The various qualities or changes in the atmosphere were regarded individually or collectively at various times as the determining causes. It was supposed that the air might become impregnated with putrid exhalations from various sources, as the holds of ships, or rendered impure by the vapors of the sea. The foul air of crowded habitations, vessels, or cities was appealed to, or the common cause was sought either in its temperature or humidity, or in both. The earlier observers gave prominence to cold as a determining cause of scurvy, and especially when combined with dampness, and hence its frequency in the north of Holland, Brabant, Belgium, Russia, and Germany. This was the current view in the seventeenth century. On the other hand, with equal confidence the disease has been supposed to be determined by excessively high temperatures, and its occurrence in India, South Africa, and the equatorial regions has been alleged in support. Personal habits have been in the eyes of earlier observers an all-sufficient cause, and thus excessive exertion attended with fatigue and exhaustion has been considered the cause of several severe outbreaks on shore and at sea. In contrast with this opinion we find the English physicians placing great stress upon indolent habits and lack of exercise as a predisposing if not a powerfully determining cause. The use of tobacco was inveighed against by Maynwaring and Harvey as a powerfully morbific cause, while to the lack of the same narcotic its occurrence was ascribed by Van der Mye. More recently it has been referred by Fabre[6] to vaso-motor disturbance due to a miasm. [Footnote 6: _Des Rélations Pathogéniques des Troubles Nerveux, etc._, Paris, 1880.]