A couple of my favorite language websites, World Wide Words and Language Log, have offered facts and commentary on a phrase that shows up in writing just as the Revolutionary War tapered down: “All my eye and Betty Martin!” That basically meant, “Stuff and nonsense!”
The earliest appearance of this phrase is in a 16 Oct 1781 letter from Samuel Crisp to his sister Sophia “Sop” Gast:
Physic, to old, crazy Frames, like ours, is all my eye and Betty Martin—(a sea phrase that Admiral Jemm frequently makes use of).Who was “Admiral Jemm”? In addition to Crisp’s letters, he shows up in the letters of Fanny Burney. He was that author’s brother James Burney, only a Royal Navy captain in 1781 but indeed eventually an admiral. He made two voyages with Capt. James Cook and wrote books on those travels, on Capt. William Bligh, and on the game of whist. The picture of him above comes courtesy of McGill University.
The “all my eye” part of the phrase is documented earlier than that, and more widely. Most likely Burney and others added “Betty Martin” as an intensifier. Some folks at Language Log find it plausible, though undocumented, that it was a British corruption of the Latin oath beate mater, or “blessed mother.”