Ever since 1952, when Joseph Prescott suggested “Johnny I Hardly Knew Ye” as the source of Bloom’s amusing comparison of a “cyclist doubled up like a cod in a pot”, commentators have stuck to this seemingly obvious explanation in spite of the fact that it takes quite some juggling with the words of two lines of the song to link it to Bloom’s crisp expression.1 The relevant lines read: “Like a cod, you’re doubled up head and tail” and “You’d have to be put in a bowl to beg”.
Joseph B. Geoghegan’s “Johnny I hardly knew ye” was first published in 1867 in London. The phrase “doubled up like a cod in a pot”, however, is several decades older.
As early as 1811 The Irish Magazine and Monthly Asylum of Neglected Biography quotes “Billy McDowell” as describing an inhuman style of hanging with the words: “A man was shoved off, doubled like a cod in a pot.” The italics may an indication that “cod in a pot” was a common expression.
On 7 September 1831 the Sydney Monitor (New South Wales) (p. 4) reports on a boxing event with the words: “He put in a tremendous blow on the jugular, which doubled his opponent up like a cod in a pot, and put him to sleep.”
The World of Fashion, and Continental Feuilletons of 1 November 1841 (p. 248/2) carries this description: “But there I lay, or rather was crudled up in the wardrobe, like a doubled up cod in a pot, for two hours at least …”
In the same year, in John Bull of 16 October (p. 496), “Paddy” remarks, in an exchange with the Magistrate: “Oh, ‘pon my sowl, your honour it’s all gospel, an sure I think I’m looking at him, doubled up in a corner ov the shop like a cod in a pot, for fear any wan would see his legs.”
"Jack Joyce and the Giant" in Fraser's Magazine for April 1859 (p. 461) has: “'Thrue for ye,' says Jack, 'I'm bint double like a cod in a pot, wid my heels in my mouth a'most.'”
The popularity of the expression in the years before the publication of “Johnny I Hardly Knew Ye” of 1867 clearly shows that the song only alludes to a set phrase that was already current in the first half of the 19th century.