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 hack Bark hack A bark hack is a tool used to remove pine tree bark to promote the flow of pine resin, which is used in naval stores production. The tool consists of a wooden shaft with a weighted butt and hook-like, replaceable, U-shaped blades at the head. The bark hack is swung much like an axe and is used to create a hatched chevron pattern ("cat face" or less frequently, a "blaze") into trees' exposed sapwood. The weighted end helps the operator follow through with the force necessary for the hooked blade to scoop out chips of hard pine wood.