Note s — BOOK IV.
Reading edition
Dr. Vieussens, before-named, discovered a Membrane, tenuissimæ raræque admodùm texturæ intra cavitatem Tympani; as he describes it. Whose use he saith is, 1. Occludens Labyrinthi januam impedit nè naturalis purissimus ac subtilissimus Aer intra cavitates——communicationem——habeat cum aere crasso. 2. Labyrinthi basin calefacit, &c. ubi supra. Probably this double Membrane may be such, or after the same Manner as it is in the Tympanum of Birds: Of which see my Observations in Book VII. Chap. 2. Note (d).