Various, Notes and Queries, Number 179, April 2…
“ I wish to note, and to suggest to students in ethnology, the Query, how it comes to pass that John Bull has a peculiar propensity to call things by his own name, his familiar appellative of Jack?Of all the long list of abbreviations and familiar names with which times past and present have supplied us, that which honest Falstaff found most pleasing to his ears, "Jack with my familiars!" is the household word with which ours are most conversant. Were not Jack the Giant-killer, Jack and the Bean-stalk, and Little Jack, the intimates of our earliest days? ”
