(born Dec. 11, 1843, Clausthal, Hannover—died May 27, 1910, Baden-Baden, Ger.) German physician. As the first to isolate the anthrax bacillus, observe its life cycle, and develop a preventive inoculation for it, he was the first to prove a causal relationship between a bacillus and a disease. He perfected pure-culture techniques, based on Louis Pasteur's concept. He isolated the tuberculosis organism and established its role in the disease (1882). In 1883 he discovered the causal organism for cholera and how it is transmitted and also developed a vaccination for rinderpest. Koch's postulates remain fundamental to pathology: the organism should always be found in sick animals and never in healthy ones; it must be grown in pure culture; the cultured organism must make a healthy animal sick; and it must be reisolated from the newly sick animal and recultured and still be the same. Awarded a Nobel Prize in 1905, he is considered a founder of bacteriology.
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Ferdinand Heinrich Strecker's parents, Ferdinand and Anna, born Kern, were originally German. His father, who had trained as a sculptor in Europe, had settled in Reading where he made and traded in marble sculptures. Ferdinand showed great aptitude for this trade, starting to work at twelve years, and succeeding his father. But sculpture was not lucrative enough and young Strecker also made tomb stones. Also as a very young person, he attended the library of the Academy of Natural Sciences of Philadelphia where he studied natural history and more particularly the butterflies. A polyglot, he traveled extensively, in particular in the Caribbean and in Mexico and Central America. At this time he was interested in Aztec monuments. By the age of around forty years, he had assembled a collection of 200,000 specimens of butterflies and moths coming from all the corners of the world, including 300 new species and around 150 subspecies. His collection occupied a whole floor of his house in Reading. At the time of his death in 1901, Strecker's collection was the largest and most important private collection of butterflies and moths in the New World. It is in the Field Museum of Natural History in Chicago. In spite of his thin resources, he published, from 1872 to 1878, with illustrations of 300 specimens, Lepidoptera Rhopaloceres and Heteroceres, Indigenous and Exotic, with Descriptions and Colored Illustrations. Richly illustrated by himself, the work is in fifty parts. In 1878, he published Butterflies and Moths of North America which also details methods for the preparation, breeding, collection, the classification and the conservation of the butterflies. In addition to his commissioned? work as a collector (and dealer?), Strecker resold a part of the specimens which he collected during his voyages. In 1890, he received an honorary doctorate of Franklin and Marshall College.