Conjointly with the powerful abbot, there is deserving of special mention a simple monk, Theophilus, an eminent artist who wrote in Latin a description of the Industrial Arts of his time (_Diversarum Artium Schedula_), and devoted seventy-nine chapters of his book to that of the goldsmith. This valuable treatise shows us, in the most unmistakable manner, that the goldsmiths of the twelfth century must have possessed a comprehensiveness of knowledge and manipulation, the mere enumeration of which surprises us the more now that we see industry everywhere tending to an almost infinite division of labour. At that time the goldsmith was required to be at once modeller, sculptor, smelter, enameller, jewel-mounter, and inlay-worker. He had to cast his own models in wax, as well as to labour with his hammer or embellish with his graver: he had to make the chalice, the vases, and the pyx, for the metropolitan churches, on which were lavished all the resources of art; and to produce, by the ordinary process of punching, the open-work or the designs of copper intended to ornament the books of the poor (_libri pauperum_), &c. The treasury of the Abbey of Saint-Denis still possessed, at the time of the Revolution, several _chefs-d’œuvre_ produced by the artists whose processes are described by Theophilus; especially the rich mounting of a cup of Oriental agate, bearing the name of Suger, which it is believed he used for the service of mass; and the mounting of an ancient sardonyx vase, known as the cup of the Ptolemies, which Charles the Simple had given to the abbey. Having been deposited, in 1793, in the Cabinet of Medals, Paris, the mounting of the cup of the Ptolemies and the chalice of Suger remained there until they were stolen in 1804. Among the examples of that period still existing, and which, conditionally, every one is permitted to inspect, we may distinguish, with M. Labarte,--in addition to “the great crown of lights” suspended under the cupola in the cathedral of Aix-la-Chapelle, and the magnificent shrine in which Frederick I. collected the bones of Charlemagne,--in the Museum of the Louvre, a vase of rock-crystal mounted in gold and embellished with gems, presented to Louis VII. by his wife Eleanora; in the Cluny Museum, several candelabra; in the Imperial Library in Paris, the covering of a Latin manuscript, numbered 622; a cup of agate onyx (Fig. 93), bordered with a belt of precious stones raised on a groundwork of filigree; and the beautiful gold chalice of St. Remy (Fig. 94), which, after having appeared in the Cabinet of Antiquities, was restored in 1861 to the treasury of the church of Notre-Dame, Rheims.