Arcane tomes are not ordinary books that happen to deal with arcane matters.  There is intrinsic power in them - a power I've learned to synthesize into a single arcane rune.$B$BShould you find an arcane tome in your travels I will give you one such rune.  Only the most powerful wielders of magic carry the books I need.  In Outland this usually means Kael's blood elves - but you'd be surprised by where such tomes often turn up.