Efforts to defeat the enemy by deliberate spread of contagious disease among his forces greatly antedate the brilliant advances in microbiological science of the 19th and 20th centuries. A major instance, related by Gabriel de Mussis, was the hurling of plague-infected cadavers over the walls of Caffa in 1346. Another episode was described by the eminent historian Varillas,1 who writes:
At his unsuccessful siege of Carolstein in 1422, Corbut caused the bodies of his soldiers whom the besieged had killed to be thrown into the town as well as 2,000 cartloads of excrement. A great number of the defenders fell victim to the fever which resulted from the stench, and the remainder were only saved from death by the skill of a rich apothecary who circulated in Carolstein remedies against the poison which infected the town.
Caffa, whose siege de Mussis describes, is presentday Feodosia, a seaport of South