MEDIUMS AND ADHESIVES 43
in connection with painting. Similar notices appear in account rolls belonging
to the reign of Edward I (1274-1295), and in others dated 1307 (Edward II).
Another series exists in the records of Ely Cathedral, from 1325 to 1351, and a
great number of the same kind are preserved in accounts belonging to the reign
of Edward III, with regard to the decoration of St Stephen's chapel (1352 to
1358). From a study of such evidence, Eastlake concludes that oil painting was
employed in Germany, France, Italy, and England, during the XIV century, if
not before. He says, however (I, 58), that proofs of its having been employed for
pictures, in the modern sense of the term, are less distinct, and are not numerous.
On the subject of the early use of oil in painting, Thompson (The Materials of
Medieval Painting, pp. 65-67) says:
Without entering upon the controversial questions of "oil painting" as it is
generally understood, some mention must be made of the uses of drying oils in
medieval painting. Long before the elaboration of the developed techniques of
fifteenth- and sixteenth-century oil painting, oils were used in connection with
painting in other media. Transparent colours are much more transparent and rich
in oil than in water colour or egg tempera, and a certain amount of oil glazing was
certainly used along with tempera painting from quite early times. We do not
know accurately how much it was used, and we are not always sure of being able
to recognize it in paintings now. One connection in which oil media were quite
regularly employed was the glazing of metal surfaces, particularly red over gold
(as may be seen in the Paolo Uccello Battlepiece in the National Gallery), and over
silver and tin as well, and green too over these metals. We know that from remote
ages oil and varnish glazes of yellow colour were applied to tin to make it look like
gold, to silver, also, and even to gold itself, to make it look more like gold. Medieval
examples of glazes of this sort are known, though they are not common until the
Renaissance. The inside of the dome in the central panel of Giovanni Bellini's
Frari Altarpiece was gilded, and then shaded down with rich, warm oil glazes; and
this technical device, which is quite common in Renaissance painting, especially
in sixteenth-century Germany, must look back to the ancient tradition of gold-
coloured lacquering in oil varnishes on metal.
How far oil glazes were used over tempera painting, and how far tempera
painting glazed with oil media was repainted in tempera colours, and what the
materials of these combined operations may have been, are questions still to be
settled. A vast amount of evidence will have to be weighed and sifteij laboriously
before any attempt to solve these problems can be regarded as in"Vny degree
authoritative. The modern tendency is to regard the development of oil techniques
as an evolution of manipulative methods primarily, rather than a sudden adoption
of new materials. We may be quite sure that the "Secret of the Van Eycks" was
not merely something which could be kept 5n a bottle; but we cannot pretend to
adequate knowledge of the physical elements of Flemish, or, for that matter, of
any fifteenth-century oil painting, at the present time.
This agrees with the earlier comment of Eastlake (I, 88) that in about 1400 the
practice of oil painting had been confirmed by the habit of at least two centuries.