Spectral analysis / by F. Hoppe-Seyler.

  • Hoppe-Seyler, Felix, 1825-1895.
Date:
1872
Catalogue details

Licence: Public Domain Mark

Credit: Spectral analysis / by F. Hoppe-Seyler. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

    19/36 (page 19)
    the notice of chemists, immediately followed these examinations: viz. Caesium and Riibidmm, of which very slight traces of their combination, are to be found in minerals and mineral waters. The disclosures of Bunsen were followed, in the department of spectral analysis, by the discovery of Thallmm, by Crookes and Larny, and of Indium, by Reich and Richter. Frauenhofer had already observed, that a Spectrum could be obtained by the decomposition of light by electric sparks, which is interrupted by black parts, and differs essentially from the light of the sun. Later, examinations by Masson, Ang- strom, Plucker and Kirchhoff have proved, that the light of electric sparks varies according to the kinds of gas, which the spark traverses and the chemical nature of the points between which it passes. We may presume, that in the ex- tremely high temperature of the electric sparks metals and other substances between which the sparks pass, become vo- latilized, and the vapour of these bodies ignites just like the gas, which fills the space between the ends of the wire. It is possible to design the characteristic spectrum of the glowing vapour of every metal, by inserting the same in a galvanic current of sufficient power, in such a manner, that the sparks passing between the metallic points can be observed with the Spectroscope. The flame, which is produced in the fabrication of the so called Bessemer metal, by atmospheric air being blown into melted carboniferous iron, contains various coloured rays of light according to the stage in which this metallurgical process takes place. Although the cause of all the light streaks, which are to be seen in the Spectrum of this flame is not known, the spectroscopical examination of the changes of the flame in the course of the process has already proved a very (816) B3