[ IGl ] 
V. Flame Spectra at High Temperatures. —Part I. Oxy-hydrogcn BIo'W-p)ipc Sp>ectra. 
By W. N. Hartley, F.R.S. 
Received May 10,—Read June 1, 1893. 
[Plates G, 7.] 
Sir David Brewster, in 1842, appears to have been the first to examine the 
spectra of salts by means of the oxygen and coal-g’as flame, about 180 of which were 
deflagrated in a platinum spoon (Edinburgh ‘Roy, Soc. Proc,,’ vol. 6, p. 145). 
Professor Norman Lockyer'" has given us a map of metallic spectra at the tem¬ 
perature of the oxygen and coal-gas blow-pipe (‘Roy. Soc. Proc.,’vol. 23, p. 120), 
The region observed in the case of twenty-two metals does not extend beyond wave¬ 
length 4000 ; and, although we have both arc and spark spectra for the region up to 
wave-length 1800, we are still unacquainted with the spectra of elements and 
compounds obtained by means of flames at high temperatures in the ultra-violet 
region. 
Methods of Obtaining Spectra ivith Flames at High Temperatures. 
In studying the spectra of flames there are many points worthy of consideration 
arising from the structure of the flame, the nature of the combustible, the heat 
evolved during combustion, and the temperature attained. The temperature of a 
candle-flame is high enough to give all the spectra capable of being produced by the 
oxy-hydrogen blow-pipe, for by such simple means we can melt Wollaston’s platinum 
wires and produce the band spectrum of carbon. The reason foi* such a flame being 
practically useless for spectroscopic purposes does not arise from the temperature 
being too low, but from the area of maximum temperature being too small, so that 
the material to be tested and the support upon which it is held in the flame exercise 
* [The following quotation contains a passage which is perhaps the earliest reference to such 
spectra;— 
“ The pure earths, when violently heated, as has recently been practised by Lieutenant Drummond, 
by directing on small spheres of them the flames of several spirit lamps urged by oxygen gas, yield 
from their surfaces lights of extraordinary splendour, which, when examined by prismatic analysis, are 
found to possess the peculiar definite rays in excess which characterize the tints of flames coloured by 
them; so that there can be no doubt that these tints arise from the molecules of the colouring matter 
reduced to vapour, and held in a state of violent ignition.” ‘ Light,’ Sir. J. F. W. Herschel, London, 
1827, also ‘ Encyclopsedia Metropolitana-’ p. 438, vol. 4, 1845.—W. N. H., September 29, 1893.] 
MDCCOXCIY.—A. Y 19.7.94 
