A week or two elapsed before Oscar’s victim discovered the imposition that had been practiced upon him.  The ring, which had been proudly worn, at length began to look dim and brassy; and on being submitted to careful inspection, it was pronounced by competent authority to be not worth one cent.  The owner was of course indignant, and he went at once to Oscar, and demanded a return of the collar and comb.  But Oscar laughed at the proposal.

“A bargain is a bargain,” said he, “and there can’t be any backing out, after it’s all settled.  You agreed to the trade, and now you must stick to it.”

“But it was n’t a fair bargain,” said the other boy; “you told me the ring was gold, and it is nothing but brass.”

“No, I did n’t tell you it was gold,” replied Oscar.  “You imagined that.  And I did n’t tell you it was the one I wore either,—­you imagined that too.  It was my other ring that I said was gold, and I told you it cost two dollars, and so it did.  I never told you this ring was gold,—­I recollect perfectly about it.”

“Well, you know I supposed it was gold, or I would n’t have traded for it,” replied the boy; “and besides, you made me think it was gold, whether you really said it was or not.”

“That was your look-out,” said Oscar.  “When a man sells a thing, he is n’t obliged to run it down.  You must look out for yourself when you make a bargain—­that’s what I do.”

“I should think you did,” replied the other; “and I guess I shall remember your advice, if I ever trade with you again.  There’s your old ring:  now give me back my collar and comb,” he continued, handing the ring to Oscar.

“I shan’t do any such thing,” said Oscar, and he refused to take the ring, and turned upon his heel, leaving the other boy in no very pleasant state of mind.

“Then you ’re a great cheat and a swindler,” cried the victim, gathering courage as Oscar retreated.

“And you ’re a little greeny,” replied Oscar, with a loud laugh.

Oscar had prepared his mind for this explosion of indignation, and though he did not care much about it, he was glad it was over with.  He regarded the transaction which led to it as a shrewd business operation, to be chuckled over, rather than repented of; and he had no idea of spoiling it all, by undoing the bargain.

In Oscar’s school, it was customary for the first class (of which he was a member) to devote the first half hour of every Monday morning to a lesson in morals.  In these lessons, the duties which we owe to God, to ourselves, and to one another, were explained and enforced.  Although a text-book was used, the teacher did not confine himself to it, in the recitations, but mingled oral instruction with that contained in the printed lessons, often taking up incidents that occurred in school, to illustrate the principle he wished to establish.

It so happened that on the Monday morning after the occurrence just related, the subject of the moral lesson was dishonesty.  The various forms of dishonesty,—­theft, robbery, fraud, &c.,—­were explained, and the distinction between them pointed out.  The teacher then proceeded as follows: