NO MICROSCOPE, NO PROBLEM
A tribe in the jungle were all falling sick. A missionary doctor went into the village to try and help them. He suspected and soon discovered that it was the contaminated water they were drinking that caused their sickness. To show the natives the missionary set up a table in the village, then using a microscope he showed them the contamination that was in the water.
Later that night when the village was quiet and everyone appeared to be asleep in bed, somebody broke into the missionaries offices and smashed the microscope.
For them, no microscope--no problem!