"What's that ?" "What, my lad ?" cried the captain.
"That curious choking sour smell.

Ah!" "Back, boy, for your life!" cried the captain, snatching at his son's arm and half dragging him towards where the cave was open to the sky.
"Are you all right ?" "Yes, yes, father," panted Mark, who was coughing violently.

"Is--is-- Oh, father! the major." The captain had taken a handkerchief from his pocket and loosely doubled it, and this he tied over his mouth and nostrils.
"Hold my gun, Mark," he whispered; and then hoarsely, as if to himself, "I can't leave him like that, come what may." He paused for a moment to breathe hard and thoroughly inflate his lungs, and then, regardless of the risk of falling, he ran rapidly in, while Mark stood horror-stricken listening to his retiring footsteps.
His next act saved the lives of the two men.
"Small!--Widgeon!" he cried.

"Here, quick!" The two men ran to his side, ready to help.
"My father has gone in to help the major.

As soon--as he comes--near enough--go and help." The men stood listening; and then, as they heard the coming steps, made a dart in, but returned.
"You can't breathe.