Alexander, J. B. (1893). Chlorophyl. In J. B. Alexander, The dynamic theory of life and mind: An attempt to show that all organic beings are both constructed and operated by the dynamic agencies of their respective environments (pp. 176-182). Minneapolis, MN, US: Housekeeper Press.
http://dx.doi.org/10.1037/12949-024
Mention has been made of chlorophyl. This substance, like protoplasm, in general, is composed of oxygen, hydrogen, nitrogen and carbon, to which is added iron. Under the influence of sunlight it becomes green. In the lower cellular plants it appears to be diffused throughout the mass of the protoplasm of the cell, coloring it all more or less. (PsycINFO Database Record (c) 2016 APA, all rights reserved)