Aids to otology / by W.R.H. Stewart.

  • Stewart, W. R. H. (William Robert Henry), 1852-1906.
Date:
[1893]
Catalogue details

Licence: Public Domain Mark

Credit: Aids to otology / by W.R.H. Stewart. Source: Wellcome Collection.

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    posed to cause the various notes—those at the base causing the high, and those at the apex the low notes. The Eustachian Tube balances the equilibrium of air on the two sides of the tympanic membrane (for if the tympanum be permanently closed, the vibrations of the membrane would be injuriously affected by variations of pressure from either outside or inside), and, together with the mastoid cells, allow the escape of superfluous sonorous vibrations. It also acts as a drain to the tympanic cavity. INSTRUMENTS REQUIRED, AND EXAMINATION OP PATIENT. INSTBUMENTS REQUIRED :— A. For making a direct examination. 1. A BRIGHT, STEADY LIGHT.—Sunlight, whcro obtainable, has no equal. Oxy-hydrogen limelight. Electric light. A bulPs-eye and Argand burner.—Can be used either with a racked bracket (Fig. 2) or on a Queen's lamp. To avoid the CHAPTER III. Fig. 2.