SEVERAL characteristic properties of solutions of hypoiodites have been recorded, that is, of solutions obtained by causing iodine (in the solid form or in solution) to react with solutions of alkalis. The evolution of oxygen from hydrogen peroxide and barium peroxide, and the liberation of iodine from potassium iodide were noted by Schijnbein ( J . pr. Chem., 1861, 84, 385) and Seliwanow (Bey., 1894, 27, 1013); and the bleaching of indigo carmine and cochineal by Lunge and Schock (Bey., 1882,

more »

... 5, 1883). The former reaction they attempted to apply quantitatively. Lonnes (Zed. anal. C h m . , 1894,33,409) found that sodium arsenite, and P6chard (Compt. rend., 1899, 128, 1453) that ferrous sulphate, were oxidised by these solutions. The authors have used a modification of a method, proposed by Lonnes (Zoc. cit.), in which the oxidation of arsenite is employed to estimate the hypoiodite, the reaction being represented by the following equation : M I 0 + H3As03 = H,AsO, + MI. * A 3/10 t o 4/10 N solution of iodine monochloride is easily made by gently warming 10 grams of iodine with a mixture of the calculated quantity (2'8 c.c.) of nitric acid of sp. gr. 1 '4, and 30 -40 c. c. of conceii trated HCI of sp. gr. 1.1 5. When all the iodine has dissolved, the solntion is diluted to 250 C.C. with water or dilute hydrochloric acid.