AMERICAN 
JOURNAL OF SCIENCE AND ARTS. 
[THIRD SERIES.] 
ArT. XX VIL—The History of Young's Discovery of his Theory 
of Colors; by ALFRED M. MAYER. 
THE object of this communication is twofold: I desire first 
to give complete abstracts from the writings of Newton, Young 
and Wollaston, in order to put the student of science in 
sion of all of the early literature of Young’s celebrated theory 
of colors. In the second place, I propose to trace the curious 
history of the steps by which Young was led to the final adop- 
tion of what is now known as Young’s theory of color-sensation. 
In accomplishing the first of these objects, I shall, at the same 
time, attempt to show, Ist, that Young first formed an hypothe- 
sis similar to that known as Brewster’s; that is, he selected 
red, yellow and blue as the three simple color-sensations ; 2d, 
that he subsequently modified his hypothesis and ado 
green and violet as the three elementary color-sensations, show- 
Ing that up to the date of this change of opinion all of his 
ideas on the subject were hypothetical, and not based on any 
observations or experiments of his own or of others; 3d, that 
this change of opinion as to the three elementary colors was 
made on the basis of a misconception by Wollaston of the 
nature of his celebrated observation of the dark lines in the 
solar spectrum, and also on the basis of an erroneous observa- 
tion made by Young in repeating Wollaston’s experiment; 4th, 
that Young subsequently tested his hypothesis of color-sensa- 
tion and found that it was in accord with facts reached by 
Am. Jour. Scr.—Tutrp Sertzs, Vou. IX, No. 52.—Aprit, 1875. 
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