The Triumph of Vulcan: Sculptors' Tools, Porphyry, and the Prince in Ducal Florence.

Suzanne B. Butters. Florence: Leo S. Olschki, 1996.2 vols. 724 pp. IL 320,000. ISBN: 88-222-4411-7.

It is the rare visitor to Florence who has stopped to examine the porphyry tablet set into the riser of the step leading up to the church of S. Maria Novella. Inscribed BERNARDO ORICELLARIO in handsome Roman capitals (originally gilded), the tablet - a species of tabula ansata - was set in place by Bernardo Rucellai, the son of the commissioner of the church's splendid Renaissance facade, shortly before his death in 1514 to signal the place of his burial in the pavement below. This discreet marker has a special place in the history of art. It is presented by Vasari as the beginning of a concerted effort on the part of Florentine sculptors at mastering the technique of carving the imperial stone of porphyry.

In this marvelous and exquisitely produced work of free-wheeling scholarship and passionate commitment to materiality, Suzanne Butters presents the story of the campaign in sixteenth-century Florence to establish the royal and imperial stone of porphyry as the special province of the Medici. Vasari created a script that placed the recovery of the "secret" of producing complex works of sculpture out of the dauntingly hard material of porphyry at the court of Cosimo de'Medici I. Not only did Cosimo's interest in porphyry bring it to the fore as a material for the sculptural and architectural productions of his reign, but, according to Vasari, it was Duke Cosimo himself who directed the manufacture of the herbal essence that made possible the tempering of the chisels - the "triumph of Vulcan" of the book's title - to be hard enough to work the stone. During the opening phase of the Medici porphyry campaign in the 1550's, the manual skill was provided by Francesco Ferrucci del Tadda, familiarly known as Tadda, a member of the long-established Ferrucci family of Fiesole, good solid stone workers and part-time architects. In Vasari's important, and under-considered, introductory chapters on technique, expanded in the 1568 edition of the Vite (and routinely ommitted from modern editions), the story is laid out in full: the loss of the skill in carving porphyry, the partial achievement of the Rucellai plaque by way of tools tempered in goat's blood (the achievement attributed, anachronistically, to no less a personage than Leone Battista Alberti), and finally, under princely aegis, the ability to make the fabulous stone - "the red stone with minute white specks brought into Italy from Egypt" - bow to human will.

Butters examines the particulars of the sixteenth-century Medici interest in porphyry, the fifteenth-century background behind it, and the motives and talents of each of the dramatis personae, with an intensity verging on the obsessive. But it would be an ungrateful reader who would begrudge a single word of it. This is a book whose riches will not be easily exhausted. Theoretically, the book is organized in two parts. An opening section treats porphyry production from antiquity into the Renaissance in somewhat general terms, followed by four sections that focus on the work of the Medici court. Volume 2 includes the statistical appendices, ranging from sixteenth-century documents connected with the procuring, commissioning and manufacturing of porphyry objects to specific recipes for hardening steel. In practice, however, the author's enthusiasm leads to tantilizing jumps to subjects that will be treated more fully in other parts of the study, and there are numerous asides. One finds mini-essays of one or two sentences that in the hands of another scholar would have been worked up into individual articles. To pull up only one example: a discussion of the implications of the color of porphyry takes her to sacrificial blood in general, to Christ's blood and Seneca's blood in particular, to the dyes used in the Florentine cloth industry, and to purple as a conceptual color in the ambient of Pope Sylvester and Constantine. Perhaps the most compelling sections are those devoted to tools. Not only has the author scoured sixteenth-century documents to bring together information on the manufacture and upkeep of sculptors' tooks, but she has exhaustively interviewed modern stone workers in order to determine with precision what kinds of practices are followed for the light that this may shed on Renaissance procedures. The book also brings to the fore one of Florence's lesser known museums, the Opificio delle Pietre Dure, in whose backyard there are still to be seen some of the blocks and fragments of porphyry that the Medici gathered.

Art historians and archaeologists have had at their disposal valuable guides to the identification and history of the use of marbles and other stones in antiquity and the Renaissance. Among the more important may be cited Raniero Gnoli's Marmora romana (Rome, 1971: 2d ed., 1988) and the more recent Marmi antichi (Ed. Gabriele Borghini. Rome, 1989). Porphyry has a literature of its own, but one that until now has concentrated on two time slots - the lavish use of porphyry by Imperial Rome following its conquest of Egypt, and the medieval use of porphyry, fueled by the emergence of a newly aggressive papacy and the brilliance of the Cosmati workshops. Now comes a study that gives the Renaissance sequel, and in the process shows us porphyry not as an object of antiquarian curiosity but as a gloriously evocative material that lives among us today: sleek, rich, trumpeting man's interest in bending the raw material of nature to his own uses. A study that, as the author tells us, began life "as a modest footnote" ends up by presenting us with a new standard for the investigation of material culture.

DEBRA PINCUS National Gallery of Art