22 Prof.. S. P. Thompson on the Conservation of Electricity , 



phenomena afford a very striking criterion on this point 

 indicates that all known electrical phenomena take place at 

 an absolute electrification far above that of the absolute zero 

 of electrification. 



10. It appears, however, worth while to inquire into some of 

 the obscure phenomena by which the two electrical states 

 differ from one another, in order to see w r hat bearing they 

 have upon the question which of these two states is to be 

 regarded as the true plus state and w r hich the true minus. 

 The chief phenomena in question are tabulated below. 





Phenomenon. 



For "resinous" 

 electrification. 



For " vitreous " 

 electrification. 



1. 



To produce discharge between 

 two unequal spheres requires 









weaker electrification 





than when it is -K 



(Faraday, Fxperim. Ees. 1501.) 





2. 



A small ball, when dischar- 

 ging, gives off apparently 

 less discharge when the elec- 









trification 





than when it is -(-. 



(Faraday, op. cit. 1491.) 





8. 



The range of variation in 

 amounts of charge required 

 to produce discharge is 









always 





than when it is -f. 



(Faraday, op. cit. 1393.) 





4. 



Drops electrified are more 









pointed when electrification 

 (Faraday, op. cit. 1593.) 



is — 



than when it is +. 





b. 



Card pierced by spark under 

 atmospheric pressure is 









pierced at a point 



nearer the — discharger 



than the +. 





(Lulliris experiment.) 



6. 



Spark-discharge turns to brush 









sooner 





than at a 4- . 



(Faraday.) 





7. 



Brush-discharge turns to 









glow later 





than at a -f-. 



(Faraday.) 





8. 



Discharge by a heated body 

 takes place at a higher tem- 









perature for 





than for -J— 





(Guthrie.) 





y. 



Discharge in vacuo has the 









appearance of a force 



emanating from — electrode. 







( Gassiot.) 







10. 



Eadiometer-ranes in vacuous 









tube are repelled 



from — electrode 



toward -f electrode. 



(Geissler.) 





11. 



In high vacua the direction of 

 the discharge is normal to 









the surface of 



the — electrode 



and independent of 

 the position of the 





(Crookes.) 











+ electrode. 



