II.

We may observe this very well in the case of the dog. Thus, a young dog, well known to me, who had never had connection with a bitch, but was always in the society of its father, once met the latter directly after the elder dog had been with a bitch. He immediately endeavored to behave toward the elder dog, in spite of angry repulses, exactly as a dog behaves toward a bitch in heat. The messages received by the sense of smell were sufficiently urgent not only to set the sexual mechanism in action, but to overcome the experiences of a lifetime. There is an interesting chapter on the sense of smell in the mental life of the dog in Giessler'sPsychologie des Geruches, 1894, Chapter XI, Passy (in the appendix to his memoir on olfaction,L'Année Psychologique, 1895) gives the result of some interesting experiments as to the effects of perfume on dogs; civet and castoreum were found to have the most powerfully exciting effect.The influences of smell are equally omnipotent in the sexual life of many insects. Thus, Féré has found that in cockchafers sexual coupling failed to take place when the antennæ, which are the organs of smell, were removed; he also found that males, after they had coupled with females, proved sexually attractive to other males (Comptes Rendus de la Société de Biologie, May 21, 1898). Féré similarly found that, in a species ofBombyx, males after contact with females sometimes proved attractive to other males, although no abnormal relationships followed. (Soc. de Biol, July 30, 1898.)

The influences of smell are equally omnipotent in the sexual life of many insects. Thus, Féré has found that in cockchafers sexual coupling failed to take place when the antennæ, which are the organs of smell, were removed; he also found that males, after they had coupled with females, proved sexually attractive to other males (Comptes Rendus de la Société de Biologie, May 21, 1898). Féré similarly found that, in a species ofBombyx, males after contact with females sometimes proved attractive to other males, although no abnormal relationships followed. (Soc. de Biol, July 30, 1898.)

With the advent of the higher apes, and especially of man, all this has been changed. The sense of smell, indeed, still persists universally and it is still also exceedingly delicate, though often neglected.[25]It is, moreover, a useful auxiliary in the exploration of the external world, for, in contrast to the very few sensations furnished to us by touch and by taste, we are acquainted with a vast number of smells, though the information they give us is frequently vague. An experienced perfumer, says Piesse, will have two hundred odors in his laboratory and can distinguish them all. To a sensitive nose nearly everything smells. Passy goes so far as to state that he has "never met with any object that is really inodorous when one pays attention to it, not even excepting glass," and, though we can scarcely accept this statement absolutely,—especially inview of the careful experiments of Ayrton, which show that, contrary to a common belief, metals when perfectly clean and free from traces of contact with the skin or with salt solutions have no smell,—odor is still extremely widely diffused. This is especially the case in hot countries, and the experiments of the Cambridge Anthropological Expedition on the sense of smell of the Papuans were considerably impeded by the fact that at Torres Straits everything, even water, seemed to have a smell. Savages are often accused more or less justly of indifference to bad odors. They are very often, however, keenly alive to the significance of smells and their varieties, though it does not appear that the sense of smell is notably more developed in savage than in civilized peoples. Odors also continue to play a part in the emotional life of man, more especially in hot countries. Nevertheless both in practical life and in emotional life, in science and in art, smell is, at the best, under normal conditions, merely an auxiliary. If the sense of smell were abolished altogether the life of mankind would continue as before, with little or no sensible modification, though the pleasures of life, and especially of eating and drinking, would be to some extent diminished.

In New Ireland, Duffield remarks (Journal of the Anthropological Institute, 1886, p. 118), the natives have a very keen sense of smell; unusual odors are repulsive to them, and "carbolic acid drove them wild."The New Caledonians, according to Foley (Bulletin de la Société d'Anthropologie, November 6, 1879), only like the smells of meat and fish which are becoming "high," likepopoya, which smells of fowl manure, andkava, of rotten eggs. Fruits and vegetables which are beginning to go bad seem the best to them, while the fresh and natural odors which we prefer seem merely to say to them: "We are not yet eatable." (A taste for putrefying food, common among savages, by no means necessarily involves a distaste for agreeable scents, and even among Europeans there is a widespread taste for offensively smelling and putrid foods, especially cheese and game.)The natives of Torres Straits were carefully examined by Dr. C. S. Myers with regard to their olfactory acuteness and olfactory preferences. It was found that acuteness was, if anything, slightly greater than among Europeans. This appeared to be largely due to the carefulattention they pay to odors. The resemblances which they detected among different odorous substances were frequently found to rest on real chemical affinities. The odors they were observed to dislike most frequently were asafœtida, valerianic acid, and civet, the last being regarded as most repulsive of all on account of its resemblance to fæcal odor, which these people regard with intense disgust. Their favorite odors were musk, thyme, and especially violet. (Report of the Cambridge Anthropological Expedition to Torres Straits, vol. ii, Part II, 1903.)In Australia Lumholtz (Among Cannibals, p. 115) found that the blacks had a keener sense of smell than he possessed.In New Zealand the Maoris, as W. Colenso shows, possessed, formerly at all events, a very keen sense of smell or else were very attentive to smell, and their taste as regarded agreeable and disagreeable odors corresponded very closely to European taste, although it must be added that some of their common articles of food possessed a very offensive odor. They are not only sensitive to European perfumes, but possessed various perfumes of their own, derived from plants and possessing a pleasant, powerful, and lasting odor; the choicest and rarest was the gum of thetaramea(Aciphylla Colensoi), which was gathered by virgins after the use of prayers and charms. Sir Joseph Banks noted that Maori chiefs wore little bundles of perfumes around their necks, and Cook made the same observation concerning the young women. References to the four chief Maori perfumes are contained in a stanza which is still often hummed to express satisfaction, and sung by a mother to her child:—

The New Caledonians, according to Foley (Bulletin de la Société d'Anthropologie, November 6, 1879), only like the smells of meat and fish which are becoming "high," likepopoya, which smells of fowl manure, andkava, of rotten eggs. Fruits and vegetables which are beginning to go bad seem the best to them, while the fresh and natural odors which we prefer seem merely to say to them: "We are not yet eatable." (A taste for putrefying food, common among savages, by no means necessarily involves a distaste for agreeable scents, and even among Europeans there is a widespread taste for offensively smelling and putrid foods, especially cheese and game.)

