944 



A TREATISE ON METAMORPHISM. 



Taking the above estimates, the amounts of the different elements of 

 the ocean salts are given in the following table: 



[Unit=10 12 metric tons.] 



CI 25,557 K 



Na 14,180 i Br 



2,445 j C. 



Mg 1,743 



S 1,187 



Ca 553 



512 



87 

 19 



Total 46,283 



Clarke, using the above results of Dittmar, computes the elemental 

 composition of the ocean, as already given (p. 936); but for convenience his 

 results are here repeated: ° 



Composition of ocean. 



0.. 



H . 



CI 



Na. 



Mg 



Ca. 



85. 79 



10. 67 



2.07 



1.14 



.14 



.05 



0.04 

 .09 

 .008 

 .002 



Excluding the subordinate constituents, air has the following compo- 

 sition : 



Composition of air. 



By volume. 



Nitrogen 

 Oxygen . 



Per cent. 

 79.08 

 20.92 



By weight. 



Per cent 

 76. 88 

 23. 12 



The amount of carbon dioxide in the air is 0.03 per cent by volume 

 and 0.045 per cent by weight. 6 There are also in the air minute proportions 

 of water vapor, ammonia (NH 3 ), argon, etc. 



According- to Woodward (see p. 933) the mass of the atmosphere is 

 equivalent to that of 5,292,000 cubic kilometers (1,268,000 cubic miles) of 

 water of unit density. This is equal to a weight of 5,292,000,000,000,000 

 metric tons. Disregarding the subordinate elements, the weight of the 

 nitrogen would be 4,068,489,600,000,000 metric tons, and of the oxygen 

 1,223,510,400,000,000 metric tons. 



"Clarke, F. W., Relative abundance of the chemical elements: Bull. U. S. Geol. Survey No. 78, 

 1891, p. 35. 



B Mendel6eff , D., The principles of chemistry, translated by George Kamensky: Longmans, Green, 

 & Co., London, 6th ed., vol. 1, 1897, pp. 235, 236, and 238. 



