S&^ Proceedings of the British Association for [Sept. 



The same light from different metallic surfaces gave 

 similarly interrupted spectra ; the divisions being distri- 

 buted in a peculiar manner in the spectra for each metal. 



In alloys and compounds of different metals the lines 

 pe^culiar to each wire were compounded. 



The voltaic light from a surface of mercury, and of other 

 metals in succession, gave analogous results. 



At different points of the connecting wire the light ap- 

 peared of different colour ; that colour was found marked 

 with a peculiarly bright line in the corresponding spectrum. 



High characteristics afford the means of distinguishing 

 the different metals, and to determine the origin of the 

 electric light in different cases. 



The light from combustion of metals gave uninterrupted 

 spectra ; thus shewing, that voltaic light is not related to 

 combustion. 



The light of the electric spark from contact of different 

 metals, gives similar light and dark spaces to those in the 

 voltaic. 



Mr. W. applies these results to the theories of electric 

 light, and thinks they point out the volatilization of pon- 

 derable matter from the conductors as the most probable 

 hypothesis. 



16. The Rev. Mr. M'Gauley exhibited and explained a 

 new principle, consisting in the application of magnetism 

 as a moving power. The apparatus consists of two powerful 

 electro-magnets, so arranged that the contact is alternately 

 changed from one pole to the other, and the poles of the 

 magnet thus reversed. This produces an alternate motion 

 in the bar connecting the poles, which moving a crank turns 

 a wheel and any machinery connected with it. The inven- 

 tor has succeeded in thus getting a moving power nearly 

 equivalent to the lifting power of the magnet. 



The main peculiarities may be thus stated : 



1. The reversing apparatus easily applied, without almost 

 sensibly altering its weight, to any number of electro- 

 magnets. 



2nd. The connexion of the reversing apparatus with the 

 vibrating bar. 



3rd. The direct application of the entire, or nearly the 

 entire lifting power to machinery. 



