National Gallery London

Mountain Landscape with Lightning" by Francisque Millet/ National Gallery Collection by kind permission of the Trustees of the National Gallery, London/CORBIS... 

Unless specified otherwise, the paintings mentioned in this chapter belong to the National Gallery London. 

Duncan et al. (1990) have noted the use of brass powders as metallic pigments on Japanese artefacts. Metallic bronze of a grey colour has recently been found on three paintings o f Pemgino, one from the National Gallery, London and two in Florence elemental analysis showed this alloy to contain a ratio of tin to copper of 1 2 which in dry ground powder form appears grey. 

Cobalt tin oxide has been identified by Roy (1985) in the palette of three Impressionist paintings in the National Gallery, London and by Hehni and Attia (1992) on a nineteenth century Egyptian oil painting. 

As identification of the exact dyestuff in red lake pigments is difficult there has therefore been httle confirmed analysis on works of art. Kirby and White have however, examined a broad range of paintings in the National Gallery, London from 1400 to 1900. Cochineal is first foimd on a painting hy Gerard David of 1510. Its use thereafter becomes increasingly more commonplace. 

Romarchite (incorrectly given as tin(I) oxide) has been identified as a corrosion product on tin leaf on the frame to Carlo Crivelli s altarpiece The Annunciation (National Gallery, London, No. 739 see Smith ef a/., 1989). 

Rosasite has been identified by Dunkerton and Roy (1996) on David Ghirlandaio s The Virgin and Child with Saint John (National Gallery, London). As they point out, this was unlikely to have been considered at that time as other than a form of malachite. Martin and Eveno (1992) also discuss the compoimd in the context of pre-eighteenth century western easel painting. 

Bomford et al (1986) Bomford, D. Roy, A. Smith, A. The Techniques of Dieric Bouts Two Pamtings Contrasted National Gallery Technical Bulletin 10 National Gallery, London (1986) 39-57... 

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