Page 25 - 《中国药房》网络版（科普刊）2024年6期

2024 年 12 月 第 6 期 Xia Ye：Searching for the Trojan Horse Humanistic Pharmacy： From Dream to Reality in 25 Years 21

Case 1：： Kekulé's Dream

Many of you may be familiar with the story of the German chemist August Kekulé （1829 –

1896） discovering the structure of the benzene ring in a dream. It was known， even long ago， that

the benzene molecule contains six carbon atoms and six hydrogen atoms. Carbon has a valence of 4，
and hydrogen has a valence of 1. In a saturated state， each carbon atom in a carbon chain should be

bonded to two hydrogen atoms （if in the middle of the chain） or three hydrogen atoms （if at the ends

of the chain）. Therefore， six carbon atoms should combine with 14 hydrogen atoms—this is the case

with hexane. However， benzene has only six hydrogen atoms， indicating a high degree of
unsaturation， suggesting it should be chemically reactive. Yet， benzene’s structure is very stable，

implying a unique structure distinct from other organic compounds， which puzzled chemists over 100

years ago and fueled scientific curiosity.

According to Kekulé’s 1865 paper on the structure of benzene， he first mentioned a dream
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during the 25 -anniversary celebration of his discovery at the Berlin City Hall in 1890. Unlike the
more popular version of the dream， where he dozed off in a carriage， Kekulé recounted sitting by the

fireplace writing a textbook， intermittently pondering the structure of benzene， and drifting into a

dream. In the dream， he saw a snake biting its own tail. Upon waking， he was inspired by the vision
to realize that the structure of benzene was a hexagonal ring.

This story not only solved the mystery of the benzene structure but also sparked widespread

interest in the connection between dreams and reality， with psychologists delving into the role of
dreams in creative thinking. However， dreams are hard to prove through mere words. Modern

scientists place a high value on evidence and proof. In the 1980s， John Wotiz， a chemistry professor