Section 103. (6) The Illusions of the Olfactory
Sense.
Olfactory illusions are very rare in healthy people and are hence
of small importance. They are frequent among the mentally diseased,
are connected in most cases with sexual conditions and then are
so vivid that the judge can hardly doubt the need of calling in the
physician. Certain poisons tend to debauch the olfactory sense.
Strychnine, e. g., tends to make it finer, morphine duller. People
with weak lungs try, in most cases, to set their difficulty of breathing
outside themselves and believe that they are inhaling poisoned air,
coal-gas, etc. If one considers in this connection the suspiciousness
which many people suffering from lung trouble often exhibit, we
may explain many groundless accusations of attempted murder by
stifling with poisonous or unbreathable gas. If this typical illusion
is unknown to the judge he may find no reason for calling in the
physician and then—injustice.
The largest number of olfactory illusions are due to imagination.
Carpenter's frequently cited case of the officials who smelled a corpse
while a coffin was being dug up, until finally the coffin was found to
be empty, has many fellows. I once was making an examination of
a case of arson, and on approaching the village noted a characteristic
odor which is spread by burned animals or men. When we learned:
that the consumed farm lay still an hour's ride from the village,
the odor immediately disappeared. Again, on returning home, I
thought I heard the voice of a visitor and immediately smelled her
characteristic perfume, but she had not been there that day.
Such illusions are to be explained by the fact that many odors
are in the air, that they are not very powerfully differentiated and
may hence be turned by means of the imagination into that one which
is likely to be most obvious.
The stories told of hyper-sensitives who think they are able to
smell the pole of a magnet or the chemicals melted into a glass,
belong to this class. That they do so in good faith may be assumed,
but to smell through melted glass is impossible. Hence it must be
believed that such people have really smelled something somewhere
and have given this odor this or that particular location. Something
like this occurs when an odor, otherwise found pleasant, suddenly
becomes disgusting and unbearable when its source is unknown.
However gladly a man may eat sardines in oil he is likely to turn
aside when his eyes are closed and an open can of sardines is held
under his nose. Many delicate forms of cheese emit disgusting
odors so long as it is not known that cheese is the source. The
odor that issues from the hands after crabs have been eaten is unbearable;
if, however, one bears in mind that the odor is the odor
of crabs, it becomes not at all so unpleasant.
Association has much influence. For a long time I disliked to
go to a market where flowers, bouquets, wreaths, etc., were kept
because I smelled dead human bodies. Finally, I discovered that
the odor was due to the fact that I knew most of these flowers to
be such as are laid on coffins—are smelled during interment. Again,
many people find perfumes good or bad as they like or dislike the
person who makes use of them, and the judgment concerning the
pleasantness or unpleasantness of an odor is mainly dependent
upon the pleasantness or unpleasantness of associative memories.
When my son, who is naturally a vegetarian and who could never
be moved to eat meat, became a doctor, I thought that he could
never be brought to endure the odor of the dissecting room. It
did not disturb him in the least, however, and he explained it by
saying: "I do not eat what smells like that, and I can not conceive
how you can eat anything from the butcher shops where the odor
is exactly like that of the dissecting room." What odor is called
good or bad, ecstatic or disgusting, is purely a subjective matter
and never to be the basis of a universal judgment. Statements by
witnesses concerning perceptions of odor are valueless unless otherwise
confirmed.
