In July 1863 Mr. Colton, in conjunction with a number of influential dentists, organized the Colton Dental Association and opened an office hi New York City for the painless extraction of teeth, nitrous oxide being the anaesthetic em ployed. This venture proved a great success, and in 1881 Dr. Colton reported 121,709 admin istrations of the gas at the office of his asso ciation and with no accidents. In a catalogue of surgical instruments and apparatus issued by James Coxeter & Son of London, England, in 1870 we find cuts and price lists of iron cylinders containing the liquefied gas together with inhalers and other apparatus. This is without doubt the first instance of the com mercial development of the liquefied gas in dustry.
Coxeter apparatus was brought to American immediately upon its introduction the den tal profession in England, and various sizes of iron cylinders, containing from 100 to 1,000 gallons of the gas, soon became common in the American dental trade. The liquefied gas was first produced commercially in this coun try by Johnston Brothers of New York City, who developed and patented improved com pressing methods and machinery, and who later united with S. S. White of Philadelphia, con tinuing the manufacture under the name of The S. S. White Dental Manufacturing Com pany.
Commercial Method of Manufacture, Etc. — Nitrous oxide may be made by a number of methods depending upon the deoxidation of the higher oxides of nitrogen, as, for instance, by the action of dilute nitric acid upon zinc or i iron. An impure gas may be made also by heating a mixture of ammonium sulphate and Filtrate of soda or potash in a closed retort.
The general commercial method for its manu facture, however, is by heating in a closed glass or metal retort having a proper protective lining a pure fused nitrate of ammonia. At a temperature of about 170° C. the salt fuses Completely and at temperatures between 240° and 260° C. gives off gas freely— the latter temperature should not be exceeded.
The formula of the reaction is: NHNO5-fliett=.11.0-1-2H20.
It thus appears that the nitrate of ammonia is completely decomposed, each molecule break ing up and forming one molecule of nitrous oxide gas and two molecules of the vapor of water or steam. The products of the distilla tion are cooled, the steam being of course con densed to water, and then having passed through proper washing apparatus the gas is collected in a holder from which it is taken by pumps and compressed into steel cylinders. Among the concerns now engaged in the manufacture of nitrous oxide are the Lennox Chemical Com pany and the Ohio Chemical Company, both of Cleveland, Ohio, The S. S. White Dental Manufacturing Company of Philadelphia, Pa., and the Standard Oxygen Company of New York City.
The American Red Cross has it is said, constructed in France at Montreux a large plant capable of producing and liquefying 100, 000 gallons of /4.0 per day, and for a few months previous to the signing of the armistice N.0 was very largely used in the army and navy hospitals with great success. The annual pro duction of N10 in America is variously esti mated at from 10,000,000 gallons (133,333 cubic feet) to three times this figure.