are highly complex, and their structural form must be very different
from that of water.
The question, then, now before us is: Does odour bear any relationship
to the molecular structure of bodies? And again it has been maintained
that a clue to the problem of the real nature of odour lies here.
There is a well-known series of chemical bodies known as the
“aromatics,” by reason of the fact that they possess strong smells more
or less similar in quality. With regard to this series, which is made up
of groups of what are known as radicles which occupy definite positions
on a molecule shaped like a ring—the benzene ring, as it is
called—Henning, a German observer, has expressed the opinion that the
odour depends, not upon the radicles as such, but upon the position they
occupy on the ring.
Transferring his argument to odorous bodies in general, and taking six
groups as embracing all (spicy, flowery, fruity, resinous, burnt, and
foul), he associates each of these types with some feature in the
constitution of the molecule which is common to all the members of each
group.
To enter more fully into this branch of the subject would carry us too
deeply into chemistry. I shall content myself therefore with saying that
Henning’s views have received considerable support from scientific
chemists and have led to several interesting and suggestive
developments.
Heyninx, however, criticising this theory, points out that hydrocyanic
(or prussic) acid and nitrobenzol, two substances with the same smell,
have each a molecular structure in no way resembling the other.
The graphic formulæ of these bodies, which I give here, plainly show the
difference between them:
H—C≡N (hydrocyanic acid) and
H
C
HC C—NO_{2}
| ||
HC CH (nitrobenzol).
\ /
C
H
(T. H. Fairbrother, to whom I am indebted for much information on the
chemistry of olfaction, would dispose of this criticism of Hcyninx’s by
denying that the odours of those two substances are identical. See
later, p. 132.)
Chemistry, then, having, according to the critics, failed us, we turn to
the allied science of physics. Physics deals with matter in its ultimate
state, beginning, so to speak, where chemistry, with its work of changes
and combinations, ceases, and taking us deep into the heart of matter
independent of its chemical properties and behaviour.
We have seen that, chemically speaking, elements and their compounds
exist as molecules made up of atoms. Now molecules may be minute, and
atoms even more minute, but in “electrons,” the name given to the last
divisible particle of matter known to the physicist, we are dealing with
minuteness inconceivable. Sir Oliver Lodge has said that if an atom
could be expanded to fill a space equal to that of the entire solar
system, the electrons composing it would each be the size of an orange!
There is supposed, indeed, to be an atomic “system” composed of a
central nucleus like the sun, with electrons revolving round it, the
nucleus having a positive, and the revolving particles a negative,
electric charge. Further (whether in virtue of these moving electrons or
otherwise is not quite clear), the molecule is supposed to be in a state
of constant vibration.
The physical theory of odour, then, refers that quality to the vibration
of the molecule. It suggests that the molecules of an odorous body
passing in the gaseous or, in fishes, the liquid state into the
olfactory region of the nose, are there received by the film of mucus in
which the olfactory hairs lie, and stimulate these hairs by their
molecular vibration. No chemical change is supposed to take place, only,
as it were, a mechanical stimulation, comparable to the mechanical
stimulation of the retina by the waves of light.
A recent development of the theory which we owe to Heyninx, a Belgian
scientist, brings the process very closely into harmony with what occurs
in the eye. According to this authority, olfaction is in reality a
perception of ethereal undulations of the same character as the
undulations of light, these undulations being provoked by the
intra-molecular vibrations of the odorous vapour in the nasal mucus and
transmitted to the olfactory hairs not by immediate contact, but through
the medium of the ether.
We owe this last suggestion to the curious fact, but recently
discovered, that many odorous substances (in their gaseous form in the
air) absorb the rays of ultra-violet light.
In order to make clear what this means, we must say a preliminary word
regarding the spectrum and spectrum analysis.
The passage of a beam of white light through a glass prism breaks it up
into its component parts, beginning with red, then orange, yellow,
green, blue, and ending with violet. Beyond the violet end of the
spectrum we know there are rays invisible to us, but capable of acting
on a photographic plate. These are called the ultra-violet rays.
In like manner, beyond the red end of the spectrum we know there are
also rays, likewise invisible to us, but perceptible by our tactile
sense as heat. These are called the infra-red rays.
Now, the rate of vibration of all these different rays, visible and
invisible, has been estimated, and they increase in frequency from the
infra-red, which are the slowest, to the ultra-violet, which are the
most rapid.
As we have already said, it has recently been shown that the odorous
vapours absorb certain ultra-violet rays. That is to say, when the beam
of light is directed through a chamber containing the odorous vapour
before entering the prism, what are known as absorption-bands—vertical
black lines in the white—appear in the photograph of the spectrum.
Similar lines are seen, as a matter of fact, in the visible spectrum of
sunlight, and as these correspond in position with the spectrum given by
chemical elements in an incandescent gaseous state, it is supposed that
they are produced by the absorption of the corresponding light-rays by
these gases in the solar atmosphere.
The physical explanation given of this phenomenon is that the molecules
of the gas in the sun absorb such light-rays as are equal in rate of
vibration to the rate of their own vibrating molecule.
In the same way, Heyninx and others argue that the odorous vapour is
composed of molecules which are vibrating with a period equal to that of
the light-rays they absorb.
Moreover, since the position of the absorption-band in the photograph
varies, lying in some cases nearer to the visible violet and in others
further away from it, and since this position varies with the particular
fundamental odour employed, it is suggested that not only do the
molecules vibrate with a period equal to that of the ultra-violet rays
they absorb, but as this vibration varies in rate, so it is to this
variation that we must ascribe the differences in odours. This is
analogous, of course, to the appreciation of colour by the eye. One
odorous molecule, that is to say, like the colour red, having a slower
rate of vibration, will give rise to one kind of smell; another, like
the colour yellow, with a more rapid rate, will give rise to another
kind of smell, and so on for all the fundamental odours. Heyninx,
indeed, goes so far as to fix the position in the olfactory gamut of all
fundamental odours, and to base upon it the classification we have
already considered.
It is supposed, that is to say, that the vibrations of the odorous
molecule set up undulations in the ether, and that it is those ethereal
undulations that stimulate the olfactory hairs, just as ethereal
undulations emanating from a luminous source stimulate the retina.
There is one great difference, however, between light and odour, a
difference admitted, we may mention, by the supporters of the undulatory
theory, but not emphasised by them. The difference is this: in the case
of visible light the ethereal undulations emanate from a source at a
distance (it may be like starlight at an enormous distance) from the
sensory end-organ, whereas in the case of odour the undulation is
supposed to be generated by the odorous molecule in close proximity to
the end-organ.
The theory makes no attempt to explain how the olfactory hairs respond
to these hypothetical ethereal waves.
