Hydrochloric Acid, CHLORHYDRIC

ACID, or MURIATIC ACID. HCl. Colorle , strongly fuming gas of acid taste and It was known to the Arabian alchemists, but Basil Valentine, irritating odor; sp.gr. 1.26. Liquid 10° C., 40 atm.; solid-115.7° С. 15th century, was the first to mention the pure acid. It occurs in the exhalations of volcanoes, and is found in the intestinal juices. It is very soluble in water; at ordinary temperatures 450 volumes are di olved by one volume of water; the water solution is the article of commerce. The strongest acid contains 43.09 per cent of the compound HCl, and has a sp. gr. of 1.22 at 0° C. The commercial acid always has a yellow color, due to impurities of organic matter and iron. It is obtained in factories where sodium carbonate is made, being formed when sodium chloride is treated with sulphuric acid. In this way enormous quantities are made. It is used in making bleaching powder. See CHLORINE.