The Chashi 茶史 "A history of tea" is a book on tea written by the Qing period 清 (1644-1911) scholar Liu Yuanchang 劉源長, courtesy name Liu Jiezhi 劉介祉. He came fron Huai'an 淮安, Jiangsu, but not much is known about his life. As stated in the preface of the Chashi, his style was Bashiweng 八十翁, a name that shows that he was already an old man when the book was finished. The 2 juan "scrolls" long Chashi speaks in the first part about different types and qualities of tea, and in the second part of the culture of drinking tea. The 30 short chapters are very detailed but not very systematic and do not talk a lot about the actual history of tea. The Chashi was presented to the compilers of the imperial reprint series Siku quanshu 四庫全書 by Wang Qishu 汪啟淑 from his private library, but it was not included in this collection.
There is a supplement called Chashi bu 茶史補 written by the Qing period scholar Yu Huai 余懷.
Source: Li Xueqin 李學勤, Lü Wenyu 呂文鬰 (1996). Siku da cidian 四庫大辭典, vol. 2, p. 1864. Changchun: Jilin daxue chubanshe.