The Gentleman's Bottle Companion is on the web:

http://www.drinkingsongs.net/html/books-and-manuscripts/index.htm

but the version of "Rural Felicity" I had in mind isn't there. It was in a copy at the National Library of Scotland - I presume it must have been a later edition. Fairly typical late 18th century bawdy song. Fucking in a carriage as it bounces along through the countryside, if I remember right.