292 Scientific Proceedings, Royal Dublin Society. 
(2) Same, but with re-fusion of undissolved particles; all 
in solution. 
Radium in grams per gram 64:5 x 10°”. 
(3) On 10 grams. 
Part soluble in HCl (7:21 grams). By method B. 
Radium in grams per gram of soluble part 64°3 x 10”. 
Insoluble part (2°79 grams). By method A. 
Radium in grams per gram of insoluble part 15:7 x 10. 
Mean radium content in grams per gram of whole amount 
HOH seo, 
Radiolarian Ooze. Chall. Station, 274. Lat. 7° 25’ 8., long. 
152° 15° W. 2750 fathoms. (Central Pacific.) Magnetic 
particles had previously been removed from this Ooze by Sir 
John Murray. 
(1) On 20 grams by method A. 
Radium in grams per gram 50°3 x 10. 
(2) On 8 grams by method A. 
Radium in grams per gram 50°77 x 107". 
(3) On 6°33 grams, method A, but all in one acid solution. 
Radium in grams per gram 49°38 x 10™. 
Manganese Nodule. Chall. Station, 274 (as above). 
On 25 grams by method B (nearly all dissolved). 
Radium in grams per gram 24:0 x 10-™. 
Manganese Nodule. Albatross Station, 4658. Lat. 8° 295 S., 
long. 85° 36:6’ W. 2870 fathoms. (Pacific Ocean, off coast 
of Africa.) 
- On 12 grams by method B, the hard manganese shell only 
used. Nearly all dissolved. 
Radium in grams per gram 21:0 x 10%. 
Tt will be seen that the deposits richest in radium are those 
which occur in the most central parts of the Pacifie Ocean. From 
this region not only the Red Clay, but the Radiolarian Ooze, is 
remarkably radioactive. ‘The Globigerina Ooze from the Pacific 
is also somewhat richer than Atlantic Ooze. The manganese 
nodules from the central Pacific are, again, rich in radium. The 
radioactivity of the Blue Mud of the Continental border region 
