the niello in this manner; take pure silver and divide it into equal parts, adding to it a third part of pure copper, and taking yellow sulphur, break it very small... and when you have liquefied the silver with the copper, stir it evenly with charcoal, and instantly pour into it lead and sulphur.”  This niello paste is then made into a stick, and heated until “it glows:  then with another forceps, long and thin, hold the niello and rub it all over the places which you wish to make black, until the drawing be full, and carrying it away from the fire, make it smooth with a flat file, until the silver appear.”  When Theophilus has finished his directions, he adds:  “And take great care that no further work is required.”  To polish the niello, he directs us to “pumice it with a damp stone, until it is made everywhere bright.”

There are various accounts of how Finiguerra, who was a worker in niello in Florence, discovered by its means the art of steel engraving.  It is probably only a legendary narrative, but it is always told as one of the apocryphal stories when the origin of printing is discussed, and may not be out of place here.  Maso Finiguerra, a Florentine, had just engraved the plate for his famous niello, a Pax which is now to be seen in the Bargello, and had filled it in with the fluid enamel, which was standing waiting until it should be dry.  Then, according to some authorities, a piece of paper blew upon the damp surface, on which, after carefully removing it, Maso found his design was impressed; others state that it was through the servant’s laying a damp cloth upon it, that the principle of printing from an incised plate was suggested.  At any rate, Finiguerra took the hint, it is said, and made an impression on paper, rolling it, as one would do with an etching or engraving.

In the Silver Chamber in the Pitti Palace is a Pax, by Mantegna, made in the same way as that by Finiguerra, and bearing comparison with it.  The engraving is most delicate, and it is difficult to imagine a better specimen of the art.  The Madonna and Child, seated in an arbour, occupy the centre of the composition, which is framed with jewelled bands, the frame being divided into sixteen compartments, in each of which is seen a tiny and exquisite picture.  The work on the arbour of roses in which the Virgin sits is of remarkable quality, as well as the small birds and animals introduced into the composition.  In the background, St. Christopher is seen crossing the river with the Christ Child on his back, while in the water a fish and a swan are visible.

In Valencia in Spain may be seen a chalice which has been supposed to be the very cup in which Our Saviour instituted the Communion.  The cup itself is of sardonyx, and of fine form.  The base is made of the same stone, and handles and bands are of gold, adorned with black enamel.  Pearls, rubies, sapphires, and emeralds are set in profusion about the stem and base.  It is a work of the epoch of Imperial Rome.