In a previous publication by one of us (D. H.)1 it was noted that the number of staphylococci in the air of an operating room varies directly with the number of occupants. On several occasions throughout the year cultures of material from the noses and throats of the operating room personnel were made, and it was found that contamination of the air with Staphylococcus aureus varied directly with the number of carriers of this organism and the density of the growth in the nasopharynx. A group selected at random from the general population on one occasion showed about the same percentage of carriers as had been found among the personnel of the operating room. During the winter of this year (1933-1934) the number of carriers at times ran as high as 80 per cent.
During the past year, sediment from the air of the operating room has been cultured