Clear glas reagent bottle labelled 'OXALIC ACID', 1940.
© Science Museum / Science & Society Picture Library
Reagent bottle with an embosed, fired label and a ground glas stopper. A reagent is a substance or mixture used in chemical analysis. Many laboratory chemicals are stored in this type of bottle. Oxalic acid ((COOH)2.2H2O) is a white poisonous acid which is soluble in water, alcohol and ether. It occurs naturally in rhubarb and has various industrial uses.