dithizone is a reagent of the first class it is most valuable for low concentrations and it is a color-producing substance. It was first used in this country in 1993 and because of the comparative recency of its introduction and the multiplicity of its possible applications it is worthy of particular consideration. diphenylthiocarbazone the complete name for dithizone was first made and studied by Email Fischer in 1882 as a part of his work on the structure and reactions of phenylhydrazine. The preparation is relatively simple and direct as indicated by the equations. On warming of the carazide in alcoholic potassium hydroxide solution, a mutual oxidation-reduction occurs,thus. The diphenythiocarbazone is soluble in the alkali and is precipitated