There are many reports in the literature dealing with the effect of ultraviolet radiation on bacteria. In an effort to kill the bacteria floating in the air of the occupied operating room we turned to such radiation, which is known to have strong bactericidal properties. (Wells1 has been working on a similar problem, an attempt to control contamination of air from the standpoint of public health.) We have used cold tubes 30 inches (75 cm.) long, containing argon, neon and mercury. Over 80 per cent of the output of such tubes (which have already been described2) is at 2,537 angstrom units, and the apparatus offers the following advantages:
1. High output in the bactericidal range of the spectrum and low output in the erythemic range.
2. Negligible production of ozone, which is rarely detectable by odor even with as many as sixteen tubes burning in the operating room.