The therapeutic problem presented by otherwise healthy individuals who suffer from persistent furunculosis is a serious one. Wright's vaccine therapy, that is, active antibacterial immunization by injection of killed staphylococci, is still extensively employed. It is not easy, however, to determine the effectiveness of treatment in a disease the course of which is so variable. The statement of Osborne and Fishbein1seems representative of current opinion: "Stock vaccines and more frequently autogenous vaccines have occasionally been found valuable. On the other hand, sometimes vaccines fail utterly to prevent the recurrence of boils." Most of us need only to turn to our own experience for confirmation of the latter statement. In certain other bacterial infections, efforts to confer an antitoxic as contrasted with an antibacterial immunity have proved more effective. Diphtheria, tetanus and scarlet fever are perhaps the outstanding examples. It would seem, then, that in a chronic infection such as