Gripla - 20.12.2011, Side 90

GRIPLA90
then is to be judged again by fire, two main colours appear in the rainbow,
that is green (viridis) and red (rubeus); and green signifies water, while red
fire.”61
Now, if both the two-coloured and the four-coloured rainbows enjoyed
a great fortune in the Middle Ages – regularly opposing fiery-red to blue
(or occasionally green) the first, more varied as related to chromatic solu-
tions the second –, Isidore’s tetrad model based on the natural elements, in
particular, formed the core of the rainbow colour-imagery in some of the
most influential Latin treatises, like Bede’s De natura rerum, and Honorius
Augustodunensis’ Imago mundi.
Bede’s exposition in chapter 31 (‘De arcu coeli’) of De natura rerum
starts as a natural description, focusing on the reflection and refraction of
the sun’s rays through hollow clouds back towards the sun, and then goes
on to the elemental tetrad according to the Isidorian model, but introduc-
ing a different colour for air (hyacinthinum, i.e., hyacinth or amethyst-
blue), where Isidore had white (album), as well as for the earth (gramineus,
i.e. grassy colour), where Isidore had dark or black (niger):62
Arcus in aere quadricolor, ex sole adverso nubibusque formatur,
dum radius solis immissus cavae nubi, repulsa acie in solem refrin-
gitur, instar cerae imaginem annuli reddentis: qui de coelo igneum,
de aquis purpureum, de aere hyacinthinum, de terra gramineum
trahit colorem...63
“The four-coloured rainbow is formed in the air by the sun against
the clouds, when the sun’s ray gets into a hollow cloud and, driven
back towards the sun, is broken and refracts, just like the wax gives
back the image of the seal ring: it [i.e., the rainbow] takes the fiery-
red colour from the sky, the purple from the waters [i.e., from the
sea], the hyacinth-blue [i.e., the colour of amethyst] from the air, the
grassy colour from the earth...”
61 Ibid., col. 185 A: ... quia prius per aquam judicatus est mundus, iterum autem per ignem est judi-
candus; ideo duo principales colores in arcu apparent, viridis scilicet, et rubeus; et viridis quidem
aquam, rubeus vero ignem praetendit.
62 Cf. above, the opening of the passage quoted as context of note 48.
63 Cf. Bede, De natura rerum, 31, in PL 90, col. 252 A.