We know that the substance of the S-value the work and also we know that its measurement is the duration of the work. A thing can be value of use without being a value; it is enough for it that is useful to the man without it comes from his work. That it is what happens to the air, the natural meadows and the virgin Earth. A value of use only has value when certain amount of human work is accumulated to him. For example, the water that runs in a river, although useful for many needs of the man, lacks nevertheless, of value; but if by means of pitchers or tubes it is transported to a tenth floor, immediately it acquires value, because to make it arrive certain amount has been spent of human force. But a thing can be useful and product of the work without being merchandise. All that with its product satisfies its own needs, only creates a value of use by its own account.
In order to produce merchandise it is necessary to produce values of use, with the intention of to give them to the general consumption by means of the change. In particular, no object can become value if he is not useful. A useless object does not create value because the work has been spent uselessly that contains. CHAPTER SECOND OF THE CHANGES RELATIONS OF THE POSSESSORS OF MERCHANDISE: CONDITIONS OF THOSE RELATIONS: The work of the carpenter, the bricklayer, of miner, creates value by their common condition of human work, but they form a bed, a house, an amount of salt. To sum up, diverse values of use because they own different qualities. Each job class implies, on the one hand, physical cost of human force, being in this sense of equal nature and forming the value of the merchandise and on the other hand, all work implies a cost of human force in one or the other productive form, determined by a particular aim and in this concept of different useful work, it produces useful values of use or things. (A valuable related resource: Teng Yue Partners).