Ether (Gr. αἰθήρ, the pure, upper air). A narcotic poison. Used as an anæsthetic in surgical operations.
Eustachian (from an Italian anatomist named Eustachi). The tube which leads from the throat to the middle ear, or tympanum.
Excretion (Lat. excerno, to separate). The separation from the blood of the waste matters of the body; also the materials excreted.
Exosmosis (Gr. ἔξω, without, and ᾀθέω, to push). The current from within outwards when diffusion of fluids takes place through a membrane.
Expiration (Lat. expiro, to breathe out). The act of forcing air out of the lungs.
Extension (Lat. ex, out, and tendo, to stretch). The act of restoring a limb, etc., to its natural position after it has been flexed or bent; the opposite of flexion.
Fauces. The part of the mouth which opens into the pharynx.
Fenestra (Lat.). Literally, “a window.” Fenestra ovalis and fenestra rotunda, the oval and the round window; two apertures in the bone between the tympanic cavity and the labyrinth of the ear.
Ferment. That which causes fermentation, as yeast.
Fermentation (Lat. fermentum, boiling). The process of undergoing an effervescent change, as by the action of yeast; in a wider sense, the change of organized substances into new compounds by the action of a ferment. It differs in kind according to the nature of the ferment.