Harmonica

Harmonica, CHEMICAL. This term is applied to the musical note which is evolved when a long dry tube, open at both ends, is held over a jet of burning hydrogen. A rapid current is produced through the tube, which occasions a flickering, and is attended by a series of small explosions, that succeed each other so rapidly and at such regular intervals as to give rise to a musical note, whose pitch and quality vary with the length, thickness, and diameter of the tube. See FLAME.