Read to the Section of Ophthalmology, Otology and Laryngology of American Medical Association, May 8, 1884.
There is no morbid condition involving the vocal organs possessing a more varied pathogeny than paralysis of the lateral crico-arytenoid muscles, the functional aphonia of pre-laryngoscopic authors.
No disease is more doubtful in its amenability to therapeutic measures, the restoration of voice in some instances following the introduction of the laryngoscopic mirror; in others baffling all our resources. That motor disturbances of the muscles under discussion resulting from fright, mental emotion, anæmia, chlorosis, dysmenorrhœa, intestinal irritation, rheumatism, syphilis, diphtheria, hysteria, and reflex influences do occur is a fact generally admitted and frequently observed by the laryngologist.
Lead, arsenic, phosphorus, opium, and belladonna, have all been accredited with having caused palsy of the various laryngeal muscles. These cases, however, are greatly scattered throughout literature, and occasionally lack important details. "The influence of certain substances taken