In an era of coldly clinical medicine, it is reassuring to read the life story of Dr. Charles Mayo (who has just died) so often misintroduced as the son of the Mayo brothers. Even before his father Charles and Uncle Will (who had an unusual symbiotic relationship) there was the first Mayo, still indomitable at ninety, a man who articulated many still valid diagnostic deductions. Dr. Mayo writes about his early years--when about nine he and his brother Joe performed a by guess and by God operation on a puppy for an umbilical hernia. By God it lived. Illness during his schooling taught him an important lesson, compassion, to be later widened by his qualifications for the good surgeon--judgment, technique and attitude to the patient, in that order. Brother Joe, a more spectacular performer (Charles was ""a plodder""--his wife) died at thirty-four. Charles specialized in abdominal surgery, developed certain basic procedures, never had a patient die on the table, only left one sponge behind. All of the medicine is very interesting--other parts concern his World War II service, his work with the U.N. and WHO. Expectedly he has always been conservative, still opposes Medicare, admires Eisenhower as the ""greatest"" of the five presidents he knew. . . . Materia medica with a solid, affirmative human interest.