2 2 POPULAR SCIENCE MONTHLY. 



proportion to such quantity of the commodity as might be accepted 

 by the seller for and yielded by the buyer to obtain the article 

 exchanged. Such a commodity used for the convenience of ex- 

 change is money ; and all peoples who at different places on the 

 earth's surface at different times have step by step risen from 

 barbarism through barter have made use of money. Different 

 commodities at different places and with different peoples have 

 served for this purpose — skins with one tribe, shells with another, 

 beads with another, and even in our own country, within the last 

 two hundred years, the leaves of the tobacco plant. But no other 

 substances known to man have so completely possessed the attri- 

 butes of permanence of form, durability, and divisibility as the 

 metals ; and therefore lead, tin, copper, silver, and gold have been 

 very extensively used as money. 



Another characteristic essential for a commodity used as 

 money is its acceptability, not only among the persons of a par- 

 ticular locality, whose efforts are interchanged, but among the 

 people of all localities whose efforts are interchanged. The shells 

 accepted by the members of one tribe might not be acceptable as 

 money by the members of another tribe among whom skins were 

 used for that purpose. If the members of the tribe using shells 

 as money wove mats and molded pots, which were acceptable for 

 exchange for tools made by the tribe using skins as money, and 

 the money of neither tribe were acceptable to members of the 

 other, there would be direct barter of the tools of one tribe for 

 the mats and pots of the other. But as barter between individ- 

 uals of one locality results in confusion, so also does barter be- 

 tween individuals of different localities, and the confusion in the 

 processes of exchange by barter becomes the more inextricable as 

 an increasing number of people in an increasing number of local- 

 ities produce an increasing number of articles acceptable for 

 exchange among the different peoples of the different localities. 

 With the extension of intercourse between tribe and tribe, race 

 and race, has therefore increased the tendency toward the use as 

 money of commodities acceptable as money over the more ex- 

 tended territory occupied by the peoples whose efforts were inter- 

 changed. With the increase of this tendency the use of metals 

 as money increased. They have been found in nearly all parts 

 of the earth, and because of their general acceptability— that is, 

 because of a certain common estimation in which they have been 

 held — they have attained to a degree uniformity of value, which 

 has the more nearly approximated perfect uniformity of value as 

 the use of metals as money has become restricted to the metals 

 meeting in greatest degree the requirements of money, which are 

 silver and gold. And as the common needs of similarly situated 

 groups of people have resulted in the formation of the more or 



