84 SMELL, TASTE, ALLIED SENSES 



case. If in a pair of such odors one is much stronger 

 than the other, its smell dominates completely. If, how- 

 ever, the two odors are closely balanced a true odor may 

 result which in quality is said to be unlike that of either 

 component. Novel odors of this kind may be produced, 

 according to Aronsohn (1886), by such combinations as 

 cologne water and oil of orange, cologne water and oil of 

 lemon, oil of bergamot and oil of orange, and so forth. 

 The condition that thus produces a noval odor is one of 

 considerable delicacy and may be easily upset by the 

 greater exhausting effect of one or other of the components 

 thus allowing the less exhausted member to assert itself 

 and to call forth its own peculiar sensation. The presence 

 of a sensation different from those of the pair of stimuli 

 producing that sensation might seem to be a condition 

 adverse to the component theory, but it must be remem- 

 bered that in vision, in which the component conception 

 is fundamental, an exact parallel occurs. Thus when a 

 pure orange light is mixed with a pure green light, there 

 may result a sensation of yellow that is wholly unlike 

 that appropriate to either member of the combination, 

 and that, as a matter of fact, may be indistinguishable 

 from a sensation of yellow produced by a pure yellow 

 light. Thus in accepting the component theory of sensory 

 activity it must be admitted that two stimuli together 

 may excite a receptor in precisely the same way as a 

 third and entirely different stimulus may do. The exist- 

 ence of a novel olfactory sensation due to the simultane- 

 ous activity of two independent stimuli is therefore, no 

 serious obstacle to this theory. 



The condition of double olfactory stimulation that 

 has just been described must not be confused with a kind 



