“If the grass is like this, what will the trees be?” asked Mark.

“There are some away over there,” Jack replied.  “We’ll have to take a sail over.  They must be several hundred feet high.”

“Well, at any rate, here’s a little brook, and the water looks good to drink,” went on Mark.  “I’m thirsty, so here goes.”

He hurried to where a stream was flowing sluggishly between grassy banks.  The water was as clear as crystal, and Mark got down on his face and prepared to sip some of the liquid up.

But, no sooner had his lips touched it, than he sprang up with a cry and stood gazing at the water.

“What’s the matter?” asked Jack.  “Hot?”

“No, it isn’t hot,” Mark replied, “but it isn’t water.  It’s white molasses!”

“White molasses?” repeated the professor, coming up at that moment.  “What are you talking about?”

He stooped down and dipped his finger into the stream.  He drew it up quickly, and there ran from it big drops that flowed as slowly as the extract of the sugarcane does in cold weather.

“You’re about right, Mark,” he said.  “It’s water but it’s almost as thick as molasses.”  He touched his finger to his tongue.  “It’s good to drink, all right,” he went on, “only it will be a little slow going down.”

Then he dipped up a palm full, and let it trickle down his throat.

“It is the strangest water I ever saw,” he added.  “It must be that the lack of some peculiar property of air, which we have on the surface, has caused this.  I must make some notes on it,” and he drew out pencil and paper.  He was about to jot down some facts when he was interrupted by a cry from Washington.

“Come and see what’s the matter with this stone!” he cried.

CHAPTER XVIII

 Caught by A strange plant

“Washington is in trouble!” exclaimed Mr. Henderson.  Followed by the two boys he ran to where the colored man stood in a stooping position over a small pile of stones.

“What is it?  Has something bit you?” asked the scientist, as he came up on the run.

“No, but I can’t git this stone up!” Washington said.  “Look at what a little stone it is, but I can’t lift it.  Something must have happened to me.  Maybe some one put th’ evil eye on me!  Maybe I’m bewitched!”

“Nonsense!” exclaimed the professor, “what did you want the stone for?”

“Nothin’ in particular,” replied Washington, still tugging away at the stone, which was the size of his head.  “I was just goin’ t’ throw it at a big bird, but when I went to lift it this little stone ‘peared t’ be glued fast.”

Washington moved aside to give Mr. Henderson a chance to try to pick up the piece of rock.  As the scientist grasped it a look of surprise came over his features: 

“This is most remarkable!” he exclaimed.  “I can’t budge it.  I wonder if a giant magnet is holding it down.”