U. S. DEPARTMENT OF AGRICULTURE, BUREAU OF ANIMAL INDUSTRY. A. D. MELVIN, CHIEF OF BUREAU. THE USE OF METALLIC CONTAINERS FOR EDIBLE FATS AND OILS. BY JAMES A. EMERY, M. D., Senior Biochemist, Biochemic Division. [Reprinted from the Twenty-sixth Annual Report of the Bureau of Animal Industry (1909).] 81268°-11 WASHINGTON GOVERNMENT PRINTING OFFICE: 1911 ORGANIZATION OF THE BUREAU OF ANIMAL INDUSTRY. Chief: A. D. MELVIN. Assistant Chief: A. M. FARRINGTON. Chief Clerk: CHARLES C. CARROLL. Animal Husbandry Division: GEORGE M. ROMMEL, chief. Biochemic Division: M. DORSET, chief. Dairy Division: B. H. RAWL, chief. Inspection Division: RICE P. STEDDOM, chief; MORRIS WOODEN, R. A. RAMSAY, and ALBERT E. BEHNKE, associate chiefs. Pathological Division: JOHN R. MOHLER, chief. Quarantine Division: RICHARD W. HICKMAN, chief. Zoological Division: B. H. RANSOM, chief. Experiment Station: E. C. SCHROEDER, superintendent. II THE USE OF METALLIC CONTAINERS FOR EDIBLE FATS AND OILS. By JAMES A. EMERY, M. D., Senior Biochemist, Biochemic Division. INTRODUCTION. The utilization of metals in the making of vessels for storing and transporting substances intended for human food originated with the ancients. In the earlier ages, before metals were known, skins and horns of animals, wood shaped by fire into the semblance of the interior of a bowl, pots made by hollowing out soapstone, and earthenware vessels were brought into use and served as containers for such substances as could be stored in them. The advance of civilization, however, with its ever-increasing knowledge of metallurgy, which brought about a large production and low cost of metals, presented possibilities, which were soon recognized, for their application in the manufacture of containers for foodstuffs of all kinds. As a consequence, metallic utensils of almost every shape and description may now be obtained on the market at a cost which in some instances seems remarkably low, when the construction of the well-made pail or can is considered. At an early period it was discovered that certain of the then known metals were less subject to deterioration through the action of atmospheric oxygen, liquids, etc., than others. Chief among these was tin. Its brilliancy, malleability, and particularly the slowness with which it was attacked by the air and other external agents, together with its price as compared with other metals possessing these properties, rendered it especially adaptable to the manufacture of culinary articles and receptacles for foodstuffs. Utensils of brass, copper, and iron were therefore frequently tinned on the interior in order to protect them, the process consisting merely in melting a mixture of resin and tin in the previously scrubbed and brightened vessel, and then by means of rags or tow quickly wiping a thin layer of the molten metal over the heated inner surface. It is stated that a skilled workman by this process could apply a uniform coating so thin that 1 square inch of the thoroughly tinned surface was found to contain only 0.15 of a grain of tin. |