Bark (botany) rope, used for example in the rigging of Viking age longships. Among the commercial products made from bark are cork, cinnamon, quinine (from the bark of Cinchona) and aspirin (from the bark of willow trees). The bark of some trees notably oak ("Quercus robur") is a source of tannic acid, which is used in tanning. Bark chips generated as a by-product of lumber production are often used in bark mulch in western North America. Bark is important to the horticultural industry since in shredded form it is used for plants that do not thrive in ordinary soil, such as epiphytes.
History of aspirin regimen (about 8,000 people) had no signs of thrombosis. However, Craven's studies were not taken seriously by the medical community, because he had not done a placebo-controlled study and had published only in obscure journals. The idea of using aspirin to prevent clotting diseases (such as heart attacks and strokes) was revived in the 1960s, when medical researcher Harvey Weiss found that aspirin had an anti-adhesive effect on blood platelets (and unlike other potential antiplatelet drugs, aspirin had low toxicity). Medical Research Council haematologist John O'Brien picked up on Weiss's finding and, in 1963, began working with epidemiologist Peter Elwood