Plants are usually only believed important if species are endangered or if mono-culture destroys habitat. But plants have exerted a marked influence on history. Seeds of Change argues the case for quinine, sugar, tea, cotton and the potato. Published in 1985, it made the case for the first time. Many more than five plants ware studied but rejected - pepper, maize, rubber, etc. The criterion was that they "transformed the world". Quinine made possible European overseas empires; sugar turned the Caribbean black; tea accelerated the destruction of China; cotton increased Southern slavery tenfold; potatoes caused the rise of the Irish population and the greening of two cities - Boston and New York. To these five case histories has now been added a sixth - coca - the precursor of cocaine and of crack.
When the Spanish arrived in the Andes, coca leaves were widely used by the Incan elite and by those whose work demanded unusual exertion at high altitude - messengers, for example. Coca leaves, chewed, or drunk as an infusion, do not create addiction in man or beast. The Incan use of coca leaves saved food, improved red corpuscle efficiency, increased concentration, reduced fatigue and altitude sickness and near-doubled what a man can carry above 3,000 metres. Taken before retiring at night, coca leaves encourage deep sleep - not always enjoyed at high altitudes; all this can be proved today. Leaf-use was rationed by the Incas but banned within a generation by the Spanish bishops. This was because coca was mind- altering and said to compete with Christian belief, but the ban did not long survive.
It was too expedient, too profitable, to use coca leaves to cheapen output in the Andean mines. At the new silver mine at Potosi (14,000ft) coca replaced food and money. Indian serfs laboured for the Spanish, their grim lives foreshortened by the (new) mercury extraction process, their drudgery only made bearable because of coca. After independence in the 1820s, use of coca leaf became universal in the Andes but was still innocently non-addictive.
Victorians tended to confuse refinement with purity and not only in social matters. Refined sugar, bread and drugs were considered "purer" and more virtuous than primary antecedents, but they did not know that purity encourages addiction.
Coca leaves became cocaine hydroxide in the 1850s and followed three routes. Liquefied cocaine made possible eye and mouth surgery and became the local anaesthetic par excellence; cocaine was used ethically - in experiments to defy fatigue and hunger and in early psychoanalysis - notably by Sigmund Freud. Thirdly, it became a recreation drink, included in the original Coca-Cola. During the 1920s, after legal restraints, cocaine became the drug of choice of the demi-monde, of night-clubs and film studios, especially in Berlin, New York and Hollywood.
Cheap flights from the Andes to the US increased the drug traffic a hundredfold between 1940 and 1970 and the 1960s culture encouraged drug use - "What I put into my body is my own business." The world-wide trade in cocaine (at street prices) is now larger than the UK GDP, but drug abuse can never be personal and cocaine and crack are much more addictive than other drugs.
It is argued that there seems to be no obvious compromise between Dutch tolerance and the savage prohibitions of Singapore. It is also true that no one can anticipate the unintended consequences of any policy.
Henry Hobhouse is the author of `Seeds of Change' (Papermac, pounds 12)Reuse content