PART II.

PHYSICAL COLOURS. IX. Dioptrical Colours X. Dioptrical Colours of the First Class XI. Dioptrical Colours of the Second Class--Refraction Subjective Experiments XII. Refraction without the Appearance of Colour XIII. Conditions of the Appearance of Colour XIV. Conditions under which the Appearance of Colour increases XV. Explanation of the foregoing Phenomena XVI. Decrease of the Appearance of Colour XVII. Grey Objects displaced by Refraction XVIII. Coloured Objects displaced by Refraction XIX. Achromatism and Hyperchromatism XX. Advantages of Subjective Experiments-- Transition to the Objective Objective Experiments XXI. Refraction without the Appearance of Colour XXII. Conditions of the Appearance of Colour XXIII. Conditions of the Increase of Colour XXIV. Explanation of the foregoing Phenomena XXV. Decrease of the Appearance of Colour XXVI. Grey Objects XXVII. Coloured Objects XXVIII. Achromatism and Hyperchromatism XXIX. Combination of Subjective and Objective Experiments XXX. Transition XXXI. Catoptrical Colours XXXII. Paroptical Colours XXXIII. Epoptical Colours