330 THE POPULAR SCIENCE MONTHLY. 



Here only a certain portion of the heat reappears in the shape of 

 available mechanical work, the proportion for the steam-engine being 

 one-twentieth of the heat produced by combustion of coal, and in the 

 human body one-sixth of the heat developed by the conversion of the 

 bodily constituents. 



Every one knows what a revolution this law has brought about in 

 physics and mechanics : it has added a new chapter to physiology. 



There is only one science which, so far, has drawn no advantage 

 from the discovery of the source of force and work, and that is no 

 other than the very science of work, or political economy in Ger- 

 man, Volkswirthschaftslelire. 



The grandest discovery in the doctrine of forces is as yet not even 

 mentioned, far less turned to account, in a science whose object, never- 

 theless, is simply force work. 



But, then, this science is called Wirthschaftslehre. Surely no 

 other name could so ill denote the thing as this, and I confess that I 

 have always had an aversion against calling honest work by such 

 a name. Wirthschaftslehre suggests ideas as remote as possible from 

 economy taverns and tavern-keeping. Far better is the Anglo- 

 French term of political economy. If we must have a German name 

 for the idea, let it be simply Arheitswissenschaft the science of 

 work for political economy, from first to last, has to do with nothing 

 but human labor and its relations.' 



But if we call this science no longer Volksvnrthschaft, or political 

 economy, but the science of labor, the very name will clearly show 

 that it can rest on no other basis save the law of energy, of motion 

 the great law of the mechanical equivalent of heat. For work, includ- 

 ing human work, is motion, and motion is heat. Of course, political 

 economy does not touch on the laws of nutrition, the laws of food- 

 substances or their transformation, for that is the province of chemis- 

 try and physiology. Political economy has to do only with the value 

 of work, its price, and thence explains the phenomena of the market. 

 Labor is the natural process whose social relations are known as 

 political economy. The fundamental idea Avhicli jjolitical economy 

 derives from labor is that of value. The production, the consump- 

 tion, and the exchange of values ( Werthschaffung , Werthverhrauch, 

 Werthtausch), are the three principal divisions of the science of po- 

 litical economy. 



In science there is no question that the value of a thing must ex- 

 press only the human labor expended on it. Price is the sum of the 

 values that are given in order to move the will of the owner to re- 

 nouncement of his right in the thing, liis possession and his enjoyment 

 of the work embodied in the thing. The idea of value requires deter- 



' For the benefit of the reader who is not acquainted with German, it may be well to 

 explain that in that language the ordinary meaning of the word Wirth is host, innkeeper; 

 and of Wirthschaft, innkeeping, tavern, public-house. 



