[38] And single forms were often parti-coloured, as III., IV., _Blue_, with _red_ serifs, or _vice versâ_ (see also pp. 208, 216).
[39] In "white light" three rays (known as the "_Primary Colour-Sensations_") have been distinguished--Red, Green, and Blue; any two of these are complementary to the remaining colour, and appear to be induced optically in its neighbourhood.
(Yellow light is combined of Red and Green rays, and this may partly explain the particular fitness of Blue and Gold Illumination.)
[40] In the case of a burnished gold letter, the _gilding_ may be deferred until the adjacent coloured parts are finished (see p. 170).
[41] It has even been supposed that we might make the inhabitants of _Mars_ aware of the existence of rational _Terrestrials_, by exhibiting a vast illumination--in lamp-light--consisting of a somewhat similar form--_the first Proposition in Euclid_.
[42] NOTE.--_Limning_ strictly means _Illuminating_, but has come to imply drawing and painting, especially of portraits and miniatures. Here, _all_ its senses are intended.
[43] The modern illuminator, having no tradition for making such scroll-work, would find that natural or organic forms--as of trees or plants (see p. 221)--would serve the same end and have more "sweet reasonableness" in modern eyes. Excellent scroll-work, moreover, might be formed out of ornamental Capitals--if sufficient excuse could be found for introducing them: a large flourished «L», for example, could be made exactly on the same lines as the pendant and scroll in Plate XV. Narrow gold rods also may be used in a border to support a floral growth, or as frames if necessary (compare _rules_, p. 364).
[44] The _steps in the development_ sketched very briefly in this chapter, refer both to the past history of the art of illumination and to its possible revival (see Author's preface, p. 16).
[45] Where it is possible it is desirable to mark the top left-hand corner of the "page" (and also the lower corner) by a branch, flourish, bud, or flower (see Plates XIX., XXII.). A top left-hand corner appearing vacant or rounded off is apt to weaken the whole effect (see p. 134).
[46] _Framing borders_, or borders which surround the text, may be allowed nearly to fill the entire marginal space.