120 ANNUAL OF SCIENTIFIC DISCOVERY. 



our sun, as indicated by the existence of a glacial period, which is now 

 placed beyond doubt by geological research, it appears to rne no very 

 wild stretch of analogy to suppose that in such former periods of the 

 earth's history our sun may have passed through portions of his stellar 

 orbit in which the light-yielding element was deficient, and in which 

 case his brilliancy would have suffered the while, and an arctic cli- 

 mate in consequence spread from the poles towards the equator, and 

 leave the record of such a condition in glacial handwriting on the 

 walls of our mountain ravines, of which there is such abundant and 

 unquestionable evidence, as before said ; it is the existence of such 

 facts as we have in stars of transitory brightness, and the above-named 

 evidence of an arctic climate existing in what are now genial climates, 

 that require some adequate cause to be looked for. 



" This view of the source of light, as respects the existence of the 

 luciferous element throughout space, accords with the Mosaic account 

 of creation, in so far as that light is described as having been created 

 in the first instance before the sun was called forth." 



ON THE CLASSIFICATION OF COLORS. 



M. CHEVREUIL, the directeur des Gobelins, has presented to the French 

 Academy a plan for a universal chromatic scale, and a methodical 

 classification of all imaginable colors. Mayer, a professor at Gottingen, 

 calculated that the different combinations of primitive colors produced 

 819 different tints ; but M. Chevreuil goes much further, and estab- 

 lishes not less than 14,424, all very distinct and easily recognized 

 all, of course, proceeding from the three primitive simple colors of the 

 solar spectrum, red, yellow and blue. His nomenclature is somewhat 

 different from that generally received ; viz., he calls full colors (couleurs 

 f ranches) the simple or binary colors of the solar spectrum ; abated, or 

 less colors, (rabatues,) these same colors tinged with black ; relieved col- 

 ors, (relevees,) the same colors mixed or tinged with white ; tones, 

 (tons,) the different gradations of a color modified by different propor- 

 tions of black or white ; gamut, the ensemble of the tones of the same 

 color ; nuances, the mixture of a full color with another. He con- 

 structs his chromatic scale in this manner : he places in a circle, at 

 60 distance each from the other, the six colors, red, orange, yellow, 

 green, blue and violet ; then between each of them, and at equal 

 distances, the intermediate nuances, red-orange, orange-yellow, yel- 

 low-green, green-blue, blue-violet, violet-red ; then he fills the inter- 

 vals between each fundamental color and its nuance by five progressive 

 nuances, which suffices to give to the eye an ensemble of perfectly con- 

 tinued tints. There would then be a series of seventy-two primitive 

 colors, which serve as a base for the classification of all others ; this is 

 the chromatic circle of the author, presenting an ensemble of comparable 

 types of simple and nuancee colors samples which M. Lebois, of the 

 Gobelins, has succeeded in fixing completely upon wool, and M. Salve- 

 tal, of the manufactory at Sevres, upon porcelain. These types or 

 samples being unalterable and methodically distributed, they can 

 always be clearly designated and found when wanted. M. Chevreuil 



