Equally as vital as gold was salt, which is fundamental to the functioning of the human body as well as for the task of preserving meat and vegetables. Although seawater could be made to evaporate to produce salt crystals, rock salt was also mined in places such as Africa, Poland and India. In the Roman Empire, salt was considered to be a type of currency. It is commonly believed, soldiers in these empires were either paid in salt or given money to buy salt with. The term "salary" derives from Latin salarium, which translates to "salt money, money to buy salt with".