Finally, we have the question of the olfactory pigment to consider, and
in this matter we cannot do better than follow the exposition of William
Ogle, an English physician who wrote as long ago as 1870. As will be
seen, he forestalls the modern undulatory theory of olfaction in a
remarkable manner.
Ogle contends that the presence of pigment must be of great importance
in the function for the following reasons:
First, the epithelium of the olfactory region is pigmented, while that
of the rest of the nasal chamber and sinuses is devoid of colouring
matter.
Secondly, there seems to be some correspondence between the degree of
pigmentation and the acuteness of smell, as the following facts
suggest:—
In macrosmatic animals, such as the dog, cat, fox, sheep, and rabbit,
pigmentation extends over a larger space and is darker in tint than in
man. In these animals also the mucus covering the olfactory area of the
nose is itself pigmented.
We have seen that human albinos are anosmic, and the same is probably
true of animal albinos. But care is necessary in making observations on
suspected albinos in animals, as even when they are altogether white a
certain amount of black pigment remains about the face and nose.
The following reports, however, would lead us to conclude that as with
man, so with the animals, a relative deficiency of pigment is associated
with a dull olfactory sense.
It is by smell that the herbivora detect and avoid plants which are
poisonous, and when poisoning does occur, it is usually a white animal
that suffers. In some parts of Virginia the farmers will only rear black
pigs, because, they say, the white ones eat and are poisoned by the
roots of _Lachtanthus tinctoria_. For the same reason in the Tarentino
only black sheep are reared.
Thirdly, the dark-skinned human races have a keener sense of smell than
the lighter races.
Fourthly, the sense grows more acute as we get older, as we have already
seen, and nasal pigmentation, it is said, also increases with age.
As to the function of the olfactory pigment, Ogle remarks first of all
that odours are absorbed more readily by dark than by light materials.
Pigment is also present in the labyrinth of the ear as well as in the
eye, and its presence in these organs seems to be essential to their
activity.
It is to be noted that the pigment does not occur on the nerve structure
in any of those end-organs, but external, though contiguous to it. In
the eye, it lies in contact with the rods and cones of the retina; in
the nose, with the olfactory hairs; in the ear, with the terminal bodies
of the auditory nerve.
Hence the pigment, he supposes, must be associated with the reception of
the sensory impressions.
In the eye and the ear those impressions are undulatory in character.
That being so, he holds that the undulatory theory of olfaction also is
probably the correct one.
Ogle finishes with the remark that the theory would be strengthened if
it could be shown that pigment was specially suited for the absorption
and modification of undulations.
It is interesting to us to learn that claims are now being made that
pigment does possess the power necessitated by Ogle’s theory. At all
events, there is a theory of vision (Castelli’s) which claims for the
ocular pigment the power of absorbing and modifying light waves, and
Heyninx holds that the olfactory pigment possesses a similar property.
Summing the whole matter up, then, we may say that the undulatory theory
of olfaction is, that an odorivector gives off in the form of vapour (in
the aerial medium) extremely attenuated portions of its substance, too
minute to be weighed, and that this vapour, disseminated through the
air, enters the nose in respiration, and, being wafted up into the
olfactory region, is received by the mucus bathing the olfactory hairs,
where, in virtue of the ultra-violet radiations which proceed from its
molecules and are modified by the olfactory pigment, it acts on the
hairs, setting up changes (it may be also undulatory in nature) in them
and in their cells, which changes are transmitted thence by the
olfactory nerves to the neurones or nerve-cells of the olfactory bulb
(or lobe) of the brain.
The undulatory theory of olfaction, then, as will be evident to the
reader, has a good deal in its favour. And in addition to what we have
already said of it as accounting for the absorption by odorous vapours
of ultra-violet rays, and as giving a hint regarding the function of
pigment in the olfactory area, there are also a number of other
phenomena which it seems to explain. We have seen, for example, how one
odorivector, such as musk or civet, may have the property of enhancing
the power of another, and this is a property which is characteristic
also of certain luminous conditions (fluorescence, lumino-luminescence).
Again, there is a harmony existing between certain of the manufacturers’
primitive odours; “they go well together,” and are employed for that
reason in the art of perfumery. This resembles the harmony existing in
another class of undulations, the sound waves.
On the other hand, just as one sound may silence another by the clashing
of their waves, so one odour may “kill” or neutralise another odour
(iodoform and coffee, _e.g._).
There are several other minor phenomena which are in agreement with this
theory. They need not detain us.
We turn now to the criticism of the undulatory theory of odour.
First of all, we shall dispose of an objection which, at first sight,
has a very serious aspect.
It may seem difficult to understand how vibrations which appear to us
when of a certain rate to be light should when they are of another rate
become to us smell. How can one and the same physical condition produce
sensations so different?
The same difference, however, is encountered when we pass to the rays at
the other end of the spectrum, the reds and infra-reds. On one side of
the dividing line we only perceive these as heat; on the other side they
also become light.
Obviously, the difference can only be due to the different character of
the sensory end-organ, the receptor of these vibrations. As Head says:
“Each peripheral end-organ is a specific resonator attuned to some
particular kind of physical vibration”—reminding us not only of
soundresonators, but also of wireless receivers, which are “tuned” or
accommodated to particular wave-lengths.
Thus, if red rays encounter certain tactile end-organs in the skin, they
are perceived by the mind as heat, and if they pass into the eye and
stimulate the retina, they are perceived as red light. In other words,
in whatsoever manner an end-organ is stimulated, it only induces its own
particular sensation.
How it comes about that the various end-organs induce such different
sensations is not yet known.
The ultra-violet theory of olfaction, however, has to run the gauntlet
of much more serious criticism than the difficulty we have just disposed
of.
One great objection to it (to my mind) is that it fails to account for
another absorption phenomenon of which I have not yet made any mention.
It was first observed by Tyndall nearly fifty years ago.
On submitting odorous vapours to examination Tyndall found, not that
they absorbed ultra-violet rays, as this method is of quite recent
usage, but that they _absorbed heat-rays_, or the _infra-red rays_ of
the spectrum. So that, if it be correct to say that odours set up
ultra-violet rays in the ether, we must be equally ready to credit them
with setting up infra-red rays also!
But there is another, and perhaps a stronger, objection to the
ultra-violet theory.
In the interesting and highly instructive schema drawn up by Heyninx of
the wave-lengths of ultra-violet absorbed by odours, we find one or two
discrepancies of a serious character.
For example, iodoform and cinnamic aldehyde show absorption-bands
occupying nearly the same position on the spectrum; and presumably,
therefore, these substances have the same molecular vibration-rate. Yet
their odours are not at all alike!
Again, acetone-methylnonic and butyric acids have _precisely_ the same
absorption bands, and yet they also exhale totally different odours.
But the most serious discrepancy remains. The absorption bands of
hydrocyanic acid and watery vapour (steam) have precisely the same
position in the spectrum, yet one of these has a highly characteristic
odour, and the other has none at all!
