42o POPULAR SCIENCE MONTHLY 



ritus, there are but four primitive colors, from which all others are 

 formed by combination. He seems to have regarded blue and green as 

 variants of black. Aristotle thought there were only two primitive 

 colors : light or white and black or dark, and that all others were pro- 

 duced by a mixture of these. Wide as this is from the mark, it shows 

 a tendency to simplify natural phenomena, though it would doubtless 

 be going too far to suspect in this belief an inkling of the composition 

 of light. In the Old Testament four prismatic colors are mentioned, 

 three of them very often and yellow four times, three times in Levit- 

 icus and once in the Psalms. In the former, it is used of hair; in the 

 latter, of gold. As the Hebrews were surrounded by nations that had 

 made great advances in technical skill, it is probable likewise that all 

 of them had made greater advances in the discrimination of colors than 

 the Greeks. 



The fact that the ancients habitually speak of only four colors is 

 almost proof positive that they did not discriminate more. In addi- 

 tion to the evidence already cited, there is to be added that of painting. 

 What is known of the art of Polygnotus, the earliest of the distinguished 

 painters of antiquity and a contemporary of Pericles, leads to the con- 

 clusion that he used no greater number, according to the ideas of his 

 time. Like all early painters he worked on terra-cotta vases and on 

 walls, not on canvas. It seems highly probable that throughout 

 antiquity no distinction was made between orange and yellow, nor be- 

 tween indigo and blue, nor between the darker colors that shade into 

 black. Many of the lower races, both at home and abroad, share this 

 defect. Both have also the same liking for what is gaudy and stri- 

 king. It is probable that the fondness for ' loud ' colors is a species 

 of survival that may be studied in children and in persons that are 

 color-blind. The latter defect is a species of arrested development, and 

 being an organic defect can not be overcome. On the other hand, 

 some primitive races are reported to exhibit a very acute color-sense. 

 This mental condition has likewise its analogy among children, some of 

 whom are indifferent to colors, while in others the color-sense shows 

 itself very early. At any rate, modern analogies will not enable us 

 to decide the question for or against any people of antiquity. Two 

 theories have long been held to account for the poverty of terms to 

 designate colors in remote times. The one most in harmony with the 

 evolution hypothesis is that the color-sense has followed the general 

 law of development; the other, that primitive races perceive colors as 

 clearly as we do, but that their languages lack words to designate minor 

 differences. Color-blindness has no connection with mental power in 

 general. It is well known that the celebrated physicist, John Dalton, 

 was not capable of distinguishing more than three colors. Many 

 similar cases are on record. This defect has become known as daltonism 

 or achromatopsia. A more correctly constructed compound would be 



