But if to the accumulated and immediate labour worked up in commodities, we add the profits upon the whole advances for the time that they are advanced, we shall then make the proper allowance for the other element of value, and may expect to obtain a more accurate measure. If we had estimated the value of the labour advanced in money, or any other medium, we should of course estimate the profits in the same medium, and the natural price of the commodity estimated in such medium, would obviously be equal to the price of the accumulated and immediate labour expended on the commodity, together with the ordinary profits estimated upon such advances. But if, with a view to the natural conditions of supply, we consider only the quantity of labour advanced, without reference to any other medium, we must of course estimate the profits in quantity of labour also, which will give us an amount of labour in proportion to which commodities will be found to exchange with each other, just in the same way as they would exchange with each other according to the quantity of labour employed on them, if labour had been the sole ingredient which had entered into their composition. Thus, if a hundred days labour were employed upon a commodity, at two shillings a day, and the average interval between the advance of such wages and the period when the commodity could be brought to sale were a year, and profits were 20 per cent. the price of the commodity would be £12, while the price of a commodity which had cost the same quantity of labour of the same kind, and could be brought to market immediately, would be only £10. And it is equally certain, that, if putting money or any other medium of exchange out of the question, we had estimated the profits for a year upon the advances of the hundred days labour actually employed, we should obtain a quantity of labour which, compared with the labour employed on the commodity sold immediately, would be in the proportion of 120 to 100, and expressing the relative conditions of supply, would accurately measure the rate at which the two commodities obtained under these different circumstances would exchange with each other.