44.(Pg. [189]) By what reasoning is it proved, that bodies do not retain their colours in the dark?
45.(Pg. [190]) What proof of the truth of this theory of colours, may be afforded by the prism?
46.(Pg. [191]) Why will green leaves, when exposed to the red ray, appear of a dingy brown?
47.(Pg. [191]) Bodies, in general, when placed in a ray differing in colour from their own, appear of a mixed hue, what causes this?
48.(Pg. [191]) Why will bodies of a pale, or light hue, most perfectly, assume the different colours of the spectrum?
49.(Pg. [192]) Upon what property in a body, does the darkness of its colour depend?
50.(Pg. [192]) Why do some bodies appear white, others black, and others of different colours?
51.(Pg. [192]) From what cause do blue articles appear green, by candle-light?
52.(Pg. [193]) What is believed to be the cause, of the red appearance of the sun, through a fog, or misty atmosphere?
53.(Pg. [193]) From what is the blue colour of the sky, thought to arise?