Dr. Archdall Reid, in his essay on race supremacy, explains that the evolution of civilised peoples is against disease, and the age of pestilence and plague is passing. This picture of an incident in the greatest plague that has affected London in historical times—in the year 1665—is from the painting by F. W. Topham, R. I.
LARGER IMAGE
All our information indicates the Eastern Hemisphere as the place of origin both of man and of his microbic diseases. Parts of it have been inhabited by a dense and settled population from a time immensely remote. “Behind dim empires ghosts of dimmer empires loom.” Beyond the traces of the oldest civilisations we find evidences of primitive agricultural communities, and far beyond these the remains of the cave-men and hunters of the Stone Age. Even a race of hunters tends to increase faster than the food supply. Doubtless the pressure of population in the Old World led to the colonisation of the New. But even in the New World there are signs of a civilisation so ancient that some authorities have placed its beginnings as far back as a score or more of thousands of years. With the exception of malaria, it is extremely doubtful whether any zymotic disease existed in the whole of the New World at the time of its discovery by Columbus.
The subject is involved in obscurity; but, while it is evident that the European adventurers introduced many diseases, there is no clear indication that they found and brought back one. Apparently all the diseases which have been prevalent in Europe and America during the last four hundred years were prevalent in the former continent before the fifteenth century. Venereal disease and yellow fever have sometimes been regarded as exceptions. But the former was well known to the Roman physicians, and was common during the Middle Ages. Moreover, the inhabitants of the New World take the disease in a very acute form, and it is not found in remote communities to which Europeans have had no access. Yellow fever was first noted with certainty in the West Indies in the middle of the seventeenth century. The records of the time “tell of the importation of the disease from place to place, and from island to island.”
Origins of Rare Diseases
Not till more than a century later was it observed on the West Coast of Africa. There can be no doubt, however, that the earlier observers confused yellow fever with bilious malaria, and that it was present both in the West Indies and Africa long before a differential diagnosis was made. The fact that of all races negroes are most resistant to the disease would seem to indicate West Africa as the place of origin. In any case, it is certain that, with the exception of malaria, zymotic diseases, if not entirely absent, were extremely rare in the New World.
THE DISAPPEARANCE OF THE NATIVE RACES
The Age of Pestilence is Passing
Z
ZYMOTIC disease, then, arose amongst the slowly-growing populations of the Old World. Air and insect borne diseases may have arisen amongst the early hunters and nomads. Similar forms of disease, murrains as they were anciently termed—for example, distemper, rinderpest, the horse sickness in South Africa, the rabbit plague in Northern Canada, and the cattle fever in Texas—occur among lower animals, when these are present in considerable numbers. With the exception of tuberculosis and leprosy, endemic disease was probably almost unknown in the sparsely-peopled ancient world. The facts that air and water borne diseases spread very rapidly, that the illnesses caused by them are comparatively short and sharp, and that recovery is followed by immunity, must have caused rapid exhaustion of the food supply of the microbes. Under such conditions the persistence of the pathogenic species was maintained among the scanty populations by a passage to new and perhaps very distant sources of supply.