Some time ago, I wrote the same in spanish, now I translate it into English, so more people will understand. I wrote that because a friend of mine asked me why the sea is salty when the rivers are not, I didn't know what to answer, so here, I'll try to explain it a good way.
When I was little, somebody told me a story about a little magic coffee grinder, which was the first explanation to the saulty taste of seawater:
Long time ago, in a fishermen village, two brothers, the little one, Nico, was really generous and humble, he fished just what he needed to eat, had old fishing gears and many days, he had no fish. His older brother, Bruno, was greedy, he managed to get rich a expenses of the others, he had the best fishing gears and the best fishing boats.
One day, after a long fishing season offshore, the little brother returned sad and hungry to harbour, because he didn't managed to fish almost nothing, and he decided to ask for help to his brother, but he just shutted the door in his face laughting at him. Even more depressed, the little fisherman returned home when a very old man, with a long white beard said to him: "I have seen all that has happened, I know that you are a good guy. I want to help you". In his hands, he had a wooden coffee grinder with a beautiful golden crank arm. Nico, incredulous, looked at the white beared man and responded: "How can a coffee grinder help me, if I have no money for the grains?" The man laughted and said: "This grinder is magic, I will tell you how it works if you promise me that you will never tell anybody, deal?". Without trusting, Nico accepted.
The man explained: "if you turn the crank arm clockwise and ask for a wish, the grinder will make it real, and when you want to stop it, you just have to say these exact words <> and the grinder will stop". The old man taught Nico the performance asking for strawberry candy and gave the grinder to him. Nico was really excited and, since then, he asked the grinder to build a new house, new fishing gears, a better boat... and always, when he had enough, he stopped the coffee grinder.
His new wealth reached his evil big brother's ears, who ran to ask him how did he get them. Nico, remembering what the old man told him, didn't tell him anything.
Thus, Bruno started to spy his brother to discover his secret, and one night, Bruno saw his brother getting the grinder: "grinder, grind me some money for the fishermen who lost the ships in the storm". The next day, when Nico was distracted, Bruno got the coffee grinder and ran away, took the boat and ran offshore, somewhere to enjoy his endless riches.
One day, in the middle of the sailing, the cooker didn't have salt, and the fisherman got the grinder and said: "grinder, grind a little bit of salt". The grinder started to grind, and when he had enough, Bruno commanede: "Grinder, stop grinding, stop it", but the grinder went on and on. Bruno didn't know the words he had to use to stop the grinder, and it just continued grinding more and more money, never stopping. The miser robber said and repeated: "stop it, stop grinding, stupid grinder, I don't want more salt!" But the grinder went on and on and on...