The possibilites of applying the zone-melting technique to a separation of xylene-ev, a'diamine(XDA) isomers were investigated.The starting sample(f, p.14.0)used in this experiment was a mixture containing about 30fe 50f P-XDA in m-XDA.In a glass tube container of 9 mm 1, D., the zone passages were carried out for 1. v8 times at a fixed zone travel rate of 32 mm/hr in the room kept at 5C.After the repetition ef refining operatiens in series, a material of freezing point 62, 1C was finally obtained, The final product was identified as highly pure p-XDA by compqFing-!tS'infraied spectrum and freezin- @point with those of an auihehtic sample ef prXDA, The yield of the final product in the last operation was 18%.t Studies on Zone Melting for Purification ef Organic Cempeund. IV.