The natives of Torres Straits were carefully examined by Dr. C. S. Myers with regard to their olfactory acuteness and olfactory preferences. It was found that acuteness was, if anything, slightly greater than among Europeans. This appeared to be largely due to the carefulattention they pay to odors. The resemblances which they detected among different odorous substances were frequently found to rest on real chemical affinities. The odors they were observed to dislike most frequently were asafœtida, valerianic acid, and civet, the last being regarded as most repulsive of all on account of its resemblance to fæcal odor, which these people regard with intense disgust. Their favorite odors were musk, thyme, and especially violet. (Report of the Cambridge Anthropological Expedition to Torres Straits, vol. ii, Part II, 1903.)

In Australia Lumholtz (Among Cannibals, p. 115) found that the blacks had a keener sense of smell than he possessed.

In New Zealand the Maoris, as W. Colenso shows, possessed, formerly at all events, a very keen sense of smell or else were very attentive to smell, and their taste as regarded agreeable and disagreeable odors corresponded very closely to European taste, although it must be added that some of their common articles of food possessed a very offensive odor. They are not only sensitive to European perfumes, but possessed various perfumes of their own, derived from plants and possessing a pleasant, powerful, and lasting odor; the choicest and rarest was the gum of thetaramea(Aciphylla Colensoi), which was gathered by virgins after the use of prayers and charms. Sir Joseph Banks noted that Maori chiefs wore little bundles of perfumes around their necks, and Cook made the same observation concerning the young women. References to the four chief Maori perfumes are contained in a stanza which is still often hummed to express satisfaction, and sung by a mother to her child:—

"My little neck-satchel of sweet-scented moss,My little neck-satchel of fragrant fern,My little neck-satchel of odoriferous gum,My sweet-smelling neck-locket of sharp-pointedtaramea."

In the summer season the sleeping houses of Maori chiefs were often strewed with a large, sweet-scented, flowering grass of powerful odor. (W. Colenso,Transactions of the New Zealand Institute, vol. xxiv, reprinted inNature, November 10, 1892.)Javanese women rub themselves with a mixture of chalk and strong essence which, when rubbed off, leaves a distinct perfume on the body. (Stratz,Die Frauenkleidung, p. 84.)The Samoans, Friedländer states (Zeitschrift für Ethnologie, 1899, p. 52), are very fond of fragrant and aromatic odors. He gives a list of some twenty odorous plants which they use, more especially as garlands for the head and neck, including ylang-ylang and gardenia; he remarks that of one of these plants (cordyline) he could not himself detect the odor.The Nicobarese, Man remarks (Journal of the Anthropological Institute, 1889, p. 377), like the natives of New Zealand, particularly dislike the smell of carbolic acid. Both young men and women are very partial to scents; the former say they find their use a certain passport to the favor of their wives, and they bring home from the jungle the scented leaves of a certain creeper to their sweethearts and wives.Swahili women devote much attention to perfuming themselves. When a woman wishes to make herself desirable she anoints herself all over with fragrant ointments, sprinkles herself with rose-water, puts perfume into her clothes, strews jasmine flowers on her bed as well as binding them round her neck and waist, and smokesûdi, the perfumed wood of the aloe; "every man is glad when his wife smells ofûdi" (Velten,Sitten und Gebraüche der Suaheli, pp. 212-214).

Javanese women rub themselves with a mixture of chalk and strong essence which, when rubbed off, leaves a distinct perfume on the body. (Stratz,Die Frauenkleidung, p. 84.)

The Samoans, Friedländer states (Zeitschrift für Ethnologie, 1899, p. 52), are very fond of fragrant and aromatic odors. He gives a list of some twenty odorous plants which they use, more especially as garlands for the head and neck, including ylang-ylang and gardenia; he remarks that of one of these plants (cordyline) he could not himself detect the odor.

The Nicobarese, Man remarks (Journal of the Anthropological Institute, 1889, p. 377), like the natives of New Zealand, particularly dislike the smell of carbolic acid. Both young men and women are very partial to scents; the former say they find their use a certain passport to the favor of their wives, and they bring home from the jungle the scented leaves of a certain creeper to their sweethearts and wives.

Swahili women devote much attention to perfuming themselves. When a woman wishes to make herself desirable she anoints herself all over with fragrant ointments, sprinkles herself with rose-water, puts perfume into her clothes, strews jasmine flowers on her bed as well as binding them round her neck and waist, and smokesûdi, the perfumed wood of the aloe; "every man is glad when his wife smells ofûdi" (Velten,Sitten und Gebraüche der Suaheli, pp. 212-214).

[24]

Emile Yung, "Le Sens Olfactif de l'Escargot (Helix Pomata),"Archives de Psychologie, November, 1903.

[25]

The sensitiveness of smell in man generally exceeds that of chemical reaction or even of spectral analysis; see Passy,L'Année Psychologique, second year, 1895, p. 380.

Rise of the Study of Olfaction—Cloquet—Zwaardemaker—The Theory of Smell—The Classification of Odors—The Special Characteristics of Olfactory Sensation in Man—Smell as the Sense of Imagination—Odors as Nervous Stimulants—Vasomotor and Muscular Effects—Odorous Substances as Drugs.

During the eighteenth century a great impetus was given to the physiological and psychological study of the senses by the philosophical doctrines of Locke and the English school generally which then prevailed in Europe. These thinkers had emphasized the immense importance of the information derived through the senses in building up the intellect, so that the study of all the sensory channels assumed a significance which it had never possessed before. The olfactory sense fully shared in the impetus thus given to sensory investigation. At the beginning of the nineteenth century a distinguished French physician, Hippolyte Cloquet, a disciple of Cabanis, devoted himself more especially to this subject. After publishing in 1815 a preliminary work, he issued in 1821 hisOsphrésiologie, ou Traité des odeurs, du sens et des organes de l'Olfaction, a complete monograph on the anatomy, physiology, psychology, and pathology of the olfactory organ and its functions, and a work that may still be consulted with profit, if indeed it can even yet be said to be at every point superseded. After Cloquet's time the study of the sense of smell seems to have fallen into some degree of discredit. For more than half a century no important progress was made in this field. Serious investigators seemed to have become shy of the primitive senses generally, and the subject of smell was mainly left to those interested in "curious" subjects. Many interesting observations were, however, incidentally made; thus Laycock, who was a pioneer in so many by-paths of psychology and anthropology, showed a special interest in the olfactory sense, and frequentlytouched on it in hisNervous Diseases of Womenand elsewhere. The writer who more than any other has in recent years restored the study of the sense of smell from a by-path to its proper position as a highway for investigation is without doubt Professor Zwaardemaker, of Utrecht. The invention of his first olfactometer in 1888 and the appearance in 1895 of his great workDie Physiologie des Geruchshave served to give the physiology of the sense of smell an assured status and to open the way anew for much fruitful investigation, while a number of inquirers in many countries have had their attention directed to the elucidation of this sense.

