BACTERIA

or Schizomycetes, a general title which embraces a great many varieties of micro-organisms. With a few exceptions they reproduce by fi ion —the full grown bacterium multiplying by dividing itself, instead of producing others by budding (as do most yeasts), or by seeds, or spores (as molds). They are found in three chief forms—round, straight-rod-shaped, and spirally-twisted rod shaped. They are of vegetable nature but some types are motile, the power of movement being often due to hair-like proce es called flagella. They are so small that they are discernible only by means of microscopes of high power—even the width of the finest needle would, compared with a bacterium, look like the width of a man’s thumb beside a speck of dust. They are as a cla the most important, both for good and evil, of all micro-organisms—the most numerous, the most vigorous—and the most difficult to control, for they are practically omnipresent and millions may result within twenty-four hours from a single active specimen left undisturbed. Bacteria are found in great numbers in various parts of the human body. Under norma! conditions the presence there of some kinds is not only harmle but is probably nece ary to health and life—for there are, from the human standpoint, both *“eood’’ and “‘had’’ bacteria, and it is believed that we need the former to guard us against or to counteract the latter. In addition to their functions in the human body —which subject belongs rather in the province of the physician than the lavman—and their value in the general economy of the universe—which is too wide a subject for discu ion here—many species of bacteria, properly controlled, are of great value in food production. Their presence in various articles a ists digestion both by the chemical changes effected and by producing flavors which stimulate the secretion of digestive fluids not excited by flavorle articles of diet. Some varieties, for example, are e ential adiuncts of butter and cheese making. One you sand million Jactic acid bacteria to the square inch is a conservative estimate for well ripened cream ready for churning. Some are indispensable to agriculture and other industries. Yet, neverthele , despite all these good counts in their favor, the housewife should, in her ordinary round of duties, look upon bacteria as enemies to be fought at every turn. They are far more generally destructive than either veasts or molds, and some of them are always at work in all kinds of moist food (unle very acrid or heavily salted or spiced or sugared, or otherwise cured) exeept it be held at the freezing or boiling point. or hermetically sealed after sterilization. Freezing will stop their increase but 18 a only heat considerably above the boiling point, or long continued boiling, is a sure destroyer of all kinds. All real putrefaction is due to their action—the breaking down of the structure of the food as they feed on certain elements in it, and other changes caused by their growth and multiplication. Their uncontrolled acce to food and undisturbed continuance in it are certain to result in lo , and sometimes in danger to health and life. Among the most actively menacing is the spore-bearing Bacillus botulinus referred to in the concluding paragraph of Home-canning in the article on CanneEp Goons.::. Dayhght, sunshine, and cleanline are opposed to bacteria, so stores and homes, and especially kitchens, should be ble ed with all three as a preliminary safeguard. Next, fresh meats, canned goods (after opening), and similar foods should be eaten as fresh as po ible, and all unsound foods—either animal or vegetable—should be avoided. When immediate consumption is impo ible, a good refrigerator offers a considerable measure of temporary protection, but it is only temporary, for the growth of some kinds of bacteria is checked by nothing short of freezing. “Dried (or ‘‘dehydrated’’) food must also be protected from the po ibility of absorbing moisture or it will regain the vulnerability that was removed by the drying proce . See also references in the articles on Burrer, Cur e, Mix, and Vinnear.