The Irish fisher-folk also gather the common brown seaweed with pods, which are really air-bladders, and serve to keep it afloat. I have many a time watched the women and children wading among the pools, cutting it from the rocks with sickles, and putting it into baskets, which they carry home on their backs; for this precious harvest of the sea is what they depend upon to make their potatoes grow well and yield a plentiful crop. There is another kind of seaweed, of a pretty purple colour, which they eat, and call it by an Irish name which means "leaf of the water." But it is far away in the watery valleys of the great Pacific, where the sea is very calm, that the ocean forests grow. I have read that there giant leaves of the sea grow upon stems longer than those of our tallest trees, and spread abroad like waving palms. Though you are not likely ever to see such seaweeds as these, you will find, wherever you may be, though much more abundantly on some shores than others, some of those beautiful "weeds"--green, red, or brown--which have their use as well as their beauty; for they help to purify the water, just as plants do the air. Perhaps I should not promise more than the brown Tangle and the green Ulva, with its bright lettuce-like leaves; for red seaweeds belong to deep water, and are not easy to find. Many an hour have I spent peering and groping in the little pools at low water in search of these same much-prized rosy-tinted "flowers of the sea"; and many a disappointment I have had, even after a fortunate find, in seeing how soon the lovely colour faded, in spite of all my efforts to keep it. We often speak of the "salt sea" or "the briny ocean," without perhaps thinking how it comes to be salt. I used to think it was because there were vast salt mines at the bottom of the sea; but that was only a guess at the truth. Let us think what happens when there is a heavy shower; how quickly the raindrops gather force until they run down the street, making gutters on each side! But how unlike the muddy water in these gutters is the rain as it fell from the sky--how is this? It is the same water, but as it hurries along each drop picks up and carries with it its own little grain of sand or dust. If tiny gutters are tinged by the mud which they carry with them, how much more must this be the case with the great rivers which empty themselves into the ocean! They carry with them not only sand and earth, but the minerals and salts which are contained in them, to form the bed of the ocean. The salt which is thus washed out of the soil by streams and rivers is not evaporated, but remains behind, for the sea has no outlet through which it can again be carried away.