THE 

 LONDON, EDINBURGH and DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE. 



♦ 



[FOURTH SERIES.] 



OCTOBER 1860. 



XXX. On the Electric Light of Mercury. 

 By J. H. Gladstone, Esq., Ph.D., F.R.8* 



[With a Plate.] 



PROFESSOR WAY has recently devised a plan by which a 

 brilliant electric light is produced in an interrupted current 

 of mercury. The metal is made to fall from a jet in a thin 

 stream into a cup, the jet being half an inch or thereabouts above 

 the surface of the metal in the cup. The upper reservoir and 

 the lower vessel are in connexion with the two wires of a Bun- 

 sen's battery. As the galvanic force traverses the thin stream 

 of mercury, it scatters and diffuses it in vapour with the produc- 

 tion of a most intense light. For obvious reasons the gaseous 

 mercury is confined in a well-closed glass cylinder ; and this is 

 made of sufficiently small diameter to become hot in the neigh- 

 bourhood of the electric flame, and thus prevent the condensa- 

 tion of the mercury on it. 



"While inspecting this light about a year ago, I was struck by 

 the strange manner in which it modified the apparent colours of 

 surrounding objects, and especially with the ghastly purple and 

 green hues which it imparted to the faces and hands of the spec- 

 tators. This led me to a more careful examination and a pris- 

 matic analysis of the light itself. As these electrical flames are 

 attracting much attention at the present moment, the observa- 

 tions then made may prove of some interest as a contribution to 

 the general stock of facts. 



Chevreul's "cercles chromatiques," when examined by this 

 mercury light, showed very little, if any, red, but the violet was 

 very luminous and distinct. Flowers, dyed wools, ribbons, &c. 



* Communicated by the Author. 

 Phil. May. S. 4. Vol. 20. No. 133. Oct. 1860. S 



