The incidence of pulmonary complications of tonsillectomy is very low today in comparison to the early part of the 20th Century. Much of the credit belongs to Samuel Crowe and his colleagues who demonstrated that pulmonary complications could be prevented by the use of improved instrumentation and techniques which were based upon sound scientific principles. A historical review of anesthesia and the mouth gags of the early 1900's is included with a brief history of the development of the Crowe-Davis mouth gag. A review of the recent literature reveals few published papers about pulmonary complications. Those that are available show incidence figures similar to those of Dr. Crowe.