. was =12*5438 at 14°*5 C. 

 » «th » ' „ » =12-6190 „ 



From the various results obtained in this research and from 

 other considerations, I conclude that this amalgam, by the act 

 of fusion and subsequent cooling, and by spontaneous change, 

 suffers a loss of molecular motion, potential heat, chemical 

 activity, voltaic energy, diminishes in volume, and becomes 

 less corrodible in a solution of chloride of sodium. The 

 changes appear to be permanent. 



It is evident that the method employed, viz. measurement 

 of volta-electromotive force, may be used for detecting and 

 measuring physical changes produced in alloys by repeated 

 melting, lapse of time, &c. 



XXVIII. On the Electrostatic Force between Conductors con- 

 veying Steady or Transient Currents. By Dr. Oliver 

 Lodge*. 



AT the last meeting of the Physical Society this session 

 Mr. Boys described some attempts he had made to detect 

 mechanical force between a pair of Hertz resonators delicately 

 suspended and immersed in a region of electromagnetic waves. 

 The attempt so far had not been successful; but Mr. Boys, by 

 attending to the energy manifested by Mr. Gregory's method 

 and by another method of his own, showed good reason why 

 the force, if any, was just too small to be observed even with 

 his extremely delicate appliances, and conjectured that a mo- 

 derate increase in sensitiveness would be necessary in order to 

 detect the effect. Everyone must have full confidence that if 

 any such mechanical effect exists Mr. Boys will show it us 



* Communicated by the Author. 



