“The history of nations,” writes the Registrar-General of England,—“the history of nations on the Mediterranean or the plains of the Euphrates and Tigris, the deltas of the Indies and Ganges, and the rivers of China, exhibits the great fact: the gradual descent of race from the highlands, their establishment on the coasts, in cities sustained and refreshed for a season by emigration from the interior—their degradation in successive generations under the influence of the unhealthy earth, and their final ruin, effacement, or subjugation by new races of conquerors. The causes that destroy individual men lay cities waste, which, in their nature, are immortal, and silently undermine eternal empires.
“A thousand years scarce serve to form a state;
An hour may lay it in the dust: and when
Can man its shattered splendors renovate,
Recall its virtues back, and vanquish time and fate?”
VIII.
During this period of two centuries of colonization the European races have attempted to perpetuate their families upon these lands in question. They brought with them strong physical forces, and a high degree of mental cultivation. Mental strength will endure extremes of climate to a singular degree, but even this gradually yields to cosmic influences. It is a well-observed law of Nature that man must be organized in harmony with the condition of climate, otherwise he perishes. This scale of the strength of resisting opposing forces depends greatly upon the purity of the blood and the cultivation of the mind, whose remarkable powers of resisting disease have been observed and pointed out by Malte-Brun, Goethe, Kant, and other philosophers.
Europeans may visit and remain for limited periods in almost every portion of the globe. The deadly miasms of Central America, the pestilential atmospheres of Central Africa, and the frozen mists of either pole, are braved by the inquiring travellers of the civilized races, but not with impunity.
Intelligent and educated men may live for a while as gentlemen of leisure, in the midst of malarial climates, almost without perceptible effect, but the moment they apply their forces to the cultivation of the earth, Nature asserts her rights.
Yet during the period of the rich man, whilst he lives without physical labor, in ease, contemplation, and contentment, degeneration is slowly but surely taking place. The law of fecundity proves it, as with the Mamelukes in Egypt, as observed by Volney.
The English race loses its energy, according to Farr, in two or three generations in the lowlands of the West India Islands and in Southern Asia. The Duke of Wellington believed that every English family in Lower Bengal would die out in the third generation.
IX.