Mexican Treasure


The present copy of the work commonly called the Tesoro Messicano (Mexican treasure), formally titled Rerum medicarum Novae Hispaniae thesaurus, seu, Plantarum animalium mineralium Mexicanorum historia (Inventory of medical items from New Spain, or, History of Mexican plants, animals and minerals) is also known as the “Esemplare Cesiano” for its rich handwritten annotations by Federico Cesi (1585‒1630), the Italian naturalist and founder of the Accademia dei Lincei in Rome. The Tesoro is a complex work: the events that culminated in its publication in 1651 date back to 1570, when King Philip II of Spain appointed his court physician, Francisco Hernández, to be chief physician of the Indies. Philip ordered Hernández to travel to Mexico to study the natural environment of the New World, with a focus on the medical applications of its as-yet-unknown plants. Seven years later Hernández returned home, but his manuscript―a huge collection of unintelligible names together with drawings depicting unknown plants and animals―did not meet with the king’s favor. Philip eventually asked Leonardo Recchi to draw up a text that was more in line with his original desire for a list of plants with medical uses. In 1610, Recchi’s manuscript found its way into the hands of Cesi, who took on the task of completing the work and ensuring that it was printed. Cesi commissioned commentary and exegesis by Johannes Faber, Fabio Colonna, and Joannes Terentius, and he had Francesco Stelluti compile the indexes. The volume carries four printing privileges dating from 1623‒27: Privilegium Summi Pontificis (by Pope Urban VIII), Privilegium Imperatoris (by Holy Roman Emperor Ferdinand II), Privilegium Regis Galliae (by King Louis XIII of France), and Privilegium Magni Ducis Etruriae (by Ferdinando II, duke of Tuscany), plus a dedication to Philip IV dated 1650 and the imprimatur of 1651. The title page, engraved by Johann Friedrich Greuter, has the incorrect date of 1649. The printed volume is the result of a quite disordered assembly of various parts that were printed at different times and put together by Vitale Mascardi, who used the material at his disposal, including parts that were printed while Cesi was alive and a few parts produced only after his death. The first part of the Tesoro consists of ten books: the first book, Prolegomena (Foreword), explains the methodology followed by Recchi in processing the text of Hernández. Books two through eight contain descriptions of plants; the ninth book has descriptions of animals; while the tenth deals with minerals. The second part of the Tesoro (pages 465‒840) is a detailed description of the animals of Mexico by Johannes Faber. The third part (pages 841‒99) contains Annotationes et Additiones (Notes and addenda) by Fabio Colonna. The work ends with 20 tables, identified as Tabulae Phytosophicae (Botanical tables) by Cesi. Even though Cesi did not finish the compilation of Tabulae Phytosophicae, in the present copy these tables appear completed. Cesi’s annotations are either brief cross-referencing notes, placed under the titles and very often close to the figures of flowers and plants, or complex marginal notes on the outside edge of the pages. His notes identify plants and, where necessary, propose new names. The work is a monumental 17th century compendium of the botany, zoology, and mineralogy of the New World, the result of teamwork over many decades between scientists and travelers.

Date Created

Subject Date

Publication Information

Vitale Mascardi, Rome


Title in Original Language

Rerum medicarum Novae Hispaniae thesaurus, seu, Plantarum animalium mineralium Mexicanorum historia

Type of Item

Physical Description

950 pages : illustrations, tables


  • The Tesoro Messicano (Mexican treasure) is included in the World Digital Library with the support of the Institute for the European Intellectual Lexicon and History of Ideas (ILIESI) – CNR. ILIESI is leading an international project to provide access to digital editions of major philosophical texts, for the purpose of facilitating research on the intercultural history of philosophy. The project traces the migration of philosophical concepts from original editions to later editions and translations of major texts.


  1. Luigi Guerrini, The “Accademia dei Lincei” and the New World (Berlin: Max Planck Institute for the History of Science, 2008).

Last updated: September 13, 2017