No discussion of the currency in this country should be complete without a proper enquiry into the history of paper money in China. The earliest period in which paper is known to have been issued is in about 806 a.d. The causes that lead to the adoption of paper money were many. In the latter part of the eighth century and also in the beginning of the ninth century coinage was irregular; although the only coin in circulation was the cash, the supply was insufficient, mainly due to want of metal to coin with, as also the very slow process of minting that was then in vogue. One report states that even copper and bronze statues and statuettes of Buddha were melted down for metal for coinage. Even so the supply proved insufficient; iron was used, and in the province of Szechuan iron coins became practically the only currency. Although trade during this period could not have been of any appreciable total there is no doubt that the copper and iron money, especially the latter, must have been very inconvenient - on account of the weight. People soon found that some method, which would obviate the carriage of huge weights of metal from one place to another, must be adopted. The authorities were approached and an understanding was arrived at that the government office would give a certificate of deposit in exchange for coins, and that such certificate should have the same value as money. The arrangement thus arrived at proved for a time very effective, because the certificate issued in one province was always cashable in another, however distant. These certificates became very popular; an ancient Chinese historian said that "because the merchants could travel or carry on trade relations in distant places with light equipment, this new currency came to be called the 'flying money'." During the few decades following upon the introduction of this 'flying money' the people began to take to it so much that the Government began to be anxious about metallic money. The Government feared that it would displace the metallic money, and therefore suppressed paper.