"Once A Gentleman, And Always A Gentleman"

Context: Arthur Clennam, bankrupt because of the failure and suicide of the wealthy Mr. Merdle, is in the Marshalsea prison. He resists the urging of his lawyer, Mr. Rugg, to be moved to the more respectable King's Bench prison; his reason for preferring the Marshalsea is that it was the home of the universally beloved Little Dorritt while her father was a prisoner. After Mr. Rugg's departure, John Baptist Cavalletto, Clennam's friend, ushers in the infamous Rigaud Blandois, who had dropped out of sight after being last seen at the home of Clennam's mother, with whom Clennam is not on the best of terms. Clennam tries to get information about what business Rigaud has had with Mrs. Clennam, but Rigaud treats the inquiry with great disdain and refuses to tell what the affair is about. It has always been Rigaud's contention that he is a gentleman born and that it is the part of a gentleman to treat everybody, especially servants and other underlings, with the utmost contempt. He addresses John Baptist, who had once been arrested for smuggling:

"Contrabrand beast," added Rigaud, "bring Port wine! I'll drink nothing but Porto-Porto."
The contrabrand beast, however, assuring all present, with his significant finger, that he peremptorily declined to leave his post at the door, Signor Panco offered his services. He soon returned, with the bottle of wine: which, according to the custom of the place, originating in a scarcity of workscrews among the Collegians (in common with a scarcity of much else), was already opened for use.
"Madman! A large glass," said Rigaud.
Signor Panco put a tumbler before him; not without a visible conflict of feeling on the question of throwing it at his head.
"Haha!" boasted Rigaud. "Once a gentleman, and always a gentleman. A gentleman from the beginning, and a gentleman to the end. What the Devil! A gentleman must be waited on, I hope? It's a part of my character to be waited on!"
He half filled the tumbler as he said it, and drank off the contents when he had done saying it.