~26- on the plates, 1,070 c/m after the addition of 1 ce of .5% oxalate (dried sample), and 15 c/m with the aluminum foil. On the basis of the above observations, the total count on the flamed oxalate plates, after subtraction of the count contributed by Feo? and Zr? _-Nb?>, was considered to be due to Fe->, Because some self-absorption oceurs, even on the flamed plates, the value of 250,000 d/m of Fe? in the oxalate fraction is probably a conservative estimate. The next elution peak for sample II occurred in the ammo- nium citrate pH 3.5 fractions d through 1. (Fig. 7) contained 7 The Y spectrum peaks of Co?! (.12 MEV, 12,900 d/n), C08 (.81 MEV, 4,130 d/n), °° (1.17 and 1.33 MEV, 13,400 d/), and zn°5 (.51 and 1.12 MEV, 78,100 d/m). were made from the sample and a maximum was observed, Mass absorption curves PBenergy of .34 MEV This is in agreement with the reported B energies for Co>!’ (.26 MEV PB * 1008), C028 (.48 MEV Bt 15%), C09 (.31 MEV B 7 100%), and zn©> (.32 MEV B * 9.5%). ‘The observed B count of 12,600 ¢/m in the fraction was identical with the B count calculated on the basis of the 97 count. The last peak observed in the elution curve for sample II eccurred in the ammonium citrate pH 4.1 fractions a and b. the basis of a low B to Y of 1.0 MEV, and a strong 7 Gm ratio, an observed maximum B energy peak at .84 MEV (Fig. 7), the isotope was identified as Mn>" (8,200 dfn). A subsequent re-elution of the 4,1 fraction according to the method of Kraus and Moore (1953) confirmed the presence of Mn 544 which in this method is eluted by 12 Mand 6M HCl. detected, A trace of Co2/? 98,6 contamination was also a