imitated and copied
by that Piero da Perugia, illuminator, who illuminated all the books
that are in the library of Pope Pius in the Duomo at Siena, and was a
practised colourist in fresco. A disciple of Agnolo, also, was Michele
da Milano, as was Giovanni Gaddi, his brother, who made, in the cloister
of S. Spirito where are the little arches of Gaddo and of Taddeo, the
Disputation of Christ in the Temple with the Doctors, the Purification
of the Virgin, the Temptation of Christ in the Wilderness, and the
Baptism of John; and finally, having created very great expectation, he
died. A pupil of the same Agnolo in painting was Cennino di Drea Cennini
of Colle di Valdelsa, who, having very great affection for the art,
wrote a book describing the methods of working in fresco, in distemper,
in size, and in gum, and, besides, how illuminating is done, and all the
methods of applying gold; which book is in the hands of Giuliano,
goldsmith of Siena, an excellent master and a friend of these arts. And
in the beginning of this his book he treated of the nature of colours,
both the minerals and the earth-colours, according as he learnt from
Agnolo his master, wishing, for the reason perchance that he did not
succeed in learning to paint perfectly, at least to know the nature of
the colours, the distempers, the sizes, and the application of gesso,
and what colours we must guard against as harmful in making the
mixtures, and in short many other considerations whereof there is no
need to discourse, there being to-day a perfect knowledge of all those
matters which he held as great and very rare secrets in those times. But
I will not forbear to say that he makes no mention (and perchance they
may not have been in use) of some earth-colours, such as dark red
earths, cinabrese, and certain vitreous greens. Since then there have
been also discovered umber, which is an earth-colour, giallo santo,[23]
the smalts both for fresco and for oils, and some vitreous greens and
yellows, wherein the painters of that age were lacking. He treated
finally of mosaics, and of grinding colours in oils in order to make
grounds of red, blue, green, and in other manners; and of the mordants
for the application of gold, but not then for figures. Besides the works
that he wrought in Florence with his master, there is a Madonna with
certain saints by his hand under the loggia of the hospital of Bonifazio
Lupi, coloured in such a manner that it has been very well p