When a need arose for the determination of small amounts of chromium in calcium metal, a rapid, direct method involving no separations was naturally desired. Thus, two methods, calorimetric and polarographic, were suggested. Of the two, a polarographic method seemed the more promising. DEMASSIEUX AND HEYROVSKY~, SPALENKA~, PRA JZLIZR~, AND KOLTHOFF AND LINGANEQ have reported that chromium is reduced stepwise at the dropping mercury electrode giving two well-defined waves. The half-wave potentials are given as -0.88 volt and -1.53 volts VS. the saturated calomel electrode (S.C.E.) in 0.1 N potassium chloride Q_ The first wave corresponds to the reduction of chromic ion to chromous ion, and the second to the reduction of chromous ion to the metal. With acid solutions of the chromic ion only the first wave is observable before the hydrogen wave-PRAJZLER~ made use of both chromium waves in a simultaneous determination of iron, chromium, and aluminium. SPALENKA~ also used both waves to determine zinc and chromium simultaneously. LINGANE AND PECSOK~ report that the diffusion current of the first wave is directly proportional to the total salt conten tration .