What is the etymology of the word ampersand?

The ampersand (&) came into English around 1837, formed by an alteration or corruption of the phrase and per se = and or and per se - and, which was the old way to represent the character &. This phrase was used in glossaries and meant '& by itself = and' or 'the character & by itself is the word and'. Latin per se 'by itself' was formerly used to name a letter that stood by itself to represent a word. An ampersand is also called short and.