chapter 53

of his third Book, ‘de Electro,’ ‘on Enamel,’ introduces the hammer in a similar connection: ‘Accipiensque singulas probati vitri ... quod mox confringas cum rotundo malleo donec subtile fiat;’ ‘take portions of the glass you have tested ... and break up each lump with a round headed hammer till it be finely powdered.’ Cellini also says the pastes are to be pounded in a mortar ‘con martello.’ _Trattati_, p. 30. It is not easy however to see how any sense of ‘pounding’ can be extracted from the verb ‘fermare’ which Vasari uses.

Footnote 291:

The difference in colour between gold and silver will naturally affect the choice of the transparent vitreous pastes that are to cover them, and there are also considerations of a chemical kind which prevent the use of certain pastes on certain metal grounds. For example tin has the property of rendering transparent enamels opaque, and transparent pastes cannot be used over metal grounds wherein tin enters into the composition. Cellini, who gives the same caution as Vasari, takes as an illustration transparent ruby coloured enamel, which he says cannot be used over silver, for a reason which has about it a reminiscence of the ancient alchemy, namely, that it is a product of gold and must be employed only over its kindred metal! On the other hand he forbids for use with gold yellow, white, and turquoise blue. We are indebted for some special information on this highly technical subject to the kindness of Mr H. H. Cunynghame, C.B., who writes: ‘There are two distinct reasons why different enamels are used on silver and gold respectively. The first is an artistic reason. Transparent reds do not show well over silver, the rays reflected from a silver surface not being well calculated to show off the colours of the gold. In fact silver absorbs those rays on the transmission of which the beauty of gold-red largely depends, whence then it follows that transparent blues and greens should be used on silver, and reds, browns, and the brighter yellows on gold. In addition to this, silver has its surface disturbed by the silicic acid in the enamel. The consequence is that ordinary enamels put on a silver surface are stained. To prevent this it is desirable to add some ingredient that dissolves and renders colourless the stain. For this purpose therefore special fluxes or clear enamels are made for silver. They usually contain manganese and arsenic. The first of these has such a property of “clarifying” enamels and glazes that it used to be called the potter’s “soap,” for it cleaned the glazes on china. The other is also used for the same purpose.... As silver alloy is more easy to melt than gold alloy, fluxes, i.e. clear enamels for silver, are much more fusible than those for gold.’

Footnote 292:

This is a practice of modern enamellers. Cellini however is against it, as if the enamels begin again to run there is a danger of losing the truth of the surface. He recommends polishing by hand alone (_Trattati_, ed. Milanesi, 35).

Footnote 293:

This may have been the so-called Venetian enamel used in Vasari’s time. This was a form of opaque painted enamel over copper, extremely decorative, but coarse as compared with the translucent enamel over reliefs. We owe this suggestion to Sir T. Gibson Carmichael.

Footnote 294:

The word ‘Tausia,’ and its connection with ‘Tarsia,’ the term used for wood inlays, has given rise to some discussion. The explanation in Bucher’s _Geschichte der Technischen Künste_, III, 14, is probably correct, and according to this the Italian ‘Tausia’ comes from the Spanish ‘Tauscia’ or ‘Atauscia,’ which is derived from an Arabic root meaning ‘to decorate.’ The art of inlaying one metal in another is one of great antiquity in the East, and was no doubt brought to Spain by the Moors, from which country, perhaps by way of Sicily, it spread to Italy. The word ‘Tarsia,’ applied as we have already seen to inlays in wood, may have been derived by corruption from ‘Tausia,’ though, as the form ‘Intarsia’ is also common, a derivation (unlikely) has been suggested from the Latin ‘Interserere.’ The ‘in’ is probably only the preposition, that has become incorporated with the word it preceded.

Footnote 295:

‘Cavasi il ferro in sotto squadra.’

Footnote 296:

If the sinkings be undercut the further process of roughening the sunk surfaces is hardly necessary, but the roughening or puncturing may suffice to hold the inlaid metal when there is no actual undercutting of the sides of the sinkings.

Footnote 297:

The ‘filiera,’ or iron plate pierced with holes of various sizes for drawing wires through, was known to Theophilus. See