The first lazarettos were established upon islands at some distance from the city, seemingly as early as the year 1485. Here all strangers coming from places where the existence of plague was suspected were detained. If it appeared in the city itself, the sick were despatched with their families to what was called the Old Lazaretto, were there furnished with provisions and medicines, and, when they were cured, were detained, together with all those who had had intercourse with them, still forty days longer in the New Lazaretto, situated on another island. All these regulations were every year improved, and their needful rigour was increased, so that from the year 1585 onwards no appeal was allowed from the sentence of the Council of Health; and the other commercial nations gradually came to the support of the Venetians, by adopting corresponding regulations.[193] Bills of health, however, were not general until the year 1665.[194] [193] _Le Bret_, loc. cit. Compare Hamburger Remarquen of the year 1700, p. 282 and 305. [194] Göttinger gelehrte Anzeigen, 1772, p. 22. The appointment of a forty days’ detention, whence quarantines derive their name, was not dictated by caprice, but probably had a medical origin, which is derivable in part from the doctrine of critical days; for the fortieth day, according to the most ancient notions, has been always regarded as the last of ardent diseases, and the limit of separation between these and those which are chronic. It was the custom to subject lying-in women for forty days to a more exact superintendance. There was a good deal also said in medical works of forty day epochs in the formation of the fœtus, not to mention that the alchymists expected more durable revolutions in forty days, which period they called the philosophical month. This period being generally held to prevail in natural processes, it appeared reasonable to assume and legally to establish it as that required for the development of latent principles of contagion, since public regulations cannot dispense with decisions of this kind, even though they should not be wholly justified by the nature of the case. Great stress has likewise been laid on theological and legal grounds which were certainly of greater weight in the fifteenth century than in more modern times.[195] [195] The forty days’ duration of the Flood, the forty days’ sojourn of Moses on Mount Sinai, our Saviour’s fast for the same length of time in the wilderness; lastly, what is called the Saxon term (Sächsische Frist,) which lasts for forty days, &c. Compare _G. W. Wedel_. Centuria Exercitationum Medico-philologicarum. _De Quadragesima Medica._ Jenae, 1701. 4, Dec. IV., p. 16.