Though all capitals are destined for the maintenance of productive labour only, yet the quantity of that labour which equal capitals are capable of putting into motion, varies extremely according to the diversity of their employment; as does likewise the value which that employment adds to the annual produce of the land and labour of the country.
A capital may be employed in four different ways; either, first, in procuring the rude produce annually required for the use and consumption of the society; or, secondly, in manufacturing and preparing that rude produce for immediate use and consumption; or, thirdly in transporting either the rude or manufactured produce from the places where they abound to those where they are wanted; or, lastly, in dividing particular portions of either into such small parcels as suit the occasional demands of those who want them. In the first way are employed the capitals of all those who undertake improvement or cultivation of lands, mines, or fisheries; in the second, those of all master manufacturers; in the third, those of all wholesale merchants; and in the fourth, those of all retailers. It is difficult to conceive that a capital should be employed in any way which may not be classed under some one or other of those four.
Each of those four methods of employing a capital is essentially necessary, either to the existence or extension of the other three, or to the general conveniency of the society.