Examples of experiments with the chrysotype process using gold. Depicts four different prints of genre paintings in the colour purple of cassius. John Herschel's experiments with Chrysotype process which uses salts of gold and iron.
The annotation describes what is there: 'specimens of chysotype, or aurophotography, illustration of Art 212 or Sir John Herschel's paper'.
He makes note that 'they should be examined in a good light, and under a pretty strong magnification'.
Experiments taken from Herschel's journal entry for the Royal Society in November 1842 called 'On the Chemical Action of the Rays of the Solar Spectrum on Preparations of Silver and Other Substances, Both Metallic and Non-Metallic, and on Some Photographic Processes'.