The Mosou 墨藪 "Assembly of Calligraphies" is a book on calligraphy authorship of which is traditionally attributed to the Tang period 唐 (618-907) scholar Wei Xu 韋續. The 2 juan "scrolls" long book begins with a register of older books on calligraphy, but unfortunately the names of the authors are not listed. The Ming period edition by Cheng Rong 程榮 ends with an appendix on errors in a book on model calligraphy, the Fatie shiwen kanwu 法帖釋文刊誤, which was written by the Song period 宋 (960-1279) scholar Chen Yuyi 陳與義. The bibliographic chapter in the encyclopedia Wenxian tongkao 文獻通考 says the Mosou was 10 juan long, the bibliography Zhengshi shumu 鄭氏書目 speaks of 5 juan, the Zhizhai shulu jieti 直齋書錄解題 or 18 or 21 chapters.
The transmitted text of the Mosou is divided into 22 chapters. The first part begins with a description of 56 writing styles and their inventors. Such are the "dragon script" (longshu 龍書, invented by Fu Xi 伏羲), the "eight-ears script" (bahuishu 八穗書, invented by Shen Nong 神農), the small seal script (zhuanshu 篆書, invented by Cang Jie 蒼頡), the "cloud script" (yunshu 雲書, invented by Yin Qingyun 因卿雲) the "phoenix script" (fenghuangshu 鸞鳳書, invented by Shao Hao 少昊, i.e. Emperor Zhi 帝摯), the "tadpole script" (kedoushu 科斗書, invented by Zhuan Xu 顓項), or the "bell-and-tripod script" (zhongdingshu 鐘鼎書, invented during the Xia period 夏, 17th - 15th cent. BCE), and so on. The second and third chapters (Jiupinshu 九品書, Xu shupin 續書品) explain the method to rate calligraphy by nine ranks of quality. In the third chapter (Shupin youlie 書品優劣) fourty calligraphers are concretely rated according to the liveliness, the shape and the fineness of their works. Chapter ten (Bizhentu shierzhang 筆陣圖十二章) describes twelve steps of creating calligraphy in analogy to military formations and training. Other chapters discuss the calligraphies of individual masters (like 4 Liang Wudi shuping 梁武帝書評, 12 Wang Yishao bishi zhuan 王逸少筆勢傳 or 14 Wang Yishao bishi tu 王逸少筆勢圖), discuss special themes (like 6 Shulun 書論, 7 Lunzhuan 論篆, 15 Biyi 論篆 or 19 Shujue 書訣) or consists of a set of rules for calligraphy, often quotations from other masters (like 8 Yongbifa bing koujue 用筆法并口訣, 11 Zhang Changshi shier yi bifa 張長史十二意筆法 or 20 Xushi shuji 徐氏書記).
The arrangement of the text is quite unsystematic and seems not to have experienced a thorough revision. The Mosou nevertheless provides important information about the history of calligraphy and is therefore often quoted in later texts. It is to be found in the collectanea Tang-Song congshu 唐宋叢書, Gezhi congshu 格致叢書, Baqianjuanlou congshu 八千卷樓, Shiwanjuanlou congshu 十萬卷樓叢書, Congshu jicheng chubian 叢書集成初編 and Siku quanshu 四庫全書.
Source: Li Xueqin 李學勤, Lü Wenyu 呂文鬰 (1996). Siku da cidian 四庫大辭典, Changchun: Jilin daxue chubanshe, vol. 2, p. 1798.