The author of Young Doctor Galahad tells the story of a doctor's problems in the Ozarks, where his arrogant ignorance of ways and customs wins him enemies and trouble. A smallpox epidemic brings into the picture a nurse whom he loves -- and who hesitates not at all in giving him some salty advice. He is emotionally involved -- but extricates himself, and sticks to his mountains, his real love and the cause of public health. These Seifert novels -- all three -- might qualify as a popular medical series, each presenting a new background, new challenges, plus heart interest, a popular formula, which Miss Seifert handles expertly. Good of its sort.