Notwithstanding, however, the amount of work which has been done in this field during recent years, it cannot be said that the body of assured conclusions so far reached is large. The most fundamental principles of olfactory physiology and psychology are still somewhat vague and uncertain. Although sensations of smell are numerous and varied, in this respect approaching the sensations of vision and hearing, smell still remains close to touch in the vagueness of its messages (while the most sensitive of the senses, remarks Passy, it is the least precise), the difficulty of classifying them, the impossibility of so controlling them as to found upon them any art. It seems better, therefore, not to attempt to force the present study of a special aspect of olfaction into any general scheme which may possibly not be really valid.

The earliest and most general tendency in regard to the theory of smell was to regard it as a kind of chemical sense directly stimulated by minute particles of solid substance. A vibratory theory of smell, however, making it somewhat analogous to hearing, easily presents itself. When I first began the study of physiology in 1881, a speculation of this kind presented itself to my mind. Long before Philipp von Walther, a professor at Landshut, had put forward a dynamic theory of olfaction (Physiologie des Menschen, 1807-8, vol. ii, p. 278). "It is a purely dynamic operation of the odorous substance in the olfactory organ," he stated. Odor is conveyed by the air, he believed, in the same way as heat. It must be added that his reasons for this theory will not always bear examination. More recently a similar theory has been seriously put forward in various quarters. Sir William Ramsay tentatively suggested such a theory (Nature, vol. xxv, p. 187) in analogy with light and sound. Haycraft (Proceedings of the Royal Society of Edinburgh,1883-87, andBrain, 1887-88), largely starting from Mendelieff's law of periodicity, similarly sought to bring smell into line with the higher senses, arguing that molecules with the same vibration have the same smell. Rutherford (Nature, August 11, 1892, p. 343), attaching importance to the evidence brought forward by von Brunn showing that the olfactory cells terminate in very delicate short hairs, also stated his belief that the different qualities of smell result from differences in the frequency and form of the vibrations initiated by the action of the chemical molecules on these olfactory cells, though he admitted that such a conception involved a very subtle conception of molecular vibration. Vaschide and Van Melle (Paris Academy of Sciences, December 26, 1899) have, again, argued that smell is produced by rays of short wave-lengths, analogous to light-rays, Röntgen rays, etc. Chemical action is however, a very important factor in the production of odors; this has been well shown by Ayrton (Nature, September 8, 1898). We seem to be forced in the direction of a chemico-vibratory theory, as pointed out by Southerden (Nature, March 26, 1903), the olfactory cells being directly stimulated, not by the ordinary vibrations of the molecules, but by the agitations accompanying chemical changes.The vibratory hypothesis of the action of odors has had some influence on the recent physiologists who have chiefly occupied themselves with olfaction. "It is probable," Zwaardemaker writes (L'Année Psychologique, 1898), "that aroma is a physico-chemical attribute of the molecules"; he points out that there is an intimate analogy between color and odor, and remarks that this analogy leads us to suppose in an aroma ether vibrations of which the period is determined by the structure of the molecule.Since the physiology of olfaction is yet so obscure it is not surprising that we have no thoroughly scientific classification of smells, notwithstanding various ambitious attempts to reach a classification. The classification adopted by Zwaardemaker is founded on the ancient scheme of Linnæus, and may here be reproduced:—I. Ethereal odors (chiefly esters; Rimmel's fruity series).II. Aromatic odors (terpenes, camphors, and the spicy, herbaceous, rosaceous, and almond series; the chemical types are well determined: cineol, eugenol, anethol, geraniol, benzaldehyde).III. The balsamic odors (chiefly aldehydes, Rimmel's jasmin, violet, and balsamic series, with the chemical types: terpineol, ionone, vanillin).IV. The ambrosiacal odors (ambergris and musk).V. The alliaceous odors, with the cacodylic group (asafœtida, ichthyol, etc.).VI. Empyreumatic odors.VII. Valerianaceous odors (Linnæus'sOdores hircini, the capryl group, largely composed of sexual odors).VIII. Narcotic odors (Linnæus'sOdores tetri).IX. Stenches.A valuable and interesting memoir, "Revue Générale sur les Sensations Olfactives," by J. Passy, the chief French authority on this subject, will be found in the second volume ofL'Année Psychologique, 1895. In the fifth issue of the same year-book (for 1898) Zwaardemaker presents a full summary of his work and views, "Les Sensations Olfactives, leurs Combinaisons et leurs Compensations." A convenient, but less authoritative, summary of the facts of normal and pathological olfaction will be found in a little volume of the "Actualités Médicales" series by Dr. Collet,L'Odorat et ses Troubles, 1904. In a little book entitledWegweiser zu einer Psychologie des Geruches(1894) Giessler has sought to outline a psychology of smell, but his sketch can only be regarded as tentative and provisional.

The vibratory hypothesis of the action of odors has had some influence on the recent physiologists who have chiefly occupied themselves with olfaction. "It is probable," Zwaardemaker writes (L'Année Psychologique, 1898), "that aroma is a physico-chemical attribute of the molecules"; he points out that there is an intimate analogy between color and odor, and remarks that this analogy leads us to suppose in an aroma ether vibrations of which the period is determined by the structure of the molecule.

