Illusions of taste are of importance for us only in cases of poisoning
in which we want the assistance of the victim, or desire to taste the
poison in question in order to determine its nature. That taste and odor
are particularly difficult to get any unanimity about is an old story,
and it follows that it is still more difficult clearly to understand
possible illusions of these senses. That disease can cause mistaken
gustatory impressions is well known. But precedent poisoning may also
create illusions. Thus, observation shows that poisoning by
rose-santonin (that well-known worm remedy to which children are so
abnormally sensitive) causes a long-enduring, bitter taste;
sub-cutaneous morphine poisoning causes illusory bitter and sour tastes.
Intermittent fevers tend to cause, when there is no attack and the
patient feels comparatively well, a large number of metallic,
particularly coppery tastes. If this is true it may lead to unjustified
suspicions of poisoning, inasmuch as the phenomena of intermittent fever
are so various that they can not all be identified.
Imagination makes considerable difference here. Taine tells somewhere of
a novelist, who so graphically described the poisoning of his heroine
that he felt the taste of arsenic and got indigestion. This may be
possible, for perhaps everybody has already learned the great influence
of the false idea of the nature of a food. If some salt meat is taken to
be a sweet pastry, the taste becomes disgusting because the imaginary
and the actual tastes seem to be mixed. The eye has especial influence,
and the story cited and denied a hundred times, that in the dark, red
wine and white wine, chicken and goose, can not be distinguished, that
the going out of a cigar is not noted, etc., is true. With your eyes
closed it may be possible to eat an onion instead of an apple.
Prior tastes may cause significant gustatory illusions. Hence, when
assertions are made about tastes, it is always necessary to inquire at
the outset what had been eaten or drunk before. Experienced housewives
take this fact into consideration in setting their tables and arranging
their wines. The values of the wines are considerably raised by complete
illusions of taste. All in all, it must not be forgotten that the
reliability of the sense of taste can not be estimated too low. The
illusions are greatest especially when a thing has been tasted with a
preconceived notion of its taste.