8 in Tables 1 and 2 are, for almost all the different algal samples, averages of replicate determinations on the same large (20 g} sample for radium and calcium, tion of the product of low temperature oxidation nitric or hydrochloric acid. These residues were four to be soluble in hydrofluoric acid and were, therefor in all probability hydrated silicates. This residue w: filtered off and weighed. All analytical results ha. been normalized to the soluble weight, and the fra: tion of each sample which dissolved is shown show in Table 1. The insoluble residue generally account« for less than 10% of the gross weight; for most of tl and on different small (< 1 g} samples for total or- ganic content, nitrogen and the neutron activation analysis experiments, which generally were in agreement to better than + 10%. In almost all of the algal samples an insoluble offwhite residue remained after wet oxidation or dissoluTABLE 2. ANALYSIS OF WATER, SAND, AND THREB SPECIES OF ALGAE COLLECTED FROM THREE DIFFERENT LOCATIONS Location Cajo Margarita (9) Material Soluble Water Sand Halimeda opuntia Penicillus capttatus 1.00 0.984 0.978 0.970 Padina gymnespora Cabo Rojo (10) Punta Arenas (12) oie pie uelfs Ra/Ca U/Ca 3.9 X 107* 0.30 0.31 0.23 7.2 * 10% 0.039 0.073 0.034 (3 &K 190° 1.68 1.62 1.70 0.18 0.13 0.24 0.15 7.6 5.3 5.2 7.4 — - — _— _ _— Water Sand Halimeda opuntia Penictllus capitatus 1.60 6.780 0.973 0.928 4.4 104 0.32 0.31 0.28 1.38 & 104 0.072 0.045 0.060 13 X 107 @ 1.08 1.48 1.69 0,29 0.22 0.15 0.21 6.8 3.4 4.8 5.9 Padina gymnospora 0.938 0.15 0.067 0.64 0.44 4.2 Water Sand Halimeda opuntia Penictllus capitatus Padina gymnospora 1.00 0.554 0.956 0.852 0.836 3.5 x 1074 0.25 0.29 0.28 0.19 4.1 * 1075 0.086 0.08 6.080 0.060 3 & 103 @ 0.59 1.46 1.65 0.70 0.12 0.34 0.37 0.29 0.31 8.7 2.4 5.0 6.0 3.6 {s)} From Ref. 15. TABLE 3. All algae Correlation Organic with Nitrogen Calcium) Radium®) Thorium® Uranium) Nitrogen with Radium Radium») Thorium Uranium) Caleium with Nitrogen™ Nitrogen“) Radium Radium) Thorium? Uranium™ Uranium»? () All data taken. ReEsutts or REGRESSION ANALYSIS Chlorophyta Rhodophyta Phaeophyta R if P R t P R ft P R tT P 0.57 —0.66 —0.23 —0.12 —0.77 64 63 64 33 62 0.001 0.001 — —_ 0.001 0.60 —0.57 —0.40 —0.15 —0.69 26 25 26 16 26 0.001 0.005 0.05 — 0.001 0.15 —0.42 —0.17 —0.67 —~0.73 23 23 23 8 22 — 0.05 — — 0.001 0.65 —0.51 —0.09 — 0.60 —0.73 15 15 15 9 14 0.01 0.05 _ — 0.005 —0.09 —0.14 — 6.09 —0.54 69 56 33 62 — — — 0.001 —0.19 —0.18 27 22 — — —0.06 —0.19 24 19 — — 0.43 0.69 18 15 0.10 0.005 —0.46 26 _ —90.34 22 — 0.29 14 —_ —0,69 —0.69 —0.10 —0.02 —0,22 0.76 0.77 67 55 67 54 32 61 50 0.001 0.001 — — —0.56 —0.67 —0.17 —0.08 25 21 25 2] 0.005 0.001 _ — —0.65 —0.60 0.19 0.51 24 19 24 19 0.001 0.01 — 0.001 0.80 0.82 —0.40 —0.81 18 15 18 15 0.001 0.001 — 0.001 0.001 0.001 0.77 0.83 25 21 0.001 0.001 0.56 0.62 22 18 0.01 0.05 0.50 0.31 14 12 0.10 _— | (b) Selected data. Individual data point dropped if KX — 3¢ < X > X + 3e for each species.