As fine white powder may be initially snorted, lifting spirits? (4-7)

'as fine white powder may be' is the definition.
(as in self-raising flour)

'initially snorted lifting spirits?' is the wordplay.
I cannot really understand how this works, but
'lifting' could be 'raising' (raising is a kind of lifting) and 'raising' is found in the answer.
The remaining letters 'self' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...