Studies in the Psychology of Sex Volume Iv Part 3

The sense of touch is so universally diffused over the whole skin, and in so many various degrees and modifications, and it is, moreover, so truly the Alpha and the Omega of affection, that a broken and fragmentary treatment of the subject has been inevitable.

The skin is the archaeological field of human and prehuman experience, the foundation on which all forms of sensory perception have grown up, and as s.e.xual sensibility is among the most ancient of all forms of sensibility, the s.e.xual instinct is necessarily, in the main, a comparatively slightly modified form of general touch sensibility. This primitive character of the great region of tactile sensation, its vagueness and diffusion, the comparatively unintellectual as well as unaesthetic nature of the mental conceptions which arise on the tactile basis make it difficult to deal precisely with the psychology of touch. The very same qualities, however, serve greatly to heighten the emotional intensity of skin sensations. So that, of all the great sensory fields, the field of touch is at once the least intellectual and the most ma.s.sively emotional. These qualities, as well as its intimate and primitive a.s.sociation with the apparatus of tumescence and detumescence, make touch the readiest and most powerful channel by which the s.e.xual sphere may be reached.

In disentangling the phenomena of tactile sensibility ticklishness has been selected for special consideration as a kind of sensation, founded on reflexes developing even before birth, which is very closely related to s.e.xual phenomena. It is, as it were, a play of tumescence, on which laughter supervenes as a play of detumescence. It leads on to the more serious phenomena of tumescence, and it tends to die out after adolescence, at the period during which s.e.xual relationships normally begin. Such a view of ticklishness, as a kind of modesty of the skin, existing merely to be destroyed, need only be regarded as one of its aspects. Ticklishness certainly arose from a non-s.e.xual starting-point, and may well have protective uses in the young animal.

The readiness with which tactile sensibility takes on a s.e.xual character and forms reflex channels of communication with the s.e.xual sphere proper is ill.u.s.trated by the existence of certain secondary s.e.xual foci only inferior in s.e.xual excitability to the genital region. We have seen that the chief of these normal foci are situated in the orificial regions where skin and mucous membrane meet, and that the contact of any two orificial regions between two persons of different s.e.x brought together under favorable conditions is apt, when prolonged, to produce a very intense degree of s.e.xual erethism. This is a normal phenomenon in so far as it is a part of tumescence, and not a method of obtaining detumescence. The kiss is a typical example of these contacts, while the nipple is of special interest in this connection, because we are thereby enabled to bring the psychology of lactation into intimate relationship with the psychology of s.e.xual love.

The extreme sensitiveness of the skin, the readiness with which its stimulation reverberates into the s.e.xual sphere, clearly brought out by the present study, enable us to understand better a very ancient contest-the moral struggle around the bath. There has always been a tendency for the extreme cultivation of physical purity to lead on to the excessive stimulation of the s.e.xual sphere; so that the Christian ascetics were entirely justified, on their premises, in fighting against the bath and in directly or indirectly fostering a cult of physical uncleanliness. While, however, in the past there has clearly been a general tendency for the cult of physical purity to be a.s.sociated with moral licentiousness, and there are sufficient grounds for such an a.s.sociation, it is important to remember that it is not an inevitable and fatal a.s.sociation; a scrupulously clean person is by no means necessarily impelled to licentiousness; a physically unclean person is by no means necessarily morally pure. When we have eliminated certain forms of the bath which must be regarded as luxuries rather than hygienic necessities, though they occasionally possess therapeutic virtues, we have eliminated the most violent appeals of the bath to the s.e.xual impulse. So imperative are the demands of physical purity now becoming, in general opinion, that such small risks to moral purity as may still remain are constantly and wisely disregarded, and the immoral traditions of the bath now, for the most part, belong to the past.

SMELL.

I.

The Primitiveness of Smell-The Anatomical Seat of the Olfactory Centres-Predominance of Smell among the Lower Mammals-Its Diminished Importance in Man-The Attention Paid to Odors by Savages.

The first more highly organized sense to arise on the diffused tactile sensitivity of the skin is, in most cases, without doubt that of smell. At first, indeed, olfactory sensibility is not clearly differentiated from general tactile sensibility; the pit of thickened and ciliated epithelium or the highly mobile antennae which in many lower animals are sensitive to odorous stimuli are also extremely sensitive to tactile stimuli; this is, for instance, the case with the snail, in whom at the same time olfactive sensibility seems to be spread over the whole body.[24] The sense of smell is gradually specialized, and when taste also begins to develop a kind of chemical sense is const.i.tuted. The organ of smell, however, speedily begins to rise in importance as we ascend the zoological scale. In the lower vertebrates, when they began to adopt a life on dry land, the sense of smell seems to have been that part of their sensory equipment which proved most useful under the new conditions, and it developed with astonishing rapidity. Edinger finds that in the brain of reptiles the "area olfactoria" is of enormous extent, covering, indeed, the greater part of the cortex, though it may be quite true, as Herrick remarks, that, while smell is preponderant, it is perhaps not correct to attribute an exclusively olfactory tone to the cerebral activities of the Sauropsida or even the Ichthyopsida. Among most mammals, however, in any case, smell is certainly the most highly developed of the senses; it gives the first information of remote objects that concern them; it gives the most precise information concerning the near objects that concern them; it is the sense in terms of which most of their mental operations must be conducted and their emotional impulses reach consciousness. Among the apes it has greatly lost importance and in man it has become almost rudimentary, giving place to the supremacy of vision.

