THE LIFELESS WATER 35 



the oceanic tides and tidal currents were similar to those of the 

 present day; for the early strata are full of such evidences as 

 ripple marks, beach footprints, and other proofs of regularly 

 recurrent tides.' 



As in the case of the earth, the chemistry of the lifeless 

 primordial seas is a matter of inference, /. c, of subtraction of 

 those chemical elements which have been added as the infant 

 earth has grown older. The relatively simple chemical con- 

 tent of the primordial seas must be inferred by deducting the 

 mineral and organic products which have been sweeping into 

 the ocean from the earth during the last So, 000, 000 to 90,000,000 

 years; and also by deducting those that have been precipitated 

 as a result of chemical reactions, calcium chloride reacting with 

 sodium phosphate, for example, to yield precipitated calcium 

 phosphate and dissolved sodium chloride.' The present waters 

 of the ocean are rich in salts which have been derived by solu- 

 tion from the rocks of the continents. 



Thus we reach our first conclusion as to the origin of life, 

 namely: it is probable that life originated on the continents, 

 either in the moist crevices of rocks or soils, in the fresh waters 

 of continental pools, or in the slightly saline waters of the 

 bordering primordial seas. 



Salt as a Measure of the Age of the Ocean 



As long ago as 1715 Edmund Halley suggested that the 

 amount of salt in the ocean might afford a means of computing 

 its age. Assuming a primitive fresh-water ocean, Becker'' in 

 1 9 10 estimated its age as between 50,000,000 and 70,000,000 

 years, probably closer to the upper limit. The accumulation 

 of sodium was probably more rapid in the early geologic periods 



' Becker, George F., 1910, p. 18. - W. J. Gies. 



^Becker, George F., 1910, pp. 16, 17. 



