January 10, 1913] 



SCIENCE 



75 



ence of sodium must have existed more abun- 

 dantly on the land. This is along the lines of 

 recent progress, and it is particularly favored 

 because it is the only apparently reasonable 

 explanation for another discrepancy arising 

 from the facts of geochemistry. This addi- 

 tional discrepancy is involved in the succeed- 

 ing paragraphs. 



FURTHER EVIDENCE FROM GEOLOGY INDICATING 



THAT SODIUM BELONGS TO A SERIES OF 



RADIOACTIVE ELEMENTS 



There are other elements carried to the 

 ocean by the rivers in a soluble state, vphich 

 indicate quite a different age of the earth, and 

 consequently favor the radioactivity of sodium. 

 Only those elements that are not deposited in 

 the ocean bed or otherwise removed from the 

 ocean vpater may be considered for reliable in- 

 formation. Clarke in his " Geochemistry," 

 second edition, p. 125, gives the following 

 facts; the figures in the last column are my 

 own deductions however. 



The geologists do not believe that the rivers 

 carried any less chlorine or sodium formerly 

 than they do nov7. In fact, Becker thinks that 

 they must have carried more previously than 

 they do now. But supposing they did carry 

 less sodium in previous ages (in order to ex- 

 plain away the discrepancies on the age of the 

 earth), there is no obvious reason why they 

 should not also have carried proportionately 

 less chlorine. We may, therefore, for checking 

 purposes, say nothing concerning the annual 

 river output further than it should have varied 

 alike with sodium and chlorine. On this as- 

 sumption the above figures show that there is 

 not as much sodium in the ocean as there 

 should be. Disregarding the radioactivity data 

 for the uranium series of elements altogether, 

 we see that the above evidence favors radioac- 

 tivity of sodium. Clarke goes on further to 

 state : 



We can understand the accumulation of sodium 

 in the ocean and some of the losses are accounted 

 for, but the great excess of chlorine in sea water 

 is not easily explained. In average sea water 

 sodium is largely in excess of chlorine; in the 

 ocean the opposite is true, and we can not help 

 asking whence the halogen element was derived. 

 Here we enter the field of speculation and the 

 evidence upon which we can base an opinion is 

 scanty indeed. 



This excess of chlorine can be accounted 

 for by the same hypothesis that was used to 

 explain the discrepancies in the age of the 

 earth in the early part of the paper, viz., 

 sodium has either accumulated radioactively 

 on the land or disintegrated in the ocean, 

 while for chlorine either these changes have 

 not taken place or else they have gone on at a 

 rate much slower than that in sodium. 



From the foregoing, it is obvious that, 

 whether we consider the radioactive data or 

 only the data of geochemistry, either method 

 of approach makes it convenient to as- 

 sume that sodium belongs to a radioactive 

 series of elements. There has not been to my 

 knowledge any satisfactory explanation for the 

 discrepancies to which attention is called in 

 this paper, either singly or in common. How- 

 ever, it may be noted that the age of the earth 

 as calculated from the chlorine content of the 

 ocean is yet much smaller than that given by 

 the radioactive data, but I do not believe this 

 to be seriously against the argument as pre- 

 sented. It may be that chlorine is accumu- 

 lating slower than sodium on the land, or per- 

 haps all matter is radioactive in varying de- 

 grees, but that is beyond the argument here 

 presented. 



It seems worth while to inquire further 

 what elements of atomic weight greater than 

 that of sodium are found more abundantly on 

 land than in the ocean. If our hypothesis is 

 correct we might obtain a list of elements one 

 or more of which should give rise to sodium. 

 And a further study of this list, both in na- 

 ture and in the laboratory, might reveal the 

 parent of sodium. Of course if the parent of 

 sodium had long ago become extinct this 

 search would be futile. F. C. Brown 



State University or Iowa 



