AbstractsBiology & Animal Science

Light in its various phases exerts a marked influence on the functional as well as the physical structure of all living matter. The phenomena of light involves two theories: (1) the wave or electro-magnetic theory conceiving light as consisting of electric emanations or waves of various frequencies and intensities given off from many substances. (The principle source of light as thus conceived is the sun with its estimated temperature of 10,000 F.); (2) the quantum theory which conceives light as a factor involved in ionization in chemical reactions (negative electrons are ejected from a surface of metallic iron when a strong light is focused upon it; i. e., the light causes a quantum of ionization in the iron.) Figure 1 is a diagram showing some of the important physical properties of light.