Coefficient of Transmission

If i denote the intensity of a beam of light incident on the surface of any medium, and ia the intensity after it has traversed one unit of thickne of this medium, a is called the "coefficient of transmi ion." In general the intensity of the light I, after traversing a thickne d, will be given by the formula I- iad. a is found to be different for lights of different colors, and hence if the incident light be white, the emergent beam will be colored, the tint usually deepening with the thickne of the medium traversed. Coefficient of Transpiration. A constant in the phenomenon of TRANSPIRATION OF GASES (q. v.), which depends on the conditions of the experiment and on the nature of the gas employed.