At the time Hans Sloane was training to be a doctor, most medicines came from plants. All doctors had to study them as part of their training.
Sailors and scientists were also bringing back exciting new plants from voyages across the world. People wanted to know all about them, especially if they might be useful. So it was natural for Sloane to use his time in Jamaica to explore everything he could about the island?s plants.
Sloane saw how Jamaicans brewed a bitter drink from the seed pods of the cocoa tree. They still prepare it in the same way today. But the drink made him feel sick, so he added sugar and milk instead of water ? and hot chocolate was born. Back home in England, he made a lot of money promoting drinking chocolate as a medicine.
Later, botanists named the cocoa plant Theobroma cacao ? Theobroma means 'food of the gods'.
If you read Sloane's descriptions of how plants were used as medicines, you?ll probably find them hard to understand, and not just because the terms he uses are very unfamiliar. When Sloane studied medicine, ideas about the body and what made you ill were very different from today.
Doctors were taught there were four fluids, or humours, in the body ? blood, phlegm, black bile and yellow bile ? an idea that went back to ancient Greece. Each humour was linked with a pair of 'qualities'.
Illness was thought to be caused by an imbalance in the humours in the body and treatments aimed to restore the balance. So you?ll find lots of references to medicines that purged or made you vomit to get rid of an excess humour. Bloodletting if you had a fever, to let out the excess ?hot, wet? blood, was also very common and could be fatal to an already weak patient.