M. Jacquemart surmises that at Caffaggiolo Luca della Robbia learnt the nature of the enamel glaze, which he applied to his relievos in terra cotta. We know that Luca painted subjects on plain surfaces, enamelled with the stanniferous glaze as early as the year 1456, when he executed the painted tiles which form a kind of framing to the tomb of Benozzo Federighi in the church of San Francesco de Paolo, under the hill of Bellosguardo. The most important work by him of this nature is the lunette over one of the doors in the entrance-hall of the “Opera del Duomo” in Florence. Whether, learnt from him, this enamel was adopted at the Grand Ducal _fabrique_ at an early period, or whether he there obtained the knowledge which he applied and modified to his own uses, remains a question, the answer to which would be facilitated by the proved date of the establishment of that pottery, or the occurrence of pieces anterior to the tiles enamelled and painted by Luca; but upon these points we unfortunately have not as yet discovered any recorded memorial. It is worthy of remark that although many are of very early date no piece of a _Mezza_ ware, confidently assignable to this establishment, is known to the writer; all that have come under his notice are enamelled with the white stanniferous glaze, no instance of the use of an _engobe_ or slip having been observed. The woodcut p. 90 is from an early and probably Tuscan plateau. The leading characteristics of the Caffaggiolo wares are a glaze of rich and even quality, and purely white; and the use of a very dark cobalt blue of great intensity but brilliant as that of lapis lazuli, frequently in masses as a grounding to the subject: and it would seem laid on purposely with a coarse brush, the strokes of which are very apparent. We give an engraving p. 91 of a curiously decorated tazza of early date. The colours are green, purple and blue. A bright yellow, an orange of brilliant but opaque quality, a peculiarly liquid and semi-transparent copper green are also found, and another characteristic pigment is an opaque bright Indian red. This pottery has a nearer affinity to that of Siena than to any other fabrique, and it is not unreasonable to suppose that they had a like origin or that the establishment at Siena emanated from Caffaggiolo. Both resemble in general style the pieces produced at Faenza and Forlì more than those of other fabriques of the northern duchies, or of the Umbrian centres of the art; and it becomes a question as to which can claim the earliest origin, as also the earliest use of the stanniferous enamel glaze. The dates inscribed upon pieces begin in 1507-9, but undated examples, assignable to this locality and of an earlier period, exist in collections. [Illustration] The use of the metallic lustre seems to have been tried at Caffaggiolo, but from the extreme rarity of examples bearing the mark of or fairly ascribable to that establishment, we may [Illustration]