15 cc of this polyvalent antitoxin (Lederle) contains antibodies against CZ. welchii (10, OOO units), Cl. septicu?n (lo,OOt~ units) CZ. novyi (1SOa units), CZ. bijermntans (1500 units), C1. histolyticum (3000 units), by guest on July 29, 2015 ebm.sagepub.com Downloaded from Surgery, 1951, v30, 652. ~5 1 , (new series 16) 267.