Martin scale Martin scale The Martin scale is an older version of color scale commonly used in physical anthropology to establish more or less precisely the eye color of an individual; it was created by the anthropologist Martin in the first half of the 20th century. Later he improved this scale with cooperation of Dr. Schulz – the Martin-Schultz scale. The original Martin scale, summarized below, consists of 16 colors (from light blue to dark brown-black) that correspond to the different eye colors observed in nature due to the amount of melanin in the iris. The numbering is reversed in order to
Color reaction is required because standard colorimeters cannot operate below a wavelength of 400 nanometers. It is also necessary to use fused quartz cuvettes because glass is opaque to ultraviolet. Many different color reagents have been developed for determining the concentrations of different substances. For example, Nessler's reagent can be used to determine the concentration of a solution of ammonia. In thin layer chromatography (TLC) color reactions are frequently used to detect compound spots by dipping the plate into the reagent or by spraying the reagent onto the plates. Color reaction In chemistry, a color reaction or colour reaction is a chemical