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DESCRIPTION OF THE FRONTISPIECE ILLUSTRATING 
OPTICS. 
THE HUMAN EYE, BEING THE ORGAN THROUGH WHICH THE PRINCIPLES, PHENO¬ 
MENA, AND THE WHOLE SCIENCE, OF OPTICS, ARE CONVEYED TO THE MIND, OCCUPIES 
THE CENTRE OF THE PRISMATICAL COLOURS EMBODIED INTO SEVEN FEMALE FIGURES, 
THREE OF WHICH ARE DISTINGUISHED, AS GENERATIVE AND PRIMITIVE ELEMENTS, BY 
A CROWN AND AN EMBROIDERED MANTLE, INTIMATING THAT THE RAY OF LIGHT IS 
COMPOSED OF YELLOW, RED, AND BLUE, ONLY; AND THAT THE OTHER COLOURS ARE 
MERE COMPOSITIONS OR INTERMIXTURES OF THE PRINCIPAL ONES AT THEIR RESPEC¬ 
TIVE CONTIGUITIES. EACH OF THESE FIGURES HOLDS A REPRESENTATIVE OF ONE OF 
THE SEVEN COLOURS IN THE RAINBOW, AS FOUND IN THE IMMENSE STORE OF NEVER- 
CHANGING NATURE, AND IN THE FOLLOWING ORDER: 
YELLOW 
VERT 
ORANGE 
BLUE 
RED 
INDIGO 
AND VIOLET* 
THE CORNERS OF THE PLATE CONTAIN SEVERAL OPTICAL INSTRUMENTS; AND, AS 
THERE WOULD BE NO OPTICS IF THERE WERE NO LIGHT, THE SUBLIME EXPRESSION 
OF THE INSPIRED WRITER OF GENESIS IS PLACED AT THE TOP OF THE COMPOSITION IN 
IIEBRAICAL CHARACTERS, THE SENSE OF WHICH IS IN ENGLISH: 
And God faid, Let there be light: and there was light. Gen. ch. i. v. 3. 
* The Violet and Indigo tints would be but one intermediate colour between red and blue, if the circular and 
undivided ray of light were not fpread on a flat furface by the operation of the triangular fliape of the prifm. 
A JONQUIL. 
A GREEN BOUGH. 
THE MARIGOLD. 
THE BLUE-BELL. 
THE CORN-POPPY. 
THE BLUE-BOTTLE. 
THE FLOWER OF THAT NAME. 
No. 12x8. 
