Yol. 65.] ANNIVERSARY ADDRESS OF THE PRESIDENT. CV 



and thus obtain a maximum limit of 421 millions of years, which 

 very certainly cannot have been exceeded, and with almost equal 

 certainty was very far from being attained. 



The method by which we have been led to this result excludes all 

 sources of sodium, except those supplied by weathering ; no juvenile 

 waters enter into the account, no salts derived from ancient deposits, 

 and the result is obviously in excess since a great but unknown 

 amount of the silica on which it depends has been removed from 

 solution by organic processes, leaving a mere residuum of the original 

 supply. 



Although excessive, this result has one merit at least, it sets 

 bounds which cannot be overstepped * to those extravagant specu- 

 lations demanding thousands of millions of years, which have some- 

 times been put forward even by distinguished investigators. 



Having reached this insuperable maximum, we may now search 

 for the irreducible minimum. 



An extremely interesting study of the Elbe and its tributaries 

 has been made by J. Hanamann. He has published 120 analyses 

 or more of the waters, and among them not the least instructive are 

 those which show the relation between the composition of the 

 streams and the rocks out of which they flow." The results of these 



are as follows ; — 



Granite. Basalt. Mica-schist. Pliyllite. Cretaceous. 



CO., 30-49 46-85 32-14 35-94 3301 



S0 4 .'. 14-12 7-94 12-86 6-45 27'69 



CI 6-39 166 7-24 10-15 2-87 



Ca 11-89 20-07 1261 11-91 2212 



Mg 3-58 5-76 5-08 5-02 5-29 



Na 10-57 6-22 10-85 11-20 3-43 



K 5-63 3-20 422 4-39 2-72 



Si0 2 .. 17-33 7-67 15-00 14-94 287 



Fe 2 6 3 0-63 



Totals 10000 10000 1 0Q-Q0 100"00 100"00 



Salinity, parts per million. 65 364 74 48 603 



It may be observed that these waters, although remote from the 

 sea coast, still contain a very considerable amount of chlorine ; this 

 is most marked in the case of the water flowing out of the granite, 



1 It is very difficult to 'prove' anything, and it may be objected here that 

 the silica is a measure of the amount of disintegration but not of the sodium 

 carried into the sea, since some of the sodium may be arrested in some 

 unknown way and retained by the land. The onus probandi rests with those 

 who raise this objection. 



2 J. Hanamann, Archiv Natur. Landesdurchforschung Bohmens, vol. ix 

 (1894) & vol. x (1898). Cited by F. W. Clarke, op. jam cit. p. 79. 



vor,. lxv. It 



