16 THE OCEAN WORLD. 
anomalies in the laws of freezing and of thermal dilatation, that 
assist the rays of heat to penetrate its bosom; the salts of the sea 
invest it with adaptations which fresh water could not possess, In 
the latter case the maximum density would be 39° 5” instead of 
25° 6", when the dynamical force of the sea would be insufficient 
to put the Gulf Stream in motion, nor could it regulate those 
climates we call marine. 
We have said that sea water contains nearly all the soluble sub- 
stances which exist in the globe. Nevertheless, when evaporated it is 
comparatively pure. ‘The water which evaporates from the sea,” 
says Youman, in his “Chemistry,” “is nearly pure, containing very 
minute traces of salts. Falling as rain upon the land, it washes the 
soil, percolates through the rocky layers, and becomes charged with 
saline substances, which are borne seaward by the returning currents. 
The ocean, therefore, is the great depository of all substances that 
water can dissolve and carry down from the surface of the continents ; 
and, as there is no channel for their escape, they would constantly 
accumulate were it not for the creatures which inhabit the seas and 
utilise the material thus brought within their reach.” These sub- 
stances are chloride of sodium or common salt, sulphates of magnesia, 
potassium, lime, and other substances, which the water of various seas 
is found to contain. 
In the year 1847 I made an analysis of water taken a few leagues 
from the coast at Havre, which gave the following result, from one 
litre (1 pint *760773) :—* 
Grammes. 
Chloride of sodium. Sts 20% 25°704 
Chloride of magnesium - 2°905 
Sulphate of magnesia ‘ a 2°462 
Sulphate of lime . . . . 5 - 1210 
Sulphate of potassium : . + 07'094 
Carbonate of lime. 3 0'132 
Silicate of soda . . .. 2... ool 
: ; : 7 
Bromide of sodium . ae bs Bh ake 0°103 
Bromide of magnesium . . . . . os S630 
Oxide of iron, carbonate and phosphate of mag- Only 
nesia, and oxide of manganese . ele traces. 
32°657 
* Examen Comparatif des Principales Eaux Minérales de ee et d’All 
magne, par MM.'L. Figuier et Mialhe. Read at the A i ee 
23rd of May, 1848. e Académie de Médecin, 
