66 PRISMATIC COLORS. 



dred and sixty, to one hundred and ninety-two, to 

 two hundred and forty, &c., until twenty-five thou- 

 sand vibrations per second are reached. Then 

 the tympanum has not time to recoil before an- 

 other impulse arrives, and the result is a cessation 

 of tympanum vibration, recognized as silence. So 

 the excessively intense vibrations of the electric 

 ether imparted to the retina by gazing at the 

 dazzling sun produce a silence of vibrations, or 

 blindness, corresponding with darkness. " Dark 

 with excess of light." 



In like manner, the prismatic or rainbow colors 

 are produced by a different rapidity of vibration 

 of the electric ether ; so that the chromatic scale 

 of musical tones of the gamut, and the chromatic 

 scale of colors, depend alike on the different rapid- 

 ity of the vibrations of the atmospheric and elec- 

 tric ethers. 



Instruments have been ingeniously devised for 

 indicating the number of vibrations per second of 

 the electric ether, requisite to produce the chro- 

 matic scale of colors. 



As sound moves with the velocity of eleven hun- 

 dred and fifty feet per second, by dividing this 

 distance by the number of aerial vibrations in a 

 second, the length of a vibratory wave is estimated. 

 The velocity of the ether producing the excitation 

 of light being one hundred and ninety thousand 

 miles per second, the length of the waves of colors 

 is similarly estimated ; as shown in the following 



