-~1Dp- Also, spike experiments were done at this Laboratory, in cooperation with Kawabata*, using radioactive Mn, Co, Fe, @n, and stable Cu and Ni according to the method of Kraus and Moore (1953). The divalent transition elements were adsorbed onto and eluted from a chloride-treated column of Dowex l. The elution pattern for these elements is given in Table 3. Table 3. Elution pattern of divalent transition elements from Dowex 1 by complexing with HCl solutions Fraction Milliliters of elutriant Element present 12 M HCl 10 Ni 6 M HCl 10 Mn 4 M HCl 10 Co 2.5 M HCl 10 Cu 0.5 M HCl 10 Fe 0.005 M HCl 20 an 10 -- -- 2n Distilled water Ignited resin In addition to the above described spike runs, ion-exchange separations were made on five samples from Bikini and Eniwetok Atolls. These included four biological samples and one soil sam- ple as follows: I Clam kidney, Belle Island, Eniwetok Atoll, collected September 22, 1956, Dr. Toshiharu Kawabata, of Health, Tokyo, Japan on leave from the National Institute wt 4 ’ \ ‘ i \ o