First, they cannot keep the race alive, they are always tending to
decay. When first encountered by civilization, they usually tell stories
of their own decline in numbers, and after that the downward movement is
accelerated. They are poor, ignorant, improvident, oppressed by others'
violence, or exhausted by their own; war kills them, infanticide and
abortion cut them off before they reach the age of war, pestilences
sweep them away, whole tribes perish by famine and smallpox. Under the
stern climate of the Esquimaux and the soft skies of Tahiti, the same
decline is seen. Parkman estimates that in 1763 the whole number of
Indians east of the Mississippi was but ten thousand, and they were
already mourning their own decay. Travellers seldom visit a savage
country without remarking on the scarcity of aged people and of young
children. Lewis and Clarke, Mackenzie, Alexander Henry, observed this
among Indian tribes never before visited by white men; Dr. Kane remarked
it among the Esquimaux, D'Azara among the Indians of South America, and
many travellers in the South-Sea Islands and even in Africa, though the
black man apparently takes more readily to civilization than any other
race, and then develops a terrible vitality, as American politicians
find to their cost.

Meanwhile, the hardships which thus decimate the tribe toughen the
survivors, and sometimes give them an apparent advantage over civilized
men. The savages whom one encounters are necessarily the picked men of
the race, and the observer takes no census of the multitudes who have
perished in the process. Civilization keeps alive, in every generation,
multitudes who would otherwise die prematurely. These millions of
invalids do not owe to civilization their diseases, but their lives. It
is painful that your sick friend should live on Cherry Pectoral; but if
he had been born in barbarism, he would neither have had it to drink nor
survived to drink it.