New/used office furniture, etc.
All surplus value, whatever particular form into which it may subsequently crystallise, is in substance the materialisation of unpaid labour time. The secret of the self-valourisation of capital resolves itself into the fact that it has at its disposal a definite quantity of the unpaid labour of other people. In this chapter, Marx is comparing his formula with that of classical political economists, looking at their formula we can observe a few things. Essentially, their formula makes it appear that both capital and labour are rewarded according to their contribution to production. By treating surplus value and the value of labour power as fractions of the total value, it ignores the rate of exploitation which occurs in production, making it appear as if both the capitalists and labourers get their fair share. This formula ignores the fact that the capitalist doesn't buy labour, they buy labour power. They buy the price of labour power at its value Marx corrects the formula to which, Marx concludes, is essentially the popular expression. And while this popular expression in its wording still confuses the difference between labour and labour power, it does highlight exactly why workers are hired, to produce a surplus. Capital, therefore, is not only as Adam Smith says, the command over labour, it is essentially the command over unpaid labour.
