Our sense organs 45

finest detail, using plenty of images so that the
listener can get a clear picture of our experience.
But in the case of odours, we can only express
general feelings like pleasant, horrible, wonderful,
or exciting. Just try to describe in words the fragrance
of your marriage partner, of a shoe shop,
a bakery, or an old library! Our memory for
odours is astounding – nothing can stir up old
memories better than a certain scent.
The scientifically incomprehensible sense:
Most smells are a mixture of a large number of
odour-causing substances. Wine, for example,
contains about 200 and coffee about 500 different
ones. It has up to now not been possible to
reduce the multiplicity of scents to mixtures of
a few primary odours. The phenomenon of smell
is still poorly understood scientifically.
Our olfactory sense is extremely sensitive and
exceeds the capabilities of most technological
measuring instruments. The threshold of detection
for ethyl mercaptan is about 10 -13 g (one ten
million millionth of a gram = 10 9 molecules). It is
not clear why many molecules which are chemically
quite different have the same olfactory
effect. On the other hand, very similar chemical
compounds can smell completely different.
D-carvone smells like cumin, while L-carvone has
a mint-like smell. But both have exactly the same
chemical formula, except that the former is
right-handed and the latter has a left-handed
structure. Like your two hands, these are identical,
but mirror images of each other (stereoisomers).
Everybody has his/her own very specific personal
scent, which is just as unique as a fingerprint.
A baby recognises its mother by smell, and adults
can distinguish between male and female. Dogs
readily identify individuals by their odour and can
even recognise their owner in the case of identical
twins. A border collie has about 220 million
olfactory cells. As far as humans are concerned,
the following traces of odour-causing substance
per liter of air are detectable:
0.000 000 004 g acetone
0.000 000 0012 g phenol
32
0.000 000 004 g naphthalene
0.000 000 000 016 g camphor
0.000 000 000 041 g nitrobenzol
0.000 000 000 005 g vanillin
0.000 000 000 0004 g skatol
Perfumes can be beneficial for health (French
parfum = pleasant scent): Perfumes began their
triumphal progress as incense in Mesopotamia.
The word “perfume” is derived from the Latin
per = by or through, and fumus = odour. The first
country known to have used perfumes regularly
and extravagantly was Egypt. Their pompous
burial and embalming rites required spices and
ointments. In the time of Queen Hatsheput
(1490 – 1468 BC) perfume became a common
passion. Cleopatra (69 – 30 BC) was also a fervent
lover of perfume. The cedarwood boat on
which she received Anthony had perfumed sails.
Incense containers surrounded her throne, and
she herself was perfumed from head to toe. The
buildings of the kings of antiquity were filled
with scents. They preferred cedarwood for constructing
their palaces, because of its sweet
resinous smell, as well as its ability to repel
insects.
The Bible and perfumes: Aromatic substances
also play a significant role in the Bible. A mixture
of flowers, aromatic seeds and fruit, and olive oil,
is described as “precious oil” in Psalm 133:2, and
in Esther 2:12 we read of “six months with oil of
myrrh and six with perfumes and cosmetics”.
Aromatic plants and spices are mentioned many
times in the Bible: aloe, balm, galbanum, henna,
nard, sweet sedge, cinnamon, and myrrh. Aloes
(Numbers 24:6, Psalm 45:8, Song of Songs 4:14)
were used for preparing Jesus’ body for burial
(John 19:39). In Solomon’s Song of Songs very
many scents, fragrances, perfumes, and ointments
are mentioned. A certain American lady
author described this portion of the Old Testament
as the most perfumed poem of all times
and as a sensual love story saturated with perfumes
and ointments. Love is described in terms
of fragrant scents: “How delightful is your love ...
How much more pleasing is your love than wine,
and the fragrance of your perfume than any
spice! ... The fragrance of your garments is like