AD&D 2nd Edition

When this spell is cast, the wizard is able to understand the spoken words of a creature or read an otherwise incomprehensible written message (such as writing in another language). In either case the wizard must touch the creature or the writing. Note that the ability to read does not necessarily impart understanding of the material, nor does the spell enable the caster to speak or write an unknown language. Written material can be read at the rate of one page or equivalent per round. Magical writing cannot be read, other than to know it is magical, but the spell if often useful when deciphering treasure maps. This spell can be foiled by certain warding magic (the 3rd level secret page and illusionary script spells), and it does not reveal messages concealed in otherwise normal text. The material components of this spell are a pinch of soot and a few grains of salt. The reverse of this spell, confuse languages, cancels a comprehend languages spell or renders a writing or a creature’s speech incomprehensible, for the same duration as above.