~4- Gamma spectra were made from plankton samples aboard the Collett by means of a single-channel fifty-position spectrometer to determine the presence of gamma-emitting radioisotopes other than the expected fission products. Selected samples containing mixtures of gamma emitters were wet ashed, dissolvedin acid solution and passed through a cation exchange column for the separation of the radionuclides. The radioisotopes were identified by beta and gamma energies and by the elution fractions in which they were found. Confirmation of the presence of wi85 was obtained by chemical precipitation techniques, by beta and gamma energies and by comparison of sample radionuclide separations with control experiments utilizing spikes of wi85 , Maximum beta energy was determined by mass absorption techniques, The precipitation method of analysis (Kleinberg, 1954) for wi85 consisted of two precipitations of tungstic acid, each followed by the dissolving of the precipitate in con- centrated NH,OH. The solution was then scavenged with Fe(OH), and with molybdenum and bismuth sulfides in the presence of tartaric acid. Niobium was removed by extraction with chloro- form and cupferron and the tungsten reprecipitated as tungstic acid. wi85, The gamma spectrum of the final precipitate showed only free from other gamma emitters. S Lily DOE AR