The chemically pure acid is a liquid composed of 31.9 per cent, of absolute hydrochloric acid and 68.1 per cent, of water. It should be preserved in glass-stoppered bottles. A colorless, fuming liquid, of a pungent, suffocating odor, an intensely acid taste and a strongly acid reaction. Specific gravity 1.160 at 16° C. Hydrochloride acid is used to produce different combinations, as aluminium chloride, calcium chloride, ferrum (iron) chloride, magnesium chloride, and sometimes to decompose sodium silicate.