The String of Pearls (1850), p. 55

"No," said the boy, "indeed I have not. I never can forget it, if I were to live a hundred years."
"That's well, prudent, excellent, Tobias. Go out now, and if those two persons who were here last, waylay you in the street, let them say what they will, and do you reply to them as shortly as possible; but be sure you come back to me quickly and report what they do say. They turned to the left, towards the city—now be off with you."

*******

"It's of no use," said Colonel Jeffery to the captain; "the barber is either too cunning for me, or he is really innocent of all participation in the disappearance of Thornhill."
"And yet there are suspicious circumstances. I watched his countenance when the subject of jewels was mentioned, and I saw a. sudden change come over it; it was but momentary, but still it gave me a suspicion that he knew something which caution alone kept within the recesses of his breast. The conduct of the boy,
too, was strange ; and then again, if he has the string of pearls, their value would give him all the power to do what he says he is about to do, viz., to retire from
business with an independence."
"Hush! There, did you see that lad?"
"Yes; why it's the barber's boy."
"It is the same lad he called Tobias—shall we speak to him?"
"Let's make a bolder push, and offer him an ample reward for any information he may give us."
"Agreed, agreed."
They both walked up to Tobias, who was listlessly walking along the streets, and when they reached him, they were both struck with the appearance of care and sadness that was upon the boy's face. He looked perfectly haggard and careworn—an expression sad to see upon the face of one so young; and, when the colonel accosted him in a kindly tone, he seemed so unnerved that tears immediately darted to his eyes, although at the same time he shrank back as if alarmed.
"My lad," said the colonel, "you reside, I think, with Sweeney Todd, the barber. Is he not a kind master to you, that you seem so unhappy ?"
"No, no—that is, I mean yes, I have nothing to tell. Let me pass on."
"What is the meaning of this confusion?"
"Nothing, nothing."
"I say, my lad, here is a guinea for you, if you will tell us what became of the man of a sea-faring appearance, who came with a dog to your master's house, some days since, to be shaved."
"I cannot tell you," said the boy,
"I cannot tell you what I do not know."
"But, you have some idea, probably. Come, we will make it worth your while, and therefore protect you from Sweeney Todd. We have the power to do so, and all the inclination; but you must be quite explicit with us, and tell us frankly what you think, and what you know concerning the man in whose fate we are interested."
"I know nothing, I think nothing," said Tobias. "Let me go, I have nothing to say, except that he was shaved, and went away."
"But how came he to leave his dog behind him?"
"I cannot tell. I know nothing."
"It is evident that you do know something, but hesitate either from fear or some other motive to tell it; as you are inaccessible to fair means, we must resort to others, and you shall at once come before a magistrate, who will force you to speak out."
"Do with me what you will," said Tobias, "I cannot help it. I have nothing to say to you, nothing whatever. Oh, my poor mother, if it were not for you!"
"What then?"
"Nothing! nothing! nothing!"