Prof. G. Elliot Smith, a leading authority on the brain, has well summarized the facts concerning the predominance of the olfactory region in the mammal brain, and his conclusions may be quoted. It should be premised that Elliot Smith divides the brain into rhinencephalon and neopallium. Rhinencephalon designates the regions which are pre-eminently olfactory in function: the olfactory bulb, its peduncle, the tuberculum olfactorium and locus perforatus, the pyriform lobe, the paraterminal body, and the whole hippocampal formation. The neopallium is the dorsal cap of the brain, with frontal, parietal, and occipital areas, comprehending all that part of the brain which is the seat of the higher a.s.sociative activities, reaching its fullest development in man.

"In the early mammals the olfactory areas form by far the greater part of the cerebral hemisphere, which is not surprising when it is recalled that the forebrain is, in the primitive brain, essentially an appendage, so to speak, of the smell apparatus. When the cerebral hemisphere comes to occupy such a dominant position in the brain it is perhaps not unnatural to find that the sense of smell is the most influential and the chief source of information to the animal; or, perhaps, it would be more accurate to say that the olfactory sense, which conveys general information to the animal such as no other sense can bring concerning its prey (whether near or far, hidden or exposed), is much the most serviceable of all the avenues of information to the lowly mammal leading a terrestrial life, and therefore becomes predominant; and its particular domain-the forebrain-becomes the ruling portion of the nervous system.

"This early predominance of the sense of smell persists in most mammals (unless an aquatic mode of life interferes and deposes it: compare the Cetacea, Sirenia, and Pinnipedia, for example) even though a large neopallium develops to receive visual, auditory, tactile, and other impressions pouring into the forebrain. In the Anthropoidea alone of nonaquatic mammals the olfactory regions undergo an absolute (and not only relative, as in the Carnivora and Ungulata) dwindling, which is equally shared by the human brain, in common with those of the other Simiidae, the Cercopithecidae, and the Cebidae. But all the parts of the rhinencephalon, which are so distinct in macrosmatic mammals, can also be recognized in the human brain. The small ellipsoidal olfactory bulb is moored, so to speak, on the cribriform plate of the ethmoid bone by the olfactory nerves; so that, as the place of attachment of the olfactory peduncle to the expanding cerebral hemisphere becomes removed (as a result of the forward extension of the hemisphere) progressively farther and farther backward, the peduncle becomes greatly stretched and elongated. And, as this stretching involves the gray matter without lessening the number of nerve-fibres in the olfactory tract, the peduncle becomes practically what it is usually called-i.e., the olfactory 'tract.' The tuberculum olfactorium becomes greatly reduced and at the same time flattened; so that it is not easy to draw a line of demarcation between it and the anterior perforated s.p.a.ce. The anterior rhinal fissure, which is present in the early human ftus, vanishes (almost, if not altogether) in the adult. Part of the posterior rhinal fissure is always present in the 'incisura temporalis,' and sometimes, especially in some of the non-European races, the whole of the posterior rhinal fissure is retained in that typical form which we find in the anthropoid apes." (G. Elliot Smith, in Descriptive and Ill.u.s.trated Catalogue of the Physiological Series of Comparative Anatomy Contained in the Museum of the Royal College of Surgeons of England, second edition, vol. ii.) A full statement of Elliot Smith's investigations, with diagrams, is given by Bullen, Journal of Mental Science, July, 1899. It may be added that the whole subject of the olfactory centres has been thoroughly studied by Elliot Smith, as well as by Edinger, Mayer, and C. L. Herrick. In the Journal of Comparative Neurology, edited by the last named, numerous discussions and summaries bearing on the subject will be found from 1896 onward. Regarding the primitive sense-organs of smell in the various invertebrate groups some information will be found in A. B. Griffiths's Physiology of the Invertebrata, Chapter XI.

The predominance of the olfactory area in the nervous system of the vertebrates generally has inevitably involved intimate psychic a.s.sociations between olfactory stimuli and the s.e.xual impulse. For most mammals not only are all s.e.xual a.s.sociations mainly olfactory, but the impressions received by this sense suffice to dominate all others. An animal not only receives adequate s.e.xual excitement from olfactory stimuli, but those stimuli often suffice to counterbalance all the evidence of the other senses.

