[C] The effects of slow or quick returns, and of the different proportions of fixed and circulating capitals, are distinctly allowed by Mr. Ricardo; but in his last edition, (the third, p. 32.) he has much underrated their amount. They are both theoretically and practically so considerable as entirely to destroy the position that commodities exchange with each other according to the quantity of labour which has been employed upon them; but no one that I am aware of has ever stated that the different quantity of labour employed on commodities is not a much more powerful source of difference of value. [D] Colonel Torrens, by representing capital under the form of certain quantities of cloth and corn, instead of value in labour, has precluded himself from the possibility of giving a just view either of value, profits, or effectual demand. An increase of cloth and corn from the same quantity of labour is of no avail whatever in increasing value, profits, or effectual demand, if this increased produce will not command so much labour as before, an event which is continually occurring, from deficiency of demand. [E] Agricultural labour is taken for the obvious reasons that it is the commonest species of labour, that it directly produces the food of the labourer, and that it is the most immediately connected with the gradations of soil, and the necessary variations of profits. It is also assumed with Adam Smith, Mr. Ricardo, and other political economists, that, on an average, other kinds of labour continue to bear the same proportions to agricultural labour. [F] In my last work, I thought that a mean between corn and labour might be a better measure of value than labour alone; but I am now convinced that I was wrong, and that labour alone is the true measure. [G] Whenever it is said that the value of labour rises in the progress of cultivation, a comparison is made between the value of a given quantity of labour at two different periods; and when it is added that wages rise in proportion to the quantity of labour required to produce them, objects are measured solely by the quantity of labour employed upon them, although the rate of profits may be totally different.