"Oh, Norah," they both shouted, as soon as they got their breath, "we"ve got something fine to show you tonight.""I"ll go and see what I can find," said Fred.
After tea Fred said, "Now, I"m teacher tonight, so sit down in your places.
"I"ve got some salt and a tumbler of water, just as we had the other night," he began. "Now we will put the salt into the water and stir it up.
"What happens to the salt, Norah?"
"The salt dissolves in the water." said his sister. "It is there, but we cannot see it.""Quite right," said Fred. "Teacher says we can call this salt water brine. Brine means salt water.
"Now, little girl," he went on, "suppose I told you that you must get the salt out of the water. That would be a puzzle for you, wouldn"t it?" Norah looked puzzled.
"See me do it, then," said clever Fred. He had found an old tin lid. He filled this with the brine, and stood it over the fire. Soon the water began to boil, and a cloud of steam rose from it.
They watched it for a long time, till all the water had boiled away.