224 ALFRED C. LANE 



Substituting in this formula the numerical data used by Joly, one 

 will get Joly 's results as to the age of the earth. By assumin_g appro- 

 priate values of R one can assign a date to the burial of any brine. 



N and C are reasonably well known. Sir John Murray's esti- 

 mates, the only ones made as yet, for c and especially n are liable 

 to be seriously in error. The quantity d (i-rR) is likely to be a 

 small correction, except in the case of volcanic emanations of chlorine, 

 for in the case of most other allowance r is likely to be pretty nearly 

 reciprocal to R. 



Inserting Joly's numerical values we obtain 

 _ 1. 41 —2.547? 



^ ~ i.S7-.84R-d{i-rR) 

 in hundreds of millions of years. 



A formula involving a slightly different volume of the ocean 

 may be as exact and is more convenient, for computation, and was 

 used by the author. 



A somewhat elaborate discussion of analyses and the probabil- 

 ities of the case led to the conclusion that, while a similar formula, 

 which was given, could be constructed for any two substances brought 

 into the ocean by the rivers, among those abundant enough to be 

 well determined by analysis the chlorine and sodium were the only 

 ones likely to accumulate, and not be modified seriously in relative 

 proportions even when buried. 



Among the difficulties discussed were the high concentrations 

 of the deeply buried waters, and the very low amount of sodium 

 in the Keweenawan, which is by no means the base of the geological 

 column. 



The suggestion was made that perhaps the volcanic contribution 

 to the ocean was by no means an unimportant one, and that there 

 had been a continuous emanation of chlorinated water, adding 

 to the volume of the ocean from the very earliest times. 



The analyses upon which the paper was based have mainly 

 been published in Water-Supply Paper No. 31 of the United States 

 Geological Survey, and in the annual report of the Geological Sur- 

 vey of ISIichigan for 1903. Tables of analyses, in ionic form, were 

 given for Murray's average river water. Lake Superior, and the 

 Mississippi River; also of the ocean and Keweenawan mine- waters. 



