Polarised light micrograph of quinic acid, which is obtained from the bark of eucalyptus and cinchona trees and coffee beans. Quinic acid, along with citric and malic acids, represent the major acids present in coffee. The roasting process approximately doubles the concentration of quinic acid. A derivative of quinic acid, KZ-41, is claimed to increase survival rates after exposure to high levels of radiation. Magnification: x27 at 10 cm wide.