Marx says: “We have seen that the means of production transfer value to the new product so far only as during the labour-process they lose value in the shape of their old use-value. The maximum loss of value that they can suffer in the process is plainly limited by the amount of the original value with which they came into the process, or in other words by the labour-time necessary for their production. Therefore, the 257 means of production can never add more value to the product than they themselves possess independently of the process in which they assist. However useful a given kind of raw material, or a machine, or other means of production may be, though it may cost £150, or say 500 days’ labour, yet it cannot under any circumstances add to the value of the product more than £150. Its value 1s determined not by the labour-process into which it enters as a means of production, but by that out of which it has issued as a product. In the labour-process it only serves as a mere use-value, a thing with useful properties, and could not therefore transfer any value to the product unless it possessed such value previously. The matter is succinctly put as follows: “The means of production on the one hand, labourpower on the other, are merely the different modes of existence which the value of the original capital assumed when from being money it was transformed into the various factors of the labour-process. That part of capital that is represented by the means of 258 production, by the raw material, auxiliary material, and the instruments of labour, does not in the process of production undergo any quantitative alteration of value. I therefore call it the constant part of capital, or more shortly constant capital.”
At first sight it might be thought that the wear and tear of the machinery, and the seeming disappearance of part of the auxiliary material (as e.g. the mordants used in dyeing cloth or yarn, or the gums, etc., used in textile printing) contradict this statement as to the alteration of value; but on closer view it will be seen that the above wear and tear and apparent consumption enter into the new product just as much as the visible raw material does; neither are really consumed, but transformed.