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 b.i.t.c.h, but was always in the society of its father, once met the latter directly after the elder dog had been with a b.i.t.c.h. He immediately endeavored to behave toward the elder dog, in spite of angry repulses, exactly as a dog behaves toward a b.i.t.c.h in heat. The messages received by the sense of smell were sufficiently urgent not only to set the s.e.xual 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's Psychologie des Geruches, 1894, Chapter XI, Pa.s.sy (in the appendix to his memoir on olfaction, L'Annee 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 s.e.xual life of many insects. Thus, Fere has found that in c.o.c.kchafers s.e.xual coupling failed to take place when the antennae, which are the organs of smell, were removed; he also found that males, after they had coupled with females, proved s.e.xually attractive to other males (Comptes Rendus de la Societe de Biologie, May 21, 1898). Fere similarly found that, in a species of Bombyx, 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. Pa.s.sy 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 gla.s.s," and, though we can scarcely accept this statement absolutely,-especially in view 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 Inst.i.tute, 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 Societe d'Anthropologie, November 6, 1879), only like the smells of meat and fish which are becoming "high," like popoya, which smells of fowl manure, and kava, 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 careful attention 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 asaftida, valerianic acid, and civet, the last being regarded as most repulsive of all on account of its resemblance to faecal 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 the taramea (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-pointed taramea."

In the summer season the sleeping houses of Maori chiefs were often strewed with a large, sweet-scented, flowering gra.s.s of powerful odor. (W. Colenso, Transactions of the New Zealand Inst.i.tute, vol. xxiv, reprinted in Nature, 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, Friedlander states (Zeitschrift fur 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 Inst.i.tute, 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 pa.s.sport 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 smokes udi, the perfumed wood of the aloe; "every man is glad when his wife smells of udi" (Velten, Sitten und Gebrauche 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 a.n.a.lysis; see Pa.s.sy, L'Annee Psychologique, second year, 1895, p. 380.

II.

Rise of the Study of Olfaction-Cloquet-Zwaardemaker-The Theory of Smell-The Cla.s.sification 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 a.s.sumed 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 his Osphresiologie, ou Traite 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 Layc.o.c.k, who was a pioneer in so many by-paths of psychology and anthropology, showed a special interest in the olfactory sense, and frequently touched on it in his Nervous Diseases of Women and 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 work Die Physiologie des Geruchs have served to give the physiology of the sense of smell an a.s.sured 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 a.s.sured 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 Pa.s.sy, it is the least precise), the difficulty of cla.s.sifying 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 a.n.a.logous 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 a.n.a.logy with light and sound. Haycraft (Proceedings of the Royal Society of Edinburgh, 1883-87, and Brain, 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, a.n.a.logous to light-rays, Rontgen 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'Annee Psychologique, 1898), "that aroma is a physico-chemical attribute of the molecules"; he points out that there is an intimate a.n.a.logy between color and odor, and remarks that this a.n.a.logy 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 cla.s.sification of smells, notwithstanding various ambitious attempts to reach a cla.s.sification. The cla.s.sification adopted by Zwaardemaker is founded on the ancient scheme of Linnaeus, 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 (asaftida, ichthyol, etc.).

VI. Empyreumatic odors.

VII. Valerianaceous odors (Linnaeus's Odores hircini, the capryl group, largely composed of s.e.xual odors).

VIII. Narcotic odors (Linnaeus's Odores tetri).

IX. Stenches.

A valuable and interesting memoir, "Revue Generale sur les Sensations Olfactives," by J. Pa.s.sy, the chief French authority on this subject, will be found in the second volume of L'Annee 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 "Actualites Medicales" series by Dr. Collet, L'Odorat et ses Troubles, 1904. In a little book ent.i.tled Wegweiser 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 ma.s.s 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. aesthetically, 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 ma.s.s of what we may call by-sensations, which are of little practical use, but inevitably become intimately mixed with the experiences of life by a.s.sociation 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 the most 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 a.s.sociations. The very same odor may be at one moment highly pleasant, at the next moment highly unpleasant, in accordance with the emotional att.i.tude resulting from its a.s.sociations. 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 inst.i.tute 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 a.s.sociational 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 att.i.tude. 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 sanct.i.ty that exhales from the bodies of holy persons, especially at the moment of death. Under the conditions of civilization these primitive emotional a.s.sociations 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 (in Emile, 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 asaftida as a seasoning, while valerian was accounted a perfume in antiquity. (Cloquet, Osphresiologie, 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 a.s.sociations, 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, Pa.s.sy 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'Annee 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; Pa.s.sy (L'Annee 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 Memoire Affective, son Importance Theorique et Pratique," Revue Philosophique, February, 1901; also Paulhan, "Sur la Memoire 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; 48 per 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 gra.s.s, etc. Pieron (Revue Philosophique, December, 1902) has described the special power possessed by vague odors, in his own case, of evoking ancient impressions.