tre dete Saat Foe Dee a at otal were t he weight basis than soft tissues. hermit and the Weighed samples of tissues in pliofillm bags were dried iopora, overnight at 100° C and sent to the Applied Fisheries Labor- long the ’ et te te de ne ae ee atory in Seattle for processing,which was usually accomplished about &@ month after collecting. land he btained In processing, the samples in pliofilm bags were applied to the plates(1 1/2-inch stainless steel, previously weighed), ashed overnight at 500° - 5509 C, slurried with alcohol, and len Gried. ted The plated ash received a few drops of Formvar dissolved in ethylene dichloride (up to 1 mg dry equivalent) and for to affix the ash to the plate. lable The plates were then weighed, and counted in methane gas-flow counters. Except in the case of rats, counts were corrected back to date of collection using the decay rate of island soil "Ive- itain- (plate 7542) collected May 15, 1954 at Belle (Fig. 5, p. 11). Iliter Hota as TA LR MTRNER con BUY LYcopa coe Ej Fase toy, ema For rats the decay correction was based upon the individual decay rate for each plate. Self-absorption correction factors were based upon land soil collected June 7, 1954 at Edna, the decay curve of which (plate 9170) appears in Figure 5, page 11. Within seven months after Nectar an increase in average energy necessitated 4 reduction in the self-absorption correction factor for the later The following tabulation illustrates these changes. counting. Ash weight in mg/plate Self-absorption correction factor for counting Before November 1, 1954 After November 1,1954 3 10 30 100 1.0 1.1 1.4 2.0 1.0 1.1 1.3 1.6 300 2.9 1.9 1000 4, 2. aaas Geometry and backscatter for the counters and plates used required a combined correction factor of 1.54. Coincidence correction factors were determined and applied for the counters employed. For the decay curves plate counts were used, corrected only for coincidence. Applying these - correction factors gave values in disinte- grations per minute per gram (d/m/g) of wet tissue as of the date of collection. Processing techniques are further discussed in UWFL-43 and WT-616. Three significant figures were retained throughout the calculations, finally being rounded to two. After plotting d/m/g against time the ordinate was in some os graphs calibrated also in picrocuries per kilogram (uc/kg), assuming 1 uc to equal 2.2 x 10° d/m. 7 MY