This scroll allows you to cast the spell Detect Magic.

Spell: For the duration, you sense the presence of magic within 30’ of you. If you sense magic in this way, you can use your action to see a faint aura around any visible creature or object in the area that bears magic, and you learn its school of magic, if any.
    The spell can penetrate most barriers, but it is blocked by 1’ of stone, 1” of common metal, a thin sheet of lead, or 3’ of wood or dirt.