Drs. Starkey and Palen operated a salon in Philadelphia in the late 1800s that provided inhalation treatments for respiratory ailments, which were a common medical practice at the time. They promoted their "scientific adjustment to oxygen and nitrogen" treatments and encouraged the public to visit their salon. The document then continues with further details about respiratory treatments, ventilation, and hygroscopic materials like spun polypropylene coated with calcium chloride that can add moisture to inhaled gases without increasing pressure.