Abstract
The marine alga, Valonia, was placed in solutions of .00035 M concentration of the oxidation-reduction dye, 2,6, dibromo phenol indophenol dissolved in sea water. The dishes containing the plant were then screened with glass screens transmitting various wave lengths from 300 to 700μ and were placed in diffuse daylight before an open window or were kept in darkness. The pH of the solution was 5.4. The temperature was 22° C. with a variation of about 0.5°.
The results show that as the length of the incident light decreases towards the ultra violet end of the spectrum, the amount of dye in the sap increases.
By extrapolating the curves to equilibrium, it was found that the penetration of the dye follows the course of a unimolecular reaction.
By calculations from curves of relative energy distribution in the visible spectrum obtained from figures as given by Luckiesh 1 for blue sky light and other sources, it was found that the effect of light on the penetration of this oxidation-reduction dye varies, not as a function of the amount of energy, but as a function of the wave length. The details of this experiment will be published elsewhere.
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