=The Kin=.—The principle of the sound of =silk= is exemplified in the Kin or Ch’in, the strings, “made of twisted silk, being stretched over a wooden frame.” This instrument was the favorite of Confucius, the great law-giver, and in _his_ time was of _great antiquity_. The number of strings was five, to agree with the five elements; the upper part was rounded, to represent the heavens; the bottom was flat, to represent the ground. The number of strings was later increased to seven, which is the favored form, tuned to G, A, C, D, E, G, A, a pentatonic scale. =The Se=.—Another stringed instrument is the _Sê_, (also written _Che_), which had originally fifty strings. As now used, it has only twenty-five strings. Four kinds are in use, differing in size and in number of strings; it is customary that they should give the sound of two notes simultaneously, generally octaves. Some of these, used by the most skilful performers, have only thirteen or fourteen strings. The strings are plucked by two small ivory picks. =Flutes=.—The sound of =bamboo= is exemplified in certain instruments of the flute family. The bamboo plant is used by the Chinese in very many ways; it is natural that they should use it for making musical instruments. There are two types of pipes or flutes: those blown at the end, as a whistle, and those blown across a hole near one end, as is our modern flute; the Chinese flutes are of the latter class. They varied in size and in the number of holes, from three to six, the little finger of each hand not being used. A popular flute, called the _Ti-Tzu_, has, in addition to the six finger holes, one for blowing and one covered with a thin membrane, to vary the sound. Another kind, very ancient, and much in use, according to Chinese writers during the period 2205-1122 B. C., may be called, shortly, the _Tche_. It has six finger holes, three near each end, and is pierced with another hole at the middle, across which the player blows. The scale is said to consist of six semitones, beginning with F, fifth line treble clef. The peculiar construction of this flute presents some acoustical problems. [Illustration: TCHE.] =Other sonorous bodies= are, =metal= from which the Chinese make gongs, bells and trumpets—they seem to have known the principle of the slide, as in the trombone, but never developed it; =stone=, certain varieties, in the shape of the letter L, pierced with a hole at the angle, suspended in a frame and struck by a hammer; =skin=, from which drums were made; =clay=, from which instruments were made in shape resembling the ocarina, familiar to us.