414 STUDIES IN SPECIAL SENSE PHYSIOLOGY 



the most general idea of colour to the imagination, without 

 reference to any very specific modification. If we were to add 

 two other qualifying terms to each of these four, as thus red- 

 yellow and yellow-red, red-blue and blue-red, yellow-green and 

 green-yellow, blue-green and green-blue, we should express the 

 gradations of the chromatic circle with sufficient distinctness ; and 

 if we were to add the designations of light and dark, and again 

 define, in some measure, the degree of purity or its opposite by 

 the monosyllables black, white, grey, brown, we should have a 

 tolerably sufficient range of expressions to describe the ordinary 

 appearances presented to us, without troubling ourselves whether 

 they were produced dynamically or atomically." ( 21 ) 



" Considered in a general point of view, colour is determined 

 towards one of two sides. It thus presents a contrast which we 

 call a polarity, and which we may fitly designate by the expres- 

 sions plus and minus. 



Plus. Minn*. 



" Yellow. Blue. 



Action. Negation. 



Light. Shadow. 



Brightness. Darkness. 



Force. Weakness. 



Warmth. Coldness. 



Proximity. Distance. 



Repulsion. Attraction. 



Affinity with Acids. Affinity with Alkalis." (*) 



We see here formulated the conception of certain colour sensa- 

 tions as occupying unique places in our sensational field, and 

 presenting also, as it were, a species of sensational contrast one 

 with the other. 



Not only is this conception present in the minds of those 

 who seek to influence us through the colour sense (painters), but 

 it is given effect to in their practice. 



In a dialogue on colours by Ludovico Dolce, published in 1565, 

 the following passage occurs : ( 23 ) " He who wishes to combine 

 colours that are agreeable to the eye, will put grey next dusky 

 orange, yellow-green next rose colour, blue next orange, dark 

 purple, black, next dark green, white next black, and white next 

 flesh colour." 



Titian, according to his biographer Ridolfi, was fond of opposing 



