[Photography as a resource of microscopic research? Joseph von Gerlach (1820-1896) and the early anatomical microphotographers].

The Erlangen anatomist Joseph von Gerlach was one of the first medical researchers who used microphotography for their scientific aims in basic tissue research. Already in 1863, Gerlach published a famous handbook on the methodology of the microphotographic technique, entitled Die Photographie als Hülfsmittel mikroskopischer Forschung. Here, he discussed the technological, practical and epistemological standards and constraints of the newly introduced visualisation technique of scientific photography. The efforts and setbacks of Gerlachs' innovative approaches shall be characterised in the present paper. Furthermore, some of the most important arguments put forward by some of his peers are closely compared and thoroughly scrutinised. These anatomical and biological microscopists objected frequently to Gerlach's photographic approach as being "unscientific" or "insufficient" to support the growth of experimental morphology and neurohistological research. In his scientific self-defence, Gerlach developed important auxiliary arguments that display many facets of the epistemological discourse of 19th-century medical research, particularly on the question of how scientific objects should be visualised and identified in the experimental laboratory.