Mercati, Michele; Metallotheca. Opus posthumum, auctoritate, & munificentia Clementis undecemi Pontificis Maximi ex tenebris in lucem eductum; Opera autem, & studio Joannis Mariae Lancisii... illustratum. Cui accessit appendix cum XIX. recens inventiis iconibus. Rome, apud Jo. Mariam Salvioni Typographum Vaticanum, 1719. Small folio,  pp. (x, including half-title and frontispiece), xiii-lxiv, 378 (with an additional cancel leaf z4, pp. 367-8(bis), (18); 53, (1) with engraved frontispiece, 2 portraits (of Mercati and Lancisi), 6 engraved plates of which 2 are double-page, 159 engravings in text (several full-page), and engraved vignettes on titles, 2 initials and one tailpiece.

The work is complete and in the original vellum with inked titles. The binding is tight with light soiling and titles faded. Owners name on end sheet and and Melvin Jahn's book plate on paste-down. The text is clean with light foxing to some signatures and the margins of some plates. Over all in very good condition.

The son of a prominent physician; Mercati was born in Tusany in 1541 and died in 1593. He followed his father's example and studied Philosophy and medicine. His studies included the study of minerals of medicinal value. Upon completion of his education he joined his father in Rome as a physician. His dedication as a physician and scientific knowledge came to the attention of Pope Pius V and he was offered the position of Prefect of the Vatican Botanical Gardens and eventually was named Chief Physician to the Pope. This was a position he held under the following six Popes. The gardens provided medicines for the Papal Court. The position allowed Mercati to travel throughout Italy in search of medicinal plants and minerals. His knowledge of minerals came to the attention of Pope Gregory XIII who suggested he found a museum of natural history in the Vatican Palace and focus on earth products. During his years of scholarly study, Mercati had full use of the Papal library and corresponded actively with natural history collectors, including Aldrovandi, Imperato, Medici and Calzolari often exchanging minerals in order to add to the Vatican collection. During his years at the Vatican, Mercati assembled an extensive and impressive collection of minerals, ores and fossils which was called the "Metallotheca". The collection was housed in 19 large, custom built cabinets and at his death in 1593 the collection ranked among the largest and finest mineral collections in all of Europe. Mercati spent years writing a scholarly description of the collection but had completed work only on the first nine cabinets when he died. His family claimed the manuscript upon his death. Within a few years the bulk of the collection had been stolen piece by piece by members of the Curia or Papal Court. The manuscript lay hidden until it was rediscovered in 1717 and published in a small number of copies by Maria Lancisi (1654-1720, physician to Pope Clement XI) and Pietro Assalti.
As a record of an important renaissance palaeontological museum, Mercati's work is of great significance, even though his views on fossils were typical of thinkers of his time. He believed them to be lusus naturae, and illustrates, side by side, Glossopetrae (fossilised sharks' teeth) with the famous depiction of a shark's head with teeth, commenting that one should not be deceived by their apparent similarity.
The Vatican collection consists of a series of cabinets with drawers in which are housed collections of earths, salts, alums, gums and resins, marine products, ores, fossils, marbles, and other objects collected by Mercati. The plates are unequalled for fidelity to originals and the care shown in their engraving and printing. The frontispiece, depicting the presentation of Mercati's Metallotheca to Clement XI, is by Jakob Frey after Pietro Bianchi. The portrait of Mercati is by Benoit Farjat after Pietro Nelli's copy of Tintoretto's original. The majority of illustrations in the text are from the original sixteenth-century plates prepared for Mercati.