- Niger is the country with most of its population under 18 years. The United Arab Emirates has the smallest number of citizens over 65.
- There are 258.9 hectares – and 640 acres – in a section of land.
- Deontology is the study of moral obligation; ethics.
- Demeter is the Greek goddess of the harvest.
- Erethism is the disease related to the ‘Mad Hatter’ in Alice in Wonderland. It was in those days caused by vapours from mercury used to stabilize the felt wool in hatmaking.