56 '^he Philippine Journal of Science 



od, one direct test was made on the same sample. Previous to 

 sealing up, the sea water was again acidified with approximately 

 20 cubic centimeters of pure hydrochloric acid. The method 

 used in this test was, as nearly as possible, a duplication of Joly's, 

 the sample being boiled under a partial vacuum and the flask 

 finally filled with distilled water in order to force all the emana- 

 tion given off into the aspirator bottle. The determination on 

 the activity of the gas was then made in the usual manner, ex- 

 treme care being taken to flush thoroughly all the tubes between 

 the aspirator bottle and the ionization chamber. 



The value obtained by this method was 0.1, or just half the 

 mean value obtained by the charcoal absorption method. In 

 dealing with large quantities of water, we are inclined to believe 

 that the charcoal absorption method will give the more accurate 

 results. In previous work we found that merely boiling a solu- 

 tion from fifteen to twenty minutes was not sufficient to remove 

 all the emanation from even a weak radium solution, but that 

 bubbling air through the boiling solution was much more effec- 

 tive. For this reason, if no other, the charcoal absorption 

 method ought to be slightly more reliable. 



Sufficient data are not at present available to permit the draw- 

 ing of conclusions regarding the radium content of the oceanic 

 waters of this part of the earth compared to such regions as the 

 northern Atlantic Ocean. But in the light of our results deter- 

 minations from different parts of the Pacific Ocean are much to 

 be desired. 