It is rather difficult, in view of these findings, to believe that this
absorption phenomenon can have anything to do with the quality of odour.
My friend Mr. T. H. Fairbrother writes regarding this controversy:—
“Whilst I do not for one moment suggest that the whole phenomena of
smell can be explained entirely in terms of chemical constitution, I
do maintain that it has much to do with it, and I certainly think
that more valuable information about the cause of various odours has
been obtained from considerations of chemical constitution than from
the many extravagant physical theories which do not lead us very
far. In my view the physicists are begging the question, because
they usually postulate something which we cannot prove, and whilst
it is possible that the vibration of electrons causes smell, how
much wiser does that statement make us? One might easily say that it
was possible that the bombardment of electrons caused smell, etc. On
the chemical side, however, we are bound down to experimental facts,
and we do know that esterification of carboxylic acids does bring
about a fruity odour invariably, etc. Chemical constitution cannot
explain fully all these phenomena, because chemical formulæ
themselves are only approximations, but the effect of groups in a
nucleus has done much to help synthetic production of odorous
bodies. When the physicist can control the vibrations of his
electrons and make them rotate in accordance with his will, then he
may be able to synthesise new odours—till then we have no means of
testing his theories.”
The older view of olfaction—and many modern scientists, as we see, still
adhere to it—is that the odorous molecule acts as a chemical reagent
upon the olfactory hairs. And there is something to be said for this
opinion.
To begin with, no one doubts nowadays that odours are material. They
pass through the air as vapours, and they are known to travel miles on
the wind. That is to say, apart from those hypothetical varieties of
odour (if we can call them odour at all) discussed by Fabre earlier in
this book, odours do not emanate from a point and disperse in all
directions as light and sound do. Why then drag in the ether? Is it not
more probable that the odorous molecule acts on the olfactory hairs by
direct material contact, and that it sets up chemical changes in them?
We are asked to believe that the ultra-violet rays of odour stimulate
the olfactory hairs as visible light-rays stimulate the retina. But it
must not be forgotten that in the eye those rays may induce first of all
chemical changes in the retina, just as they would act on the silver
salt of a photographic plate, and that it may be by these changes that
the retina is stimulated.
In the phenomenon of olfactory exhaustion, as we said in our first
chapter, we have a circumstance which suggests the presence of some
chemical reagent in the olfactory area.
It may be, of course, that in the nose as well as in the eye the process
is a combination of chemical and physical changes. And in any case we
are here dealing with that obscure region where chemistry and physics
meet and mingle.
We have now come to the end of our discourse upon the theories of odour,
and it must be confessed that we are still very much in the dark as to
the nature of the odorous, and as to the manner in which it excites the
olfactory organ to activity.
Still more mysterious, however, is the process by which the physical
quality of odour becomes the sensation of the mind we call smell.
The transmutation of a physical quality into a sensation is indeed the
great mystery of all our senses. Olfaction is not the only one before
which we throw up our hands, and this in spite of the detailed and
voluminous information which modern physiology, neurology, and
psychology place at our disposal, perhaps less in spite of this
information than because of it, seeing that the further our knowledge
extends the wider seems the unknown realm beyond. Our science is an
ever-expanding sphere, no doubt, but it is expanding into the infinite.
How is it that the rhythmic vibration of matter becomes what we call
“sound,” or the rhythmic vibration of the ether “light”?
How does the physical pass into and become part of the psychic?
According to recent teaching, the physical can be followed as such from
the sensory end-organ itself as far as the first synapse, or junction
with the neurone. But there something happens; ... then it reappears in
a new guise, vibration becomes sensation, the physical psychic, the
objective subjective, the real ideal, the dead alive! In that brief
tumble of time what a miraculous transformation!
Modern science has cleared up much of the mystery of the objective
world, and although it may be far from the end of its search, although,
indeed, the search, one must think, can never entirely elucidate the
dense obscurity that envelops us on every side, dark as a starless night
around a candle, yet we already know this much, that the real world is
very different from the world depicted for us by our senses.
Only a little imagination is needed to convey us out of the magic circle
into which we have been born, and what a strange universe do we then
find ourselves in! Entangled in a meshwork of space-time and permeated
by whirling maelstroms of varied and innumerable oscillations, we lose
all hold on reality in the very act of grasping it.
But although we do possess some sort of vague notion as to the
constitution of the outer universe, before the inner we stand ignorant
and speechless.
Regarded as a machine, the brain, it is true, like the world without, is
reluctantly yielding up its secrets one by one. We are learning how it
works as a chemical factory, as a physical power-house, so that already
we can surmise that here also we have probably to deal with a
multiplicity of vibrations, of exquisitely minute transformations of
energy, of involved intercommunications, of deft though intricate
associations, of rapid yet permanent recordings and registrations.
We are now able to follow the undulations we term light, not only into
the eye, but into the brain itself, locating their central station in
the occipital lobe, whence their effects radiate all over the organism.
And in the case of olfaction Pawlow has taught us that its chief
vegetative function, the result of radiations from the olfactory central
station in the brain, is the arousing of the digestive glands to
activity. The first act of digestion is olfaction. But the routes which
the olfactory stimuli follow in the central nervous system and their
communications with other sensory paths are not yet known.
The secrets of the brain which have been disclosed to us, however
wonderful they may be, concern only, we must remember, the machinery of
the nervous system, that part, namely, which is of the same nature and
order as the objective world, of which indeed it is a member. Hitherto
have we come, but no further:
“The traveller hails. The echoing walls respond.
And there the matter ends. The wilds beyond
Are broken rock and desert where no foot
Can venture on to trace a further route,
For none hath trodden or shall ever tread
This hither limbus of the outer dread.
Cloven abrupt, the absolute abyss
Falls sheer beneath us, fathoms fathomless,
And still high o’er us heaves the unclimbed hill,
And the unanswered questions front us still.”
The “thought” escapes us. Somewhere beyond the boundary of the physical
flits this elusive, this tantalising ghost. How it is acted upon and how
it reacts we know to some extent. But what the nature of its action may
be is more than we can determine.
Nay! A moment ago we lightly spoke of passing out of the magic circle
into which we have been born, and we forthwith proceeded to talk as if
we had in reality escaped from this our prison. But there is no escape
for us, of course. No man can jump out of his skin. There undoubtedly
are such things as “waves,” or “undulations,” or “oscillations,” or
“vibrations,” or whatever we like to call them. But they are not what we
imagine them to be. There is, we may suppose, a four-dimensioned
universe of “space-time.” But it is beyond our conception. There is
“objective reality,” in a word. But it is no reality to us. Those very
expressions, glibly used though they be, are but metaphors—“pretendings”
a child would call them—attempts to bring the remote a little nearer to
us, to clothe the uncouth in the garments we ourselves wear; all of
which is nothing but Maya—illusion—shadowplay.
