Here is a list of important points:
- Bolognese Phosphor is strongly phosphorescent in violet light, but weakened in red light. The effect of the red region is not due to thermal effects.
- Phosphorescence was studied by Becquerel, Lenard, Lommel, Dahms, who all found the same behavior.
- In phototropy (change of color of a solid crystals or other substances under light), for organic substances called Fulgids, radiation through blue glass they became darker, and lighter when radiated through red glass. Stobble found 18 phototropic Fulgids.
- Special phosphors, whose phosphorescence has been destroyed by applying pressure, also show phototropism of a type. Absorption of blue/violet is decreased, while that of red/IR is increased.
- Photographic plate: silver salts turn bluish dark in the negative half of the spectrum, and yellow red in the positive half. Also shows a reduction in the negative, and oxidation in the positive, without immediately altering the chemical constitution, but only through charge imbalances. It's been called the "Herschel effect" and relegated to some obscure corner in photography.
- When oxidizable substances were kept in the violet, dark and red light respectively, the reduction in oxygen was as follows: O2(violet) < O2(dark) < O2(red).
- Heinricher noted in the germination of many seeds that red accelerated the growth, while blue retarded it. Klebs got the same result with fern spores.
- Smallpox is reduced by red light, at least superficially, and increased in blue light. Apparently Charles V was cured by putting him in a room full of red stuff in 1509-10.
- An oxidized copper plate shows a change in potential when part of a Daniell cell, in opposite directions depending on red or violet light. The actual value of the potential depended on the initial voltage.
- Photocurrents are obtained in contrary directions when one of the electrodes is exposed to blue/red light.
- Red strengthens the residual current in the retinae of birds, blue extinguishes it.
- Typical color complementarity in the visual field, e.g. afterimage of red is blue and vice versa.
- Daphnia, or waterflea, is very sensitive to light. When a white light is bright, it moves away, and towards it when the light is weak. However, when a red light is there, even if the intensity is stronger than the white, it moves towards the red, and even a very low intensity blue light is applied, it moves away from the blue.
- In the gas discharge tube, at the cathode there is a blue color, and a red color at the anode.