Joseph Ernest Cogit, 1831 - 1912

E. Cogit
E. Cogit et Cie.
Etablissements Cogit

by Brian Stevenson
last updated May, 2025

Ernest Cogit began selling prepared microscope slides, slide-making supplies, and related apparatus during 1875 in Geneva, Switzerland. He moved to Paris, France during the early 1880s, opening a business at 17 Quai Saint Michel. Around 1892, he formed a partnership that operated as “E. Cogit et Companie”. At the same time, the business address changed to 49 Boulevard Saint Michel. Another moved occurred ca. 1900, to 36 Boulevard Saint Michel, where it remained through at laast the 1950s. The business name “Etablissements Cogit” was adopted during the 1920s.

Figure 1. Microscope slides that were retailed by E. Cogit et Cie. Two bear the address of 36 Boulevard Saint Michel, dating them to after ca. 1900. From the author's collection or adapted for nonprofit, educational purposes from an internet auction site.

Figure 2. Cogit-branded microscopes, described as “Medical” or “Bacteriological” models. Manufactured ca. 1920s or later. Adapted by permission from https://www.lecompendium.com/dossier_optique_97_microscope_cogit/microscope_cogit.htm or for nonprofit, educational purposes from an internet auction site.

Joseph Ernest Cogit was born on May 21, 1831, in Luyères, France. He was a son of Jean-Baptiste Rene Cogit and Rose Julie Dubois.

Ernest Cogit married Emma Aline Louise Monnier, probably prior to 1857. The death record of their son, Albert Alexandre René Cogit, states that he was born on July 2, 1857, in Orival, France. The marriage record of their daughter, Marie Jeanne Gabrielle Cogit, states that she was born in Nyon, Switzerland on September 3, 1858. Emma had also been born in Nyon. It is not known whether Ernest had lived in Switzerland prior to marrying Emma, or whether she had lived in France and the young family moved to her home town in 1857-58.

Ernest’s occupation until 1875 is not known, although his opening a microscope supply house in that year suggests that he had substantial experience in that field.

Cogit exhibited prepared microscope slides and supplies for slide-making at the 1878 Universal Exposition in Paris. He was awarded an Honorable Mention for his work.

I found records up through 1880 that show Cogit in Geneva. He must have moved to Paris during the early 1880s, as Strasburger’s 1886 Manuel Technique d'Anatomie Végétale stated that, “Les porte-objets et les couvre-objets se trouvent chez la plupart des opticiens et constructeurs; Cogit, quai Saint-Michel, 17, à Paris, en fournit de toutes dimensions et de toutes épaisseurs” (“Object holders and coverslips are available from most opticians and manufacturers; Cogit, Quai Saint-Michel, 17, in Paris, supplies them in all sizes and thicknesses”).

A partnership was established between 1889 and 1893, based on advertisements of those years (Figures 4 and 5). The new firm of “E. Cogit et Companie” relocated to 49 Boulevard Saint Michel. The business gained an international reputation as a source of high quality glasses, stains, and other apparatus used in microscopy. By 1910 the business was at 36 Boulevard Saint Michel.

Ernest Cogit died on August 21, 1912, in Paris.

The business of E. Cogit et Companie (also known as “Les Établissements Cogit”) continued for several decades after the founder’s death, until at least the early 1950s.

Figure 3. An 1879 advertisement, when Ernest Cogit had his shop in Geneva. It notes the Hororable Mention that was awarded at the 1879 Paris Universal Exposition. From “Journal de Micrographie”.

Figure 4. Two 1889 advertisements, from 17 Quai Saint Michel, Paris. Cogit was the sole retailer of Leitz microscopes for Paris. From “Traité de Microscopie Médicale et Pharmaceutique”.

Figure 5. By 1893, the business had become “E. Cogit et Cie.”, and relocated to 49 Boulevard Saint Michel. From “Zeitschrift fur Wissenschaftliche Mikroskopie”.

Figure 6. A 1910 advertisement. The business address had changed to 36 Boulevard Saint Michel. From “Revue Générale de Botanique”.

Figure 7. 1912 advertisements, from “Bulletin de l'Institut Pasteur”.

Figure 8. 1921 advertisement for the introduction of "Le Boromica” laboratory glassware. From “L'Industrie Chimique”.

