[ 1029 J 
XX. Flame Spectra at High Temperatures. —Part II. The Spectrum of Metallic 
Manganese, of Alloys of Manganese, and of Compounds containing that Element. 
By W. N, Hartley, F.R.S., Professor of Chemistry, Royed College of Science, 
Dublin. 
Received April 25, 1894,—Read June 14, 1894. 
[Plate 14.] 
The Srectrum of Metallic Manganese. 
The spectrum of manganese obtained in various ways has been the subject of much 
investigation. Huggins, Thalen, and Lecocq de Boisbaudran have studied the 
spark spectra of manganese compounds; Angstrom, Thalen, Cornu, Lockyer, 
also Liyeing and Dewar, the arc spectrum; Simmler, yon Lichtenfels, Lecocq 
de Boisbaudran and Lockyer have investigated the flame spectra, while Marshall 
Watts has given us most accurate measurements of the wave-lengths of lines and 
bands observed in the spark and oxyhydrogen flame spectra of spiegel-eisen, 
manganese dioxide, and other compounds of this metal. 
An account of the spectrum of mangauese obtained by the oxyhydrogen flame w^as 
prepared for insertion in Part I. of this research, but it was omitted for the reason 
that when investigating the spectrum of the Bessemer flame, I found it necessary to 
compare the spectrum of elementary manganese under different conditions with that 
of its oxide. Comparative experiments were made with various alloys containing 
manganese, and with compounds of that substance ignited in the oxyhydrogen flame. 
The results showed that the alloys invariably gave a more distinct and extensive 
series of bands than the compounds containing the same proportion of manganese as 
the alloys. Moreover, the bands were always accompanied by lines, and the lines 
were stronger in the spectra of the alloys than in the compounds. The principal 
lines were always distinctly visible when the conditions were such that the bands 
could barely be seen. For instance, when the spectrum of spiegel-eisen was photo¬ 
graphed with a very short exposure, in fact by a mere flash of light, or when steel 
containing a very small amount of manganese was burnt in the oxyhydrogen flame 
and its spectrum photographed. The various materials used have been ferro¬ 
manganese, containing 80 per cent, of manganese, spiegel-eisen, containing 18 to 20 
per cent., silico-spiegel, containing 10 per cent, of silicon and 18 to 20 per cent, of 
manganese, pig-iron, composition undetermined, and Turton’s tool steel. 
15.1.95 
