FORMIC ACID

A sour liquor which ants eject when irritated, and which was formerly obtained by bruising the insects and distilling them, mixed with water: a peculiar volatile acid pa ed over. It has been ascertained by DSbereiner, that an analogous acid may be artificially obtained by distilling, from a capacious retort, a mixture of 2 parts of tartaric acid, 3 of peroxide of manganese, and 3 of sulphuric acid diluted with 5 of water. The tartaric acid acquires oxygen from the oxide of manganese, and is resolved into water, carbonic acid, and formic acid. From the analysis by Berzelius of formiate of lead, it appears that formic acid is a compound of 2 atoms of carbon, 3 of oxygen, and 1 of hydrogen; or of 2 atoms of carbonic oxide and I of water. [s. 480]