Slave Productivity

In the days of the Old South the Master invited his overseer, his banker, and his mathematician to discuss the best way to improve the productivity of the slaves. The overseer said, "Fear is the best way to control an animal. If we beat the niggers when they make a mistake and lynch a few to set an example, they'll work the hardest." The banker replied, "Niggers work harder when they think they're free. Give them some fake money and some trinkets to buy, and they'll work the hardest." The mathematician begins, "First, assume a spherical nigger..."

>>12
spreading the plague and stuff
Actually, this one myth is true.

http://www.william-shakespeare.info/bubonic-black-plague-world-history.htm
The Black Death (Bubonic Plague) followed the Trade Routes. The Trade routes provided access to all corners of the known world. The increased use of the trade routes ensured that the disease spread throughout the World.

i.e. Jewish traders really spread plague.