Fossil fuel is made from plants and animals which have died millions of years ago and with time they take the form of sedimentary rocks, such as coal and liquid hydrocarbons such as oil or gas. Each one of us uses fossil fuels in one way or another and this has led to an alarming increase in the demand and production of it.

Canning of foods first occurred in the 18th century but in jars! Due to the demands of long sea voyages, armies being away from home for long periods and the increasing needs of urban populations, effective means of food preservation were required.