History of aspirin tree in 1758 and noticed an astringency reminiscent of the standard—and expensive—ague cure of Peruvian bark. He collected, dried, and powdered a substantial amount of willow bark, and over the next five years tested it on a number of people sick with fever and agues. In his letter, Stone reported consistent success, describing willow extract's effects as identical to Peruvian bark, though a little less potent. (In fact, the active ingredient of Peruvian bark was quinine, which attacked the infectious cause of malaria, while the active ingredient of willow extract, salicin, relieved the symptoms of malaria but could not cure
Bark pocket Bark pocket Bark pockets can be formed by inosculation, formation of a tree fork, encapsulation of a branch, joining together of an uneven trunk, or encapsulation of another object. During inosculation, the bark trapped between the two joining trunk becomes surrounded with wood once the trunks fuse. The resulting bark pocket formed during inosculation or in a tree fork is referred to as included bark. When a branch is encapsulated, the outer bark on the branch may remain inside the wood of the tree, as the trunk widens and grows around the branch. Bark pockets can be used as an