Investigations of historical objects utilizing spectroscopy and other optical methods

Historical investigations employing spectroscopy and other optical methods frequently date from the time the instrument was first introduced into the field of analysis or physical examination. The use of optical emission spectrography in the study of ancient metals dates from 1931 when an extensive investigation on the metallurgy of central Europe was first begun. This investigation has been continued into the present. Analyses, which must be performed on a microscale, were done, and frequently still are, by observing reactions of the sample and reagents under a light microscope: chemical microscopy. As the usefulness of methods such as the electron microprobe, ir spectrophotometry, and powder x-ray diffraction techniques has become more evident, these and others have been used in the identification of pigments and other inorganic samples as well as of organic materials.