"No gold!" cried Bud.
"No gold!" echoed his cousins.
"No—no—gold!" faltered Billee Dobb, his jaw falling. He saw his self-playing piano fading back into the dim vista of his dreams.
"No gold," repeated Professor Dodson. "What we have here," and he indicated the ore specimens held by himself and Professor Snath, "is a selected lot of samples of iron sulphid. It is a yellow ore that looks very much like gold, but which has none of the properties of real gold. In fact it is so often mistaken for the valuable metal that it has come to be called 'Fools' Gold.' I am sorry, but such is the case. I shall so report to Mr. Merkel, who engaged me to come out here after hearing his son's account."
"Fools' gold!" murmured Bud. "Well, it fooled us all right."
"Yes, and it fooled those other fellows," said Nort. "The men with the gas cylinders," he added.
As the two professors looked a little puzzled, Dick explained:
"There were some men hiding in this cave who must have thought, the same as we did, that it contained gold. They drove out Mr. Tosh, who used the cavern to brew his medicine. Then they drove us out. They used tanks of some poison gas, or at least gas that made a man unconscious. We had to put on gas masks, the kind used in the war, to fight 'em. But we drove 'em out."
"And a lot of good it did us," said Bud gloomingly, "if there isn't any gold in there."
"No, the evidence is too plain to be mistaken," said Professor Snath. "It does not even require a laboratory test to prove that the cave is rich in iron sulphid, but not gold."