The Life and Opinions of Tristram Shandy, Gentleman Book 3, Chapter 1 Summary
Remember Book 2, Chapter 18? "I wish you'd seen what big armies we had in Flanders," Toby says.
This wish came just as Dr. Slop was explaining the wonders of obstetrics, and it threw the poor doctor for such a loop—as such non sequiturs always do—that he couldn't finish his thought. Mr. Shandy, who was very interested in the original discussion, came to Slop's rescue.