I should rather draw a contrary inference and consider it an argument of their fullness, though this inference is not certain, because there are many thinly inhabited states that are yet stationary in their population.

To speak, therefore, correctly, perhaps it may be said that the number of unmarried persons in proportion to the whole number, existing at different periods, in the same or different states will enable us to judge whether population at these periods was increasing, stationary, or decreasing, but will form no criterion by which we can determine the actual population.
There is, however, a circumstance taken notice of in most of the accounts we have of China that it seems difficult to reconcile with this reasoning.

It is said that early marriages very generally prevail through all the ranks of the Chinese.

Yet Dr Adam Smith supposes that population in China is stationary.

These two circumstances appear to be irreconcilable.