Capital of under 80 per cent. constant portion and over 20 per cent. variable portion he calls capital of a lower composition. And rightly, because the higher the ladder of capitalist production is, the more costly and extensive are the machinery and factory buildings and the greater is the outlay on raw materials, whereas primitive businesses employ less machinery, cheaper workshops, but a relatively greater number of workers. The relation between (c) and (v) reveals at the same time the stage to which production has developed. Thus, according to Marx, it is solely the variable capital which creates surplus value, or, as it is commonly expressed, profit. We have seen above, in the explanation of the nature of wages, why variable capital creates more value than it is paid for by the capitalist; the worker does indeed receive the exchange value of his labour power, but the use value of the labour power functions, we have assumed, twice as many hours as are necessary for its reproduction. This surplus labour is embodied in surplus value. While the worker receives, let us say, a daily wage of three shillings, for the reproduction of which five hours of work suffice, his labour power will be used for ten hours. These five hours of surplus labour appear in the exchange value of the commodity, so that the value of the commodity is composed of the transferred portion of the constant capital, the outlay on wages, and the added surplus value. Immediately before the production process only constant and variable capital existed, or, in brief (c) and (v); after the completion of the production process, the commodity embodies constant and variable capital and also surplus value, or (c) and (v) and (s). This is the actual value of the commodity, (c) or, shortly expressed, c + v + s. The relation between wages and surplus value, or between paid and unpaid labour, or, shortly, s/v, Marx calls the rate of surplus value: it expresses the degree of the exploitation of labour. If wages amount to three shillings, which can be produced in five working hours, and if the worker works in the factory ten hours for these wages, so that he creates exchange value to the amount of six shillings, then the rate of surplus value is 100 per cent. The whole of the surplus value which arises in this manner in the process of production is called the mass of the surplus value, or shortly, m.s., that is to say, the individual rate of surplus value multiplied by the total number of workers engaged in an undertaking, or the total amount of wages. 5. _Profit._ The mass of surplus value appears to the capitalist in the shape of profit. Surplus value is a Marxian scientific term which exactly expresses the principle of profit. Profit is a commercial expression which describes surplus value as it appears in practical life as a subject of experience, i.e., empirically.