Manchester Memoirs, Vol xli. (1897), No. 8. 13 



•dark brown precipitate with cobalt ; but this also is 

 decomposed completely when boiled for a few minutes. 

 It also gradually decomposes when kept in the dark, and 

 a sample tested on one occasion, after being left for three 

 days, had lost entirely its bleaching power. 



Since the appearance of Lunge and Schoch's paper 

 there have been occasional references to hypoiodites in 

 other papers. Thus C. Lonnes (Zeit. anal. Chem., 35, 

 409-436) has pointed out that the conversion of iodine 

 into an iodide and an iodate by an alkali is not imme- 

 diately complete, part remaining uncombined, and part 

 being converted into hypoiodite, and that the hypoiodite 

 has greater stability in presence of excess of alkali. 



Chattaway (Chem. Soc. Jour., lxix., p. 1572) has stated 

 that in several of the decompositions which the so-called 

 " Nitrogen Iodide" undergoes, hypoiodites are produced. 



Quite recently (Proc. Roy. Soc. Edin., xxi., 235) Dr. J. 

 Walker and S. A. Kay, B.Sc, have published a paper on 

 the so-called " Magnesium Hypoiodite," a brown sub- 

 stance formed by the union of magnesia, either wet or 

 dry, with free iodine, and which has sometimes been 

 supposed to be magnesium hypoiodite. They conclude, 

 however, that it is simply a case of absorption of iodine, 

 without any chemical combination. They find that this 

 brown precipitate is produced when potash is added to a 

 solution of iodine in potassium iodide until the iodine 

 just disappears, and then a solution of magnesium 

 sulphate is added, magnesium hydrate being precipitated, 

 and iodine manifestly liberated. They have concluded 

 from this that, as pointed out above, the reaction between 

 iodine, potash, potassium iodide, and water is a balanced 

 one. 



