1. (a) Hell, C. Ber. 1881, 14, 891-893. Carl M. von Hell (1849-1926) was born in Stuttgart, Germany. He studied under Fehling and Erlenmeyer. Hell became a professor at Stuttgart in 1883 where he discovered the Hell-Volhard-Zelinsky reaction.
2. (b) Volhard, J. Ann. 1887, 242, 141-163. Jacob Volhard (1849-1909) was born in Darmstadt, Germany. He apprenticed under Liebig, Will, Bunsen, Hofmann, Kolbe, and von Baeyer. He improved Hell's original procedure in preparing α-bromo-acid during his research in thiophenes.
3. (c) Zelinsky, N. D. Ber. 1887, 20, 2026. Nikolay D. Zelinsky (1861-1953) was born in Tiraspol, Russia. He studied in Germany, receiving his degree in 1891. In 1885, Zelinsky was the first to prepare mustard gas unintentionally while exploring polymerization of sulfur dichloride. Zelinsky returned to Russia and became a professor at the University of Moscow, where he discovered activated charcoal gas mask. He was awarded the Order of Lenin in 1934.
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