Science: Dry Ice

Secretary D. H. Killeffer of the New York section of the American Chemical Society last week helped the lay public to catch up with a notable advance in commercial refrigeration. He described the properties and uses of "dry ice," as this commercial solid carbon dioxide is called from the fact that it forms a gas instead of a liquid when it melts. U. S. manufacturers, said Secretary Killeffer, had now perfected "dry ice," a practical portable refrigerant, and brought it into wide use. For shipping ice cream it was 1500% more efficient than water ice. Between Manhattan and Philadelphia, 200 lb. of solid carbon dioxide replaced 3,000 lb. of water ice and 600 lb. of salt. For shipping frozen fish from Manhattan to Detroit, 1,200 lb. of carbon dioxide supplanted 17,000 lb. of ice and 1,700 lb. of salt. The slightly higher cost of "dry ice" was much more than offset by the gain in space available for pay freight and the cleanliness and ease of handling.

Credit for the perfection of "dry ice" belongs largely to Chemist Pierre E. Haynes, now with the Dry Ice Corp. of New York. General Carbonic and Liquid Carbonic are other corporations now making "safe dry," a form of "dry ice," which became a commercial product in 1925. To make solid carbon dioxide: invert a tank of liquid carbon dioxide under pressure, open the valve. The sudden lessening of the pressure causes the liquid as it squirts out to turn part cold solid, part gas.