It seems particularly fitting that the annual lectureship established by the Section on Practice of Medicine should commemorate the name of Dr. Frank Billings. His eminent leadership influenced in a large measure the development of this and other scientific sections of the Association. Furthermore, in the field of medical education and as a builder of medical schools, hospitals and research institutes he left an enduring impress on American medicine.
Of his many contributions to clinical medicine the most outstanding is the modern concept of focal infection as related to chronic systemic disease, which was first presented in his classic article1 entitled "Chronic Focal Infections and their Etiological Relations to Arthritis and Nephritis."
In the passing of a quarter of a century the many implications of this concept, some rather controversial, have been widely discussed, so that it appears timely to attempt an evaluation or survey of focal infection at