This study is based on the ink stick unearthed from the tombs of the Northern Song Dynasty (960 CE–1127 CE) in Xi ’an, Shaanxi Province. The sample was analyzed by Scanning electron microscopy (SEM), ...

Have you ever walked in the shade of a mighty oak tree? In late summer or fall, you may find an odd little brown woody ball attached to a fallen twig. Look up into the tree, and you may see more ...