BROWN, J.H.

A second Dutch edition of the English book ""Spectropia, or surprising spectral illusions showing ghosts everywhere and of colour"" (London, 1864), about a specific optical illusion. The reader should stare for about 40 seconds at a coloured illustration. After that, he should look at a blank paper or wall and the illustration reappears in a different colour.
Ref. Papertoys p.376