Life in the Ghetto was intense and both commercial and intellectual contact during the day with the Venetian population was continual. As already mentioned, besides usury and the sale of used clothing (estrazzaria»), the Jews were allowed to practise medicine.
From the 15th century onwards the Venetian Republic had granted the Jews the right to study at Padua University and exonerated them from having to pronounce an oath professing their faith and from wearing an identifying mark. As the practice of medicine was permitted, many young Jews devoted themselves to the study of this discipline and very soon excelled in it.
When, in 1516, the Serenissima decreed that all Jews be confined to the Ghetto, the problem arose of the doctors who would not be able to assist the Christians during the night when the gates were closed. In July 1516, only a few months after the Ghetto was created, Jewish doctors were allowed by official decree to leave even during those hours forbidden to other Jews; however, they had to provide precise indications of where they were going and whom they would be visiting.
As for having to wear a means of identification, the famous «yellow cap» (bereta zala) as opposed to the black one (bereta negra) worn by Christians, the Republic applied the same wavering policy as with the permit, instituting it for a few years and then withdrawing it, in order to maintain appearances and thus keep both the Christians and the Jews happy.