The story
Derived from experiments described by A. W. Clayden.
Etymology from Wiktionary, CC BY-SA 4.0.
Today it means: A dark streak that appears in a photograph when there has been a very brief flash of intense light, such as a stroke of lightning, while the photographic plate is being exposed. This effect is due to the flash causing the part of the photographic plate exposed to be less sensitive, so that it is less affected than the surrounds during the rest of the exposure. Full definition →
Derived from experiments described by A. W. Clayden.
Etymology from Wiktionary, CC BY-SA 4.0.