Competently handled record of achievements of 20th century medical research, supported by brief histories of earlier work. Lucid and not too technical details about the discovery of penicillin, sulfa drugs, streptomycin; improvements in blood typing; the Rh factor, viruses, DDT, vitamins and radioactive elements in medicine. Here and there the simplification lies in the use of simple words rather than simple ideas, but on the whole this should prove interesting background material for junior high level-with special appeal for youngsters thinking of nursing or medical careers.