1090 
PROFESSOR W. K HARTLEY OR 
4. The question of vaporization of manganese and of manganese oxide from slag is 
put beyond all doubt by actual experiment with the oxyhydrogen blowpipe flame. 
Tills explains the fact observed by Brunner, namely, that when a converter is being 
heated with coke after it has been used, but not re-lined, the spectrum of the Bessemer 
flame makes its appearance. 
5. The luminosity of the flame during the “ boil” is due, not only to the combustion 
of highly-heated carbonic oxide, but also to the presence of the vapours of iron and 
manganese in the gas. 
6. The disappearance of the manganese spectrum at the end of the “fining stage” 
is primarily clue to a reduction in the quantity of heated carbonic oxide escaping 
from the converter, which arises from the diminished quantity of carbon in the metal. 
When the last traces of carbon are gone, so that air may escape through the metal, 
the blast instantly oxidizes any manganese either in the metal or in the atmosphere 
of the converter, and furthermore oxidizes some of the iron. The temperature must 
then fall with great rapidity. 
7. The entire spectroscopic phenomena of the “blow” are undoubtedly determined 
by the chemical composition of the molten iron and of the gases within the converter, 
the temperature of the metal, and of the issuing gases. 
8. The probable temperature of the Bessemer flame at the finish is that produced 
by the combustion in cold air of carbonic oxide heated to 1580° C. ; that is to say, to 
the temperature which, according to Le Chatelier, is that of the bath of molten 
metal from which the gas has proceeded. The bath of metal acts at the same time 
as a means of heating the blast, producing the gas, and as a furnace on the regenerative 
principle which heats the gas prior to its combustion. 
9. If we may judge by the lines and bands belonging to iron and manganese which 
have been measured in photographed spectra of the Bessemer flame, the temperature 
must nearly approach that of the oxyhydrogen flame, and may easily attain the 
melting-point of platinum. 
10. The spectrum obtainable from Bessemer slag by the oxyhydrogen flame is 
composed of precisely the most characteristic features of the flame-spectrum, as seen 
issuing from the converter at Crewe. The continuous spectrum of carbonic oxide, 
bands and lines of that compound, and of elementary carbon, are, as a matter of course, 
absent. 
The flame at Dowlais differs from this, and resembles the spectrum of metallic 
manganese. These differences may not be entirely due to the higher temperature at 
Dowlais, but to the difference in composition of the metal. The manganese at Crewe 
would be oxidized to slag within the first seven minutes—that is say, before the 
manganese spectrum makes its appearance in the flame. That at Dowlais would 
probably not be all removed from the bath of metal by oxidation before the end of 
the “ blow.” The former yields such a spectrum as may be obtained from slag, the 
latter, one which is obtainable only from spiegel, ferro-manganese, or pure metallic 
