The Chemical Constituents of Piper Methysticum: The Chemical Constituents of the Active Principle of the Ava Root is a comprehensive scientific treatise authored by Alice R. Thompson and published in 1907. This pioneering work delves into the detailed chemical analysis of Piper methysticum, commonly known as kava or ava, a plant native to the South Pacific and renowned for its psychoactive and medicinal properties. The book meticulously documents the methods and results of isolating and identifying the active chemical constituents responsible for the plant’s effects, focusing particularly on the root, which is traditionally used to prepare a ceremonial beverage. Thompson’s research, conducted at the College of Hawaii, represents one of the earliest systematic studies of kava’s chemistry. The text outlines the extraction processes, the use of various solvents, and the application of chemical reactions to separate and characterize the compounds present in the root. The author provides detailed descriptions of the physical and chemical properties of the isolated substances, including their solubility, melting points, and reactions with reagents. Special attention is given to the identification of kavalactones, the primary active compounds, and their potential physiological effects. In addition to the experimental findings, the book discusses the historical and ethnobotanical context of kava use among Pacific Island cultures, highlighting its significance in social, religious, and medicinal practices. The work is supplemented with tables, analytical data, and references to contemporary scientific literature, making it a valuable resource for chemists, pharmacologists, ethnobotanists, and anyone interested in the intersection of traditional knowledge and modern science. Overall, The Chemical Constituents of Piper Methysticum stands as a landmark publication in the field of natural product chemistry, offering a thorough and methodical exploration of the compounds that give kava its unique properties and cultural importance.