These photographic records show conclusively that the color of the light of luminous animals is not a subjective phenomenon due to the purkinje effect and the low intensity of the light, but is real, an actual difference in spectral composition of the light emitted.
"The Nature of Animal Light"
E. Newton Harvey
purkinje carried his study of the patterns on fingers beyond all comparison with Bewick's use of them, of whose existence indeed he could hardly have been aware.
"The Origin of Finger-Printing"
William J. Herschel