Virus particles

By this point, forty major diseases were known to be caused by viruses but their nature remained a mystery. Elford used fine filters to determine that viruses were smaller than bacteria but larger than most molecules. This contributed significantly to understanding the size and nature of viruses.
 William Joseph Elford England 1931 Virus particles

By this point, forty major diseases were known to be caused by viruses but their nature remained a mystery. Elford used fine filters to determine that viruses were smaller than bacteria but larger than most molecules. This contributed significantly to understanding the size and nature of viruses.