"We eat what we can; and what we can't, we can."

- The Punster.

IT is said that modern canning was first thought of when a jar of perfectly preserved fruit was found embedded in a heap of lava among the ruins of Pompeii. Very evidently the heat of the molten lava, together with the exclusion of air, had kept the contents of the jar from "spoiling." So experiments were tried, and for many years it was thought that exclusion of air would "keep" food. But scientists have proved that floating about in the air there are billions of billions of micro-organisms known as yeasts, molds, and bacteria, which attack foods and cause fermentation or "spoiling." And it may be added, in passing, that not all such tiny organisms are destructive, but many are helpful, doing such things as making milk into cheese, changing cider to vinegar, and performing a multiplicity of other beneficial services for mankind.

The secret of successful canning and preserving lies in destroying the micro-organisms which "spoil" food. Yeasts and molds are killed at a temperature of 160° F. Bacteria are destroyed at 212° F., or the boiling point. If this temperature is maintained the proper length of time, they are rendered sterile, or incapable of growing or reproducing, or of throwing off spores which in turn will develop into bacteria. Spores are more difficult to kill than bacteria; therefore, if the heat does not penetrate the whole mass some parts may not be sterilized and will ferment.

Methods. - There are two methods of sterilizing commonly used in home canning: the cold-pack; and the open-kettle, or hot-pack.

The cold-pack method is greatly to be preferred, because the food is packed in the containers before cooking, and is not touched again with spoons or other utensils. In the open-kettle method, the food is cooked before it is put into the jars, and there is always danger of bacteria and spores being introduced on spoons and other utensils. The simplicity of the cold-pack method recommends it. Fruits are put in syrups. Vegetables require only salt for flavoring and water to fill the containers.