A Chip in Porridge

That is the origin and exact force of this phrase? Sir Charles Napier, in his recent general order, informs the Bengal army that "The reviews which the Commander-in-Chief makes of the troops are not to be taken as so many 'chips in porridge.'" I heard a witness, a short time since, say, on entering the witness-box— "My Lord, I am like a 'chip in porridge'; I can say nothing either for or against the plaintiff."