"It's just a mirage," said Bill, grimly.
The rest of the miners did not care to place on record the state of their feelings, their usually fluent enough speech failed them on this trying occasion. Mackay broke the silence.
"There can be no doubt aboot the gold being there, boys," said he, "an' in sufficient quantities to make a' oor fortunes—if we could only catch it before it vanished." He stopped, absolutely nonplussed.
Bob, who had not yet spoken, advanced and scrutinized the now wholly dulled ore fragments with alert eyes.
"I don't know that I can help you," he said quietly, "but I should like to try. Anyhow, it's more in my line than yours, for I've studied chemistry a bit."
"What do you make of it, Bob?" asked Mackay, quickly.
The reply came promptly from the lips of the thoughtful student.
"The formation contains gold in an unstable state, but more so gold in solution, both of which oxidize on contact with the air."
To say that Bob's words created extreme interest would be a very mild statement of fact. His audience was comprised of gold-miners of very varied experience and knowledge, yet none of them had ever heard of such a tantalizing deposit as that they had now encountered.
"I may be wrong," continued Bob, "but I don't think there was any mistaking the colours on the stones before they regained their normal aspect. I've seen the same thing often in the laboratory. It was simply Purple of Cassius, and you'll get the same result by dissolving a small piece of gold in nitric and hydrochloric acids."