Let us not deceive ourselves. Along with the recent revelations of
physical science there comes, say certain modern philosophers, the
suspicion that the universe is irrational. At every point we are brought
up short by the unknowable.
For example, Einstein tells us that what we call the “ether” has no
existence. It is merely a “void.”—But how can we call that void which
contains something—undulations, to wit?
“Nay!” you argue; “the undulations traverse the ether, but they are not
it. The ether is a non-entity. It has no existence. It is nothing.”
To which I reply: “But ‘nothing’ is an absolute term. It means ‘no
thing.’ How, then, can undulations, or anything else for that matter,
pass through nothing?”
“What nonsense!” you cry; “this kind of verbal poser is just the silly
old metaphysicians’ parlour game of playing with words.”
I know it is. But the word-play has its uses. It demonstrates to us that
words, language, logic, all alike, fail our thought, not so much because
those instruments are limited in power as because the thought itself is
lacking in precision and comprehensiveness.
It is when our word-play probes the expression that the vagueness of the
idea is made manifest. Our foil, even with the button on, goes clean
through the phantom.
The mind, in short, has not absorbed, nor can it absorb, the _fact_. We
seize a glass of water to drain it, and presently, like Alice, we find
ourselves swimming about in an ocean! Obviously the universe _is_ beyond
our comprehension, a conclusion desperate if you like, yet undeniable.
But how very annoying it is, after all our heavy labour, to hear the
ancient scoff of Zophar the Naamathite still ringing triumphant:
“Canst thou by searching find out God? Canst thou find out the Almighty
unto perfection?”
(Still we mean to go on trying!)
Yet of all the senses none surely is so mysterious as that of smell.
For, as we have shown, the nature of the emanations that stir it to
activity is still unknown; the simple structure of its end-organ
confronts us, like a sphinx, with silence; and after the reception of
the stimulus in the olfactory lobe of the brain its further connections
and communications still remain unsurveyed, albeit, as I have already so
amply displayed, its effects upon the _psyche_ are both wide and deep,
at once obvious and subtle.
CHAPTER IX
DUST OF THE ROSE PETAL
By way of relief from the exacting mental strain of the last chapter, I
have thought that the reader who has got this length might be grateful
for something more simple, and so it is not altogether egotism that
leads me to finish up with a few of the olfactory pictures I cherish.
Before proceeding with the subject-matter proper of the chapter,
however, let me put in a plea for the conscious cultivation of the sense
of smell. But little more, I take it, is needed in this way than to pay
attention to the olfactory sensations that reach us, for the very fact
of taking note of them is sufficient probably to increase the power and
delicacy of olfaction, this being always the effect of the mental
process known as attention.
Smell may thus be easily cultivated and improved, and with the increase
in its appreciation of the world comes an enriching of the other
sense-impressions that is quite surprising.
It is possible that there is no substance in the natural world entirely
devoid of odour. At all events, after a time the amateur in smell may
find himself able, like Rousseau, to perceive perfumes when other people
do not notice any, and as a mark at which he can aim let it be said that
when he finds himself able to distinguish streets from each other by
their smell alone he has made some little progress in the art.
The innate acuteness of the sense varies widely in different people.
Some go through life blunt to all but the coarser smells, while others
are gifted with a sensitiveness as delicate almost as that of a
macrosmatic animal. This is scarcely an exaggeration. I am acquainted
with people—English people—who are able to recognise by olfaction not
only different races and the two sexes, but even different persons. One
of those sensitives informs me that to her the personal olfactory
atmosphere is every whit as characteristic and unmistakable as the play
of features or the carriage of the figure.
Another remarkable feat within the capacity of human macrosmatics, and
one that seems almost incredible to the ordinary individual, is that of
being able to distinguish the clothing of different persons by its
aroma. Some can even recognise their own, a remarkable circumstance in
view of the almost universal rule that each is anosmic to his own
particular atmosphere.
It is true that we can get on quite well without smelling. Probably
congenital anosmia is the least crippling of all sense-deprivations. But
how much it enters into our enjoyment of life when we have once
possessed it is shown by the blankness that attends its loss; we feel
then as if a tint had been bleached out of the world.
At this juncture we may stay a moment to allude to the action of tobacco
on olfaction. There are few people nowadays who would uphold King
Jamie’s “Counterblaste,” wherein he denounces smoking as—
“a custome loathsome to the Eye, hatefull to the Nose, harmefull to
the Braine, dangerous to the Lungs, and in the black stinking fume
thereof, neerest resembling the horrible Stigian smoke of the pit
that is bottomlesse.”
But, in fact, regarding the influence of the tobacco-habit on the sense
there is a conflict of opinion. Some say it dulls olfaction; others, it
has no deleterious effect. My own experience would lead me to agree with
the former opinion.
We now proceed with our memories.
Who does not become a boy again when the fragrance of a gardener’s
bonfire fills the air? In my own case when I smell it my eyes begin to
smart and to water, and I hear the laughter and shouts of my brothers
as, daring the wrath of Olympus, we leap over the blaze and land on the
white powdery ash that rises in clouds around us to the ruination of
boots and clothing. It is always evening, “’twixt the gloamin’ and the
mirk.” The moon, still golden, is hung low in the sky; the wind is sharp
with a touch of frost, but the glare and the glow of the embers reddens
and warms us—at least that part of us we turn to the fire. (Have you
ever felt the fierce pleasure of being at once scorched and frozen?)
In those few country places in Scotland where the old Beltane fires of
midsummer or midwinter are still kindled, children are encouraged to
pass through the smoke, that being good for their health. The custom,
frankly pagan, is probably the maimed rite of a sacrifice of children to
the old gods. That may be quite true, and yet I concur in believing the
practice to be beneficial. At all events, the bonfires of so many years
ago have left with me a memory that has often recurred since, and always
with healing on its wings.
Again, the fainter, keener odour of burning pine-wood combined with the
fanning sensation on the face of the cold wind of the dawn always brings
back to me a summer morning at the Swiss frontier station of Pontarlier
after an evening when vin ordinaire had induced effects extraordinaire
upon a youth unaccustomed to that fiery beverage. Those, no doubt, were
the days when nothing mattered much. Nevertheless the fragrant coolness
of that morning after touches my aching brow to this day with the
soothing gentleness of a hand fraught with understanding and
forgiveness.
Then what sea-lover is there but responds to the salt pungency of
seaweed on an empty beach?
It is an interesting fact that the smell of the sea may travel inland
for miles on a favouring breeze. With the south-west wind blowing moist,
I have in the heart of Lanarkshire repeatedly been stirred out of
everyday hebetude by the smell of the sea on the Ayrshire coast, some
thirty miles away. And Réné Bazin (in “Les Oberlé”) says you can even
smell it sometimes in Alsace, 250 miles from the Mediterranean.
