 In March 1878, Wilhelm Hack of Freiburg published a paper describing the use of non-surgical orotracheal intubation in the removal of vocal cord polyps.In November of that year, he published another study, this time on the use of orotracheal intubation to secure the airway of a patient with acute glottic edema, progressively introducing sizes 3 through 11 of "Schrotter's graduated triangular vulcanite bougies" into the larynx.In 1880, the Scottish surgeon William Macewen (1848–1924) reported on his use of orotracheal intubation as an alternative to tracheotomy to allow a patient with glottic edema to breathe, as well as in the setting of general anesthesia with chloroform.