tutor Li Xun 李訓 (d. 835) and said (tr. Kieschnick 2003:145), "The ruyi may serve you as a lecture baton (tanbing)." The (945) Old Book of Tang biography of Li Xun (tr. Davidson 1950:247) says this occurred on a hot summer day and the emperor's ruyi present was made from "heat-repelling rhinoceros horn", which is believed to be cooling in Traditional Chinese Medicine. Ruyi were both emblems of power and tools of discourse. Herbert Giles (1912:185) quoted the Song dynasty archaeologist Zhao Xigu 趙希鵠 (d. 1240) that the ruyi "was originally made of iron, and was used 'for pointing the way' and also 'for guarding against the unexpected,' i.e. for self-defence. It was, in fact, a kind of blunt sword, and traces of basket-work are still to be found inside what must have been the sword-guard." In the Ming dynasty (1368–1644 AD), ruyi became popular as ornaments or gifts symbolizing blessings and good luck. The ca. 1627 AD Zhangwuzhi 長物志 "Treatise on Superfluous Things", by Ming painter Wen Zhenheng, discussed ruyi aesthetics. The ruyi was used in ancient times to give directions or to protect oneself from the unexpected. It was for this reason that it was made or iron, and not on the basis of strictly aesthetic considerations. If you can obtain an old iron ruyi inlaid with gold and silver that sparkle now and then, and if it has an ancient dull color, this is the best. As for ruyi made of natural branches or from bamboo and so on, these are all worthless. (tr. Kieschnick 2003:151) During the Qing dynasty (1644–1912 AD), ruyi scepters became luxuriant symbols of political power that were regularly used in imperial ceremonies, and were highly valued as gifts to and from the Emperor of China. Since 3 and 9 are considered lucky numbers in Chinese culture, Qing craftsmen elaborated the traditional handle and head type ruyi into two-headed sanjiang-ruyi 三鑲如意 "3-inlay ruyi" with precious stones set in both heads and middle of the handle and jiujiu-ruyi 九九如意 "9-9 ruyi" presentational sets of nine. The Qianlong Emperor presented a ruyi to the British ambassador George Macartney in 1793, and in his description (quoted by Kieschnick 2003:139–140), "It is a whitish, agate-looking stone, about a foot and a half long, curiously carved, and highly prized by the Chinese, but to me it does not appear in itself to be of any great value." During