Since the physiology of olfaction is yet so obscure it is not surprising that we have no thoroughly scientific classification of smells, notwithstanding various ambitious attempts to reach a classification. The classification adopted by Zwaardemaker is founded on the ancient scheme of Linnæus, and may here be reproduced:—

A valuable and interesting memoir, "Revue Générale sur les Sensations Olfactives," by J. Passy, the chief French authority on this subject, will be found in the second volume ofL'Année Psychologique, 1895. In the fifth issue of the same year-book (for 1898) Zwaardemaker presents a full summary of his work and views, "Les Sensations Olfactives, leurs Combinaisons et leurs Compensations." A convenient, but less authoritative, summary of the facts of normal and pathological olfaction will be found in a little volume of the "Actualités Médicales" series by Dr. Collet,L'Odorat et ses Troubles, 1904. In a little book entitledWegweiser zu einer Psychologie des Geruches(1894) Giessler has sought to outline a psychology of smell, but his sketch can only be regarded as tentative and provisional.

At the outset, nevertheless, it seems desirable that we should at least have some conception of the special characteristics which mark the great and varied mass of sensations reaching the brain through the channel of the olfactory organ. The main special character of olfactory images seems to be conditioned by the fact that they are intermediate in character between those of touch or taste and those of sight or sound, that they have much of the vagueness of the first and something of the richness and variety of the second. Æsthetically, also, they occupy an intermediate position between the higher and the lower senses.[26]They are, at the same time, less practically useful than either the lower or the higher senses. They furnish us with a great mass of what we may call by-sensations, which are of little practical use, but inevitably become intimately mixed with the experiences of life by association and thus acquire an emotional significance which is often very considerable. Their emotional force, it may well be, is connected with the fact that their anatomical seat is themost ancient part of the brain. They lie in a remote almost disused storehouse of our minds and show the fascination or the repulsiveness of all vague and remote things. It is for this reason that they are—to an extent that is remarkable when we consider that they are much more precise than touch sensations—subject to the influence of emotional associations. The very same odor may be at one moment highly pleasant, at the next moment highly unpleasant, in accordance with the emotional attitude resulting from its associations. Visual images have no such extreme flexibility; they are too definite to be so easily influenced. Our feelings about the beauty of a flower cannot oscillate so easily or so far as may our feelings about the agreeableness of its odor. Our olfactory experiences thus institute a more or less continuous series of by-sensations accompanying us through life, of no great practical significance, but of considerable emotional significance from their variety, their intimacy, their associational facility, their remote ancestral reverberations through our brains.

It is the existence of these characteristics—at once so vague and so specific, so useless and so intimate—which led various writers to describe the sense of smell as, above all others, the sense of imagination. No sense has so strong a power of suggestion, the power of calling up ancient memories with a wider and deeper emotional reverberation, while at the same time no sense furnishes impressions which so easily change emotional color and tone, in harmony with the recipient's general attitude. Odors are thus specially apt both to control the emotional life and to become its slaves. With the use of incense religions have utilized the imaginative and symbolical virtues of fragrance. All the legends of the saints have insisted on the odor of sanctity that exhales from the bodies of holy persons, especially at the moment of death. Under the conditions of civilization these primitive emotional associations of odor tend to be dispersed, but, on the other hand, the imaginative side of the olfactory sense becomes accentuated, and personal idiosyncrasies of all kinds tend to manifest themselves in the sphere of smell.

Rousseau (inEmile, Bk. II) regarded smell as the sense of the imagination. So, also, at an earlier period, it was termed (according to Cloquet) by Cardano. Cloquet frequently insisted on the qualities of odors which cause them to appeal to the imagination; on their irregular and inconstant character; on their power of intoxicating the mind on some occasions; on the curious individual and racial preferences in the matter of odors. He remarked on the fact that the Persians employed asafœtida as a seasoning, while valerian was accounted a perfume in antiquity. (Cloquet,Osphrésiologie, pp. 28, 45, 71, 112.) It may be added, as a curious example familiar to most people of the dependence of the emotional tone of a smell on its associations, that, while the exhalations of other people's bodies are ordinarily disagreeable to us, such is not the case with our own; this is expressed in the crude and vigorous dictum of the Elizabethan poet, Marston, "Every man's dung smell sweet i' his own nose." There are doubtless many implications, moral as well as psychological, in that statement.The modern authorities on olfaction, Passy and Zwaardemaker, both alike insist on the same characteristics of the sense of smell: its extreme acuity and yet its vagueness. "We live in a world of odor," Zwaardemaker remarks (L'Année Psychologique, 1898, p. 203), "as we live in a world of light and of sound. But smell yields us no distinct ideas grouped in regular order, still less that are fixed in the memory as a grammatical discipline. Olfactory sensations awake vague and half-understood perceptions, which are accompanied by very strong emotion. The emotion dominates us, but the sensation which was the cause of it remains unperceived." Even in the same individual there are wide variations in the sensitiveness to odors at different times, more especially as regards faint odors; Passy (L'Année Psychologique, 1895, p. 387) brings forward some observations on this point.Maudsley noted the peculiarly suggestive power of odors; "there are certain smells," he remarked, "which never fail to bring back to me instantly and visibly scenes of my boyhood"; many of us could probably say the same. Another writer (E. Dillon, "A Neglected Sense,"Nineteenth Century, April, 1894) remarks that "no sense has a stronger power of suggestion."Ribot has made an interesting investigation as to the prevalence and nature of the emotional memory of odors (Psychology of the Emotions, Chapter XI). By "emotional memory" is meant the spontaneous or voluntary revivability of the image, olfactory or other. (For the general question, see an article by F. Pillon, "La Mémoire Affective, son Importance Théorique et Pratique,"Revue Philosophique, February, 1901; also Paulhan, "Sur la Mémoire Affective,"Revue Philosophique, December, 1902 and January, 1903.) Ribot found that 40 per cent. of persons are unable to revive any such images of taste or smell; 48per cent, could revive some; 12 per cent, declared themselves capable of reviving all, or nearly all, at pleasure. In some persons there is no necessary accompanying revival of visual or tactile representations, but in the majority the revived odor ultimately excites a corresponding visual image. The odors most frequently recalled were pinks, musk, violets, heliotrope, carbolic acid, the smell of the country, of grass, etc. Piéron (Revue Philosophique, December, 1902) has described the special power possessed by vague odors, in his own case, of evoking ancient impressions.Dr. J. N. Mackenzie (American Journal of the Medical Sciences, January, 1886) considers that civilization exerts an influence in heightening or encouraging the influence of olfaction as it affects our emotions and judgment, and that, in the same way, as we ascend the social scale the more readily our minds are influenced and perhaps perverted by impressions received through the sense of smell.

