Not until about 1909 was any liquid chlorine made commercially in the United States, but since that time the production of liquid chlorine has grown very rapidly. It is estimated that during the year 1918, over 15,000 tons of liquid chlorine were manufactured in the United States.
Medicinal During the war the manufacture of chlorine and of liquid chlorine grew rapidly because chlorine was used to make picric acid and very large quantities of the various poison-gases, most of which were chlorine compounds.
However, chlorine during the war was not only used to destroy human beings but also to protect them from typhoid fever and other diseases. The drinking water in the various war zones was sterilized nearly always by the use of liquid chlorine which no doubt has helped to reduce mortality from epidemics far below the figures prevailing in former wars. Nearly all large cities in the United States to day are sterilizing their drinking water by use of liquid chlorine, which is introduced into the water main either directly as a gas or mixed with water and then introduced into the main. This application of liquid chlorine is constantly growing and a number of cities have already started to use liquid chlorine for sterilization of sewage. During the last few years liquid
chlorine has started to replace chlorine of :line for bleaching purposes to a considerable ex tent. The detinning industry uses large quan tities of chlorine to recover the tin and the steel of tin scrap according to the Goldschmidt patents. The product, tetrachloride of tin, is used in the silk industry. Zinc chloride is used to impregnate telegraph poles, railroad ties, etc., and is also used for vulcanizing fibres.
Carbon tetrachloride is used to a large ex tent for the extraction of fats and in the rubber industry. It is also used in dry cleaning estab lishments and in fire extinguishers. In the medical field chlorine is used to make chloro form, aspirin and a great many other pharma ceutical products. In the organic chemistry chlorine is used in the manufacture of synthetic indigo, sulphur colors, benzoic acids, etc. The chlorination of ores in future will probably con sume very large quantities of chlorine. Consult Lunge, Dr. G., (Hand-Buch der Soda Industries (Eng. trans. as 'Manufacture of Sulphuric Acid and Alkali'), and Geoffrey-Martin, and Chlorine Products.'