“Not we, my lad,” growled Small. “I know. It’s bad gas.”

“It’s the sulphur,” cried Mark piteously.

“Well, aren’t that bad gas? I know. They’re just the same as if they was drowned, and we’ve got to pump their chesties full of wind till they begins to breathe as they ought to.”

Small’s ideas were doubtless quite correct, and fortunately but little effort was needed to bring the sufferers to their senses, for the fresh air soon recovered them, and they sat up looking wild and confused.

With the help of an arm to each they were soon able to walk back to the open mountain side, and after a rest declared themselves ready to proceed.

“I think we’ll go back away north of the hot springs,” the captain said.

“Certainly,” exclaimed the major with quite a sound of contrition in his voice.

“The jungle is dense, but I think with a little managing we can find our way.”

“Well, yes, perhaps so,” said the major. “It’s down hill, and half our way will be fairly open.”

“If it proves too dense we can but turn to the right and go back as we came,” said the captain. “There, Mark, you need not look so anxious. There is nothing worse the matter than a bad headache. How are you, major?”