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W. A, Miller on Electric Spectra of the Metals. 107 
es. 
ranging a quartz-train in the manner already described. Among the 
elements so examined are the following :— 
Platinum, Arsenic, Copper, 
Palladium, Tellurium, Aluminum, 
; Tungsten, Cadmium, 
Silver, Molybdenum, Zine, 
Mercury, Chromium, Magnesium, 
Lead, Manganese, Sodium, 
Tin, ron, Potassium, 
Bismuth, Cobalt, Graphite, and 
Antimony, Nickel, i Gas-coke. 
The commencement of each spectrum in. its less refrangible portion is 
similar in nearly all cases; and, as it is this portion only which is trans- 
missible through bisulphid of carbon, this circumstance explains the sim- 
ilarity of all the spectra procured by the author from different metals in 
his earlier experiments, already laid before the British Association. 
the more refrangible parts of the spectrum, great and characteristic differ- 
ences between the results obtained with the different metals are at once 
manifest. In some cases, as in those 
greatly prolonged in the more refrangible extremity, whilst the intense 
es. 
It will be observed, on examining the photographs of these spectra 
of the various metals, that the impressions, particularly in the more re- 
frangible portions, consist of a double row of dots, running parallel with 
the length of the spectrum, and forming the terminations of lines 
than lines themselves, as though the intense ignition of the detached par- 
ticles of metal, necessary to furnish rays capable of exciting chemical 
action, had ceased before the transfer of these particles to the opposite 
electrode had been completed. 
If each electrode be composed of a different metal, the spectrum of 
each metal is impressed separately upon the plate, as is evident on exam- 
ae the photographs. 
hen Pitti ans exaployed as electrodes, the spectrum exhibited is that 
