454 OTOLOGY AND LARYNGOLOGY 



by reflected light, and its image is in turn thrown back upon the 

 mirror, and hence reflected into the eye of the observer, which is 

 parallel with the rays thrown upon the reflecting surfaces. Exactly 

 the same principle applies if, instead of the larynx, the nasopharyn- 

 geal cavity has to be examined, and the law of physiological optics 

 just described is as all-important for posterior rhinoscopy as it is for 

 laryngoscopy. But in order to obtain a really good image of either the 

 larynx or of the nasopharyngeal cavity it is necessary that the light 

 which is thrown upon the reflecting mirror should be a powerful one. 

 Hence every progress which is made in concentrating and intensify- 

 ing the light used for illumination of these parts is of the greatest 

 interest for my branch of science. It sounds nowadays almost like 

 a myth that the progress of laryngology in its infancy should have 

 been retarded for almost half a year, and that Professor Turck of 

 Vienna, who first utilized Manuel Garcia's epoch-making discovery 

 of the laryngoscope for the investigation of pathological processes 

 in the larynx, should have given up his studies for the time because 

 the winter of 1857 in Vienna was a very dark one, and because suffi- 

 cient light for illumination of the larynx could not be obtained from 

 the direct rays of the sun. Yet such was actually the case, and it was 

 only, as Morell Mackenzie has tersely stated, through Professor 

 Czermak's substituting artificial light for the uncertain rays of the 

 sun, and using the large ophthalmoscopic mirror of Reute for con- 

 centrating the luminous rays, that the initial difficulties were over- 

 come. Thus already at this early stage lenses, another achievement 

 of physiological optics, were employed to help our young science. 

 Ever since, every improvement in the way of light has been a subject 

 of the keenest interest for laryngology and rhinology. What progress 

 have we made from the Schusterkugel a large glass globe filled 

 with water, originally employed by Tiirck and Stoerk until we 

 have been actually enabled to introduce a small electric lamp into 

 the cavities of the body themselves to illuminate them properly for 

 purposes of diagnosis and operation, or to throw light into the 

 esophagus or the bronchial tubes, or to transilluminate the face for 

 diagnostic purposes, as, for instance, for the diagnosis of disease of the 

 maxillary antra or the frontal sinuses. 



The employment of gas, recently followed by its new incandes- 

 cent modification; the introduction of hydro-oxygen light, and, 

 above all, that wonderful source of light, now in general use, the 

 electric, have formed so many steps in the way of improving our 

 powers in laryngology and rhinology. Quite recently the invention 

 of the Nernst lamp has proved a great boon to us, enabling those who 

 had been accustomed to the, if excellent, rather cumbersome use 

 of hydro-oxygen light, to get illumination almost equally good at 

 infinitely less trouble. 



