October 28, 2022, by Nate Smith

1,3,7-trimethylxanthine (C8H10N4O2), also known as caffeine, is the most commonly used psychoactive drug in the world. Potentially, you’ve consumed more than 100 mg by the time you’re reading this post. While the average is about 135 mg per day according to Harvard University T.H. Chan School of Public Health, that amount varies depending on the vehicle.
Caffeine is most associated with coffee and was first isolated from the coffee bean by Ferdinand Runge in 1819. The Library of Congress recently acquired Neueste Phytochemische Entdeckungen (Latest Phytochemical Discoveries), the 1820 publication that contains his experimental results, which is currently in process with a catalog record forthcoming. In these experiments (pgs. 144-159), Runge applied a variety of reagents to both raw and roasted beans in order to determine what chemical compounds were present.
Source: Caffeine: The Motivation Molecule | Inside Adams: Science, Technology & Business