- n light microscope that uses scattered light to show particles too small to see with ordinary microscopes
- Are they germs too small to see with the microscope or the ultramicroscope? Are they germ poisons? Are they transitional forms which germs adopt?.
- Microscopists have sneaked considerably beyond the Abbe limit with an instrument called the ultramicroscope, in which very small particles are strongly illuminated from the side.