When commodities are obtained by the assistance of a large proportion of fixed capital of a very durable nature, the advances are only consumed in part, and the whole produce of the accumulated and immediate labour employed must be considered as composed of the new produce obtained, together with the remainder of the fixed capital which is unconsumed.[B] In reference to the separate value of the new produce, this will be the same as if to the labour actually worked up in such produce were added the profits of the whole capital advanced. It sometimes happens that the proportion of value arising from these profits is very considerable; and commodities so produced will necessarily have much less labour worked up in them, and will be much more affected in their value by a rise or fall of profits, than those which are composed mainly of immediate labour. Thus, if a commodity were produced by the aid of accumulated labour in machinery worth £2,000, the annual wear and tear of which was one-twentieth, or £100, and the labour employed on cheap materials and in the working of the machinery were worth £200, while profits were 20 per cent. then the value of the labour worked up in the commodity would be £100 added to £200, equal to £300; and the whole capital advanced being £2,300, the profits upon it would be £460, which, added to £300 would make the whole value of the produce £760. Compared with a commodity of equal value which had been produced without fixed capital, and had yet been brought to market in the same time and with the same rate of profits, it would contain less than half of the labour worked up in it; while, if profits were to fall from 20 per cent. to 10 per cent. the value of the commodity would fall in the proportion of from £760 to £530, or, if profits had been 10 per cent. and were to rise to 20 per cent. the value of the commodity would rise in the proportion of from £530 to £760, or above 42 per cent., without any change in the quantity of labour employed.[C] It must be allowed, then, that whenever two elements are necessary to the supply, and enter into the composition of commodities, their value cannot depend exclusively upon one of them, except by accident, or when the other can be considered as a given or common quantity. But it is universally acknowledged, that the great mass of commodities in civilized and improved countries is made up at the least of two elements--labour and profits; consequently, the exchangeable value of commodities into which these two elements enter as the conditions of their supply, will not depend exclusively upon the quantity of labour employed upon them, except in the very peculiar cases when both the returns of the advances and the proportions of fixed and circulating capitals are exactly the same. It cannot, then, be said with any thing like an approximation towards correctness, that the labour worked up in commodities is the measure of their exchangeable value.