Bayer 1853—a modification of salicylic acid or salicin, a folk remedy found in the bark of the willow plant. By 1899 Bayer's trademark Aspirin was registered worldwide for Bayer's brand of acetylsalicylic acid, but it lost its trademark status in the United States, France and the United Kingdom after the confiscation of Bayer's US assets and trademarks during World War I by the United States, and because of the subsequent widespread usage of the word. The term "aspirin" continued to be used in the US, UK and France for all brands of the drug, but it is still a registered trademark
Hippocrates of Chios would be known too. Only much later was it proven (by Ferdinand von Lindemann, in 1882) that this approach had no chance of success, because the factor pi (π) is transcendental. The number π is the ratio of the circumference to the diameter of a circle, and also the ratio of the area to the square of the radius. In the century after Hippocrates at least four other mathematicians wrote their own "Elements", steadily improving terminology and logical structure. In this way Hippocrates' pioneering work laid the foundation for Euclid's "Elements" (c. 325 BC) that was to remain the standard