Magic is brought into play by various means. The only way to actually learn the spells, is to read them from a book. Both scrolls and books will disappear after being read (applied actually). Magic that comes from quaffing (applying) a potion will stay in effect over a period of time. Not all magic found in wands would be found in e.g. scrolls etc. The Wonder spell will produce random magic (rather unpredictable).
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