TABLE II. ----------------------+--------+------+------+------+-------+------ | Lime |Blue |Lamp |Ivory |Zinc | White |Sulphate|Black |Black |Black |White | Lead ----------------------+--------+------+------+------+-------+------ Standard light units | 25·0 | | | | | ----------------------+ | | | | | Black units | | | | | | (light absorbed) | | 9·0 | 9·2 | 9·2 | -- | ·08 Violet units | | | | | | (colour developed) | | 2·2 | 1·4 | 1·4 | -- | -- Blue units | | | | | | (colour developed) | | 1·0 | 1·9 | ·4 | ·01 | ·05 Green units | | | | | | (colour developed) | | -- | -- | -- | -- | ·07 Associated white light| | 12·8 | 12·5 | 14·0 | 24·99 | 24·80 ----------------------+--------+------+------+------+-------+------ Totals | 25·0 | 25·0 | 25·0 | 25·0 | 25·0 | 25·0 ----------------------+--------+------+------+------+-------+------ The analyses demonstrate that black is not itself an active energy analogous to colour, but is a minus quantity distinguishable by contrast with the original light. The reflected beam consists of the colour developed, associated with the residue of unaltered light. _Note._--Suitable proportions of Violet and Blue give character and value to black, whilst Orange and Yellow are less pleasing as tending to rustiness. CHAPTER VI. Qualitative Colour Nomenclature. SIMPLE COLOURS. The vision can separate six monochromatic colours from a beam of white light, therefore in practical work six must be dealt with, no matter how they may be theoretically accounted for. They naturally take the accepted spectrum names and symbols already in use. To these are added two other terms, Bk. to signify black, and L. for light; these terms deal with the brightness, or dinginess, of a colour. Simple Terms. Symbols. Red R Orange O Yellow Y Green G Blue B Violet V Black Bk White L COMPLEX COLOURS.