The preceding paragraphs relating to the curing of meats by salting, smoking, etc., describe the process as applied to meats of the hog. Beef is cured in like manner by pickling and is generally shipped to destination and kept in the pickle until removed for consumption. An exception is ((dried beef," being the suitable lean pieces, which, after curing in pickle, are smoked slowly for several days so as to dry them to a firm condition.
Preservation by Hermetically Sealed Cans, The method of preserving meat by pack ing in hermetically sealed tin cans and the like was introduced commercially into the United States about the year 1873 at Chicago, Ill., by William Wilson and John Wilson. In the following year Libby, McNeil and Libby also en tered this trade, and during succeeding years other houses followed. The business grew rap idly from the beginning, and has reached great magnitude.
The process in brief is as follows: The meat after being trimmed from the bones and cut into small pieces is put into a curing pickle composed of common salt and a little sugar in solution. It is left in this pickle any length of time from a few days to 20 days, depending upon the degree of saltiness desired. It is then taken out of the pickle and cooked in hot water until thoroughly done. After this the gristle is trimmed out, the surplus fat is removed, and the pieces are cut into small and comparatively even sized bits, usually not exceeding four cubic inches. In this condition, and while still hot, it is stuffed by an automatic machine into tin cans which have previously been prepared and thoroughly washed. Each can is then weighed so as to get the correct quantity of meat in it, and is 'capped," that is, a small tin disc is soldered over the hole through which the meat is introduced into the can. The further steps of the process embrace the sterilization, or so called 'processing," which consists in heating the cans for a number of hours up to a tempera ture of 250° to 350° F., depending upon the size of the can and the kind of meat. The object in heating is sterilization, being the same process as is pursued by the housewife in canning fruit, etc. The cans are then washed, cooled, labeled and the exposed surfaces are coated with a varnish to prevent rust. They are then ready to
be packed and shipped to all parts of the world, and will keep for years without deterioration.
The business of meat pack ing as practised in Chicago and the other large packing centres of the United States involves not alone meat preserving, but the entire range of slaughtering, preparation of the fleshy and other edible parts, and preparation of the by products, such as hides, hoofs, horns, bones, hair, fats, intestines, blood and viscera. In many of the most prominent establishments these by-products are manufactured into glue, buttons, combs, curled hair, soap, candles, oils, glycerin, etc. All the modern establishments manufacture the blood and residual solids from their fat rendering apparatus into fertilizers, in some cases the blood-albumen being first separated and dried independently.
The accompanying diagram will illustrate graphically the disposition usually made of the different parts of beef cattle.
Corresponding parts of other animals are put to similar uses. The stomachs of hogs are utilized for pepsin manufacture. Some of the glands of hogs, sheep and cattle, notably the thyroid and pancreatic, are used in the produc tion of pharmaceutical preparations. Sheep skins first have the wool pulled from them and are then utilized for leather, the cuttings being made into glue. Hog hair and bristles are made into curled hair and brushes. Curled hair is sold for mattress making. All scraps and Darla not put to some other important use, are cooked desiccated and used in many valuable products and as fertilizing material, the chief property of which is nitrogen.
By the careful study of economy in utilization of by-products large values are now derived from parts formerly wasted. To day there is practically nothing wasted. This close study of economy in saving everything enables the packing business to be done on an unprecedently small margin of profit. For a series of years, including 1915, the fiscal re ports, made by some of the largest and most successful packing corporations to their stock holders, show that their profits ranged from 2 to a per cent of their distributive sales.