538 Transactions of the Canadian Institute. [Vol. VII. 



but from sedimentary rocks, or from what Sterry Hunt calls " fossil sea 

 water, still to be found imprisoned in the pores of the older stratified 

 rocks, and presumably in the younger as well." To answer this affirma- 

 tively would be of necessity to assert that the sodium which now goes 

 to the sea as sodium chloride comes from the supply derived from and 

 deposited by the sea in ancient geological strata — that is, what was at 

 one time in the sea is being returned to it again. Fisher also points out 

 that the strata which are now in the process of formation, imprison 

 sodium chloride in their mass, taking it from the sea. There would 

 thus be a constant circulation of sodium chloride from the ocean to the 

 stratified rocks and back again to the ocean. That would also postulate 

 that the sea was almost as rich in sodium chloride in Silurian times as 

 it is now, and it would go far to support the view that " the sea was salt 

 from the first ;" but if we assume that the sodium of the sea is derived 

 from those sodium compounds supplied by rivers other than the 

 chloride, the estimate of the age of the earth, as given by Joly, would 

 have to be multiplied several times in order to get the approximate 

 length of the period which has elapsed since the oceans of the globe 

 were first formed. 



Another criticism of Joly's view, made along the lines followed by 

 Fisher, is that advanced by Dubois,* who, from a comparison of the 

 amounts of sodium and chlorine supplied to the sea by a large number 

 of rivers, concluded that only a small portion, if any at all, of the sodium 

 derived from denudation appears in river water as sodium chloride ; 

 that the sodium chloride discharged into the sea annually is derived 

 from the rainfall, and the salt deposited in the older strata by the sea. 



As Fisher has already pointed out, it is the sodium compounds 

 other than the chloride that ought to be considered as being primarily 

 derived from the disintegration of rock mass, and, therefore, primarily 

 added to the sea. What the total amount of this sodium is cannot be 

 determined with approximate certainty, but Dubois is inclined to regard 

 it as about one quarter of the total discharge of sodium into the sea as 

 given in Murray's tables, and, consequently, Joly's estimate of the length 

 of the period which has elapsed since water first condensed on the 

 earth's surface would have to be multiplied by four, the product being 

 approximately 400 million years. 



* On the Supply of Sodium and Chlorine by the Rivers to the Sea. Kon. Akad. v. Wetensch., Amsterdam, 

 Proceedings of the Section of Sciences, Vol. 4, p. 388, 1902. 



