subjects all experienced a disagreeable laryngeal sensation, "the smell catches the throat," a sensation which occurs when amyl acetate is vigorously inhaled either via the nose or by the mouth. Hence the unpleasant affect in these cases, which cannot be regarded as being abnormal, and, in cases pleasantly affected also affording a reason for the occasional association of the "smell " of amyl acetate with that of benzole, which is liable to cause a similar laryngeal reflex and sensation.

It will be noted that subjects 7 and 59, display an unusual liking for amyl alcohol, asafoetida, sandalwood oil and ferric valerian, a combination of unusual reactions which does not occur in any of the other subjects, although, especially in cases of nasal catarrh (absent in 7 and 59), unpleasant odors may appear faint enough

not to be unpleasant. These two subjects had one factor in common which may be tentatively put forward as an explanation, they were both red-green color blind. Subject No. 51 is red-green color-weak, and No. 21 blue-green slightly weak.

The olfactory mucus membrane, like the retina, is pigmented, and it has been observed on the one hand, that albinos are unable to distinguish smells and may be altogether anosmic, and on the other that animals with a darkly pigmented olfactory mucus membrane (e.g. the dog) have a keen sense of smell. In addition, there are the vibrations of light and the molecular vibrations of odorous molecules (according to Heyninx), the sensations in both cases depending on wave-lengths. It is not unreasonable to put forward the hypothesis, which requires new physiological, histological, and chemical research, that abnormalities in the pigmentation are correlated with each other and with abnormalities of sensation. Abnormalities of sensation, again, may and often do cause unusual affective reactions.

A somewhat more evident cause for unusual reactions and fluctuations of the affect is afforded by catarrhal conditions of the nose and nasopharynx. Subjects 12g, 13, 23a, 34b, 43b, and 54a, were suffering from a cold at the time of the experiment. Their affective reactions are shown in Table I.

Nasal conditions are closely related to sexual metabolism, and many of the affective fluctuations recorded in these experiments are due to this correlation. It was not expedient to obtain data with regard to catamenial phenomena, except in one case. The latter a week before judged musk to be +, when "not feeling well" the affect was + and a week after, again —+. The affect due to ferric valerian was found to be then +

and again on the same dates. Similar fluctuations were observed in subjects complaining of a very slight cold (catamenial engorgement of nasal mucosa) or headache. Smoking does not appear to have any noticeable influence on the affective reactions given.

Subjects Nos. 9 and 53 were not in very good health, and both had rather a dislike to odors in general, the former subject in

addition being responsible for an excessive number of egocentric associative reactions.

The deviations from the mean affect observed in the case of reactions to rose oil provided an interesting example of deviation due to association. The affect is so uniformly entirely pleasant that even a + reaction seemed abnormal, and a + reaction was the occasion for some surprise. The scent of rose oil recalled in subject No. 1 the smell of burning and a serious motor car accident in which the subject had received an injury causing atrophy of the optic nerve of the left eye. The content of this associative reaction was extremely large and recalled the accident which had occurred nine years previously with such vividness and intensity, that the rose affect was completely swamped. There had been a garden with roses in full bloom by the scene of the accident, as the subject remembered on introspection, but not before. It was thought at first that the accident had caused a parosmia; however, this was not the case.

Of the other exceptional reactions to rose oil, some were due to associative, others to constitutional conditions. Subject 11 had an idiosyncrasy against sweets, and both oil and vanillin. were voted + instead of ++ as being too sweet. Subject 13 was suffering from a cold as was 20. Subject 53 has already been mentioned as being in indifferent health and regarded the odor as nauseating. No definite reason could be assigned to explain the reaction of 47 and 50.

Musk is the most puzzling of all the odors in the series of experiments, because both metabolic conditions and associations of an emotional nature contribute to make the affective reaction somewhat more complex than the reaction to other osmyls in the series. In one subject musk produced a violent aversive reflex and an "egocentric" "horrid ”—a not infrequent occurrence with such osmyls as asafoetida or carbon bisulphide—while in another the first sniff caused a laugh reaction which accompanied or perhaps preceded the recollection of an exceptionally happy scene of "auld lang syne." Laugh reflexes to pleasant scents are more usual in children, adults merely smile, sometimes. In yet another subject

musk was considered pleasant and an entirely unpleasant scene was recalled.

All the experiments tend to show that an increasing knowledge of mean affects to a wide range of odors, and of olfactory syndromes, in health and disease, will provide many data of diagnostic value. The question particularly of the relation between odor preferences and state of physical and mental health, requires further elucidation.

VI. TYPES OF SMELL ASSOCIATIONS

In the course of the experiments the possibility of utilizing mental reactions to odors in psychotherapeutics become a matter of attention. The affective reactions demonstrated the possibility of inducing different " moods," the odor of rose oil being soothing, tranquillizing, causing a sense of well being in most of the subjects; musk, a veritable chameleon of odors, sometimes pleasing, sometimes irritating, at other times causing a reflective mood; the tang of pine oil bracing and friendly; ferric valerian uncomfortable; vanillin "drowsy." H est," sings Baudelaire,—

"Il est des parfums frais comme des chairs d'enfants,
Doux comme le hautbois, verts comme les prairies;
Et d'autres, corrompus, riches et triomphants,

Ayant l'expression des choses infinies,

Comme l'ambre, le musc, le benjoin et l'encens,

Qui chantent les transports de l'esprit et des sens."

Induced "frames of mind" have their value in the treatment of certain neuroses, and odors carefully selected to produce a required "mood" would be quite as effective, perhaps more so, than the analogous color therapy.

The other application the experiments tend to point out is to deliberately utilize odorous stimuli in order to recall "forgotten incidents, or to obtain an insight into a patient's mentality. Only a small number of the innumerable olfactory stimuli inspired with every breath, cause a reaction of which the individual is aware at the time; however, that a rection has been caused is demonstrable by applying identical or similar stimuli later, when the conditions prevailing formerly are reproduced, and the circumstance may more or less fully become the content of an image, often, but not invariably, of a visual character.

In 1922, one of the subjects was given some camphor to smell. He immediately felt mentally distressed and visualized at first, the door of a wardrobe, then the entire wardrobe, then the emotion of fear at being suffocated or being in the dark, remembered kicking and hammering at the door to be let out. It was as if