BLOCH, MARCUS (Mordecai) ELIEZER

BLOCH, MARCUS (Mordecai) ELIEZER (1723–1799), physician and zoologist. He was born in Bavaria, the son of a poor trader. Bloch received a traditional Jewish education and, at the age of 19, he began to learn German, French, and Latin. He was helped by wealthy relatives to study medicine at Frankfurt on the Oder, and received his doctor's degree in 1747. He became a physician in Berlin, and soon gained a reputation at all levels of society. His friends included moses mendelssohn , who was also his patient. Bloch's main achievement was in his morphological and systematic work on fish. He built himself an aquarium and acquired a marine collection which after his death was incorporated in the Berlin Zoological Museum. He wrote his great ichthyological work, Allegemeine Naturgeschichte der Fische, in 12 volumes (1781–1795). The work describes and classifies over 1,500 species of fish. Although Bloch's classification system was primitive and superficial, his book retains its scientific value, with its excellent drawings and diagrams. Bloch also wrote several short works on medical and zoological subjects. -BIBLIOGRAPHY: Hirschberg, in: Deutsche Medizinische Wochenschrift, 39 (1913), 900; Biographisches Lexikon der hervorragenden Aerzte, 1 (19292), 571–2.