Standard reagent bottle, 20th century.
© Science Museum / Science & Society Picture Library
Reagent bottle with a ground glas stopper and sand blasted label reading 'Ammon.Acetate'. A reagent is a substance or mixture used in chemical analysis. Many laboratory chemicals are stored in this type of bottle. Ammonium Acetate (CH3COONH4) is used as a buffer solution to maintain a steady pH in chemical reactions.