The extended military campaigns in Central Asia during this period brought China into touch with Bactria, then an outlying province of ancient Greece. From this last source, the Chinese learnt many things which are now often regarded as of purely native growth. They imported the grape, and made from it a wine which was in use for many centuries, disappearing only about two or three hundred years ago. Formerly dependent on the sun-dial alone, the Chinese now found themselves in possession of the water-clock, specimens of which are still to be seen in full working order, whereby the division of the day into twelve two-hour periods was accurately determined. The calendar was regulated anew, and the science of music was reconstructed; in fact, modern Chinese music may be said to approximate closely to the music of ancient Greece. Because of the difference of scale, Chinese music does not make any appeal to Western ears; at any rate, not in the sense in which it appealed to Confucius, who has left it on record that after listening to a certain melody he was so affected as not to be able to taste meat for three months. CHAPTER II--LAW AND GOVERNMENT In the earliest ages of which history professes to take cognizance, persons who wished to dispose of their goods were obliged to have recourse to barter. By and by shells were adopted as a medium of exchange, and then pieces of stamped silk, linen, and deerskin. These were followed by circular discs of copper, pierced with a round hole, the forerunners of the ordinary copper coins of a century or two later, which had square holes, and bore inscriptions, as they still do in the present day. Money was also cast in the shape of "knives" and of "trouser," by which names specimens of this early coinage (mostly fakes) are known to connoisseurs. Some of these were beautifully finished, and even inlaid with gold. Early in the ninth century, bills of exchange came into use; and from the middle of the twelve century paper money became quite common, and is still in general use all over China, notes being issued in some places for amounts less even than a shilling.