The modern authorities on olfaction, Passy and Zwaardemaker, both alike insist on the same characteristics of the sense of smell: its extreme acuity and yet its vagueness. "We live in a world of odor," Zwaardemaker remarks (L'Année Psychologique, 1898, p. 203), "as we live in a world of light and of sound. But smell yields us no distinct ideas grouped in regular order, still less that are fixed in the memory as a grammatical discipline. Olfactory sensations awake vague and half-understood perceptions, which are accompanied by very strong emotion. The emotion dominates us, but the sensation which was the cause of it remains unperceived." Even in the same individual there are wide variations in the sensitiveness to odors at different times, more especially as regards faint odors; Passy (L'Année Psychologique, 1895, p. 387) brings forward some observations on this point.

Maudsley noted the peculiarly suggestive power of odors; "there are certain smells," he remarked, "which never fail to bring back to me instantly and visibly scenes of my boyhood"; many of us could probably say the same. Another writer (E. Dillon, "A Neglected Sense,"Nineteenth Century, April, 1894) remarks that "no sense has a stronger power of suggestion."

Ribot has made an interesting investigation as to the prevalence and nature of the emotional memory of odors (Psychology of the Emotions, Chapter XI). By "emotional memory" is meant the spontaneous or voluntary revivability of the image, olfactory or other. (For the general question, see an article by F. Pillon, "La Mémoire Affective, son Importance Théorique et Pratique,"Revue Philosophique, February, 1901; also Paulhan, "Sur la Mémoire Affective,"Revue Philosophique, December, 1902 and January, 1903.) Ribot found that 40 per cent. of persons are unable to revive any such images of taste or smell; 48per cent, could revive some; 12 per cent, declared themselves capable of reviving all, or nearly all, at pleasure. In some persons there is no necessary accompanying revival of visual or tactile representations, but in the majority the revived odor ultimately excites a corresponding visual image. The odors most frequently recalled were pinks, musk, violets, heliotrope, carbolic acid, the smell of the country, of grass, etc. Piéron (Revue Philosophique, December, 1902) has described the special power possessed by vague odors, in his own case, of evoking ancient impressions.

Dr. J. N. Mackenzie (American Journal of the Medical Sciences, January, 1886) considers that civilization exerts an influence in heightening or encouraging the influence of olfaction as it affects our emotions and judgment, and that, in the same way, as we ascend the social scale the more readily our minds are influenced and perhaps perverted by impressions received through the sense of smell.

Odors are powerful stimulants to the whole nervous system, causing, like other stimulants, an increase of energy which, if excessive or prolonged, leads to nervous exhaustion. Thus, it is well recognized in medicine that the aromatics containing volatile oils (such as anise, cinnamon, cardamoms, cloves, coriander, and peppermint) are antispasmodics and anæsthetics, and that they stimulate digestion, circulation, and the nervous system, in large doses producing depression. The carefully arranged plethysmographic experiments of Shields, at the Johns Hopkins University, have shown that olfactory sensations, by their action on the vasomotor system, cause an increase of blood in the brain and sometimes in addition stimulation of the heart; musk, wintergreen, wood violet, and especially heliotrope were found to act strongly in these ways.[27]

Féré's experiments with the dynamometer and the ergograph have greatly contributed to illustrate the stimulating effects of odors. Thus, he found that smelling musk suffices to double muscular effort. With a number of odorous substances he has found that muscular work is temporarily heightened; when taste stimulation was added the increase of energy, notablywhen using lemon was "colossal." A kind of "sensorial intoxication" could be produced by the inhalation of odors and the whole system stimulated to greater activity; the visual acuity was increased, and electric and general excitability heightened.[28]Such effects may be obtained in perfectly healthy persons, though both Shields and Féré have found that in highly nervous persons the effects are liable to be much greater. It is doubtless on this account that it is among civilized peoples that attention is chiefly directed to perfumes, and that under the conditions of modern life the interest in olfaction and its study has been revived.

It is the genuinely stimulant qualities of odorous substances which led to the widespread use of the more potent among them by ancient physicians, and has led a few modern physicians to employ them still. Thus, vanilla, according to Eloy, deserves to be much more frequently used therapeutically than it is, on account of its excitomotor properties; he states that its qualities as an excitant of sexual desire have long been recognized and that Fonssagrives used to prescribe it for sexual frigidity.[29]

[26]

The opinions of psychologists concerning the æsthetic significance of smell, not on the whole very favorable, are brought together and discussed by J. V. Volkelt, "Der Æsthetische Wert der niederen Sinne,"Zeitschrift für Psychologie und Physiologie der Sinnesorgane, 1902, ht. 3.

[27]

T. E. Shields, "The Effect of Odors, etc., upon the Blood-flow,"Journal of Experimental Medicine, vol. i, November, 1896. In France, O. Henry and Tardif have made somewhat similar experiments on respiration and circulation. See the latter'sLes Odeurs et les Parfums, Chapter III.

[28]

Féré,Sensation et Mouvement, Chapter VI;ib.,Comptes Rendus de la Société de Biologie, November 3, December 15 and 22, 1900.

[29]

Eloy, art. "Vanille,"Dictionnaire Encyclopédique des Sciences Médicales.

The Specific Body Odors of Various Peoples—The Negro, etc.—The European—The Ability to Distinguish Individuals by Smell—The Odor of Sanctity—The Odor of Death—The Odors of Different Parts of the Body—The Appearance of Specific Odors at Puberty—The Odors of Sexual Excitement—The Odors of Menstruation—Body Odors as a Secondary Sexual Character—The Custom of Salutation by Smell—The Kiss—Sexual Selection by Smell—The Alleged Association between Size of Nose and Sexual Vigor—The Probably Intimate Relationship between the Olfactory and Genital Spheres—Reflex Influences from the Nose—Reflex Influences from the Genital Sphere—Olfactory Hallucinations in Insanity as Related to Sexual States—The Olfactive Type—The Sense of Smell in Neurasthenic and Allied States—In Certain Poets and Novelists—Olfactory Fetichism—The Part Played by Olfaction in Normal Sexual Attraction—In the East, etc.—In Modern Europe—The Odor of the Armpit and its Variations—As a Sexual and General Stimulant—Body Odors in Civilization Tend to Cause Sexual Antipathy unless some Degree of Tumescence is Already Present—The Question whether Men or Women are more Liable to Feel Olfactory Influences—Women Usually more Attentive to Odors—The Special Interest in Odors Felt by Sexual Inverts.

