PIGMENTS 123
most intense of all the black pigments (Colour Index, p. 314). The term is now
commonly used for the black from animal bones (see Bone Black).
Kaolin (see China Clay).
Kermes (kermes lake, grain lake) is one of the most ancient of the natural
dyestuffs. It was derived from the dried bodies of the female insect, Coccus ilicisy
found on the kermes oak, which was indigenous to many parts of southern Europe
(see Beckmann, I, 385-404). It is similar to the New World * cochineal' in origin,
color, and chemical composition. It contains the coloring matter, kermesic acid,
CisHiaOg (Colour Index > p. 295). Lucas suggests (p. 37) that it was used very
early in Egypt for dyeing leather, and, he thinks, with an alum mordant. It was
well known to the Romans; Pliny called it Coccum granum and praised it highly
(see Bailey, I, 33 and 218). Thompson (The Materials of Medieval Painting^
p. 112) says that the English word for it, 'grain/ comes from the Latin, grana,
the equivalent of the Greek, KOK/COS, which means * berry.' The ancients mis-
took the dried red clusters of the dead insect, Coccus Hlcis, for berries. He goes
on to say, however (loc. cit,> p. 113), that grain and kermes dyestuffs are not the
same, though similar in origin. According to him, the English word, vermilion,
comes indirectly from the Latin, vermiculum, or 'little worm,' which was de-
scriptive locally of the clusters of dead insects and the berries they caused to
grow around them. The word, 'kermes,' is Arabic in origin and is the source of
the English word, 'crimson.' Kermes and grain dyes were precipitated with alum
to form crimson lakes. Sometimes they were prepared with clippings of cloth
that had been dyed with grain. The dye was extracted with alkali and then was
precipitated with alum (see Thompson, loc. cit.y p. 115). Kermes lakes are not
brilliant, and in the Middle Ages they were displaced by the lac lakes from India
and, still later, by cochineal lakes from Mexico. They are perhaps of no importance
in modern painting.
King's Yellow (see Orpiment).
Kremnitz White (see White Lead).
Lac, Lac Lake (Indian lake), is a natural organic red dyes tuff prepared from
the resin-like secretion of the larvae of the lac insect, Coccus lacca^ which lives on
certain trees of the species, Crotonficus^ in India, Burma, and the Far East. From
the lac secretion which also produces the * seed lac' or c shellac' of commerce, the
red dye is extracted with hot dilute sodium carbonate solution when the shellac
is purified. The dye infusion is evaporated and the residue is made into cakes and
dried. The lake may be prepared by extracting the dry residue with sodium car-
bonate, after purification in turpentine or benzene, and by precipitating it with
alum. The coloring principle is laccaic acid, C2oHuOn, or its salts (see A. Dim-
roth and S. Goldschmidt, '0ber den Farbstoff des Stocklacks,' Annalen der
Chemie, CCCXCIX [1913], pp. 62-90). It is similar in composition and color to
the carmine dyes from cochineal, but the lac dye is somewhat faster if duller in
shade. Perkin and Everest (pp. 91-94) say that lac dye is a very ancient dyestuff