INTRODUCTION. 5 
they dash. In some localities the colour of the sea is exceptional. 
The water appears white in the Gulf of Guinea; yellow near Japan; 
a grass-green to the west of the Canaries; and black round the 
Maldive Islands. The Mediterranean, towards the Archipelago, 
becomes more or less red; the Vermille Sea, near California, 
presents a similar tint. The names of the White Sea and the 
Black Sea appear to be derived solely from the ice of the one and 
the frequent storms of the other. 
The sea has a peculiar saline taste, slightly acid, mixed with a 
bitter which is somewhat nauseous. It possesses an odour peculiar 
to itself, and is feebly viscid. We know that pure water is a 
compound of one volume of oxygen and two of hydrogen; or by 
weight, eight of oxygen and one of hydrogen. The water of the 
sea has a like composition; but, besides these gases, the presence 
of other ingredients has been discovered by chemists. An analysis 
of 100 grains of the water of the Atlantic is as follows :— 
Grains. 
Water sec ae sus sa = ... 96°470 
Sodium Chloride Le aa sae Bee pee 700) 
Magnesium ... bia es aioe sh sea Ox300 
Potassium s 00 oe fe wii ee OLO7O 
Magnesium Bromide ... i 906 Hie se 0002 
Magnesium Sulphate ... cee a Bi tee OF280 
Calcium Sulphate met oa tee ae oe OLLAO 
Carbonate of Lime ... ae ae age =) ©0038 
Residue sc ae ihe ee ace se OO2ZG 
100°000 
Besides these substances, the ocean contains—in very small 
quantities, it is true—iodine, sulphur, silica, ammonia, iron, and 
copper. On examining, at Valparaiso, sheets of copper stripped 
from the keel of a vessel which had been long submerged, it was 
ascertained that traces of silver had been deposited upon it by the 
sea. And lastly, we find, in solution in sea water, a peculiar 
mucous matter, which seems to be of a vegeto-animal nature— 
organic matter arising from the decomposition of innumerable 
successive generations of living things which have appeared and 
disappeared since the creation of the world. This matter has been 
well described by Count Marsigli, who sometimes calls it glue, 