Once, indeed, at King’s Cross, London, I beheld monstrous
railway-stations and muddy streets, with their motor-’buses, dingy
wayfarers, yelling newsboys and all, melting away into the glimmer and
space of the sea in a sort of magical transformation, just as mist
low-lying in Russell Square will turn at times those garish hotels into
sea-girt palaces.... Only this time there was no mist. There was,
indeed, no need of mist. For the spell of power was a sudden whiff of
the sea from far across the bricks, slates, and sooty chimneys.
But there is another sea-smell, equally powerful and much less romantic.
Can you endure the breath of hot oil and metal from the engines of a
steamer without a qualm?
If ever a boy has watched and helped the fishermen clean and tan their
nets, he will always after, as often as chance brings the smell to his
nostrils, revive again the pit in the ground and the gruff voices of the
heavy-booted men pulling the twisted net up and down, in and out.
Or the bean-flowers’ boon?
This, as it happens, concerns also somebody else, but as she has long
since been lost in the crowd, I am not breaking any confidences in
recalling the scene.
We are standing together beside the gate of a hill plantation, and I see
a tall lady’s delicately cut profile against the sombre green and brown
of the fir-trees. Although the flush of the sunset has almost entirely
faded from the sky, it seems to be lingering yet a while on her cheek as
if reluctant to leave her. As for me, I am as keen to every breath of
emotion as the little loch below is to the slightest stir of air. The
time is past for talk, and I am watching her in silence. So I see the
thin curved nostril dilate a little, at once to be quietly restrained,
as if even this little display of feeling on her part were out of
place,—and then I also turn to look at the butterfly bean-flowers in the
field at our feet.
Now as often as the bean blooms, so does her memory.
How powerfully associations affect our olfactory likes and dislikes we
hinted on a former page, and in this matter of smell-memories we can
observe the same effect. Smells which to others seem offensive may, if
they arouse a pleasant memory, borrow from it a tinge that turns their
offence into a joy for ever. In my own case iodine and the rather
irritating odour of bleaching powder are always welcome and always
sweet. Yet they recall nothing more interesting than the days of
childhood to me! On the other hand, perfumes generally considered to be
pleasant will be objectionable to us if they arouse unhappy memories.
The most beautiful, however, are those which have been young with us,
and yet have never forsaken us, by continual refreshment keeping an
eternal youth. And of all the odours in life none surely is so rich both
in retrospect and in prospect as the smell of books to him who loves
them. The cosy invitation of a library! Not a public library, needless
to say, where the intimate appeal is lost in a jumble of smells—dust,
paste, ink and clammy overcoats. Such public mixtures the bookworm, that
solitary self-centred individual, must, by reason of his shyness, ever
consistently shun. But usher him into the private room of a private
house where books, many books, have reposed for many years. Then go away
and leave him to it.
The smell of a room full of books is slow to form. Like the bouquet of
wine, it must ripen. You have to wait. But if you are able to wait, then
one fine day you will be welcomed there by the snuggest smell in all the
world, which, when once it comes, will for ever remain, like rooks in a
clump of elms. I know a few houses where this most seductive of all
perfumes has resided for untold years, and whence it will never depart
as long as our immemorial England endures. But alas! like most people, I
have only been a fleeting visitor to those nooks of enchantment, and
have had to wait myself not once, but many times, as often indeed as I
have shifted my roof-tree, for that ancient fusty atmosphere. There is,
I fear, no way of hastening the appearance of this beckoning finger to
oblivion. We need not linger over the analysis of this particular odour.
Book-lovers know it. Others don’t care.
“You are a reader, I see,” said an observant doctor to me once.
“How d’you know that?” I asked in surprise, as we had just met for the
first time.
“I know it,” was his reply, “by the caressing way you took up that
book!”
Your real bookworm loves all books. Like the modern genius, he is
amoral. But unlike the genius, his amorality, simple soul, is confined
within the four walls of a library. He could never, I am sure, bring
himself to agree with André Theuriet, who in “La Chanoinesse” depicts
“les _Bijoux indiscrets_ auprès des œuvres de Duclos; _Candide_,
_Jacques la Fataliste_ et _le Sophia_ voisinant de _Restif de la
Brétonne_ à deux pas de _l’Emile_, et _les Aventures du Chevalier de
Faublas_—une nouveauté—non loin de _l’Histoire philosophique des
Indes_,”
all of which books, by a kind of moral exercise of his imagination we
cannot sufficiently deplore, he found exhaling “une odeur de volupté
perverse, quelque chose comme le parfum aphrodisiac des seringes et des
tubereuses dans une chambre close.”
Every dwelling-house has its own peculiar atmosphere, sometimes
agreeable, sometimes not. But, whatever its quality, so characteristic
and persistent are some of them that I am sure a blind man would always
be able to tell them by the smell alone. Few of us may be gifted with
the analytical nose of a Charles Dickens to detect the ingredients that
make up a complex domiciliary atmosphere, but everybody must have
noticed that basement houses smell differently from bungalows, the
former greeting you with a harmonious blend of earthiness, soapsuds, and
sinks.
Nay! The house you live in has a separate odour for each room: the
drawing-room with its chintzes; the snuggery with its stale tobacco,
and, perhaps, like an insinuating nudge, with a whiff of the stronger
alcohols; the bedrooms, if your housekeeper knows her business, with the
freshness of well-aired linen.
The very days of the week have each its own particular olfactory mark,
dating from our childhood: Sundays (in Scotland), peppermint followed by
roast beef and richness; Mondays, pickles and soapsuds; Tuesday, the
damp airs from the washing hung up to dry; Wednesdays, warmth and
beeswax from the laundry, with ever and anon the thump of the flat iron;
Thursdays, bread new from the baker and the washing of floors with soft
soap—“Mind yer feet, now!”—Fridays, jam-boiling and the
never-to-be-forgotten aroma of oat-cakes on the girdle; Saturdays—but
Saturday is a day of wind and banging doors, of tops and dust; all its
smells are out of doors.
Shops, too! What of the coffee-shop?—Who does not pause a moment at that
door when the beans are roasting? One of the richest of all odours that;
curious how you lose it in the beverage! Then there is the ironmonger’s,
where the sharp smell of steel strikes, by some strange reflex, the
upper incisor teeth and gums; the oil and colour shop, with its putty,
turpentine, and general clamminess; and, last and best of all, the
druggist’s!
What about the fried fish-shop? Faugh! I once for a reason connected
with my calling had cause to spend a whole night in a room above a
fish-shop—once only. The next time (there never will be a next time, she
swears, but there always is)—the next time I happened, curiously enough,
to arrive late!