In approaching the specifically sexual aspect of odor in the human species we may start from the fundamental fact—a fact we seek so far as possible to disguise in our ordinary social relations—that all men and women are odorous. This is marked among all races. The powerful odor of many, though not all, negroes is well known; it is by no means due to uncleanly habits, and Joest remarks that it is even increased by cleanliness, which opens the pores of the skin; according to Sir H. Johnston, it is most marked in the armpits and is stronger in men than in women. Pruner Bey describes it as "ammoniacal and rancid; it is like the odor of the he-goat." The odor varies not only individually, but according to the tribe; Castellani states that the negress of the Congo has merely a slight "goût de noisette" which is agreeable rather than otherwise. Monbuttu women, according to Parke, have a strong Gorgonzola perfume, and Emin told Parke that he could distinguishthe members of different tribes by their characteristic odor. In the same way the Nicobarese, according to Man, can distinguish a member of each of the six tribes of the archipelago by smell. The odor of Australian blacks is less strong than that of negroes and has been described as of a phosphoric character. The South American Indians, d'Orbigny stated, have an odor stronger than that of Europeans, though not as strong as most negroes; it is marked, Latcham states, even among those who, like the Araucanos, bathe constantly. The Chinese have a musky odor. The odor of many peoples is described as being of garlic.[30]

A South Sea Islander, we are told by Charles de Varigny, on coming to Sydney and seeing the ladies walking about the streets and apparently doing nothing, expressed much astonishment, adding, with a gesture of contempt, "and they have no smell!" It is by no means true, however, that Europeans are odorless. They are, indeed, considerably more odorous than are many other races,—for instance, the Japanese,—and there is doubtless some association between the greater hairiness of Europeans and their marked odor, since the sebaceous glands are part of the hair apparatus. A Japanese anthropologist, Adachi, has published an interesting study on the odor of Europeans,[31]which he describes as a strong and pungent smell,—sometimes sweet, sometimes bitter,—of varying strength in different individuals, absent in children and the aged, and having its chief focus in the armpits, which, however carefully they are washed, immediately become odorous again. Adachi has found that the sweat-glands are larger in Europeans than in the Japanese, among whom a strong personal odor is souncommon that "armpit stink" is a disqualification for the army. It is certainly true that the white races smell less strongly than most of the dark races, odor seeming to be correlated to some extent with intensity of pigmentation, as well as with hairiness; but even the most scrupulously clean Europeans all smell. This fact may not always be obvious to human nostrils, apart from intimate contact, but it is well known to dogs, to whom their masters are recognizable by smell. When Hue traveled in Tibet in Chinese disguise he was not detected by the natives, but the dogs recognized him as a foreigner by his smell and barked at him. Many Chinese can tell by smell when a European has been in a room.[32]There are, however, some Europeans who can recognize and distinguish their friends by smell. The case has been recorded of a man who with bandaged eyes could recognize his acquaintances, at the distance of several paces, the moment they entered the room. In another case a deaf and blind mute woman in Massachusetts knew all her acquaintances by smell, and could sort linen after it came from the wash by the odor alone. Governesses have been known to be able when blindfolded to recognize the ownership of their pupil's garments by smell; such a case is known to me. Such odor is usually described as being agreeable, but not one person in fifty, it is stated, is able to distinguish it with sufficient precision to use it as a method of recognition. Among some races, however this aptitude would appear to be better developed. Dr. C. S. Myers at Sarawak noted that his Malay boy sorted the clean linen according to the skin-odor of the wearer.[33]Chinese servants are said to do the same, as well as Australians and natives of Luzon.[34]

Although the distinctively individual odor of most persons is not sufficiently marked to be generally perceptible, there are cases in whichit is more distinct to all nostrils. The most famous case of this kind is that of Alexander the Great, who, according to Plutarch, exhaled so sweet an odor that his tunics were soaked with aromatic perfume (Convivalium Disputationum, lib. I, quest. 6). Malherbe, Cujas, and Haller are said to have diffused a musky odor. The agreeable odor of Walt Whitman has been remarked by Kennedy and others. The perfume exhaled by many holy men and women, so often noted by ancient writers (discussed by Görres in the second volume of hisChristliche Mystik) and which has entered into current phraseology as a merely metaphorical "odor of sanctity," was doubtless due, as Hammond first pointed out, to abnormal nervous conditions, for it is well known that such conditions affect the odor, and in insanity, for instance, the presence is noted of bodily odors which have sometimes even been considered of diagnostic importance. J. B. Friedreich,Allgemeine Diagnostik der Psychischen Krankheiten, second edition, 1832, pp. 9-10, quotes passages from various authors on this point, which he accepts; various writers of more recent date have made similar observations.The odor of sanctity was specially noted at death, and was doubtless confused with theodor mortis, which frequently precedes death and by some is regarded as an almost certain indication of its approach. In theBritish Medical Journal, for May and June, 1898, will be found letters from several correspondents substantiating this point. One of these correspondents (Dr. Tuckey, of Tywardwreath, Cornwall) mentions that he has in Cornwall often seen ravens flying over houses in which persons lay dying, evidently attracted by a characteristic odor.

The odor of sanctity was specially noted at death, and was doubtless confused with theodor mortis, which frequently precedes death and by some is regarded as an almost certain indication of its approach. In theBritish Medical Journal, for May and June, 1898, will be found letters from several correspondents substantiating this point. One of these correspondents (Dr. Tuckey, of Tywardwreath, Cornwall) mentions that he has in Cornwall often seen ravens flying over houses in which persons lay dying, evidently attracted by a characteristic odor.

