We have already shown [Karl Marx, Capital, Vol. I, Ch. VI, pp. 167-76. — Ed.] that the money which the capitalist pays to the labourer for the use of his labour-power is nothing more or less than the form of the general equivalent for the means of subsistence required by the labourer. To this extent, the variable capital consists in substance of means of subsistence. But in this case, where we are discussing turnover, it is a question of form. The capitalist does not buy the labourer’s means of subsistence but his labour-power. And that which forms the variable part of his capital is not the labourer’s means of subsistence but his labour-power in action. What the capitalist consumes productively in the labour-process is the labour-power itself and not the labourer’s means of subsistence. It is the labourer himself who converts the money received for his labour-power into means of subsistence, in order to reconvert them into labour-power, to keep alive, just as the capitalist for instance converts a part of the surplus-value of the commodities he sells for money into means of subsistence for himself without thereby warranting the statement that the purchaser of his commodities pays him in means of subsistence. Even if the labourer is paid a part of his wages in means of subsistence, in kind, this nowadays amounts to a second transaction. He sells his labour-power at a certain price, with the understanding that he shall receive a part of this price in means of subsistence. This changes merely the form of the payment, but not the fact that what he actually sells is his labour-power. It is a second transaction, which does not take place between the labourer and the capitalist, but between the labourer as a buyer of commodities and the capitalist as a seller of commodities, while in the first transaction the labourer is a seller of a commodity (his labour-power) and the capitalist its buyer. It is exactly the same as if a capitalist, on selling his commodity, say, a machine, to an iron works, has it replaced by some other commodity, say, iron. It is therefore not the labourer’s means of subsistence which acquire the definite character of circulating capital as opposed to fixed capital. Nor is it his labour-power. It is rather that part of the value of productive capital which is invested in labour-power and which, by virtue of the form of its turnover, receives this character in common with some, and in contrast with other, component parts of the constant capital.