The following article on nebulization equipment calls attention to the fact that there is no single simple method of humidification which does not carry at least some risk of contamination. A study is made of several mechanical devices that are in common use and well known by their trade names. It is shown that techniques for decontamination are not equally effective in all cases. Strongly implied is the conclusion that all such pieces of mechanical equipment should in their distribution be accompanied by carefully specified instructions for effective decontamination.—Ed.