"The point is this: the difficulty with a poor man is to get rich, while with the rich man the greatest trouble is to prevent the increase of his wealth. Some men, of course, make no effort in that direction, and those men are a menace to society. My own idea of the proper use of a fortune is to manage it for the benefit of others, as well as one's self, and especially to prevent its increase."
"And is it so difficult to do this? Cannot money be spent without limit?"
"Yes; but unlimited evil follows such a course. This is sufficient to indicate to you that I am ever in search of a legitimate means of spending my income, provided that I may do good thereby. If I can do this, and at the same time afford myself pleasure, I claim that I am making the best use of my money. Now, I happen to be so constituted that the most interesting studies to me are social problems, and of these I am most entertained with the causes and environments of crime. Such a problem as the one you have brought to me to-day is of immense attractiveness to me, because the environment is one which is commonly supposed to preclude rather than to invite crime. Yet we have seen that despite the wealth of all concerned, some one has stooped to the commonest of crimes,—theft."
"But what has this to do with your collection of jewels?"
"Everything. Jewels—especially those of great magnitude—seem to be a special cause of crime. A hundred-carat diamond will tempt a man to theft as surely as the false beacon on a rocky shore entices the mariner to wreck and ruin. All the great jewels of the world have murder and other crimes woven in their histories. My attention was first called to this by accidentally hearing a plot at a ball to rob the lady of the house of a large ruby which she wore on her breast. I went to her, and told her enough to persuade her to sell the stone to me. I fastened it into my scarf, where the plotters might see it if they remained at the ball. By my act I prevented a crime that night."
"Then am I to understand that you buy jewels with that end in view?"
"After that night I conceived this idea. If all the great jewels in the world could be collected together, and put in a place of safety, hundreds of crimes would be prevented, even before they had been conceived. Moreover, the search for, and acquirement of, these jewels would necessarily afford me abundant opportunity for studying the crimes which are perpetrated in order to gain possession of them. Thus you understand more thoroughly why I am anxious to pursue this problem of the Aztec Opal."
Several hours later Mr. Mitchel and Mr. Barnes were sitting at a quiet table in the corner of the dining-room at Mr. Mitchel's club. On board the yacht Mr. Mitchel had acted rather mysteriously. He had been closeted a while with Mr. Gray, after which he had had an interview with two or three of the others. Then, when Mr. Barnes had begun to feel neglected, and tired of waiting alone on the deck, Mr. Mitchel had come towards him, arm in arm with Mr. Gray, and the latter had said:
"I am very much obliged to you, Mr. Barnes, for your services in this affair, and I trust the enclosed check will remunerate you for your trouble."
Mr. Barnes, not quite comprehending it all, had attempted to protest, but Mr. Mitchel had taken him by the arm, and hurried him off. In the cab which bore them to the club the detective asked for an explanation, but Mr. Mitchel only replied: