Scurvy was known from the earliest times as a condition likely to arise when men were constrained to live upon a limited diet because of crop failure, siege or extended voyaging. It was first clearly described in the thirteenth century but, although its connexion with restricted supplies and especially with paucity of vegetables and fruit in the diet, was recognized from that period, its occurrence was ascribed to many other factors. Thus, because it often affected many members of a closed community at about the same time, it was thought to be contagious; and although conditions such as cold, the diminution of daylight in polar regions and the constant humidity of sea voyages were the reason for lack of fresh fruits and vegetables, these conditions themselves were suggested as causes of the disease. Likewise poverty, resulting in overcrowding and insanitary conditions, was blamed, whilst in reality economic conditions prevented the poor from buying antiscorbutic foods.