228 
PROFESSOR EORCHHAMMER ON THE COMPOSITION 
Greenland current is a returning branch of the Gulf-stream ; but I may here remark 
that the great quantity of salt which it contains almost by itself proves the more equa- 
torial nature of this current. 
As to the chemical substances which constitute the salts of the sea-water, it must be 
remarked that the polar current of West Greenland contains a larger quantity of sul- 
phuric acid than any other region, with the exception of the south polar region and the 
East Greenland current. 
The proportion between chlorine and sulphuric acid is — 
For the West Greenland current . 
For the East Greenland current . 
Near Coulman’s Island, Victoria Land 
From 65° 57' S. lat 
100 : 12-27 
100 : 12-34 
100 : 12-47 
100 : 12-55 
The mean proportion for the ocean is 
100 : 11-89 
This excess of sulphuric acid in the Antarctic Sea might be explained by the decided 
volcanic character of its islands and shores ; even for the East Greenland current, the 
neighbourhood of Iceland and its volcanos might account for the excess of sulphuric 
acid; but the West Greenland polar current is under no such influence, and the sur- 
face-water of the Mediterranean, where so many volcanos exist, has 11-82 sulphuric 
acid, which is even a little below the mean proportion, 11-89. Only the water from the 
depth of the Mediterranean has an increased proportion of sulphuric acid, viz. 12-07. 
Thus it appears improbable that the excess of sulphuric acid in these polar regions 
should be owing only to volcanic action. It might depend upon the want of fucoidal 
plants. I have formerly, in a paper printed in the Report of the British Association for 
1844, shown that the fucus tribe has a great attraction for sulphuric acid, and that the 
sulphuric acid, by the putrefaction of the plant, is reduced to soluble sulphurets and to 
sulphuretted hydrogen, which with the oxide of iron, which is partly dissolved, partly 
suspended in water, will form sulphuret of iron. Thus the sulphur will disappear from 
sea-water, and a great quantity of sea-weeds will diminish the quantity of sulphuric acid 
in the sea- water. Now it is well known that the polar regions have few or no sea-weeds, 
and Sir James Ross, when returning from the Antarctic polar region, remarks expressly 
that he observed the first sea-weed very far from the southernmost port of his voyage. 
An unusually small quantity of sulphuric acid seems to exist in the first of my regions, 
that part of the Atlantic which lies between the Equator and 30° N. lat., its relative 
quantity being 11*75. Does that depend upon the Sargassum Seal 
The greatest proportion of lime in the ocean occurs in its second region, the middle 
part of the northern Atlantic, where its proportion is 3"07, the mean proportion being 
2*96; the least quantity of lime is found in the West Greenland polar current, with a 
proportion of 2-77 ; and next to that in the Patagonian polar current, with a proportion 
of 2*88. Wherever in other regions the influence of land is prevailing, the lime is like- 
wise prevailing. In the Baltic I found its proportion 3-59, in the Kattegat 3-29, in that 
