JEW'S EARS, the popular name of a fungus, known botanically as _Hirneola auricula-judae_, so called from its shape, which somewhat resembles a human ear. It is very thin, flexible, flesh-coloured to dark brown, and one to three inches broad. It is common on branches of elder, which it often kills, and is also found on elm, willow, oak and other trees. It was formerly prescribed as a remedy for dropsy. JEW'S HARP, or JEW'S TRUMP (Fr. _guimbarde_, O. Fr. _trompe_, _gronde_; Ger. _Mundharmonica_, _Maultrommel_, _Brummeisen_; Ital. _scaccia-pensieri_ or _spassa-pensiero_), a small musical instrument of percussion, known for centuries all over Europe. "Jew's trump" is the older name, and "trump" is still used in parts of Great Britain. Attempts have been made to derive "Jew's" from "jaws" or Fr. _jeu_, but, though there is no apparent reason for associating the instrument with the Jews, it is certain that "Jew's" is the original form (see the _New English Dictionary_ and C. B. Mount in _Notes and Queries_ (Oct. 23, 1897, p. 322). The instrument consists of a slender tongue of steel riveted at one end to the base of a pear-shaped steel loop; the other end of the tongue, left free and passing out between the two branches of the frame, terminates in a sharp bend at right angles, to enable the player to depress it by an elastic blow and thus set it vibrating while firmly pressing the branches of the frame against his teeth. The vibrations of the steel tongue produce a compound sound composed of a fundamental and its harmonics. By using the cavity of the mouth as a resonator, each harmonic in succession can be isolated and reinforced, giving the instrument the compass shown. The lower harmonics of the series cannot be obtained, owing to the limited capacity of the resonating cavity. The black notes on the stave show the scale which may be produced by using two harps, one tuned a fourth above the other. The player on the Jew's harp, in order to isolate the harmonics, frames his mouth as though intending to pronounce the various vowels. At the beginning of the 19th century, when much energy and ingenuity were being expended in all countries upon the invention of new musical instruments, the _Maultrommel_, re-christened _Mundharmonica_ (the most rational of all its names), attracted attention in Germany. Heinrich Scheibler devised an ingenious holder with a handle, to contain five Jew's harps, all tuned to different notes; by holding one in each hand, a large compass, with duplicate notes, became available; he called this complex Jew's harp _Aura_[1] and with it played themes with variations, marches, Scotch reels, &c. Other virtuosi, such as Eulenstein, a native of Würtemberg, achieved the same result by placing the variously tuned Jew's harps upon the table in front of him, taking them up and setting them down as required. Eulenstein created a sensation in London in 1827 by playing on no fewer than sixteen Jew's harps. In 1828 Sir Charles