In 1880, Dr. O'Dwyer began to devise some method of providing a channel for the passage of air and secretions through the larynx. He knew that tracheotomy, as a serious, bloody operation, always is put off until the condition of the patient is quite alarming, if not hopeless, and that some device for holding the larynx open, if not too difficult of application, would surely prove life-saving in a great many cases. His first thought was that the introduction of a wire spring within the larynx might serve to hold the inflamed sides apart. He realized, however, that the edema and false membrane would force their way around the wires, and so gradually occlude the throat passage in spite of the presence of the spring. His next thought was a small bivalve speculum, that is to say, two portions of tubes cut longitudinally and fastened together in such a way that the ends could be forced apart. Such instruments are used very commonly for the examination of various cavities in the human body. The laryngeal spring, or speculum, was more successful than the wire, but it had one of the faults of the wire spring. Into the slit between the two portions of the speculum the inflamed mucous membrane was apt to force itself, so that before long difficulty of breathing would recur. Besides, if the spring which kept the blades of the speculum apart were weak, the instrument would fail of its purpose in {331} keeping the mucous membrane apart, while, if it were strong, the pressure of the blades would cause ulceration. Notwithstanding its faults, however, the bivalve laryngeal speculum accomplished somewhat of the purpose intended. In one case it kept a child alive until the dangerous period of the disease was passed, and thus was the means of saving the first little patient suffering from membranous croup in the thirteen years that the Foundling Asylum had been in existence. Dr. O'Dwyer continued to experiment with the speculum for some time, but finally gave it up and began to study the detailed anatomy of the human larynx. These studies included not only the normal larynx, but also its conditions under the influence of various pathological lesions. Finally (as one of Dr. O'Dwyer's assistants at that time says), he appeared one day in the autopsy-room with a tube. This tube was a little longer than the speculum that before had been in use. It was somewhat flattened laterally, and had a collar at its upper end. This tube was very soon to prove of practical value.