Chapter 5: The Origin of a Chemical Concept: The Ongoing Discovery of Potassium

This chapter discusses the historical ‘discovery’ of potassium, and the formation and development of the scientific concept {potassium}. The chemical concept {potassium} has developed over time. Davy characterised potassium using the range of laboratory techniques available to him. Since then, new techniques have allowed potassium to be characterised in additional ways. These developments have changed the chemical concept {potassium} by adding new associations not available in Davy's time. The content of the concept has grown, such that there are a wider variety of ways to discriminate samples of potassium from non-examples, although this has not changed which samples would be included as examples of potassium. The {potassium} concept now includes properties of potassium that are completely unobservable without sophisticated apparatus that was not even imagined when the concept was first introduced into chemistry.