Page:Eleanor Gamble - The Applicability of Weber's Law to Smell.pdf/11

Rh that there are as many elementary odors as there are simple substances.

One reason is, that it is extremely improbable that either the structure of the fibres or endings, or the snbstance of the olfactory nerve, is differentiated to correspond to the innumerable odorous substances which we encounter; and, on the other hand, it is probable by analogy with other sense-organs, that there are “specific energies” of smell which are limited in number and capable of combination.

A second reason is that we have experimental evidence that the action of the sense organ is differentiated into more and less separable processes. We have sure evidence in the results of exhaustion-experiments, which were first instituted by Frolich and Aronsohn. For example, a subject whose organ is fatigued by the continuous smelling of tincture of iodine can sense ethereal oils and ethers almost or quite as well as ever, oils of lemon, turpentine and cloves but faintly, and common alcohol not at all. We have also evidence of some slight value in the regarded traces of partial anosmia. Unfortunately, very few such cases have been described by persons who took experimental precautions, and such cases as are noted in medical literature fail to show typical anomalies comparable to the uniform phenomena of color-blindness or “tone-islands,” which have played such an important part in the formation of theories of vision and audition.

A third reason is that there are countless instances of smell- fusions in which the components cannot be detected. Nagel intimates that there is no proof of the existence of smell- fusions in which different components can be sensed as differ- ent at the same instant, and points ont that, in this respect, smell-mixtures resemble color-mixtures rather than clangs.

Zwaardemaker, following Arnonsohn and bearing in mind the usages of the perfume trade, holds that only similar odors will