You are right there is almost no easy to find information 'about them'. Well here goes.
Quote:
sylph
Main Entry: sylph
Pronunciation: ˈsilf
Function: noun
Etymology: New Latin sylphus
Date: 1657
1 : an elemental being in the theory of Paracelsus that inhabits air
2 : a slender graceful woman or girl
— sylph·like ˈsil-ˌflīk adjective
Merriam Webster OnlineFirst modern usage occured in The Rape of the Lock by Alexander Pope. I was going to post it but it is...somewhat long.
So
here is the poem.
Also appears in
Bulfinches Mythology.
Also a species of hummingbird appearing in Colombia and Ecuador.
gonk Maybe when I eat my brain will be working again and I can find more...