CHEMICAL COLOURS. XXXIV. Chemical Contrast XXXV. White XXXVI. Black XXXVII. First Excitation of Colour XXXVIII. Augmentation of Colour XXXIX. Culmination XL. Fluctuation XLI. Passage through the Whole Scale XLII. Inversion XLIII. Fixation XLIV. Intermixture, Real XLV. Intermixture, Apparent XLVI. Communication, Actual XLVII. Communication, Apparent XLVIII. Extraction XLIX. Nomenclature L. Minerals LI. Plants LII. Worms, Insects, Fishes LIII. Birds LIV. Mammalia and Human Beings LV. Physical and Chemical Effects of the Transmission of Light through Coloured Mediums LVI. Chemical Effect in Dioptrical Achromatism