118 
POLITICAL ECONOMY 
pieces of money are not wanted to keep 
but to pass on. However, to this objection 
it may be retorted that all the things that 
we buy are not goods which we retain per 
manently or for long. Many of the things 
really sought when we make purchases are the 
services associated with objects which are 
passed on to perform the same services for 
other people when so much of each service 
as we require has been used up by ourselves. 
When we habitually have recourse to railway 
trains, we do not and cannot buy them for 
our private use, but we take on each occasion 
from a public conveyance just as much of 
the service of transportation as we require. 
It is not only money that circulates, as it is 
put : railway trains and ships, and telegraph 
boys and hired waiters circulate also, and in 
circulating do work for which the community 
is ready to pay a price 
Let us consider next how the prices of 
these things that circulate are settled. In 
dealing, say, with the price of cabs in a 
community, we have to analyse the forces of 
demand and supply. Certain utilities con 
sisting in rides in cabs are demanded, and the 
supply with which we are primarily concerned 
is the supply not of cabs but of the services 
performed by cabs. These services, however,