SMELL. Sensations of smell are set up through the stimulation of the end-organs of the olfactory nerve, by odorous particles contained in the current of inspired air. The ultimate number of smell qualities is difficult to determine. Like tastes, odors come to us highly fused with affective qualities, with other sensations, pres sure, temperature, tickling, or even pain, and with secondary effects such as drowsiness, sneez ing, or weeping. Compare the effects of carbon disulphide, chlorine, acetic acid. In 1896 Aronsolin suggested a method of classification by exhaus tion. A given substance is smelled until entire fatigue ( perhaps better, adaptation) ensues ; other substances are then applied with the result that ) some remain at their normal intensity, (2) others possess a lessened intensity, and (3) others are entirely imperceptible. Thus, after ex haustion by iodine, cajeput is strong, mace very weak, pine imperceptible; after exhaustion by camphor, cajeput is very faint, mace strong, pine very faint. Certain smells are compensatory; if given simultaneously, they cancel one another. Compensation, it should be noted, is not the mere swamping of one odor by the sheer intensity of a second, which is often observed in actual life, e.g. in the operating room: it is a complete nulli
fication of olfactory sensation, comparable to the production of neutral gray by the mixture of complementary colors. Finally, there are smell contrasts. Cheese and Bordeaux, high game and Burgundy, are evidently opposed odors. Ex perimental investigation shows that sensitivity to either one of the scents of a compensation-pair will be increased by previous stimulation with the other.
BIBLIOGRAPHY. Aronsohn, Archie fiir AnatBibliography. Aronsohn, Archie fiir Anat- omic and (Leipzig, 1886) : Gamble, Am. Journal of Psychology, x. (1S9S) ; Kuelpe, Outlines of Psychology (London, 1895) ; Nagel, Zeitsehrift fiir Psychologie Physiologic, xv.
(1397) ; Titchener, An. Outline of Psycho/arty (New York, 1899) ; id.. Experimental. Psychology (ib., 1901) ; Vintschgau, "Physiologic des Geruchs sins," in Hermann's Handbuch der Physiologic, iii. (1880) ; Zwaardemaker, Die Physiologie des Genichs (German trans., Leipzig, 1895). Sec INTENSITY : NOSE.