504 



Mr. J. Swinburne on the 



or polymerized. Silver being a metal with a very low affinity 

 for oxygen, could not be expected to show in the atomic state 

 the same inflammability as more oxidable metals. 



In conclusion, it may be said that there is much reason to 

 suppose that elements may exist in the atomic form, and that 

 allotropic silver may present such a case. This is, of course, 

 far from being proved, and is offered only as a " working- 

 hypothesis." As such, it may afford a useful aid in further 

 investigations. 



Philadelphia, April, 1891. 



LXII. The Electrometer as a Wattmeter. By J. Swinburne * 



IN 1881, when M. Joubert published his experiments on a 

 Siemens machine, in the course of which he had used a 

 Thomson or Mascart electrometer as a voltmeter, Professors 

 Ayrton and Fitzgerald simultaneously proposed to use the 

 quadrant electrometer as a wattmeter. 



The ordinary method of arranging the instrument is shown 

 in fig. 1. The resistance is wound so as to be non-inductive ; 



Fi- 1. 



and the power to be measured is spent in the apparatus 

 marked W. If the foil of potential between x and y is very 

 great in comparison with that over the resistance, the instru- 

 ment reads like a charged electrometer, and it may be taken 

 to read in watts. In practice such conditions do not occur ; 

 * Communicated by the Physical Society : read March 6, 1*91. 



