"Leeuwenhoek (invented the microscope) examined uric acid (C5H4N4O3) crystals from gout patients and found them to resemble needles. He expounded on his observations in an 11 July 1679 letter responding to an earlier query from Mr. Lambert van Velthuysen (1622–1685), a physician, https://t.co/mY2wqYlRda