Population

The population of the Jewish people  was able to increase dramatically for a number of reasons.  First was of course that the persecution that they had received in the early modern period had greatly abated.  No longer confined the ghettos the standard of living for Jews living in cities began to rise rapidly.  Contrary to popular belief cities of Europe, even in the 19th century, were filthy with little in the ways of sewage systems and disease was a constant concern.  The ghettos that Jews were confined to were often the worst of these areas and the crowding only intensified the problem.  When the laws that had forced Jews to live in these areas were lifted, it was not surprising that the lifespan of Jews in cities increased.  Bolstering the effect of finally being allowed to move out of the ghettos were practices of hygiene that greatly helped Jews avoid sickness.  We saw in the documents pertaining to the Alliance Israelite Universelle that part of their goals were teaching habits that promoted good hygiene such as washing hands.  While such practices may seem small they were hugely helpful in preventing the spread of germs.  Another benefit Jews received was due to the food that they consumed.  Kosher food needed a rabbi to certify that it was handled in the correct way, an early version of health inspectors.  There is also evidence to suggest that Jewish women breastfed their children longer than their non-Jewish counterparts.  Breastfeeding passes on anti-bodies to infants helping them ward off potential illnesses.  Contrary to popular belief alcohol was in some places safer than water.  Standing water breeds germs and the rivers that many cities were located near were contaminated by sewage and other waste.  However, by abstaining from drinking Jews were less likely to be injured or get into an altercation.  Jew of the time on average had fewer children but were able to focus their resources on those children.  Many Jewish mothers stayed home to care for children and their education was better as a result.  Jewish men were better able to find a wife due to their education and as a result were able to continue to reproduce.  The result of all these factors was that the population of Jews greatly increased in the 19th century.
I'll do a second question later this week.