defend themselves with greater assurance. This custom, by the unwise
practice of princes and republics, having gone into desuetude, the ruin
and weakness of territories has followed; for this ordination is that
by which alone empires are made secure, and countries become populated.
Safety is the result of it; because the colony which a prince
establishes in a newly acquired country, is like a fortress and a
guard, to keep the inhabitants in fidelity and obedience. Neither can
a province be wholly occupied and preserve a proper distribution of its
inhabitants without this regulation; for all districts are not equally
healthy, and hence some will abound to overflowing, while others are
void; and if there be no method of withdrawing them from places in which
they increase too rapidly, and planting them where they are too few the
country would soon be wasted; for one part would become a desert, and
the other a dense and wretched population. And, as nature cannot repair
this disorder, it is necessary that industry should effect it, for
unhealthy localities become wholesome when a numerous population is
brought into them. With cultivation the earth becomes fruitful, and the
air is purified with fires--remedies which nature cannot provide. The
city of Venice proves the correctness of these remarks. Being placed in
a marshy and unwholesome situation, it became healthy only by the
number of industrious individuals who were drawn together. Pisa, too, on
account of its unwholesome air, was never filled with inhabitants,
till the Saracens, having destroyed Genoa and rendered her rivers
unnavigable, caused the Genoese to migrate thither in vast numbers, and
thus render her populous and powerful. Where the use of colonies is not
adopted, conquered countries are held with great difficulty; districts
once uninhabited still remain so, and those which populate quickly
are not relieved. Hence it is that many places of the world, and
particularly in Italy, in comparison of ancient times, have become
deserts. This has wholly arisen and proceeded from the negligence of