The general formula for enlarged reproduction under the rule of capital thus runs as follows: _c + v + s/x + s´_. Here _s/x_ stands for the capitalised part of the surplus value appropriated in an earlier period of production; _s´_ stands for the new surplus value created by the increased capital. Part of this new surplus value is capitalised again, and expanding reproduction is thus, from the capitalist point of view, a constantly flowing process of alternate appropriation and capitalisation of surplus value. So far, however, we have only arrived at a general and abstract formula for reproduction. Let us now consider more closely the concrete conditions which are necessary to apply this formula. The surplus value which has been appropriated, after it has successfully cast off its commodity-form in the market, appears as a given amount of money. This money-form is the form of its absolute value, the beginning of its career as capital. But as it is impossible to create surplus value with money, it cannot, in this form, advance beyond the threshold of its career. Capital must assume commodity-form, so that the particular portion of it which is earmarked for accumulation can be capitalised. For only in this form can it become productive capital; that is, capital begetting new surplus value. Therefore, like the original capital, it must again be divided into two parts; a constant part, comprising the inanimate means of production, and a variable part, the wages. Only then will our formula _c + v + s_ apply to it in the same way as it applied to the old capital. But the good intent of the capitalist to accumulate, his thrift and abstinence which make him use the greater part of his surplus value for production instead of squandering it on personal luxuries, is not sufficient for this purpose. On the contrary, it is essential that he should find on the commodity market the concrete forms which he intends to give his new surplus value. In the first place, he must secure the material means of production such as raw materials, machines etc. required for the branch of production he has chosen and planned, so that the particular part of the surplus value which corresponds to his constant capital may assume a productive form. Secondly, the other, variable part of his surplus value must also be convertible, and two essentials are necessary for this conversion: of first importance, the labour market must offer a sufficient quantity of additional labour, and secondly, as the workers cannot live on money alone, the commodity market, too, must offer an additional amount of provisions, which the workers newly to be employed may exchange against the variable part of the surplus value they will get from the capitalist.