caffeine

plural caffeines · alternative dated caffein

1. uncountableusuallyAn alkaloid, C₈H₁₀N₄O₂, found naturally in tea and coffee plants, which acts as a mild stimulant on the central nervous system.First known use 1830

   For example, 0.100 grams of caffeine yield by combustion, by weight, 0.180 grammes of carbonic acid.

   1839, Justus von Liebig, translated by William Gregory, Instructions for Organic Analysis, Glasgow, Scotland, United Kingdom: Richard Griffin & Company, page 35

   2 more examples

   Hitherto, in consequence of its slight solubility, caffeine has been administered hypodermically only in very small doses ; in fact, at the ordinary temperature, it requires 93 parts of water to dissolve, so that a cubic centimeter would contain scarcely more than a centigram.

   1882 October 28, C. Tanret, “Soluble Salts of Caffeine”, in American Journal of Pharmacy, volume 45, page 495

   The US Food and Drug Administration defines this limit as anything more than 400 milligrams of caffeine daily for healthy adults. This is equivalent to four or five cups of coffee.

   2024 March 11, Jocelyn Solis-Moreira, “Dark roasted and dangerous: Everything you should know about caffeine intoxication”, in CNN, archived from the original on 05 Apr 2024