But although houses and rooms and, as we hinted, streets also, all smell
differently, each town and city has its own peculiar fundamental odour.
There is a town in Yorkshire that smells of “mungo.” I know another that
smells of mineral oil, and many that exhale the dank smell of the
coal-mine.
London has a smell of its own, a fundamental familiar odour, which, by
the way, has changed of late. Twenty years ago it was faintly acid with
a background of horses and harness. To-day it is a mixture of tar and
burned lubricating oil, by no means so pleasant. In addition to these,
however, there is another and less prominent odour characteristic of the
London atmosphere, which I confess I cannot describe.
“Once upon a time, some forty years ago, there lived at Highgate,
which then still retained some of the characters of a village, a
lady who declared that when a yellow fog drifted up from London she
could detect the smell of tobacco smoke in it. To most people the
odour is flatly that of coal smoke, which is perhaps always more or
less to be perceived in London air. This at any rate would seem to
have been the opinion of Edward Jenner, if we may trust a note made
by Farington in his diary for 1809, which is being printed in the
_Morning Post_. Farington’s note is as follows:
“‘Dr. Jenner observed to Lawrence that He could by smelling at His
Handkerchief on going out of London ascertain when he came into an
atmosphere untainted by the London air. His method was to smell at
His Handkerchief occasionally, and while He continued within the
London atmosphere He could never be sensible of any taint upon it;
but, for instance, when He approached Blackheath and took His
Handkerchief out of His pocket where it had not been exposed to the
better air of that situation—His sense of smelling having become
more pure he could perceive the taint. His calculation was that the
air of London affected that in the vicinity to the distance of three
miles’” (_The Lancet_).
Paris, in like manner, has its own peculiar aroma. Lord Frederick
Hamilton analyses it correctly into “one-half wood-smoke, one-quarter
roasting coffee, and one-quarter drains.” But for myself the Paris air
always brings a curious half-suppressed feeling of excitement, part of
it pleasure, part apprehension, as if something tremendous were about to
happen. But here perhaps we cross the border-line between conscious
sensation and subconscious stimulation.
Rome is a city of candles and incense mingled with the dry mustiness of
crumbling skeletons.
In Edinburgh you encounter here and there the smell of old Scotland.
Thatch enters into its make-up, why I cannot tell you. But the cold grey
metropolis still preserves the soul of the thatch, a cosy sensation that
is prone to bring tears to the eyes of the returning exile.
In Glasgow damp soot struggles with the smell of the Bromielaw for the
mastery.
Dublin mingles the warm, rich aroma of Guinness’s Brewery with the cold
smell of a corpse from the Liffey.
Those are the cities I know best myself. But I have often been told, and
can quite believe it, that every city has its own particular atmosphere.
Some days, both in a city and in the country, are as rich and full of
odours as a Turner picture is rich and various in colour. Other days
bring us but a grey Whistlerian monotone, in which, nevertheless, the
trained sense delights to distinguish an infinity of tender shades,
unobserved by the casual.
I used to think that country smells were particularly dear to the
country-born only, and that their charm lay in their evocation of
childish memories. But that is not the whole of the story. They attract
us by their own inherent beauty. I have known town-bred lads linger
about a stable because the smell, I was told, was “so sweet.” And most
of us are, to be sure, sufficiently horsey to enjoy that smell of straw
and ammonia. We linger near it as bees haunt clover or cats valerian.
And we are all horse-lovers sitting behind a smart cob on a hot day when
the smell of the harness is mingling with the horse-odour. But these now
old-world odours are being every day more and more ousted by the less
pleasant smells of the motor-car, petrol, lubricating oil, and
acetylene—a pure stink this last.
But the farm is an olfactory museum, a library, a symphony! How warm and
comforting is the smell of a byre full of cows! Plunge into it from the
cool of the evening and listen again to the sudden swish of the warm
milk into the pail, the uncompleted low of the sober cattle and the
rattle of the chain as they turn to look at the new-comer. A gentle
relaxation of the spirit attends the visit like the relief of the limbs
from a cramped position, and we readily fall into that mood, so rare
these latter days, when attention disperses and the reins drop on the
neck of the mind so that it wanders on at its will up and down the lanes
and by-ways of fancy. These paths are dangerous, to be sure, leading as
they do to the Castle of Indolence, where you may dream your life away
and be none the wiser.
Yet there must be many who have so wandered regardless, and have wakened
up too late to recapture the days they have lost in dreaming, if they
ever do want to recapture them, which is doubtful. If we really intended
happiness in life—as we do not; what we intend, and ensure, too, for
that matter, is excitement—but if we really intended happiness, here is
where we should find it, in and about a farmyard as hangers-on. Not as
the farmer, needless to say, to whose mind these olfactory stimuli are
stimulant, not anodyne. So that there can be no greater contrast than
that between him and us. Every one knows how the idler idling irritates
the worker working. And so we are brought back to reality all too soon
by the slap of fate, waking up from a bank of thyme and dreams to the
pavement of worry and hard work.
But it is sweet while it lasts, and if you can acquire, or are lucky
enough to have been born with, pachydermia of the soul, then it may last
for a lifetime—unless, that is to say, fate, as aforesaid, in the shape
of the farmer, brings you back a-bump to earth with a clout on the side
of the head and an order to take the hook and cut down thistles.
Stevenson has told us that idling is no loss of time. Perhaps not, if we
happen to be geniuses. But the mischief is that the rest of your family
deny (with oaths) the major premiss, and the prophet-without-honour
consolation prize is but a poor substitute for the loss of comfortable
eternities dozed away beside the lazy kine.
Some time in the ’eighties of last century a French professor (Jaccoud)
recommended the air of a byre as beneficial in phthisis.
I have known worse cures.
Why do not the perfume-makers present us with more of these gateways to
Paradise, short cuts beside which De Quincey’s laudanum in the
waistcoat-pocket is but a by-path to hell? We might be given odours of
peace and contentment—think of them in the hands of a clever wife! We
might make libraries of them as people make libraries of gramophone
records. So far all we have are flower scents, like roses, lilies,
violets, and outlandish Eastern aromata, redolent rather of vice and its
excitements than of virtue and its placidity.
Then there is the scent of thyme and roses in the farm garden. This
brings to me old Sundays and ladies passing the open garden-gate on
their way to church, with their Bible carefully wrapped up in a clean
pocket-handkerchief, bearing with them also what somebody in Scotland
calls “the odour of sanctity”—peppermints, to wit—and all the time the
bees are humming in the warm air a deep note to the trills and runs of
the skylark lost in the blue.
