Aristotle,the Greek philosopher,sum

Aristotle,the Greek philosopher,summed up the four chief qualities of money some 2000 years ago. It must be lasting and casy to recognize,to devide,and to carry about. In other words it must be: durable,distinct,divisible,and portable. When we think of money today,we picture it either as round,flat pieces of metal which we call coins,or as printed paper notes. But there are still parts of the world today where coins and notes are of no use. They will buy nothing,and a traveller might starve if he had none of the particular local "money" to exchange for food
Among isolated people,who are not often reached by traders from outside,commerce usually means barter. There is a direct exchange of goods. Perhaps it is fish for vegetables,,meat for grain,or various kinds of food in exchange for pots,baskets,or other manufactured goods. For this kinds of simple trading,money is not needed,but there is often something that everyone wants and everybody can use,such as salt to flavour food,shells for ornament,or iron and copper to make into tools and vessels. These things: satl,shells or metals are still usedas money in out of the way parts of the world today.
Salt may seem rather a strange substance to use as money,but in countries where the food of the people is mainly vegetable,it is often an absolute necessity. Cakes of salt,stamped to show their value,were used as money until recent times. Cakes of salt will still buy goods in Borneo and some parts of Africa...