Public domain "acetylsalicylic acid" (2-acetoxybenzoic acid) is better known as "aspirin" in the United States—a generic term. In Canada, however, "Aspirin", with an uppercase A, is still a trademark of the German company Bayer, while aspirin, with a lowercase "a", is not. Bayer lost the trademark in the United States, the UK and France after World War I, as part of the Treaty of Versailles. So many copycat products entered the marketplace during the war that it was deemed generic just three years later. Bayer also lost the trademark in the same jurisdictions for "Heroin" which it trademarked a year before it
Pyrophosphoric acid red heat of a sodium phosphate salt. It was found that phosphoric acid when heated to red heat formed pyrophosphoric acid that was readily converted to phosphoric acid by hot water. Pyrophosphoric acid Pyrophosphoric acid, also known under the name diphosphoric acid, is colorless, odorless, hygroscopic and is soluble in water, diethyl ether, and ethyl alcohol. The anhydrous acid has two different forms, which melt at 54.3 °C and 71.5 °C. It is best prepared by ion exchange from sodium pyrophosphate or by reacting hydrogen sulfide with lead pyrophosphate. When phosphoric acid is dehydrated pyrophosphoric acid is produced as one