The control of respiratory cross infections in infants' wards has always presented a serious problem.1 Since the introduction of gamma globulin, sulfonamides and antibiotics this problem has become less acute. Nevertheless, there are still far too many respiratory tract infections—bacterial, viral and of unknown cause— which are acquired after admission to a hospital ward. The relative importance of contact versus air-borne infection has not been established. However, in recent years the air-borne mode of transmission has received much emphasis.2 The study to be described is concerned with two measures for the control of air-borne infection—use of triethylene glycol vapor and dust suppression by oiling. Triethylene glycol vapor possesses marked bactericidal and virucidal properties against a variety of airborne micro-organisms. Robertson and his associates3 demonstrated that it was rapidly lethal for hemolytic streptococci, pneumococci, staphylococci, influenza bacilli and the PR8 strain of influenza virus. Rosebury and his associates