TABLE 1.—Continued Division or BNE and speci Sample SPECIES No. Sargassum polyceratium Turbinaria turbinata 4 15 32 48 53 | | I 19 62 liecti Collection Date 1961 1961 1961 1961 1961 1961 1961 _ Site 7 10 1 12 14 10 14 Soluble Organic, 0.992 0.360 fraction Calcium, 8.600 0.040 mg/g g/g . . . Radium, Thorium, Uranium, 0.100 0.130 0.440 pCi/g ug/g ug/g 0.981 0.928 0.970 0.970 0.380. 0.500 11.200 14.000 9.400 8.800 0.031 0.044 0.061 0.080 6.080 0.080 0.150 0.090 ‘N X ox 3 0.413 0.063 5 10.400 1.842 5 0.051 0.039 5 0.100 0.013 i 0.130 2 0.435 0.000 0.997 0.850 0.310 &. 200 17.100 0.024 0.007 0.110 0.130 0.220 0.610 N xX ox tion with ionized oxygen.* Samples of the ash were then irradiated in the Argonne National Laboratory CP-5 reactor, along with suitable standards. The in- tegrated neutron flux was approximately 5 x 101° n/ em’. After irradiation the samples were dissolved in concentrated hydrochloric acid and fractionated by passage through an anion exchange column. The daughter products, #3Pa and *8°Np from the *%°Th and **°U, produced by neutron irradiation were eluted from the column and assayed by gamma-rayspectros- copy. PEE get § armen g/g . Nitrogen, Calcium Calcium was determined by atomic adsorption spectrophotometry.“ The determinations were made on the same solutions used for radium analysis, Protein Nitrogen Protein nitrogen was determined by the micro Kjeldah] method. One-hundred-milligram samples of the algae were suspended in 5% trichloracetic acid and allowed to remain overnight at 4° C. The precipi- tate was washed by centrifugation with the trichlor- acetic acid and then oxidized with concentrated sulfuric acid and hydrogen peroxide. After partial neutralization of the digestion mixture, the nitrogen content was determined colorimetrically using Ness- ler’s reagent. ‘® Total Organic Matter The total organic matter content was estimated irom the loss in weight during the low temperature * Tracerlab Low Temperature Asher, Model LTA 600, Large Sample Assembly. 1 0.310 0.000 2 12.650 0.000 2 0.015 0.000 2 0.120 0.000 0.430 1 0.220 1 0.610 0.000 oxidation with ionized oxygen. The oxidation of or- ganic matter is presumed to be the major contributor to the loss of weight, but it must be recognized that the oxidation of varlous inorganic compounds, i.e., bromides and iodides, may also occur and contribute to the loss in weight. RESULTS AND DISCUSSION The results of the analyses for (1) total organic material, (2) the concentration of nitrogen precipitated by trichloracetic acid (as an index of protein content), (3) calcium, (4) radium, (5) thorium, and (6) uranium are given in Table 1 together with other data pertinent to the identification of the individual algal samples. The first three of these analyses are representative of the major chemical components of the algae. Calerum is considered a major component because, of the ten divisions into which algae have been classified, five contain members which lay down appreciable concentrations of calectum carbonate.Three of the five divisions, the green algae (Chlorophyta), the brown algae (Phaeophyta) and the red algae (Rhodophyta) are represented in the samplings made in this study. For Chlorophyta the calcareous algae belong to the families of the order Siphonales—the Dasy- cladeceae (Cympolia) and the Codiaceae (Halimeda opuntia and Penicillus capitatus). On the other hand Padina gymnospera is the sole representative of the Phaeophyta which calcifies, and for the Rhodophyta there was a single collection of Galaxaura cylindrica which is highly calcified. The results from the analysis of a limited series of samples of seawater and sand are given in Table 2. The analytical results presented