Now, if we were to compare an oak tree, worth 25_l._, with a quantity of hardware worth the same sum, the value of which was chiefly made up of human labour; and as the reason why these two objects were of the same value, were to state that the same quantity of labour had been worked up in them—we should obviously state a direct falsity, according to the common usage of language; and nothing could make the statement true, but the magical influence of a new meaning given to the term labour. But to make labour mean profits, or fermentation, or vegetation, or rent, appears to me quite as unwarrantable as to make stones mean plums. To _measure_ profits by labour is totally a different thing. Adam Smith always keeps wages, profits, and rent quite distinct; and when he mentions one of them, never thinks of including in the same term any other. But he observes, that “labour _measures_ the value not only of that part of the price of a commodity which resolves itself into labour, but of that which resolves itself into rent, and of that which resolves itself into profit.”[44] This is perfectly just; and, in particular, nothing can be more natural and obvious than to measure by labour the increase of value which commodities derive from profits; because profits are a per centage upon the advances, and the main original advances in the great mass of commodities are the necessary quantity of labour.[45] Thus, if a hundred days’ labour be advanced for a year,[45] in order to produce a commodity, and the rate of profits be 10 per cent., it is impossible in any way to represent so correctly the increase of value which the commodity derives from profits as by adding 10 per cent., or whatever may be the rate of profits, to the quantity of labour actually employed, and saying, that the completed commodity when sold would be worth ten days’ labour more than the quantity of labour worked up in it. On the other hand, if we were ignorant of the rate of profits, but found that a hundred days’ labour advanced for a year would produce a commodity which would ordinarily sell for the value of one hundred and ten days, we might safely conclude that ordinary profits were 10 per cent. Now, if we were to compare two commodities, on each of which a hundred days’ labour had been employed, and one of them could be brought to market immediately, the other in not less time than a year, it is quite obvious, that we could not say that they would exchange with each other according to the quantity of labour worked up in them; but we evidently could say, that they would exchange with each other according to the quantity of labour _and of profits_ worked up in them, and that one of them would be 10 per cent. more valuable than the other, because profits had added the value of ten days’ labour to the labour actually employed upon the one; while there being no profits in the other, its value was only in proportion to the labour actually employed upon it.