Table 1. Radioactivity of Marsh Samples Plankton values in disintegrations per minute per gram of wet sample Water _ Filter paper " " Surface Stn. W. fp. Ww. 1 14356 2859 6 8064 8 fp. w. fp. 150m fp. w. fp. v. fp. 35 21 9 370 166 58 -1228 29 4 -#306 35 692 27 453 3738 281 4346 261 472 48 178 96 11683 5460 1343 3020 218 5172 276 552 128 308 30 12604 10 3072 1323 664 36 284 18 186 10 2122 18 713 11 12 13 14 15 1834 2926 3286 1650 1886 548 8329 779 2353 256 16 17 18 19 20 1824 1450 1606 1354 1378 502 214 380 108 5428 9 1786 2096 * Sample from 500m 1112 88 666 140 27 41 93 388 188 648 670 214 434 10 22 46 =22 37 106 106 104 100 234 248 200 1690 2ejk 302 15 #418 18 18 ©8662 1 194 1124 14 56 6 68 =i 82 158 1252 164 598 672 468 528 27 42 AT 8947 38-459 250 190 250 238 222 «24 116 3922 =—1T 8638 1184 46 20 31 34 16 15 #4156 #174 40 50 4s : 483 796 1065 1448 14788 3426 3692 10 18 20 22 27 8348 3313 2065 886 596 3 122 36—COT 8 16 2 -8 4 66 4S0 459 382 466 612 88 72 90 #110 84 } Plankton 226 168 126 5310 136~=6#(1 12 74% =56 -6 298 46 252* 400m 8059 54 12 124 1582 1306 100m } : . 277 634 98 w. E “ liter for the residue from 1 liter of water 4O4 2860 294 2080 10838 5140 6706 6552 302 50m " " 1766 7 \ \.\ 25m " " 8022 3117 1510 588 2 3 i 5 Ge~ " " ie