Zenker, Wilhelm. Lehrbuch der Photochromie.

8vo. Berlin: Selbstverlag des Verfassers, 1868. First edition.

A sober octavo, Berlin 1868, printed by its author at his own expense — the surest bibliographic signal that nobody else believed in it. Wilhelm Zenker believed in it enough to bind a painstakingly complicated photograph into the book: an unfixed silver-subchloride Probebild of the Poitevin type, made in 1867. We think it is the first direct colour photograph ever issued in a printed book.

Forty years later Gabriel Lippmann took the Nobel Prize in Physics for interference colour photography. In his Nobel lecture he dismissed Zenker’s explanation of Becquerel’s results — then called the interference layers at the heart of his own method Zenker’s laminae. The theory was vindicated; simply not where Zenker had aimed it.

This episode is about the extraordinary survival of one private copy of this book and its photograph, and the unlikely tale of how we found it. It survived, we think, because everyone who owned it worked with light and knew exactly what they had: Felix Fritz, a German industrial chemist writing on who first saw light darken silver; then René Mächler and Roger Humbert, the Swiss photographers who founded Concrete Photography by abandoning the camera altogether. Three other Probebilder are in institutions. No other copy of the 1868 edition, complete or not, is in the trade.

We also talk about what the specimen looks like now: shifted to a warm reddish-brown, no discrete hues separable, the image carried by tone alone and legible only in raking light. Whether any colour survives below the visible threshold is a question for a reflectance spectrometer, and we would like to hear from someone who owns one.

The full collation, condition report and provenance are on the book’s catalogue entry, where there is also video of the specimen under raking light.

• ☞  Zenker, W. Lehrbuch der Photochromie. Berlin: Selbstverlag des Verfassers, 1868. The copy in question.
• ☞  Lippmann, G. Nobel lecture, 1908 — where Zenker is dismissed and his laminae named in the same breath.
• ☞  Eder, J. M., on the earliest observations of light-sensitive silver — his exchange with Felix Fritz.
• ☞  On Concrete Photography: the work of René Mächler and Roger Humbert, camera-less, from the 1960s.
• ☞  Episode transcript and full collation notes — available to readers of the Prospectus.