Summary Granulated 1 (+) glutamic acid was administered to a series of sixteen children between the ages of 7 and 15 years, with intelligence quotients ranging from 42 to 77, at Storängen Children's Home, Söderköping, for the purpose of studying its effect on the intelligence quotient. The dosage was 18 Gm. per day in three doses, and the duration of treatment just over four months. A control group comprising fifteen children of corresponding ages and intelligence was treated concurrently with a granulated substitute. The treatment had no demonstrable effect.