The old gentleman stared at Rob a moment and then laid down his magazine and took the box in his hands, examining the tablets curiously.
"Are these patented?" he asked.
"No," said Rob; "they are unknown to any one but myself."
"I will give you a half million dollars for the recipe to make them," said the gentleman.
"I fear I must refuse your offer," returned Rob, with a laugh.
"I'll make it a million," said the gentleman, coolly.
Rob shook his head.
"Money can't buy the recipe," he said; "for I don't know it myself."
"Couldn't the tablets be chemically analyzed, and the secret discovered?" inquired the other.