274 Scientific Intelligence. 



The soutBern polar or Humboldt's Current (Region XV) gave +03 

 it conducts waters from the Antarctic ocean, where - 54 (Reg. XVF 

 has been observed, 



(3.) Counter-currents.— T\\Q Sound, between Zealand and Sweden, ex 

 hibits the best investigated example of counter-currents : the surface 

 current being commonly south from the Baltic, the bottom-current al 

 ways north, ivlo the Baltic. According to observations made fron 

 April to Sept. 1846, the direction and saltness of these currents wen 



c „4- \ days, - - - 24 86 24 



^"'^^^^' I saltness, - - - 15994 133« llsoi 



Bottom, - - - - i9no2 

 and mean saltness of Reg. VIT, the Baltic, 4807, of VI, Cattegat and 

 Sound 15126 and North Sea (Reg, V) 32806 thousandths. 



Thus the bottom current contains constantly by far the greatest 

 amount of salt, even in winter, when its temperature is 2-3° F. higher 

 (waters of the Atlantic) than the surface current, partaking of the ffia- 

 ter temperature of the Baltic sea. 



The saltness of about 20 points of the ocean has been determined 

 for diflFerent depths. A diflFerence of about one thousandth corresponds 

 to the greatest depth observed, lat. 12° 36', N. long. 25° 35' W., depth 

 11,100 feet. The saltest water of the surface here evidently is the 

 hottest. 



In Davis Strait and Baffins Bay, no considerable difference of saltness 

 for different depths is observed ; but in the adjacent Atlantic the lower 

 water is less salt than the warmer above it ; and this same cold and less 

 salt bottom current may be traced along the Atlantic, except where great 

 quantities of fresh water are introduced by European and Americaa 

 rivers : making the lower strata the saltest. 



In the Indian and Pacific the lowest water everywhere seems to be 

 the saltest (only 4 observations), 



(4.) Composition of the sa/fs.— Twenty-five different elements hare 

 been observed in the salt of the ocean or in plants and animals of the 

 sea : 0, H, CI, Br, I, Fl, S, P, C, N, Si, Fe, Mn, Mg, Ca, Sr, Ba, No, Ka: 

 Ag, Cu, Pb, Zn, Co, Ni ; but only those printed in Capital -' "'*' 



chlorine, sulphuric acid, lime and magnesia m*; 

 with great exactitude. Comparing all analyses of ocean 

 ig the North Sea) it is found that the relative proportion 



be determined with great exactitude. Comparing all 



wo^er (inclnding the North Sea) 



of the components is nearly co! 



Chlorine 100, sulphuric aci. 



IBli (for each 100 of chlorine). 



components is nearly constant, being : 



"="" 100, sulphuric acid ll9i, lime 296, magnesia 



.-,.„. .., ^„^ .^^vj^x, v.uuni,ttub^ yet there are small but constant 



ferences for the different regions of the ocean— differences enlarging wU^ 



the proximity of land, greatest in gulfs and bars, as may be seen from 



the following interesting comparison of the composition of the salt ftoni 



^..roiistadt (near St. Petersburgh) through the Baltic to the ocean. 



To each 100 of chlorine corresponds : ^^^^^ 



Cronstadt Harbor, ^^^^ ^^1^^^' 207» 



Gulf of Finland, midst, 591 1331 183» 



