Now, if we take a closer look at the released, or rather suspended, capital, we find that a considerable part of it must always be in the form of money-capital. Let us adhere to our illustration: Working period — 6 weeks, period of circulation — 3 weeks, investment per week — £100. In the middle of the second working period, end of the 9th week, £600 return, and only £300 of them must be invested for the remainder of the working period. At the end of the second working period, £300 are therefore released. In what state are these £300? We shall assume that ⅓ is invested for wages and ⅔ are for raw and auxiliary materials. Then £200 of the returned £600 exist in the form of money for wages and £400 in the form of productive supply, in the form of elements of the constant circulating productive capital. But since only one half of this productive supply is required for the second half of the second working period, the other half exists for 3 weeks in the form of a surplus productive supply, i.e., of a supply exceeding the requirements of one working period. But the capitalist knows that he needs only one half, or £200, of this portion (£400) of the returned capital for the current working period. It will therefore depend on market conditions whether he will immediately reconvert these £200, in whole or in part, into a surplus productive supply, or keep them entirely or partially in the form of money-capital in anticipation of a more favourable market. On the other hand it goes without saying that the portion to be laid out for wages (£200) is retained in the form of money. The capitalist cannot store labour-power in warehouses after he has bought it, as he may do with the raw material. He must incorporate it in the process of production and pay for it at the end of the week. At any rate these £100 of the released capital of £300 will therefore have the form of money-capital set free, i.e., not required for the working period. The capital released in the form of money-capital must therefore be at least equal to the variable portion of capital invested in wages. At a maximum, it may comprise the entire released capital. In reality it fluctuates constantly between this minimum and maximum.