THE CALUMET OF PEACE
He offered a cigarette to the professor and took one himself. Lenehan promptly struck a match for them and lit their cigarettes in turn. J. J. O’Molloy opened his case again and offered it.
—Thanky vous, Lenehan said, helping himself.
The editor came from the inner office, a straw hat awry on his brow. He declaimed in song, pointing sternly at professor MacHugh:'Twas rank and fame that tempted thee, 'Twas empire charmed thy heart.
The professor grinned, locking his long lips.
—Eh? You bloody old Roman empire? Myles Crawford said.
He took a cigarette from the open case. Lenehan, lighting it for him with quick grace, said:
—Silence for my brandnew riddle!
—Imperium romanum, J. J. O’Molloy said gently. It sounds nobler than British or Brixton. The word reminds one somehow of fat in the fire.
Myles Crawford blew his first puff violently towards the ceiling.
—That’s it, he said. We are the fat. You and I are the fat in the fire. We haven’t got the chance of a snowball in hell.
the quote ‘Twas rank and fame that tempted thee, ‘Twas empire charmed thy heart.’ is taken from an opera called The Rose Of Castile by Micheal William Balfe (source). Balfe started his career as a violinist but found his success in writting opera, The Bohemien Girl being his most famous work (source). I found a recording of The Rose Of Castile. It doesn’t include the the line that is quoted in Ulysses but it is a portion sung by the same character from the opera.