When Josef Von Fraunhofer (1787 to 1826) discovered dark lines in the solar spectrum in 1814, he opened an entirely new field of optical investigations. Appropriately, it began with Fraunhofer’s continued investigations of the spectral characteristics of the light emitted by various lamps. The paths to the use of spectroscopy as an investigative tool, however, had several bridges yet to cross. It is of interest to review some of these.
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