Longan

„tong; 筒 - Literally a barrel or barrel shaped object. A tong in Yunnan tea culture is a bundle of 7 tea cakes wrapped in the outer skin of bamboo which naturally sheds from around the base of the bamboo stem. Each cake weighs 357grams so making a total of 2,499 gm. Said by some to have been calculated in order to remain under a specific legislated weight of 2.5 kg. There were originally said to be 8 cakes in a tong. The 8th being paid as a levy. An earlier unit of weight in China was the liang. A cake of tea weighed 7 liang and 7 cakes in a tong made 49 liang. “