Between is generally applied to two things; as 'There is a river between the opposing aimies.'
But "In expressing mutual relation, 'between' may correctly apply to more than two, as a treaty between six nations'."
So also in comparisons, as. "There is a great difference between New York, London and Paris.' Of the five following words each is given a single definition with a view merely to suggesting the natural relation between these.'-MEU under 'Time'.
The preposition among is used primarily to mean, 'surrounded by, or associated with, more than two separate things. It is regularly followed by a plural or a collective noun. Among his books are many rare editions.'