# The Hidden Value of Early Photographic Technology Manuals: Mapping the Genome of 19th Century Photography

From daguerreotype plates to silver gelatin papers, 19th-century manufacturers supplied photographers with materials to produce photographic images. But because so few of these papers are identifiable, the history of these manufacturers and their materials are untraceable and virtually unknown. Within the Library of Congress' vast holdings of photographic technology manuals, original 19th-century samples of identified photographic papers survive. Senior Photographic Conservator Adrienne Lundgren discusses this project and how a rich history documenting the first century of photography reveals new lines of inquiry for photographic history scholars.

- Kind: Talk
- Year: 2018
- By: Library Of Congress. Prints And Photographs Division
- Genres: Science, History
- Archive: [Library of Congress](https://www.loc.gov/item/2021690758/)
- Licence or status: Rights statement at the Library of Congress (as the archive states it)
- Credit: Library of Congress
- Who can watch: Tweens profiles and older (the archive gives no rating; placed by Invisible Network from its collection and subjects)

[Watch now](https://invisiblenetwork.ai/watch/archive/loc/2021690758?play=1)