An expert on disease prevention and the use of food for special medical purposes will speak at noon tomorrow in 103 Mumford Hall. Dr. George Blackburn of the Harvard Medical School will speak on "The Principles of Nutritional Oncology" during the free lecture, which is open to the public. Blackburn studies surgical metabolism, critical care medicine, lipid protein and energy biochemistry, clinical nutrition, hospital protein calorie malnutrition and obesity pathogenesis and treatment, as well as health policy issues related to medical uses of food. Blackburn is a professor of surgery at Harvard. At New England Deaconess Hospital in Boston, he is the chief of the Nutrition and Metabolism Lab and the director of the Center for the Study of Nutrition Medicine. He holds academic appointments at the Boston University Medical and Dental School and at the Massachusetts Institute of Technology. His lecture is funded by the Albert L. Elder Endowment in the food science and human nutrition department and by the Functional Foods for Health Program, a joint program of the UI at Urbana-Champaign and at Chicago.