These facts disprove Mr. Sadler’s principle; and the fact on which he lays so much stress—that the fecundity is less in the great towns than in the small towns—does not tend in any degree to prove his principle. There is not the least reason to believe that the population is more dense, on a given space, in London or Manchester than in a town of 4,000 inhabitants. But it is quite certain that the population is more dense in a town of 4,000 inhabitants than in Warwickshire or Lancashire. That the fecundity of Manchester is less than the fecundity of Sandwich or Guildford is a circumstance which has nothing whatever to do with Mr. Sadler’s theory. But that the fecundity of Sandwich is greater than the average fecundity of Kent,—that the fecundity of Guildford is greater than the average fecundity of Surrey,—as from his own tables appears to be the case,—these are facts utterly inconsistent with his theory.
We need not here examine why it is that the human race is less fruitful in great cities than in small towns or in the open country. The fact has long been notorious. We are inclined to attribute it to the same causes which tend to abridge human life in great cities,—to general sickliness and want of tone, produced by close air and sedentary employments. Thus far, and thus far only, we agree with Mr. Sadler, that, when population is crowded together in such masses that the general health and energy of the frame are impaired by the condensation, and by the habits attending on the condensation, then the fecundity of the race diminishes. But this is evidently a check of the same class with war, pestilence, and famine. It is a check for the operation of which Mr. Malthus has allowed.
That any condensation which does not affect the general health will affect fecundity, is not only not proved—it is disproved—by Mr. Sadler’s own tables. Mr. Sadler passes on to Prussia, and sums up his information respecting that country as follows:—
After the table comes the boast as usual:
“Thus is the law of population deduced from the registers of Prussia also; and were the argument to pause here, it is conclusive. The results obtained from the registers of this and the preceding countries exhibiting, as they do most clearly, the principle of human increase, it is utterly impossible should have been the work of chance; on the contrary, the regularity with which the facts class themselves in conformity with that principle, and the striking analogy which the whole of them bear to each other, demonstrate equally the design of Nature, and the certainty of its accomplishment.”
We are sorry to disturb Mr. Sadler’s complacency. But, in our opinion, this table completely disproves his whole principle. If we read the columns perpendicularly, indeed, they seem to be in his favour. But how stands the case if we read horizontally? Does Mr. Sadler believe that, during the thirty years which elapsed between 1754 and 1784, the population of Prussia had been diminishing? No fact in history is better ascertained than that, during the long peace which followed the seven years’ war, it increased with great rapidity. Indeed, if the fecundity were what Mr. Sadler states it to have been, it must have increased with great rapidity. Yet, the ratio of births to marriages is greater in 1784 than in 1754, and that in every province. It is, therefore, perfectly clear that the fecundity does not diminish whenever the density of the population increases.
We will try another of Mr. Sadler’s tables: