The difference between these various elements of the commodity-value, which together make up the cost-price, leaps to the eye whenever a change takes place in the size of the value of either the expended constant, or the expended variable, part of the capital. Let the price of the same means of production, or of the constant part of capital, rise from £400 to £600, or, conversely, let it fall to £200. In the first case it is not only the cost-price of the commodity which rises from £500 to 600c + 100v = £700, but also the value of the commodity which rises from £600 to 600c + 100v + 100s = £800. In the second case, it is not only the cost-price which falls from £500 to 200c+100v = £300, but also the value of the commodity which falls from £600 to 200c + 100v + 100s = £400. Since the expended constant capital transfers its own value to the product, the value of the product rises or falls with the absolute magnitude of that capital-value, other conditions remaining equal. Assume, on the other hand, that, other circumstances remaining unchanged, the price of the same amount of labour-power rises from £100 to £150, or, conversely, that it falls from £100 to £50. In the first case, the cost-price rises from £500 to 400c + 150v = £550, and falls in the second case from £500 to 400c + 50v = £450. But in either case the commodity-value remains unchanged = £600; one time it is 400c + 150v + 50s, and the other time, 400c + 50v + 150s. The advanced variable capital does not add its own value to the product. The place of its value is taken in the product rather by a new value created by labour. Therefore, a change in the absolute magnitude of the variable capital, so far as it expresses merely a change in the price of labour-power, does not in the least alter the absolute magnitude of the commodity-value, because it does not alter anything in the absolute magnitude of the new value created by living labour-power. Such a change rather affects only the relative proportion of the two component parts of the new value, of which one forms surplus-value and the other makes good the variable capital and therefore passes into the cost-price of the commodity.