In its photosensory effect, the action of light depends on two variables,—intensity and time. If the intensity alone is varied, the photochemical effect is proportional to the logarithm of the intensity. If the time alone is varied, the effect is proportional to the time. Experiments here reported show that when both the intensity and the time are varied, the photochemical effect is equal to the product of their separate activities: E = kt log I. These results furnish the means of expressing directly the relation between the intensity of illumination and the reaction time of Mya.
Article| January 20 1921
TIME AND INTENSITY IN PHOTOSENSORY STIMULATION
From the Physiological Laboratory, College of Medicine, Creighton University, Omaha.
Received: November 11 1920
Online ISSN: 1540-7748
Print ISSN: 0022-1295
Copyright, 1921, by The Rockefeller Institute for Medical Research
Selig Hecht; TIME AND INTENSITY IN PHOTOSENSORY STIMULATION . J Gen Physiol 20 January 1921; 3 (3): 367–373. doi: https://doi.org/10.1085/jgp.3.3.367
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