This episode is based on a real-life incident from the 19th Century, in which the philosopher and historian Thomas Carlyle sent the only copy of his monumental History of the French Revolution to fellow philosopher John Stuart Mill, only to have him return days later to tell him that one of his servants had mistakenly used the manuscript to light a fire. Undaunted, Carlyle proceeded to rewrite the entire work from scratch, and published the completed book in 1837. However, modern consensus is that Mill intentionally burned the manuscript in a fit of jealous rage, having tried and failed to produce a similar work on the Revolution for many years, and concocted the story as a cover.
In his dream, Blackadder refers to Baldrick as an Alsatian rather than a German Shepherd. The word Alsatian was coined in 1916 when anti-German sentiment caused by the First World War meant that anything German was renamed.
Robbie Coltrane had previously played Dr. Samuel Johnson in a one-man show, 'Your Obedient Servant' in 1987 at the Lyric Theatre, Hammersmith, which both Richard Curtis and Ben Elton attended.
The original English Dictionary, written by Samuel Johnson, actually took only six years to create and not ten, as this episode indicates. Also, the word "aardvark" wouldn't have been in the dictionary anyway as the word hadn't entered the English language yet.