into mountainous masses and drives them back so violently that he seems bent on forcing them to the summits of the mountains from whence they have descended. Obstacles thus numerous and various cause apparent tidal irregularities, which at once impress and confuse our minds. None of those irregularities is more surprising than the difference of their time between two quite closely neighboring ports. One Havre tide, for instance, equals two of Dieppe,--as is mentioned by Chazallon, Baude, &c. It is greatly to the honor of human genius to have subjected phenomena so complex to even proximately accurate calculation and positive laws. But beneath these exterior movements, the sea has others within; those under currents by which she is traversed in various directions and at varying depths. Superposed at different depths, or flowing laterally in opposite directions, hot currents in one direction, cold counter currents in another, they, between them, keep up the circulation of the sea, the exchange of salt and fresh waters, and the alternating pulsation which is the result. The hot _pulse-beat_ is from the line to the pole; the cold, from the pole to the line. Shall we be warranted in saying, as it has sometimes been said, that these currents so distinct and unmingling, may be strictly compared to the vessels, veins and arteries, of the superior animals? Strictly speaking, we cannot so compare them; but they have considerable resemblance to the less determinate circulation which materialists have lately discovered in some inferior creatures, as molluscs and annelides. That _lacunary_ circulation supplies the want of, and at the same time prepares, the _vascular_; the blood flows in currents before it has precise channels. Such is the sea. She resembles a vast animal that has stopped short at the first degree of organization. Who has developed the currents, those regular fluctuation of the abysses into which we never descend? Who has taught us the geography of those dark waters? Those that live within or float upon those waters;--animals and vegetables. We shall see how the huge whale and the minute shelled atomies, how even the woods of America, floating to bleak Iceland, have concurred in revealing the flow of hot water from the Antilles to Europe, and the counter current of cold meeting it at Newfoundland, passing it beside or below, and thus getting its ices melted into immense fogs. A vast cloud of red animalcules, carried by a tempest from Orinoco to France, explained the great aërial current of the Southwest which brings to our Europe the rains that have their birth place in the far Cordilleras of South America.