Figure 9. Figures from Langeron’s 1925 “Précis de Microscopie”, illustrating items that were available from E. Cogit et Cie. The images were presumably taken from a current catalogue.

Figure 10. A 1927 advertisement that features an image of the “Medical” / “Bacteriologica;” microscope by Cogit. The business was now referring to itself as “Etablissments Cogit”. In addition to Leitz, the firm distributed microscopes by Koriska and Spencer. From “Revue Internationale de Botanique Appliquée et d'Agriculture Tropicale”.

Figure 11. Advertisement from 1928, which states that the Cogit business was founded in 1875. From “Bulletin d'Histologie Appliquée à la Physiologie et à Pathologie et de Technique Microscopique”.

Figure 12. A 1936 advertisement, from “Bulletins de la Société de Pathologie Exotique”.

Figure 13. Advertisement from 1938, from “Paris Medical”.

Acknowledgement

Thank you to Albert Balasse for sharing images from his microscope collection.

Resources

Aesculape (1913) Advertisements for E. Cogit et Coampanie

Bulletin d'Histologie Appliquée à la Physiologie et à Pathologie et de Technique Microscopique (1928) Advertisements for Etablissments Cogit, Vol. 5

Bulletin de l'Institut Pasteur (1912) Advertisements for E. Cogit et Coampanie, Vol. 10

Bulletins de la Société de Pathologie Exotique (1936) Advertisements for Etablissments Cogit

Death record of Albert Alexandre René Cogit (1915) accessed through ancestry.com

Death record of Emma Aline Louise Monnier Cogit (1899) acessed through ancestry.com

Death record of Joseph Ernest Cogit (1912) acessed through ancestry.com

France public records, accessed through ancestry.com

L'Industrie Chimique (1921) “Les Établissements Cogit, 36, bd St-Michel établi au point compris toute la portée des décisions qu'ils ont à prendre. Les de vue de l'installation des laboratoires de Sciences, Chimie, Bactériologie, Biologie, présentent un nouveau verre de laboratoire ‘Le Boromica’ qui est fabriqué par la Cristallerie du Val St-Lambert, dont les établissements connus dans le monde entier occupent actuellement 5600 ouvriers, possèdent 26 fours de fusion, 250 creusets de 100 kg chacun de capacité dont la production totale est d'à peu près 50 millions de pièces par an” (“The Cogit Establishments, located at 36 Boulevard St-Michel, has established a comprehensive understanding of the full scope of the decisions they must make. The projects, in view of the installation of the Science, Chemistry, Bacteriology, and Biology laboratories, present a new laboratory glass, ‘Le Boromica,’ manufactured by the Cristallerie du Val St-Lambert, whose world-renowned facilities currently employ 5,600 workers, have 26 melting furnaces, and 250 crucibles, each with a capacity of 100 kg, with a total production of approximately 50 million pieces per year”), Vol 8, page 451

International Scientists’ Directory (1894) “Cogit, E. et Cie, 49 Boulevard St. Michel, Paris. Microg. Bacteriol. Depôt des microscopes, Leitz”, page 69

Journal de Micrographie (1879) Advertisements for E. Cogit, multiple issues

Journal de Micrographie (1880) Advertisements for E. Cogit, multiple issues

Langeron, Maurice (1925) Précis de Microscopie, L’Académie de Médicine, Paris

Marriage record of Marie Jeanne Gabrielle Cogit (1890) (lists the family home as 17 Quai St. Michel) accessed through ancestry.com

Paris Medical (1938) Advertisements for Etablissments Cogit

Revue Générale de Botanique (1910) Advertisements for E. Cogit et Companie, Vol. 22

Revue Internationale de Botanique Appliquée et d'Agriculture Tropicale (1927) Advertisements for Etablissments Cogit, Vol. 7

Strasburger, Eduard (1886) Manuel Technique d'Anatomie Végétale, F. Savy, Paris, page 9

Suisse Catalogue special, Education et enseignement, Exposition Universelle Paris (1878) “Cogit, E. rue des grottes, 28, á Genéve”, page 33

Traité de Microscopie Médicale et Pharmaceutique (1889) Advertisements from E. Cogit

Zeitschrift fur Wissenschaftliche Mikroskopie (1893) Advertisements from E. Cogit et Companie