By using a specially designed apparatus it was possible to study the yield of airborne organisms when various hospital textiles, artificially and naturally contaminated, were shaken under reproducible conditions. The results indicated that contaminant organisms are most effectively liberated when a textile is shaken in contact with a second fabric. The yield of airborne organisms was approximately doubled under the conditions used. Similarly, a 95 % removal of surface con taminants was also demonstrated by shaking in contact with a second textile, compared to 52 % removal when the textile was shaken alone.

These findings confirm those described in an earlier study of the spread of air borne organisms in a ward environment. It is suggested that this increase in aerial spread of infectious particles, previously referred to as a ‘counterpane effect’, is due to friction between the contaminated textile and its covering material.

Other points which emerged in the course of this work were the demonstration that cotton blankets tended to yield higher airborne counts than woollen ones and that the size distribution of bacterial particles dispersed by textiles is the same as that of the particles which contaminate the textiles.

It is with pleasure that we acknowledge the encouragement and advice of Prof. Walsh McDermott, in whose Department at the Cornell Medical College, New York, this work was carried out. We are also grateful to the National Institutes of Health, Bethesda, for financial support under Grant No. E-635(C 7).