In the age of Justinian great scourges devastated the world. In A.D. 526 Antioch was destroyed by an earthquake, and it is said that 250,000 people perished, but the most dreadful visitation on mankind was the great plague which raged in A.D. 542 and the following years, and, as Gibbon writes, "depopulated the earth in the time of Justinian and his successors." _Procopius_, who was versed in medicine, was the historian of the period. This fell disease began between the Serbonian bog and the eastern channel of the Nile. "From thence, tracing as it were a double path, it spread to the east, over Syria, Persia, and the Indies, and penetrated to the west, along the coast of Africa, and over the continent of Europe. In the spring of the second year, Constantinople, during three or four months, was visited by the pestilence; and Procopius, who observed its progress and symptoms with the eyes of a physician, has emulated the skill and diligence of Thucydides in the latter's description of the plague of Athens. The infection was sometimes announced by the visions of a distempered fancy, and the victim despaired as soon as he had heard the menace and felt the stroke of an invisible spectre. But the greater number, in their beds, in the streets, in their usual occupation, were surprised by a slight fever, so slight, indeed, that neither the pulse nor the colour of the patient gave any signs of the approaching danger. The same, the next, or the succeeding day, it was declared by the swelling of the glands, particularly those of the groin, of the armpits, and under the ear; and when these buboes or tumours were opened they were found to contain a _coal_, or black substance, of the size of a lentil. If they came to a first swelling and suppuration, the patient was saved by this kind and natural discharge of the morbid humour. But if they continued hard and dry, a mortification quickly ensued, and the fifth day was commonly the term of his life. The fever was often accompanied with lethargy or delirium; the bodies of the sick were covered with black pustules or carbuncles, the symptoms of immediate death; and in the constitutions too feeble to produce an eruption, the vomiting of blood was followed by a mortification of the bowels. To pregnant women the plague was generally mortal; yet one infant was drawn alive from its dead mother, and three mothers survived the loss of their infected fœtus. Youth was the most perilous season: and the female sex was less susceptible than the male; but every rank and profession was attacked with indiscriminate rage, and many of those who escaped were deprived of their speech, without being secure from a return of the disorder. The physicians of Constantinople were zealous and skilful, but their art was baffled by the various symptoms and pertinacious vehemence of the disease; the same remedies were productive of contrary effects and the event capriciously disappointed their prognostics of death or recovery. The order of