REFEREE "SENDS HIMSELF OFF".

In the early days of football games were refereed by two "umpires", one in each half of the pitch. They carried a stick to point direction that a free kick should be played and if a player was not deemed to be behaving like a gentleman, the umpire would "refer" the matter to his team mates, who would decide whether or not the player should stay on the field. Indeed, the umpire would carry a book of "laws" to help decision making.
This alerts you to the origins of the "referee" and "ungentlemanly conduct" (which as you know justifies an indirect free kick).

The first use of a whistle in football was in 1878 during a friendly between Nottingham Forest (Geoff!!) and Sheffield Norfolk. Prior to this referees used hand signals (something the crowd tends to use these days) . In 1879 the FA sanctioned the use of the Acme Whistle made by Joseph Hudson in London.

Prior to the whistle, the referee would hold up  and wave a yellow flag (as per American Football).
Perhaps this chap should have read the "History of Soccer Referees" volume...if there is one?
https://www.youtube.com/watch?v=QjM827E4_k0
A league referee between 1951-7 was called Arthur Bookim and at the same time there was a Scottish League ref called Charlie Faultless. Until 1978 the FA Cup Final referee was given the choice between the match fee or a souvenir medal. In 1978 the rule changed to provide both thanks to the enormous generosity of the FA Cup committee.