Zhang's Ancestral Formulas (Yitong Zufang)

Zhang's Ancestral Formulas (Yitong Zufang) is a manuscript on formula studies by Zhang Lu (1617–1700; courtesy name Zhongyu, style name Shiwan, a native of Changzhou), a physician of the early Qing dynasty. It is now included in the series Rare Manuscripts of Classical Chinese Medicine, collated and typeset by Shanghai Scientific and Technical Publishers, with collation by Tong Shunhua. The work draws on a large number of classical and contemporary formulas, arranged by "ancestral formula" categories: each category first lists the ancestral formula, such as Guizhi Tang (Cinnamon Twig Decoction), then in sequence the "descendant formulas" derived from it through modification, such as Xiao Jianzhong Tang, Huangqi Jianzhong Tang, Yangdan Tang, and Yindan Tang. Descendant formulas generally retain the principal ingredients of the ancestral formula or inherit one aspect of its action; through additions, omissions, and dosage adjustments, one function—releasing the flesh and inducing sweat, harmonizing the constructive and defensive, warming the channels and unblocking the vessels, or warming the center and relieving urgency—is strengthened, sometimes producing new functions and thus broadening the scope of application. Xiao Jianzhong Tang, for example, is Guizhi Tang with double the peony and added maltose, strengthening its power to relieve urgency and supplement the center, making it a specific formula for cold-heat abdominal pain with tenesmus; Huangqi Jianzhong Tang consolidates the exterior and harmonizes the constructive, and is particularly used for consumptive illness with contraction of cold, fever, and spontaneous sweating. The whole book classifies patterns by formula and analyzes patterns through formulas, using the lineage relationships among formulas to display the logic of pattern differentiation and treatment. The collator worked from the manuscript held in the library of Shanghai University of Traditional Chinese Medicine; the main text is arranged under categories such as Guizhi Tang, Mahuang Tang, Xuming Tang, Xiao Chaihu Tang, Sini Tang, Lizhong Tang Wan, Erchen Tang, Siwu Tang, and Pingwei San, and may be consulted by those studying the origins of formulas and clinical modifications. Some classifications in the original are debatable—for instance, Linggui Zhugan Tang placed under the Guizhi Tang category—and readers should examine them critically.