It must be borne in mind, however, that, while every person has, to a sensitive nose, a distinguishing odor, we must regard that odor either as but one of the various sensations given off by the body, or else as a combination of two or more of these emanations. The body in reality gives off a number of different odors. The most important of these are: (1) the general skin odor, a faint, but agreeable, fragrance often to be detected on the skin even immediately after washing; (2) the smell of the hair and scalp; (3) the odor of the breath; (4) the odor of the armpit; (5) the odor of the feet; (6) the perineal odor; (7) in men the odor of the preputial smegma; (8) in women the odor of the mons veneris, that of vulvar smegma, that of vaginal mucus, and the menstrual odor. All these are odors which may usually be detected, though sometimes only in a very faint degree, in healthy and well-washedpersons under normal conditions. It is unnecessary here to take into account the special odors of various secretions and excretions.[35]

It is a significant fact, both as regards the ancestral sexual connections of the body odors and their actual sexual associations to-day, that, as Hippocrates long ago noted, it is not until puberty that they assume their adult characteristics. The infant, the adult, the aged person, each has his own kind of smell, and, as Monin remarks, it might be possible, within certain limits, to discover the age of a person by his odor. Jorg in 1832 pointed out that in girls the appearance of a specific smell of the excreta indicates the establishment of puberty, and Kaan, in hisPsychopathia Sexualis, remarked that at puberty "the sweat gives out a more acrid odor resembling musk." In both sexes puberty, adolescence, early manhood and womanhood are marked by a gradual development of the adult odor of skin and excreta, in general harmony with the secondary sexual development of hair and pigment. Venturi, indeed, has, not without reason, described the odor of the body as a secondary sexual character.[36]It may be added that, as is the case with the pigment in various parts of the body in women, some of these odors tend to become exaggerated in sympathy with sexual and other emotional states.

The odor of the infant is said to be of butyric acid; that of old people to resemble dry leaves. Continent young men have been said by many ancient writers to smell more strongly than the unchaste, and some writers have described as "seminal odor"—an odor resembling that of animals in heat, faintly recalling that of the he-goat, according to Venturi—the exhalations of the skin at such times.During sexual excitement, as women can testify, a man very frequently, if not normally, gives out an odor which, as usually described, proceeds from the skin, the breath, or both. Grimaldi states that it is as of rancid butter; others say it resembles chloroform. It is said to be sometimes perceptible for a distance of several feet and to last for several hours after coitus. (Various quotations are given by Gouldand Pyle,Anomalies and Curiosities of Medicine, section on "Human Odors," pp. 397-403.) St. Philip Neri is said to have been able to recognize a chaste man by smell.During menstruation girls and young women frequently give off an odor which is quite distinct from that of the menstrual fluid, and is specially marked in the breath, which may smell of chloroform or violets. Pouchet (confirmed by Raciborski,Traité de la Menstruation, 1868, p. 74) stated that about a day before the onset of menstruation a characteristic smell is exuded. Menstruating girls are also said sometimes to give off a smell of leather. Aubert, of Lyons (as quoted by Galopin), describes the odor of the skin of a woman during menstruation as an agreeable aromatic or acidulous perfume of chloroform character. By some this is described as emanating especially from the armpits. Sandras (quoted by Raciborski) knew a lady who could always tell by a sensation of faintness andmalaise—apparently due to a sensation of smell—when she was in contact with a menstruating woman. I am acquainted with a man, having strong olfactory sympathies and antipathies, who detects the presence of menstruation by smell. It is said that Hortense Baré, who accompanied her lover, the botanist Commerson, to the Pacific disguised as a man, was recognized by the natives as a woman by means of smell.Women, like men, frequently give out an odor during coitus or strong sexual excitement. This odor may be entirely different from that normally emanating from the woman, of an acid or hircine character, and sufficiently strong to remain in a room for a considerable period. Many of the ancient medical writers (as quoted by Schurigius,Parthenologia, p. 286) described the goaty smell produced by venery, especially in women; they regarded it as specially marked in harlots and in the newly married, and sometimes even considered it a certain sign of defloration. The case has been recorded of a woman who emitted a rose odor for two days after coitus (McBride, quoted by Kiernan in an interesting summary, "Odor in Pathology,"Doctor's Magazine, December, 1900). There was, it is said (Journal des Savans1684, p. 39, quoting from theJournal d'Angleterre) a monk in Prague who could recognize by smell the chastity of the women who approached him. (This monk, it is added, when he died, was composing a new science of odors.)Gustav Klein (as quoted by Adler,Die Mangelhafte Geschlechtsempfindungen des Weibes, p. 25) argues that the special function of the glands at the vulvar orifice—theglandulæ vestibulares majores—is to give out an odorous secretion to act as an attraction to the male, this relic of sexual periodicity no longer, however, playing an important part in the human species. The vulvar secretion, however, it may be added, still has a more aromatic odor than the vaginal secretion, with its simple mucous odor, very clearly perceived during parturition.It may be added that we still know extremely little concerning the sexual odors of women among primitive peoples. Ploss and Bartels are only able to bring forward (Das Weib, 1901, bd. 1, p. 218) a statement concerning the women of New Caledonia, who, according to Moncelon, when young and ardent, give out during coitus a powerful odor which no ablution will remove. In abnormal states of sexual excitement such odor may be persistent, and, according to an ancient observation, a nymphomaniac, whose periods of sexual excitement lasted all through the spring-time, at these periods always emitted a goatlike odor. It has been said (G. Tourdes, art. "Aphrodisie,"Dictionnaire Encyclopédique des Sciences Médicales) that the erotic temperament is characterized by a special odor.

During sexual excitement, as women can testify, a man very frequently, if not normally, gives out an odor which, as usually described, proceeds from the skin, the breath, or both. Grimaldi states that it is as of rancid butter; others say it resembles chloroform. It is said to be sometimes perceptible for a distance of several feet and to last for several hours after coitus. (Various quotations are given by Gouldand Pyle,Anomalies and Curiosities of Medicine, section on "Human Odors," pp. 397-403.) St. Philip Neri is said to have been able to recognize a chaste man by smell.

