PAINTING MATERIALS
Yellow lead monoxide was known, certainly, as early as metallic lead, which
has been found in sites that date from predynastic times in Egypt (see Lucas,
p. 200). Laurie (The Pigments and Mediums of the Old Masters^ p. 10) found it
on a scribe's palette dating 400 B.C. Davy (p. 105) identified an orange color on
a piece of stucco in the ruins near the monument of Caius Cestius as a mixture
of massicot and minium. Pliny described the preparation of both litharge (see
Bailey, I, 117-119, and II, 73) and massicot (see Bailey, II, 83-85).
Yellow lead oxide was an important pigment in European painting. De Wild
(pp. 49-50) lists thirty-nine Dutch and Flemish paintings of the XV to the XVII
centuries on which he identified it. In modern times, however, it seems com-
pletely to have passed out of use, and it is no longer listed by colormen.
Mauve is an artificial organic dyestuff belonging to the azine group of dyes; it
is mainly amino-phenylamino-p-tolyl ditolazonium sulphate, C27H25N4(SO4)i/2
(Colour Index, p. 211). This was the first dyestuff ever to be made synthetically.
It was discovered in England in 1856 by Sir William Perkin, who prepared it by
the oxidation of crude aniline with chromic acid. Because aniline was the starting
point for this as well as for several others which followed, the term, 'aniline dyes/
came to indicate all those made synthetically, particularly those from chemicals
derived from the distillation of coal tar (see also Coal-Tar Colors). The term
has been carelessly applied to dyes not derived from aniline or related to it.
Pure mauve dye comes in the form of reddish violet crystals. When applied, the
color is dull violet. It was early patented in England where it was widely used
for a time in dyeing cloth. Although it is fugitive, it has been used as an artists'
water color to a small extent, and today is still listed by some colormen among
water color paints.
Mayan Blue is a name here provisionally given to a peculiar blue pigment
which is found rather extensively on wall paintings and painted objects from
ancient" Mayan sites like Chichen Itza in Yucatan and other localities in Central
America. It is green-blue, an inorganic pigment, probably natural in origin.
Apparently, it owes its color to the iron it contains and not to any copper. In a
microscopic study made for the Fogg Museum of a sample from Chichen Itza,
it was observed to be of grains that are very small and faintly greenish blue by
transmitted light. The mineral is weakly birefracting and has a refractive index
between 1.54 and 1.55. It is pleochroic, being blue in one direction and yellow in
another. The blue is intimately mixed with calcite. A spectrogram shows the
elements, calcium, magnesium, silicon, aluminum, and iron. It is not affected by
alkalis and is only taken into solution by hot concentrated acids. This mineral,
in its optical and chemical behavior, compares quite well with the rare mineral,
aerinite1 (from Spain), of the chlorite group.
Merwin has described a blue pigment from Chichen Itza (see E. EL Morris,
Jean Chariot, and Axtell Morris, 'Temple of the Warriors/ Carnegie Institution
of Washington, Publication no. 406,1 [1931], pp. 355-356), and he says;