Ir si. Upon strong ignition, the fibers would char but retain most of their form, turning 4 white Salt, which was then easily soluble in dilute HCl. The fibers, therefore, appear to be an organic material. Emission spectra of these droplet residues revealed the presence of macroscopic amounts of aluminum and iron presumably from the device casing. Macroscopic amounts of calcium and magnesium were also observed; these elements are probably due to the inclusion of coralline material and thermally altered sea saits. In addition to the radiochemical determinations of samples from the destroyers, IC samples from coracles were subjected to the standard analysis for molybdenum (Reference 114). The total fissions determined from Mo” analysis are presented in Table 3.41 together with the net activity of the analyzed tray on Shelf 5 of End-Window Gamma Counter 3 (a counter system similar to that described in Section 3.3.1). The data may be used in conjunction with the IC decay data to obtain additional information on the gross fractionation of the fission product mixture, by plotting the change in fission product ratios with time, as described in Reference 115. No consistent variation with time of collection or with distance from surface zero could be established for the total fissions determined from Mo”analysis of the IC trays. The lack of a consistent variation with distance is probably due to the fact that the selected IC trays do not represent a total sample. Additional Mo” analyses of total samples from Wigwam and Umbrella are given in Reference 105. Special rapid recovery techniques were also employed to permit early chemical analysis of gross fallout collections for induced ci™. The rapid analytical techniques and a full account of A theoretical capture-to-fission ratio of 0.0028 has been calculated in Reference 116. The difference between the calculated and observed ratios is believed to be caused by the marked fractionation of the different nuclides used for the fission determinations. 341 ~ Page 342 daleted