But I could wander on for an eternity with these smell memories and
pictures. One more, and I have done with the farm, and that is the cool
smell of the milk-house. It is dark there after the blaze outside, and
the stone flags strike cold to a boy’s bare feet wandering in from the
burning cobbles of the courtyard. As your eyes become accustomed to the
dimness you can see on the floor the wide, shallow milk coolers, silvery
as full moons in that twilight, the only light that enters coming
through the long slit of a narrow unglazed window where blistery leaves
of green docken, springing rank from the unkempt garden without, show a
splash of sunlight. The smell is sourish and cold, if we may speak, as I
think we may, of the temperature of a smell. This is forbidden land to
boys for obvious reasons, but so strong is the impression that I have
never forgotten my one and only visit to that secluded chamber.
What is it that gives to a dungeon its characteristic smell? Emphatic as
a blow. Obviously, we have here a combination of several sense
impressions, tactile, visual, olfactory: tactile, for the air is damp
and chilly; visual, for it is a blank, a negative, and yet a powerful
influence; olfactory, smelling ominous and of death. Old dried bones
emit precisely the same exhalation. In a subtle way, too, the presence
of mould is perceptible, all blending into the horrible and grisly
atmosphere of despair; the Valse Triste and the Dance of Death.
Smell can bring as certainly and as irresistibly as music emotions of
all sorts to the mind.
In this same category we may place the dusty smell of a dry hay-loft,
which is curiously like that of bitter almonds and hydrocyanic acid. It
has a sensation like ghostly fingers fumbling about your neck with a
threat, half playful, half serious, of suffocation. And, curiously
enough, the mental feeling of throttling fingers is not amiss. Prussic
acid kills by paralysing the respiratory centres.
Let us get out into fresh air again! The sun is shining. A gentle breeze
from the west is snowing the lawn with fragrant hawthorn blossoms. I
catch a whiff of delicate lilac, and see coming towards me over the
grass a slender figure in white....
And so we close with the perfumes of the spring, sunshine, and beauty.
ACKNOWLEDGMENTS
The impulse of which this study of olfaction is the outcome emanated
from Sir St. Clair Thomson, who three years ago handed me for my
edification and growth in knowledge the _Essai d’Olfactique
Physiologique_, a _Thèse de Bruxelles_, by _A. Heyninx_, dated 1919.
In addition to that work the following have been utilised, for the
scientific side of the subject at all events:—
_Poncelet, P. P._ Chimie du Goût et de l’Odorat, etc. Paris. 1755.
_Parker, G. H._ Smell, Taste, and Allied Senses in the Vertebrates.
n.d.
_Deite, C._ Manual of Toilet Soap-Making. Eng. Trans., 2nd ed. London.
1921.
_Ogle, Wm._ Medico-Chir. Trans., Vol. LIII., p. 263.
_Bonvier, E. L._ The Psychic Life of Insects. Eng. Trans. London.
1922.
In Heyninx’s book there is a good bibliography, but the English reader
will find an excellent _résumé_ of recent scientific literature in
_Osmics_, by Mr. J. H. Kenneth, published by Oliver & Boyd, Edinburgh.
It is impossible in the space at my disposal to print a bibliography
dealing with the historical aspect of olfaction.
In addition to my debt to books, I am also under deep obligation to Dr.
Wyatt Wingrave, Dr. Arnold Renshaw, Mr. Archer Ryland, Mr. F. W.
Watkyn-Thomas, and Mr. T. H. Fairbrother, for many valuable hints and
criticisms, as well as for much useful information, and I take this
opportunity of offering my thanks to them for their kind interest.
INDEX
Acetone poisoning, Odour of, 84
Adsorption of odours, 113
Æneid, The, Odour in, 72
Albinos, Anosmia of, 116, 126
Alcoholism, Odour of, 84
Alexander the Great, 77
Ambergris, 106
Ammonia, 94
Animals, Lower, Olfaction in, 21
Aniseed, 71
Anosmia, 23, 115, 142
Anti-demoniac treatment by fumigation, 67
Ants, Olfaction in, 28
Apoplectick, Balsam of Horstius, 69
Aromatics, The, 119
Asthma from horses, 93
Asafœtida, 71
Aura, Olfactory, 91
Bacon, Francis, 84
Badger, Olfaction in, 37
Bat and sound-pictures, 32
Bath, The domestic, 18
Baudelaire, 51
Bay, 73
Bazin, Réné, 144
Bean-flowers, Fragrance of, 145
Beltane fires, 143
Bolboceros beetle, 37
Books, Smell of, 146
Brain, Olfactory Routes in, Unknown, 136
Brewer, Anthony, 53
Browning, Robert, 71
Burton, Robert, 78
Cairo, Cholera in, 68
Camphor as disinfectant, 70
Carminatives, 71
Castelli’s theory of vision, 127
Cats, Aversion towards, 92
Cities and towns, Smells of, 150
Civet, 106
Collins, Wilkie, 47
Colosseum, Perfumes in the, 56
Coumarin, 105
Creighton, 84
Crowd-psychology and Odour, 97
Death, Odour of, 84
Deite, 104, 117
Devil, Odour of the, 63, 73
Dickens, Charles, 54, 148
Disease, Epidemic, and Stenches, 5, 66
Odours of, 83
Disraeli, Benj., 12
Dog, The, and the Abominable, 80
Olfaction in the, 34, 87
truffle-hunter, the, 34
Dostoievsky, 56
Dwelling-houses, Odours of, 148
Eau de Cologne, 57
Einstein and the ether, 138
Ellis, Havelock, 86, 87, 96
Equilibration, Vocabulary of, 59
Fabre, 25, 29, 36, 92
Olfaction in dogs, 36
insects, 25
on nature of odour, 38
Fairbrother, T. H., 120, 132
Farington’s Diary, 151
Farm, Smells of, 153
Favus, Smell of, 84
Fischer and Penzoldt, 108
Fish, Olfaction in, 32
Flavour an odour, 43, 114
Flavours, High, 82
compounding of, 101
Flowers, Perfumes of, Diffusion of, after rain, 112
and insects, 28
Folk-lore, Smell in, 66
Forel, Olfaction in insects, 25, 30
Fumigation, treatment by, 66
for cholera, in modern times, 68
Garlic, 45, 57
Geraniol, 105
Gladstone, W. E., 90
