M. Schele de Vere, Modern Magic
“ The excitement usually attendant upon specially fatal plagues and contagious diseases increases the tendency which the latter naturally have to cause hallucinations. During a plague in the reign of Justinian, men were seen walking through the crowd and touching here and there a person; the latter were at once attacked by the disease and invariably succumbed. Upon another such occasion marks and spots appeared on the clothing of those who had caught the contagion, as if made by invisible hands, the sufferers began next to see a number of spectres and died in a short time. ”
