have swelled within two centuries to upward to two millions and a half. The capacity of increase is necessarily in a geometrical progression: the numerical ratio alone is different.
To this property of organized beings, the human species forms no exception. Its power of increase is indefinite, and the actual multiplication would be extraordinarily rapid, if the power were exercised to the utmost. It never is exercised to the utmost, and yet, in the most favorable circumstances known to exist, which are those of a fertile region colonized from an industrious and civilized community, population has continued, for several generations, independently of fresh immigration, to double itself in not much more than twenty years.
| Years. | Population. | Food. |
|---|---|---|
| 25 | 11 mills | x |
| 25 | 22 mills | 2x |
| 25 | 44 mills | 3x |
| 25 | 88 mills | 4x |
| 25 | 176 mills | 5x |
By this table it will be seen that if population can double itself in twenty-five years, and if food can only be increased by as much as x (the subsistence of eleven