Goethe, 95
Gordon, Douglas, and olfaction in badger, 37
Hæmorrhage, Odour of, 83
Hamilton, Lord Frederick, 151
Harte, Bret, 51
Hay fever, 93
Head, Henry, 130
Health, Public, and Olfaction, 1
Hearing, End organ of, 98
Exhaustion of, 17
Vocabulary of, 60
Hell, Odour of, 73
Henning, 119
Heyninx, 110, 119
Classification of odours, 103, 124
Undulatory theory of odour, 121
History, Smell in, 77
Hogarth, 70
Holmes, Oliver Wendell, and Olfactory memory, 51
Homer, 73
Homing instinct, 30
Hospitals of olden days, of, 83
Humboldt, 64
Hutchison, 116
Hydrocyanic acid, 119, 131, 157
Hysteria, Treatment of, by stenches, 71
Incense, 51, 53, 56, 68, 72
Incubus repelled by aromatics, 74
Industries, Malodorous, 14
Infra-red light rays, 122, 129
absorption by odorous vapours, 131
Insects, Olfaction in, 25
and hygiene, 29
Iodoform, 16, 103, 129, 131
Ireland, Odours in, 3, 152
James I., “Counterblaste,” 142
Jenner, Edward, 151
Kipling, Rudyard, 55
Lavender, English, 106
Lodge, Sir Oliver, 121
London, Smells of, 150
Louis XI., 78
Louis XIV., 77
Love and Olfaction, 85
Lubbock, Sir John, 25, 30
Macrosmatic animals, 22
Memory, Olfactory, 43
Strengthening of, by Odours, 53, 69, 70
Mercaptan, 39
Meredith, George, 89
Microsmatic animals, 22
Mignonette, 105
Molecular structure of odorous bodies, 117
Molecules, Vibration of, 121
Montaigne, 53
Moths, Olfaction in, 25
Mummification by aromatics, 67
Musk, 28, 75, 104, 106, 107, 109, 110, 117
Nauseous remedies, 70
Nephritis, Acute, Smell of, 83
Nerve, Fifth Cranial, 94
Olfactory, 23
Nitrobenzol, 119
Nose, Olfactory Region of, 114
Pigment in, 116
Odericus Vitalis, 76
Odours, Clashing of, 129
Classifications of, 102
Clinging of, 113
Concentrated, Anosmia for, 110
Diffusion of, 39, 108, 112
Effect of cold on, 112
of Disease, 83
Harmony between, 129
Identification of, 65
Nature of, 38, 98 _et seq._
Novel, 101
Personal, 76
Physical theory of, 42, 116
of poisonous herbs, 126
Recollection of, 47
Repulsive, 79
in water, 33
Theories of, 98
Chemical, 116, 132
Undulatory theory of, 42, 116, 120
Criticism of, 129
Varieties of, 100
Ogle, 116
Olfaction. _See also_ SMELL.
Allusions to, in literature, 51 _et seq._
and digestion, 136
a primitive sense, 21
Evolution of, 21
in fish, 33
in insects, 25
in the lower animals, 21
in the sex-life, 85
Theories of, 98 _et seq._
and ventilation, 17, 109
Olfactory cells, 23
hairs, 23, 121
memory, 43
organ, 23
of insects, 28
pictures, 140 _et seq._
pigment, 24, 116, 125
region of nose, 114
Onions, effect of, 94 f.n.
Orientation. _See_ Homing Instinct.
Paracelsus, 70
Paris, Smell of, 151
Parker, G. H., 100, 104, 108
Pawlow, 136
Peppermint, 71
Perfumes, Classification of, 103
New varieties of, 107
Sources of, 105
Pigment, Olfactory, 24, 125
Pinewood, Odour of burning, 143
Plague, Sweet smell of, 84
Poncelet, P. P., 59
Queen Elizabeth, 3
Reality, Objective, 137
Religion, Smell in, 72
Remedies, Nauseous, 70
Olfactory, 66
Rheumatism, Acute, Acid smell of, 83
Ribot and olfactory memory, 48, 50
Rimmel, Classification of odours, 103
Roberts, Lord, and cats, 92
Rohmer, Sax, 74
Rose perfume, 57, 105
and exhaustion, 16
Roses, Attar of, 105
Rousseau, 100, 141
Sacrifice, Savour of, 72
Saints, Odour of the, 74
Saintsbury, George, 103
Salerno, Teaching of, on garlic, 47
Salmon’s Dispensatory, Fumigation in, 68
Sandal-wood, 113
Scatol, 16, 80
Scott, Sir Walter, 67
Sea, Smell of, 144
Sea-anemone, Olfactory cells of, 24
Sensation, Nature of, 134
Tactile. _See_ Touch.
Sensory end-organ, Specific reaction of, 130
Shakespeare, 52, 86–89
Shelley, 47
Shops, Smell of, 149
Sinistrari of Ameno, 74
Sins, Odour of the, 74
Small-pox, Smell of, 83
Smell and the Emotions, 91, 95, 142 _et seq._
in Folk-Lore, Religion, and History, 66
and the Personality, 74, 87, 141
Exhaustibility of, 15, 133
Sensation of, 134
Sense of, Acuteness of, in man, 141
Cultivation of, 140
in old age, 82, 126
in uncivilised man, 64
mystery of, 139
Reaction-time of, 111
Sense Organ of, 23, 101, 107
Delicacy of, 107
Potential responsiveness of, 101
and Speech, 59
Subtlety of, in man, 44, 56
Vocabulary of, Emotional, 61
Etymology of, 61 _et seq._
Smith, Elliot, 72
Spectrum analysis of odours, 123
Speech and smell, 59
Spiders, Aversion towards, 92
Stenches a nuisance in law, 12
in Cologne, 8
in the East, 10
in Edinburgh, 11
in France, 9
in London, 11, 13
in Lucerne, 8
Industrial, 14
Subconsciousness, Smell and the, 44, 56, 64, 65, 79, 91, 95, 139
Sulphur compounds, Organic, 15
Taste and smell contrasted, 43
Exhaustion of, 17
Vocabulary of, 60
Tasting wine with closed eyes, 115
Terminology, Olfactory, Scanty, 59 _et seq._
Theatre, The, Perfumes in, 56
Theuriet, André, 148
Tobacco, Effect of, on olfactory sense, 142
Touch, Vocabulary of, 60
Truffle-hunter, The, 36
Tyndall, 130
Typhus fever, Odour of, 83
Ultra-violet light rays, 122
absorbed by odorous bodies, 122
Unconscious, The. _See_ Subconsciousness.
Valerian, 71, 115
Vanillin, 39
Ventilation and sense of smell, 17, 109
Vervain, 80
Violets, 110
Vision, End organ of, 98
Vocabulary of, 59
Vocabulary of Smell, Scanty, 59 _et seq._
Volatility and odours, 113
Walking-stick, Medical, 70
Watkyn-Thomas, F. W., 53
Wilkes, John, 90
Whitman, Walt, 77
Zebethum occidentale, 71
Zwaardemaker, 114
Classification of odours, 102
Olfactometer, 107
PRINTED IN GREAT BRITAIN BY THE WHITEFRIARS PRESS, LTD., LONDON AND
TONBRIDGE.
------------------------------------------------------------------------
TRANSCRIBER’S NOTES
1. Silently corrected typographical errors.
2. All spelling errors were left uncorrected.
3. Footnotes have been re-indexed using numbers.
4. Enclosed italics font in _underscores_.
5. Enclosed bold font in =equals=.