VEGA-EXfEDITJOKENH VETENSKAPLIGA A/IBETEX. 



305 



Table 3. Sea-ice. 



Ice-water froi 



Peicentage of 

 chlorine (titr.). 



Cl 

 (= 100) 



SOo 



Marstrand 



Danes Gat (Spitzbergen). 

 ' Cloven cliff 



Magdalena Bay ■> 



Ice-fiord » glacial ice (floating). 



0.727 . % 



0.0145 % 



0.0020 % 



0.0019 /o 



0.0014 % 



O.OOIO % 



100 



100 

 100 

 100 

 100 

 100 



12.80 

 1497 

 4365 

 43-67 

 62.8 . 

 76.6 . 



From the above tables we may draw the following con- 

 clusions: 



I. Ocean-water is divided b}" freezing, not into pure water 

 and a more or less concentrated solution of ordinary sea-salt, 

 as was formerly believed, but into two saliniferous parts, one 

 liquid and one solid, which are of different chemical compo- 

 sition. 



II. The formation of sea-ice is chemically a selective 

 process. Some of the elements of the salt water are more fit 

 than others to enter into the solid state by freezing, those, 

 which are rejected by the ice, will be preponderating in the 

 brine and vice versa. Taking the relation Cl : SO3 as standard 

 of comparison, we may characterize the most striking feature 

 of the freezing process thus: that the ice is richer in sulphates, 

 the brine in chlorides. 



III. The extraordinary variation botli in saltness and in 

 ohemical composition of every individual specimen of sea-ice 

 and sea-brine, shown by the tables, depends upon a secondary 

 process or raetamorphosis of the ice, Its ultimate tendency 

 is similar to that of the original act of freezing. The ice 

 seems to give up its chlorides more and more, but to retain 

 its sulphates. The cause of this metamorphosis has justly 

 been ascribed to the combined infiuence of time and varia- 

 tions of temperature. 



IV. The circumstance just alluded to forbids us to regard 

 the percentage of chlorine, found by titration in the ice or in 

 the brine, as a standard index of its entire saltness, but it 

 will prove invaluable to us, if we wish to form an idea of the 

 development of the metamorphosing action of time and tem- 

 perature on sea-ice. In the daily journal of the Vega for the 

 winter months 1878 — 79 many titrations on ice-waters and on 

 salt brines are recorded. The results are given in the fol- 



20 



