Volume 164 in the The Civilization of the American Indian Series The Treatise of Hernando Ruiz de Alarc n is one of the most important surviving documents of early colonial Mexico. It was written in 1629 as an aid to Roman Catholic churchmen in their efforts to root out the vestiges of pre-Columbian Aztec religious beliefs and practices. For the student of Aztec religion and culture is a valuable source of information. With great care and attention to detail Ruiz de Alarc n collected and recorded Aztec religious practices and incantations that had survived a century of Spanish domination (sometimes in his zeal extracting information from his informants through force and guile). He wrote down the incantations in Nahuatl and translated them into Spanish for his readers. He recorded rites for such everyday activities as woodcutting, traveling, hunting, fishing, farming, harvesting, fortune telling, lovemaking, and the curing of many diseases, from toothache to scorpion stings. Although Ruiz de Alarc n was scornful of native medical practices, we know now that in many aspects of medicine the Aztec curers were far ahead of their European counterparts. "J. Richard Andrews and Ross Hassig have produced what will undoubtedly be the definitive translation for some time.. The editors provide a valuable and comprehensive explanation of the ecclesiastical context of the conquest, native religion and medicine, and religious syncretism."- THE AMERICAS