230 THE POPULAR SCIENCE MONTHLY. 



some industries the tendency is one way, and in some the other. In 

 still others it is merely a question of how much of the work each con- 

 tributor shall do. Shall the iron-master buy his iron in the bar, in the 

 pig, or in the ore ? Shall the woolen manufacturer buy his wool in 

 the crude web, in the yarn, or in the fleece ? Fifty years ago it was 

 quite common for the same family to rear and shear the sheep, wash 

 the fleece, card it, spin it, weave it, color it, and make it into clothing 

 though different members of the family attended to different parts 

 of the work. That was a combination of the second form. At present 

 wool-growing and woolen-manufacturing are separated. Sometimes 

 the spinning and weaving are separated. As a rule, the weaving and 

 making are separated. 



It is into this third form of combination that what is called exchange 

 enters. Exchange is so important a phenomenon that political economy 

 is often called the science of exchanges. This definition, as we now 

 see, narrows its field. The real subject-matter of political economy is 

 the mutual helpfulness of human beings in making a living. Exchange 

 is only one of the ways of making this helpfulness effective. None the 

 less, persons between whom exchange is hindered or prohibited are to 

 that extent kept from helping one another to make a living. The 

 wool-grower and the sheep-shearer are just as truly engaged in the 

 production of cloth as the weaver. If the wool-grower is prohibited 

 from furnishing wool to the weaver, it is plain that both are hindered 

 in their joint work. 



4. In the fourth form of combination, also, exchange prevails as a 

 pi-ominent feature. But here we take leave of one feature which has 

 thus far characterized all forms of combination. It is unity of f)roduct. 

 Each party now completes his product, ready to enter into the living 

 of a fellow-being. One hunts and the other fishes, and the hunter 

 trades game for fish. Each then has for his supper a variety consist- 

 ing of game and fish. Rarely, indeed, is the exchange so simple as 

 this. In civilized societies it is highly complex, and its problems baffle 

 the best of brains. If we sit down to a meal, we find that one set of 

 men have furnished us the table, another set the table-cloth, another 

 the dishes, another the silver, another the bread, another the butter, 

 another the pepper, another the salt, another the sugar, another the 

 coffee, another this, and another that, until a score of groups and thou- 

 sands of persons might be counted, all of whom have helped us to get 

 our dinner to make our living. 



5. There is a fifth form of combination, more simple than the third 

 or fourth, and yet in one sense more complex. In this the service ren- 

 dered on one side is direct, and on the other indirect. There is no ex- 

 change of products, and, in fact, generally no product. The physician, 

 the minister, the lawyer, the teacher, and the housemaid, all help us in 

 making a living. They do not help us by making some material thing 

 and sending it to us. They help us personally and directly. We in 



