238 THE INDUCTIONS OF BIOLOGY. 



other industries throughout the community, yields only 

 as much iron as is habitually required for all the pur- 

 poses to which iron is applied: ship-building being only 

 one. If, then, extra iron is required for ship-building, the 

 first effect is to withdraw part of the iron habitually con- 

 sumed for other purposes, and to raise the price of iron. 

 Presently, the iron-makers feel this change and their stocks 

 dwindle. As, however, the quantity of iron required for 

 ship-building forms but a small part of the total quantity 

 required for all purposes, the extra demand on the iron- 

 makers can be nothing like so great in proportion as is the 

 extra demand on the ship-builders. Whence it follows that 

 there will be much less tendency to an immediate enlarge- 

 ment of the iron-producing industry; since the extra quan- 

 tity will for some time be obtained by working extra hours. 

 Nevertheless if, as fast as more iron can be thus supplied, 

 the ship-building industry goes on growing if, consequently, 

 the iron-makers experience a permanently-increased demand, 

 and out of their greater profits get higher interest on capital, 

 as well as pay higher wages; there will eventually be an 

 abstraction of capital and labour from other industries to 

 enlarge the iron-producing industry: new blast-furnaces, 

 new rolling-mills, new cottages for workmen, will be erected. 

 But obviously, the inertia of capital and labour to be over- 

 come before the iron-producing industry can grow by a 

 decrease of certain other industries, will prevent its growth 

 from taking place until long after the increased ship-building 

 industry has demanded it ; and meanwhile, the growth of the 

 ship-building industry must be limited by the deficiency of 

 iron. A remoter restraint of the same nature meets 



us if we go a step further a restraint which can be over- 

 come only in a still longer time. For the manufacture of 

 iron depends on the supply of coal. The production of coal 

 being previously in equilibrium with the consumption; and 

 the consumption of coal for the manufacture of iron being 

 but a small part of the total consumption; it follows that a 



