title: Temporality, sequential iconography and linearity in figures: the impact of the discovery of division in infusoria.
abstract: The paper analyses the impact of the discovery of the division of infusoria on eighteenth century microscopical iconography. In Autumn 1765, when reproducing the antispontaneist experiments of Lazzaro Spallanzani, Horace-Bénédict de Saussure (1740-1799) discovered a new method of generation of the animalcules of the infusions, namely their division. Drawing a dividing animalcule raised particular problems, notably the question of how to depict the time sequence of a microscopical creature. Although Saussure's journal of microscopical experiments remained unpublished, the discovery was soon diffused and acknowledged by the European naturalists who began to repeat the observations and quickly faced iconographic problems similar to those experienced by Saussure. Indeed, linearity, used to picture time, is a construction, and, notably for public images, scholars had to contend with the conventions of drawers and engravers. The analysis of microscopical iconographic material of the period 1740-1786 shows that during this period, certain naturalists invented new solutions for depicting time, but diffusion of their innovations was not immediate. Nevertheless, in regards to the illustration of microscopical creatures, it is between 1765 and 1776 that the use of linearity was established as a solution enabling an audience to read an iconographic time process as a text.
authors.affiliation: Wellcome Institute for the History of Medicine and Institut Louis Jeantet d'histoire de la médecine CMU-Case postale, CH-1211 Genève 4, Switzerland.
authors.forename: M J
authors.initials: MJ
authors.lastname: Ratcliff
mesh_terms: D001690:Biological Science Disciplines / Q000266:history*; D049671:History, 18th Century; D006801:Humans; D008853:Microscopy / Q000266:history*; D013557:Switzerland