ANALYSIS OF SEA-WATER. 91 
_ The water of the different seas is much more uniform in its composition 
_ than is generally believed. In that respect my analyses agree with the newer 
_ analyses of atmospheric air, in showing that the differences are very slight 
_ indeed. Sea water may contain more or less salt, from a very small quantity, 
as in the interior part of the Baltic, to an amount of 37°] parts in 1000 parts, 
_ which I found in water from Malta, and which is the greatest quantity I ever 
_ observed ; but the relative proportion of its constituent saline parts changes 
_ very little. 
In order to get rid of those differences which might arise from the dif- 
ferent quantity of saline matter in sea water, I have compared sulphuric acid 
oo lime with chlorine, and the following results are the mean of many ana- 
lyses :— 
In the Atlantic, the proportion between chlorine and sulphuric acid is 
10,000 : 1188; this is the mean of twenty analyses, which differ very little 
from each other. 
In the sea between the Faroe islands, Iceland and Greenland, the same 
proportion, according to the mean of seventeen analyses, is 10,000 : 1193. 
In the German Ocean, according to ten analyses, it is 10,000 : 1191. 
i In Davis's Straits, according to the mean of five analyses, it is 10,000: 1220. 
In the Kattegat, according to the mean of four analyses, it is 10,000: 1240. 
_ Thus it appears that the proportion of sulphuric acid increases near the 
shores, a fact which evidently depends upon the rivers carrying sulphate of 
_ lime into the sea. 
The proportion between chlorine and lime in the Atlantic Ocean, according 
_ to the mean result of seventeen analyses, is 10,000 : 297; and in the sea 
_ between Farde and Greenland, according to the mean of eighteen analyses, 
it is 10,000 : 300. 
In the longitude of Greenland, and more than 100 miles to the south of 
the southernmost point of that large tract of land, sea water contains only 
35°0 in 1000 parts. In going from this point towards the north-west it de- 
" creases constantly, and in Dayis’s Straits, at a distance of about forty miles 
1 from the land, it only contains 32°5 parts of salt in 1000 parts of sea water. 
_ This character seems to remain in the current which runs parallel to the 
shores of North America; and at N. lat. 433° and W. long. 464 the sea water 
_ contained only 33°8 parts of salt. Thus tropical and polar currents seem not 
_ only to be different in respect to their temperature, but also in the quantity 
_ of salt which they contain ; from which it appears, that while the quantity 
_ of water carried away from the éropical sea by evaporation is greater than 
_ that which rain and the rivers give back to that sea, the reverse takes place 
in the polar seas, where evaporation is very small and the condensation of 
_ vapour very great. The circulation must on that account be such, that a 
"part of the vapour which rises in tropical zones will be condensed in polar 
regions, and in the form of polar currents flow back again to warmer climates. 
_ Although my analyses are only made on water from the ocean between Eu- 
Tope and America, yet little doubt can be entertained that that part of the 
Ocean which separates America from Asia is constituted in a similar manner, 
and that currents flowing from the poles are the rule, and currents flowing 
wards the poles the exception. 
_ Lime is rather rare in the sea around the West Indian islands, where mil- 
lions of coralline animals constantly absorb it, the proportion according to 
five analyses being 10,000 : 247; and it is rather copious in the Kattegat, 
here the numerous rivers of the Baltic carry a great quantity of it into the 
oe 
ey 
ocean. The proportion is there, according to four analyses, 10,000 : 371. 
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