‘A crowd of mercurial globules’: Microscopic Examination as a Precursor to Etching Daguerreotypes in 1839 and 1840
Following its introduction to the world in 1839, the daguerreotype was quickly implemented as a tool for recording microscopic views of specimens. With the goal of printing these photomicrographs in ink on paper, daguerreotypes were also etched in acid to convert them into intaglio plates. Studying first-hand reports on how daguerreotypes were examined with loupes and microscopes in 1839 and the following years helps understand how these etching techniques were devised. Magnifications of up to 300x revealed detailed views of the image-forming particles on the plate that surpassed the mere enlargement of the image which was attainable with a loupe. This study re-enacts the first microscopic examinations of daguerreotypes with two historical compound microscopes to see first-hand what a highly magnified view looked like at that time. The resulting images are similar to what can be obtained with today’s typical optical microscopes. The concept of the daguerreian ‘telescope’ is discussed in its relationship to image resolution and viewing distance, and a modern daguerreomicrograph of a daguerreotype, made by the author, helps diversify this exploration. This study argues that it was primarily the examination of daguerreotypes under a microscope that allowed pioneers of the medium to devise the first theories about image-forming processes and the final microstructure of the daguerreian plates, which then in turn led them to develop etching methods that would convert the daguerreotypes into intaglio printing plates.
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