To pretend, as does the defender of the principle of property in inventions, in the ninth paragraph of his work, that the sudden and inconsiderate introduction of a new invention may cause a sensible injury to existing manufacturers, and that it is consequently advisable to maintain the system of Patents, which during a certain time limits their use and hinders production, to prevent the lowering of prices immediately at least; so to pretend is to renew the plea of the protected manufacturers, who demanded that the greatest precautions should be taken to facilitate the transition from Protection to Free-trade. But we do not see clearly what benefit there can be to the community at large in delaying the advantages to be derived from an invention. The misunderstood interests of certain manufacturers may appear to require this delay, but common sense tells us that manufacturers and consumers have every interest in immediately adopting every invention which saves labour, capital, and time. If we look back, we will see that a delay of this kind would have retarded for an indefinite period the discoveries of Columbus in order to avoid a sensible injury to the monopoly which Venice had acquired in Eastern commerce. We maintain, as indeed experience proves, that however innovating inventions may be, displacement of labour occurs gradually. We will only cite, in support of this assertion, the well-known instance of the substitution of printing for manuscript copying. It may be answered that the substitution of mechanical spinning and weaving for hand-work caused great suffering. We answer, that you should blame the system of Patents, which, raising inordinately the cost of the machines, must have restricted labour, although they lowered the price of the product. If there had been no royalty to pay to the inventor, the number of the machines would have rapidly increased, and a greater number of workmen would at once have found employment similar to that to which they had been accustomed. How many enterprising and intelligent speculators would most eagerly have availed themselves of these new outlets for their activity, if the course had been cleared of all these obstructions which the law has arbitrarily established. At the risk of being considered by the honourable Professor grossly ignorant of the laws of political economy, we do not believe that monopolies will always exist, as he ventures to affirm. We know that there always will be intellectual superiority, unrivalled artistic ability, or special natural advantages; but these do not constitute monopolies, in the proper acceptation of the term; and the object we shall not cease to strive for is that no others shall exist. X.