European powers and the Qing Empire, the Cohong often held precarious positions, with the Hoppo holding tremendous power over their appointment and their finances. Additionally, because of the low social status of merchants within traditional Confucian social hierarchy, the Cohong merchants were often at the mercy of their bureaucratic masters within the Hoppo. Throughout his three-year term in the office, a Cohong merchant would be forced to pay numerous bribes, levies, donations, and gifts to his superiors, resulting in a steep drop in profits. Nevertheless, as a result of the lucrative trade they controlled, Cohong guilds became very wealthy, with their personal fortunes numbering among the highest in the Qing dynasty, and even in the world. To maintain their influence they ensured that local residents and officials up to the highest level of the bureaucracy made overtures to the Qing government to maintain Canton's status as the sole site of official trade with the western world. From time to time, this municipal trade monopoly came to rankle the British government, who sought out other ports of call through which to obtain the goods that their Empire craved. Consoo fund The Cohong further functioned as controller of the Consoo Fund (公所, gōngsuǒ)(actually the name of the office of the Cohong in Thirteen Factory Street), a system established in 1781 that utilized a pool of money raised by levies (公所费, gōngsuǒfèi) on the trades of individual merchants to cover the debts of any bankrupt hong at year end and to pay the various exactions demanded by the government and the Hoppo bureaucrats. Officially, the rate levied for the fund was 3% of the value of goods. This tax originally applied only to tea but by the late eighteenth century had expanded to cover 69 different products. Opium trade Due to the heavy need for silver in the trade between European colonial powers and the Qing in Canton and complications with its silver supply due to revolts within the American Colonies, the British required a substitute for the precious metal. In short order, British merchants employed opium as a valuable trade good to obtain the goods it desired. As the Qing Empire's trade with the West transitioned from silver to opium, the Cohong Guilds transitioned themselves to the trade in the addictive narcotic substance. Opium from British India moved swiftly into the Chinese markets, largely overtaking silver as the most traded good between