942 



A TREATISE ON METAMORPHISM. 



As a result of the work of the Challenger expedition, the ocean is esti- 

 mated to have a volume of 1,283,840,000 cubic kilometers." This estimate, 

 equivalent to 307,000,000 cubic miles, is somewhat in excess of Woodward's 

 estimate of 302,000,000 cubic miles, given on page 933. The weight of 

 1,283,840,000 cubic kilometers of the ocean, with a specific gravity of 1.03 

 (see p. 933), is 1,322,355,000,000,000,000 metric tons. Of this 85.79 per 

 cent, or 1,134,448,354,500,000,000 metric tons, is oxygen, and 10.67 per 

 cent, or 141.095,278,500,000,000 metric tons, is hydrogen. Taking the 

 maximum salinity of sea water as given by Dittmar, b 37.37 grams of salts 

 per kilogram of water, sea water is 96.263 per cent water and 3.737 per cent 

 salts. The 3.737 per cent salts is made up of the following compounds: 



.Composition of salts in sea water." 



Dittmar, William, Composition oi ocean-water salts: Narrative of the cruise of H. M.S. Chal- 

 lenger, vol. 1, pt. 2, 1885, pp. 951, 980. 



& Dittmar, William, Report of the scientific results of the exploring voyage of H. M. S. Challenger, 

 1873-1876: Vol. I, Physics and Chemistry, London, 1884, p. 201. 



''Dittmar, Narrative of the cruise, etc., p. 954. 



