ORIGIN OF "HAIR OF THE DOG"

"Hair of the dog" is a colloquial English expression predominantly used to refer to alcohol that is consumed with the aim of lessening the effects of a hangover. Because it kick starts your liver into processing all the alcohool tha's still around your system from the night before.
But, where this term comes from?
It refers back to the practice of treating dog bites with an ointment containing the hair of the dog that attacked you.
The use of the phrase to refer to a hangover dates back to the mid-16th century until nowadays, while the practice of putting dog hair on bites is much, much older.