During menstruation girls and young women frequently give off an odor which is quite distinct from that of the menstrual fluid, and is specially marked in the breath, which may smell of chloroform or violets. Pouchet (confirmed by Raciborski,Traité de la Menstruation, 1868, p. 74) stated that about a day before the onset of menstruation a characteristic smell is exuded. Menstruating girls are also said sometimes to give off a smell of leather. Aubert, of Lyons (as quoted by Galopin), describes the odor of the skin of a woman during menstruation as an agreeable aromatic or acidulous perfume of chloroform character. By some this is described as emanating especially from the armpits. Sandras (quoted by Raciborski) knew a lady who could always tell by a sensation of faintness andmalaise—apparently due to a sensation of smell—when she was in contact with a menstruating woman. I am acquainted with a man, having strong olfactory sympathies and antipathies, who detects the presence of menstruation by smell. It is said that Hortense Baré, who accompanied her lover, the botanist Commerson, to the Pacific disguised as a man, was recognized by the natives as a woman by means of smell.

Women, like men, frequently give out an odor during coitus or strong sexual excitement. This odor may be entirely different from that normally emanating from the woman, of an acid or hircine character, and sufficiently strong to remain in a room for a considerable period. Many of the ancient medical writers (as quoted by Schurigius,Parthenologia, p. 286) described the goaty smell produced by venery, especially in women; they regarded it as specially marked in harlots and in the newly married, and sometimes even considered it a certain sign of defloration. The case has been recorded of a woman who emitted a rose odor for two days after coitus (McBride, quoted by Kiernan in an interesting summary, "Odor in Pathology,"Doctor's Magazine, December, 1900). There was, it is said (Journal des Savans1684, p. 39, quoting from theJournal d'Angleterre) a monk in Prague who could recognize by smell the chastity of the women who approached him. (This monk, it is added, when he died, was composing a new science of odors.)

Gustav Klein (as quoted by Adler,Die Mangelhafte Geschlechtsempfindungen des Weibes, p. 25) argues that the special function of the glands at the vulvar orifice—theglandulæ vestibulares majores—is to give out an odorous secretion to act as an attraction to the male, this relic of sexual periodicity no longer, however, playing an important part in the human species. The vulvar secretion, however, it may be added, still has a more aromatic odor than the vaginal secretion, with its simple mucous odor, very clearly perceived during parturition.

It may be added that we still know extremely little concerning the sexual odors of women among primitive peoples. Ploss and Bartels are only able to bring forward (Das Weib, 1901, bd. 1, p. 218) a statement concerning the women of New Caledonia, who, according to Moncelon, when young and ardent, give out during coitus a powerful odor which no ablution will remove. In abnormal states of sexual excitement such odor may be persistent, and, according to an ancient observation, a nymphomaniac, whose periods of sexual excitement lasted all through the spring-time, at these periods always emitted a goatlike odor. It has been said (G. Tourdes, art. "Aphrodisie,"Dictionnaire Encyclopédique des Sciences Médicales) that the erotic temperament is characterized by a special odor.

If the body odors tend to develop at puberty, to be maintained during sexual life, especially in sympathy with conditions of sexual disturbance, and to become diminished in old age, being thus a kind of secondary sexual character, we should expect them to be less marked in those cases in which the primary sexual characters are less marked. It is possible that this is actually the case. Hagen, in hisSexuelle Osphrésiologie, quotes from Roubaud'sTraité de l'Impuissancethe statement that the body odor of the castrated differs from that of normal individuals. Burdach had previously stated that the odor of the eunuch is less marked than that of the normal man.

It is thus possible that defective sexual development tends to be associated with corresponding olfactory defect. Heschl[37]has reported a case in which absence of both olfactory nerves coincided with defective development of the sexual organs. Féré remarks that the impotent show a repugnance for sexual odors. Dr. Kiernan informs me that in women after oöphorectomy he has noted a tendency to diminished (and occasionally increased) sense of smell. These questions, however, await more careful and extended observation.

A very significant transition from the phenomena of personal odor to those of sexual attraction by personal odor is to be found in the fact that among the peoples inhabiting a large part of the world's surface the ordinary salutation between friends is by mutual smelling of the person. In some form oranother the method of salutation by applying the nose to the nose, face, or hand of a friend in greeting is found throughout a large part of the Pacific, among the Papuans, the Eskimo, the hill tribes of India, in Africa, and elsewhere.[38]Thus, among a certain hill tribe in India, according to Lewin, they smell a friend's cheek: "in their language, they do not say, 'Give me a kiss,' but they say 'Smell me.'" And on the Gambia, according to F. Moore, "When the men salute the women, they, instead of shaking their hands, put it up to their noses, and smell twice to the back of it." Here we have very clearly a recognition of the emotional value of personal odor widely prevailing throughout the world. The salutation on an olfactory basis may, indeed, be said to be more general than the salutation on a tactile basis on which European handshaking rests, each form involving one of the two most intimate and emotional senses. The kiss may be said to be a development proceeding both from the olfactory and the tactile bases, with perhaps some other elements as well, and is too complex to be regarded as a phenomenon of either purely tactile or purely olfactory origin.[39]

As the sole factor in sexual selection olfaction must be rare. It is said that Asiatic princes have sometimes caused a number of the ladies to race in the seraglio garden until they were heated; their garments have then been brought to the prince, who has selected one of them solely by the odor.[40]There was here a sexual selection mainly by odor. Any exclusive efficacy of the olfactory sense is rare, not so much because the impressions of this sense are inoperative, but because agreeable personal odors are not sufficiently powerful, and the olfactory organ is too obtuse, to enable smell to take precedence of sight. Nevertheless, in many people, it is probable that certain odors, especially those that are correlated with a healthy and sexually desirable person, tend to be agreeable; they are fortified bytheir association with the loved person, sometimes to an irresistible degree; and their potency is doubtless increased by the fact, to which reference has already been made, that many odors, including some bodily odors, are nervous stimulants.

It is possible that the sexual associations of odors have been still further fortified by a tendency to correlation between a high development of the olfactory organ and a high development of the sexual apparatus. An association between a large nose and a large male organ is a very ancient observation and has been verified occasionally in recent times. There is normally at puberty a great increase in the septum of the nose, and it is quite conceivable, in view of the sympathy, which, as we shall see, certainly exists between the olfactory and sexual region, that the two regions may develop together under a common influence.

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