Dispersion and colour

Appearance of coloured objects in coloured light

Appearance of coloured objects in coloured light A convenient source of light of various colours may be obtained by placing an ordinary electric lamp in a box with an opening which may be covered with gelatine sheets of different colours. By means of such a lamp the appearance of different coloured objects in different colours of light …

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Light filters

Light filters Interesting results are obtained when light filters in the form of sheets of gelatine coloured with various dyes are placed, in turn, in front of the slit in Fig. 25.2 or 25.3. By this means, the light transmitted by the filter can be analysed into its component colours. It is observed that certain colours, depending …

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Improvement on Newton’s original experiment

Improvement on Newton’s original experiment The spectrum formed in Newton’s first experiment was impure. This resulted from the fact that it consisted of a series of circular coloured images all overlapping. Later Newton devised the arrangement shown in Fig. 25.2, which produced a fairly pure spectrum. A converging lens L is placed so as to form an …

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