COLOR VISION. 



The frequent appearance of new theories of color vision is suffi- 

 cient proof that there is still a feeling of dissatisfaction with the theo- 

 ries chiefly in vogue. The most recent candidate' for public favor has 

 been somewhat caustically reviewed by Mrs. Ladd-Fraxklin in the 

 Fsychological Rtvicio (X, 5, Sept., 1903) and, as the monograph is still 

 incomplete, notice is withheld. But the occasion is opportune for call- 

 ing attention to the very excellent and useful summary of this subject 

 published by Professor Maey Whiton Calkixs in Arch.f. Anat. u. 

 Phys., Physiol. Abt., Suppl. 1902, entitled "Theorien iiber die Emp- 

 finduug farbiger und farbloser Lichter." 



We desire, however, first to call attention to what we deem a 

 fundamental error (often in language only, it may be admitted) which 

 serves to introduce more or less confusion into all of the current dis- 

 cussions. 



Considered from the purely psychic point of view, such a thing 

 as composition or "mixing" of sen.sations is impossible, and this will ap- 

 ply with special force to color sensations. As a matter of fact — of im- 

 mediate experience — any color, shade or tint is a separate discrete fact 

 of apprehension. From a score of shades of red we may select any 

 one as an objective unit and no one of the twenty will be experienced 

 as a mixture. If it be a fact that there are four primary colors in the 

 spectrum by the mingling of which all secondary colors can be pro- 

 duced, this mixing is not a psychological mixing (though it is a psycho- 

 logical mixing so to describe it) and the fact in no way dis2)roves the 

 statement of the discrete and separate character of every color sensa- 

 tion. Black has just as real an experimental independence as though 

 it had a definite wave length as its external occasion. 



That this should be so is readily seen on the basis of the writer's 

 equilibrium theory of consciousness. If every conscious state is but 

 the result of an equilibrium of the cortical activities involved, it makes 



' Egon RrrxER von Oi'PorzEK. (Jnindziige einer P'arbentheorie. Zeils. 

 f. Psychol, u. Physiol, d. Sinnesorgane, XXIX, 3, 1 83-2 113. 



