Uncle George poured some of the clear water into a clean flat dish. Then he took a spirit-lamp from a little cabinet, and heated the water in the dish with it.
The children watched to see what would happen. Soon a cloud was seen over the dish, and by and by all the water had gone.
“But what is that at the bottom of the dish?” asked Uncle George.
“It looks like powder,” said Frank.
“And it must have been in the water all the time,” added Tom.
Evaporating Salt Water.
“And yet the water was clear,” said Uncle George. “Look once more.”
As he spoke, Uncle George took a glass of clean water from the tap. He put two large spoonfuls of salt in, and stirred it up.
“You see,” he said, “the salt has gone from sight. Still the water is clear. Where has it gone?”