German physician; born in Bonn 1743; died in Hanover Jan. 24, 1789; studied medicine in Halle (M. D. 1765). He traveled for scientific purposes in Holland and England, in the latter country making the acquaintance of Dr. John Fothergill. He finally settled in Hanover, where he made himself greatly beloved. He has been reproached with inability to free himself from the prejudices of his time when he opposed Herz for attacking the Jewish burial customs of the period. Marx wrote: "Dissertatio de Spasmis et Motibus Convulsivis Optimaque Iisdem Medendi Ratione" (Halle, 1765); "Observata Quædam Medica" (Berlin, 1772); "Observationes Medicæ" (Hanover, 1774-87), in three parts: part one was translated into German by Böhm (Berlin and Hanover, 1786), parts two and three by Marx himself (Hanover, 1787); "Abhandlung über die Lungenschwindsucht" (Hanover, 1784); "Gesch. der Eicheln und Erfahrungen über die Diät und Medizinischen Gebrauch Derselben" (1784); "Bestätigte Kräfte der Eicheln" (1787); "Ueber die Beerdigung der Toten" (Hanover, 1787); etc.
- Allg. Deutsche Biog.; Allg. Zeitschrift des Judenthums, 1840, p. 711.