ON AN EXPLORING EXPEDITION—A FIND IN A CAVE—THE SEPULCHRAL VOICE—THE EXPLANATION—DESMOND GETS SQUARE ON A TRICK—STRANGE LONGINGS—THE FINDING OF A NUGGET.BOY'S DETERMINATION—GOING THROUGH A CREVICE—THE MOVABLE ROCK—AID TO DISCOVER—UP THROUGH A HOLE—THE GOLDEN HEAP—DESMOND'S GREAT TRIUMPH—THE OLD MEXICAN'S SECRET EXPOSED.CHAPTER V.