When the roentgen rays were first contributed to medical science, early workers failed to realize their menace to the unprotected worker; hence the passing of the years has seen the mutilation and death of many of those who conducted the earliest experiments. They were all martyrs to the advancement of medical science. Dr. Percy Brown gives brief biographies of twenty-eight of these martyrs, indicating as well their scientific contributions to the field they helped to advance. Today there are still among us many roentgenologists who will also in the coming years die as a result of their efforts in this field. Some day, no doubt, medical literature will make available a long list of these physicians who throughout the world have given their careers and their lives to the advancement of roentgenology. Even this brief collection is an inspiration.