. The Family tutor . Fk Fig. 7. at some distance from the prism, where itforms an oblong coloured image, composedof seven colours. This image is called theprismatic or solar spectrum. The light from Hames of all kinds, theoxy-l)ydrogen blowpipe, and the electricspark, or galvanic light, is also compoundin its nature, like that of the sun andother celestial bodies. Prismatic Colours.— The colours of thesolar spectrum are in the following order,upwards : red, orange, yellow, green, blue. Blue, Vellovr, Keil, .Solar Spectrum. Violet,Indiijo,p Blue,Oreeii,g^ Yellow,Orange, 76 CHEMISTRY. indig
. The Family tutor . Fk Fig. 7. at some distance from the prism, where itforms an oblong coloured image, composedof seven colours. This image is called theprismatic or solar spectrum. The light from Hames of all kinds, theoxy-l)ydrogen blowpipe, and the electricspark, or galvanic light, is also compoundin its nature, like that of the sun andother celestial bodies. Prismatic Colours.— The colours of thesolar spectrum are in the following order,upwards : red, orange, yellow, green, blue. Blue, Vellovr, Keil, .Solar Spectrum. Violet,Indiijo,p Blue,Oreeii,g^ Yellow,Orange, 76 CHEMISTRY. indigo, violet. These colours are of verydiiierent refrangibility, and for this rea-son are presented in a broad surface, thered being the least refracted, and theviolet the most. The seven colours ofNewton, it is believed, are really composedof the three primitive ones,—red, yellow,and blue. This idea is well expressed inFig. 18. The three primitive colourseach attain their greatest intensity in thespectrum at the points marked at thesummit of the curves ; while the four othercolours, violet, indigo, green, and orange,are the result of a mixture in the spec-trum of the other three. A portion ofproper white light is also found in allparts of the spectrum, which cannot beseparated by refraction. We may henceinfer that there is a portion of each colourin every part of the spectrum, but thateach is most intense at the points whereit appears strongest. The light is mostintense in the yellow portion, and fadestowards each end of the spectrum. Sir John Herschel has detected
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