This review reports the developments in ultraviolet and light absorption spectrometry from January 1992 through December 1993, primarily as documented in the Ultraviolet & Visible Spectroscopy section of CA Selects, and extends the series of reviews on these topics sponsored by Analytical Chemistry starting with Light Absorption Spectrometry in 1945 (1-3), followed by Ultraviolet Absorption Spectrometry in 1949 (4-9) and combined Ultraviolet and Light Absorption Spectrometry in 1978 (10, II). The format of this review follows that of its recent predecessors, with the subject matter divided into sections on chemistry, physics, and applications.The applications section is comprised of tables which summarize the routine determinations of inorganic and organic substances. The literature on ultraviolet and light absorption spectrometry continues to be so extensive and varied in scope that citations in this review are limited to those developments which the authors believe are of greatest interest to analytical chemists and those engaged in the chemical analysis of materials. Asa result of this necessary selectivity, the authors apologize in advance for any errors of judgement made in the omission of specific citations.It is with great sadness that this year's review must report on the death of the founder of this review series and a giant in the development of analytical chemistry as a discipline, Melvin Guy Mellon. Professor Mellon died September 6, 1993, at the age of 99. He authored or coauthored with his former student. Professor David Boltz, the first 17 review articles on Light Absorption Spectrometry, starting in 1945.