The birch was nicknamed the nephritic tree in the 16th century

Birch water is a plant sap whose consumption has been documented since the Middle Ages for its medicinal virtues. In 1565, the Italian physician and botanist Pierandrea Mattioli attributed draining properties to it and described it as a nephritic tree. He advised piercing the trunk with an auger to collect the liquid supposed to break stones in the kidneys and bladder.