Numerical Connexion between Atomic Weights. 103 



Finally, a well oxidized copper wire was tried in hydrogen. 



Temperature .... 267° 287° 307° 316° 



Hate of Leak ... . 1-05 1'4 60 21-4 



10 div. per hour at 310°. 



These experiments fall into two classes. 



(1) Those cases where chemical action was occurring 

 between the electrified surface and the surrounding gas. 



(2) Those cases where there was no such action. 



To summarize the results : under the first head we have — 



Copper in air ... 10 div. of leak per hour at 287 

 Copper oxide in hydrogen ,, „ „ at 310 



under the second — 



Silver in air. . 10 div. leak per hour at 250° 

 Silver in hydrogen „ ,, ,, 228° 



Copper oxide in air „ „ „ 26b'° 



So far as the experiments go they suggest that chemical 

 action is rather unfavourable than otherwise to the escape of 

 positive electrification. 



The result of most interest in the present investigation is 

 that the discharge of positive electrification by hot metals 

 can be detected at much lower temperature than has hitherto 

 been supposed, becoming apparent very far below a red heat, 

 and increasing rapidly with the temperature. 



IX. On a General Numerical Connexion between the Atomic 

 Weights. By J. H. Vincent, D.Sc, B.A* 



[Plates 1. & II.] 



Historical. 



MANY relationships have been made out between the 

 atomic weights of the elements when these are con- 

 sidered in small groups : and there are a few formulae which 

 have been proposed to express the connexion between the 

 atomic weight of an element and the order in which it stands 

 in a list of elements of ascending atomic weights. 



Mills (Phil. Mag. [5] xviii. p. 393 & xxi. p. 151) states 

 that u it is probable that the equation 



?/=p.l5-15(-9375)* 

 * CommuuicatHd by Prof. J. J. Thomson, F.R.S. 



