Open AccessXVIII. On the photographic arc spectrum of electrolytic iron
Author(s) -
J. Norman Lockyer
Publication year - 1894
Publication title -
philosophical transactions of the royal society of london. a
Language(s) - English
Resource type - Journals
eISSN - 2053-9231
pISSN - 0264-3820
DOI - 10.1098/rsta.1894.0018
Subject(s) - impurity , spectral line , manganese , line (geometry) , nickel , barium , meteorite , chemistry , physics , materials science , inorganic chemistry , metallurgy , geometry , mathematics , astrobiology , astronomy , organic chemistry
In the Bakerian Lecture for 1873 I gave an account of my early researches on the spectrum of iron, which had been commenced in 1870, and suggested a possible method of spectroscopically eliminating impurities. I then hazarded the statement that “in cases of coincidences found between the lines of various spectra, the line may be fairly assumed to belong to that one in which it is longest and brighest." The method was illustrated by three plates, one of which showed the long and short lines of iron near F; another the spectra of manganese, nickel, Lenarto meteorite, and iron from about G to H; whilst the third was a comparison of the spectra of calcium and barium with the solar spectrum. The subject was subsequently referred to in communications to the Royal Society, in 1874; and with regard to the method of treatment for the elimination of lines due to impurities, I remarked: “The spectrum of the element is first confronted with the spectra of substances most likely to be present as impurities, and with those of metals, which, according to Thalén’s measurements, contain in their spectra coincident lines. Lines due to impurities, if any are thus traced, are marked for omission from the map and their true sources recorded, while any line that is observed to vary in length and thickness in the various photographs is at once suspected to be an impurity line, and, if traced to such, is likewise marked for omission." This work was very laborious, and I appealed “to some other man of science, if not in England, then in some other country, to come forward to aid in the work, which it is improbable that I, with my small observational means and limited time, can carry to a termination.”