"Oh yes," said Norah. "Sponge, bread, sugar, chalk, dry clay, charcoal, and coke are all porous. They all suck up liquids into their pores.""Quite right," said Fred. "Now watch me. This is a tumbler about half-full of turpentine. This piece of cane has been standing in thetumbler a few minutes. See what happens when I put a match to the top of the cane.""Why, it bursts into a flame at once," said his sister. "How is that?""I"ll show you," said Fred, "just as teacher showed us. Look at the holes in the bottom of the cane.""Then I suppose," said Norah, "the pores of the cane absorb the turpentine, and take it up to the top.""That"s just it," said both the boys. "The cane is porous. ""Now look here. Do you know what this is?" said Fred.
"It is a piece of the wick of the lamp," said Norah.
"See," said Fred, "I will dip it into this water. Now when I take it out and squeeze it, some water runs out of it. What does that prove, Norah?""It proves," said she, "that the wick is porous, and that it absorbs liquids.""Quite right," said Fred. "Now think of the wick inthe lamp itself. The lower part
