--------+---------+-----------+--------------+------------ Scale | Wave- | Readings. | Extinction in| Persistency number. | length. | | 1/100000. | curve. --------+---------+-----------+--------------+------------ 63 | 7082 | 0 | | 62 | 6957 | 1 | | 60 | 6728 | 7 | | 58 | 6520 | 18 | | 57 | 6423 | 28 | | 56 | 6330 | 43 | | 54 | 6152 | 76 | 900 | 2 52 | 5996 | 90 | 250 | 7 50 | 5850 | 95 | 130 | 13·5 48 | 5720 | 93 | 60 | 29 46 | 5596 | 83 | 34 | 51 44 | 5481 | 71 | 22 | 80 42 | 5321 | 58 | 18·5 | 92 40 | 5270 | 46 | 17·5 | 100 38 | 5172 | 32 | 18 | 94 36 | 5085 | 21 | 19·5 | 90 34 | 5002 | 12·5 | 22 | 79 32 | 4924 | 7 | 27 | 65 30 | 4848 | 4·5 | 34 | 51 28 | 4776 | 3·0 | 40 | 38·5 25 | 4675 | 1·5 | 60 | 29 20 | 4518 | 0·4 | 250 | 7 19 | 4488 | 0·0 | 350 | 5 16 | 4404 | -- | 600 | --------+---------+-----------+--------------+------------ INDEX PAGE Absorption by the Yellow Spot 90 Artificial Spectrum 33 Cases of Defective Colour Vision unrecognised 67 Clerk Maxwell’s Colour-Box 42 Clerk Maxwell’s Colour Curves 47 Colour, and the Sensations required to produce it 50 Colour Blindness due to Disease 137 Colour-Blind Persons see a Grey in the Spectrum 65 Colour Discs 32 Colour Fields 13 Colour Matches made by the Colour Blind 70 Colour Patch Apparatus 18 Colour Patch Apparatus, Original Form of 19 Comparison of the Young and Hering Theory 189 Complex Colours matched by Simple Colours 22 Contrast Colours 187 Curious Case of Congenital Colour Blindness, A 164 Dalton Colour Blindness 58