The triptych is of larch, or some such undecaying wood, and measures, when the leaves are opened wide, forty inches over its entire breadth, by twenty-two in height. Linen is stretched upon the wood, and over that the silver-gilt _repoussé_ plates which form the principal adornment of the reliquary. "The outside is decorated with twelve medallions containing the arms of Castile and Aragon, and forty-eight others in which are repeated alternately the subjects of the Adoration of the Magi and the Annunciation of the Virgin, also in _repoussé_. In the centres are eagles, allusive, it is possible, to Don Alfonso's claim to be crowned Emperor.... The ornamentation which surrounds the panels belongs to the sixteenth century" (Riaño). The arms here spoken of contain the crowned lion and the castle of three towers; and the interesting fact is pointed out by Amador that the diminutive doors and windows of these castles show a strongly pointed Gothic arch. The sixteenth-century bordering to the panels is in the manner known as Plateresque.[30] The clasps are also Plateresque, and prove, together with the border, that the triptych was restored about this time. [30] So named because the silversmiths (_plateros_) of this country used it in their monstrances (_custodias_) and in many other objects or utensils of religious worship. The most refined and erudite of Spanish silver-workers, Juan de Arfe, thus referred to it in rhyme:-- _"Usaron desta obra los plateros Guardando sus preceptos con zelo; Pusiéronle en los puntos postrimeros De perfección mi abuelo."_ [Illustration: X THE "TABLAS ALFONSINAS" (_View of Interior; 13th Century. Seville Cathedral_)] Inside (Plate x.), it consists of fifteen compartments, "full of minute ornamentation, among which are set a large number of capsules covered with rock crystal containing relics, each one with an inscription of enamelled gold, _cloisonné_. Several good cameos with sacred subjects appear near the edge of the side leaves" (Riaño). These cameos, handsomely engraved with figures of the Virgin and other subjects of religious character, are fairly well preserved; but the designs upon enamel are almost obliterated. Eight precious stones, set in as rude a style as those upon the ancient crowns and crosses of the Visigoths, have also fallen out, or been removed, from the interior.