386 Scientific Intelligence. 



Reducing to the absolute mass of the ocean as given above, we 

 arrive at the following numbers : 



Absolute composition of the Salts of the Ocean. 



Unit=1 Billiox=10 12 Tons. 



Chloride of sodium 35990 



Chloride of magnesium 5034 



Sulphate of magnesium 2192 



Sulphate of lime ]666 



Sulphate of potash.. 1140 



Bromide of magnesium 100 



Carbonate of lime.. _ 160 



46283 

 Total bromine 87-2 ("W. D.) 



Total iodine 0*03 (Kottstorfer.) 



Total chloride of rubidium 25 (C. Schmidt.) 



Mi - . Dittmar adopted Tornoe's expression numerically for the 

 alkalinity of the water by stating the number of milligrams of 

 C0 2 which would convert the surplus base into normal carbonate, 

 and referring it to one litre of sea-water analyzed, or — to get rid 

 of degree of salinity — referring it to 100 parts by- weight of total 

 salts in the water, or to 55*42 parts of halogen counted as chlorine. 

 The statement that the alkalinity = -154 signifies that per 100 

 parts of total salts the water contains 0*154 parts of C0 2 as nor- 

 mal carbonate, or rather in the R"0,C0 2 part of the carbonate a& 

 formulated. The alkalinity ranged from 0*140 to 0*164, with a 

 tendency to the highest results in the bottom waters. One cause 

 of more lime carbonate in the bottom waters is found in the shells 

 of dead crustaceans, etc., over the bottom. Some free C0 2 also 

 may be present. 



The salinity of the waters is oceanographically a function of 

 the geographic position, depth, and time. Mr. Dittmar deter- 

 mined, from comparisons of ascertained specific gravities with 

 chlorine determinations, that the per-millage of chlorine in an 

 ocean water at a given temperature is proportional to the excess 

 of its specific gravity above that of pure water at the same tem- 

 perature. This is expressed in the formula, 



4 S- 4 W t = /Y (a + ^ + 0, 



where 4 S t denotes the specific gravity of sea-water, and 4 W t that 



of pure water at t°, both referred to pure water at +4° C. as 



= 1000, while a, b, and c are constants having the values 



a=l : 45993, b=— 0*0055922, 0=0*0000649. 



The results agree closely with the determinations ■ of specific 

 gravities of Challenger waters by Mr. Buchanan, of the Challenger 

 expedition. 



The atmospheric constituents of the waters were also studied. 

 Buchanan followed Jacobsen's method in collecting the gases from 

 the waters. Mr. Dittmar found that in the surface waters the 

 oxygen and nitrogen vary in amount from temperature, but the 



