ANCIENT EPIDEMICS 277 



formerly much more common and severe. The Great Plague of 

 1666 was the last very destructive epidemic in England, but it was 

 not nearly so destructive as the Black Death, which occurred some 

 centuries previously. Both these pestilences had spread from 

 regions in the East, where they were endemic, where the inhabitants 

 were so resistant that the victims were comparatively few, and 

 where they caused no more comment in histories, poems, and ex- 

 hortations than malaria in Africa or tuberculosis in England. As 

 has always been customary, preachers in Europe attributed them to 

 the anger of the Deity, and called the peoples to repentance for 

 sins committed against this or that religion, and to a more 

 strenuous support of this or that sect. Similarly, while no great 

 epidemic of our domestic diseases is recorded in history, they have 

 occasioned some terrible pestilences amongst peoples to whom they 

 were previously unknown, to whom we conveyed them, and by whom 

 they were regarded as evidence of divine or diabolical anger. 



460. The inference is irresistible that historians are mistaken 

 when they attribute ancient epidemics to diseases which, owing to 

 war, bad sanitation, or similar causes, came suddenly into being, 

 but have since died out of the world. In each case in which the 

 accounts are sufficiently ample and clear, every ancient pest may 

 be identified with an air, water, or insect-borne malady now, as then,, 

 endemic in some part of the world, whence it has spread periodically 

 whenever the conditions, such as a hot, dry summer and much inter- 

 course between neighbouring nations, have become favourable. 

 Bad sanitation tends, of course, to render a strange water- or insect- 

 borne disease epidemic when once it has arrived, but, other things 

 equal, it tends also to perpetuate it afterwards in the endemic 

 form. Yet, though sanitation did not noticeably improve, the Black 

 Death, the Great Plague, and other exotic diseases retreated to 

 their normal habitats in India or farther east. Both the former 

 were evidently the same bubonic plague which is now ravaging 

 India. They " spent their force," they disappeared from Europe 

 because they were epidemic because the disease became so pre- 

 valent that it exhausted its nutrient supply of susceptible rats or 

 human beings so effectually that it could not persist. Very 

 modern sanitation has rendered its return to Europe difficult. 

 Rats are less numerous. Probably all our earth- and air-borne 

 diseases, which are much better able to travel than insect and 

 water-borne complaints and therefore sooner become permanently 

 established, were endemic amongst our ancestors before the dawn 

 of established history. But from remote periods, from myth and 



