The care of food between the time of purchase and cooking, and that of cooking and serving is highly important. The fact that spoiled food represents an economic loss, important as it is, is much less significant than the fact that not only spoiled food, but good food which is contaminated with germ life, is a possible source of disease.

Exposed food, i. e., food exposed to dust, insects, etc., becomes contaminated with disease germs without necessarily becoming spoiled or in any way offensive to the senses. The most crisp salad or luscious fruit may be covered with dangerous microorganisms.

By far the most frequent and abundant forms of microorganisms, which grow at such rate as quickly to become visible to the naked eye, are molds. These are not on the whole harmful to man, and their chief significance is that they give to foods a bad flavor and cause a certain amount of decomposition. These organisms attack food which is stored in dark, damp places, chiefly cellars, and although themselves generally harmless, they are likely to be associated with poisonous bacteria. Certain butchers hang steaks until they become covered with mold, but the mold does not make the meat tender and highly flavored, for these changes are due largely to the bacteria of putrefaction which are also present, thriving under the same conditions as does the mold.

In case of substances which have a natural protective covering, it is highly important that this should not be broken in handling. Thus when fruits and vegetables are bruised, the pulp is quickly attacked by microorganisms and local changes occur, resulting in economic waste, since such articles can only be partly utilized.

1 For further information, note "Care of Food in the Home. " Farmers' Bulletin, No. 375 U. S. Dept. of Agriculture, Washington, D. C.

Foods should therefore be stored in places which admit plenty of sunlight and air, which will antagonize the growth of molds and putrefactive bacteria. Ice, by producing temperatures unfavorable for the growth of microorganisms, is a valuable aid in this sort of cleanliness. Some use of soap and water is necessary, but the benefits are partly lost if the shelves, etc., are left damp. In cellars repeated whitewashing is the most available resource for cleanliness.

Food should be bought in the freshest and cleanest state, should be placed in clean containers, and handled with clean hands. Foods should always be washed if there is any suspicion of contamination. The cases of violent cholera morbus which often follow the use of unripe apples, and even of ripe fruit like cherries, are believed to be due not to the irritating acids present in fruit, but to the presence of a well-known bacterium mingled with the dust which collects on such fruit. To be absolutely on the safe side, all fruits and vegetables should be eaten cooked, but this would deprive us of salads and fresh fruits and berries which form so large and pleasurable a part of the average dietary. It has been found by experience that if celery, greens, asparagus, berries, etc., are. washed repeatedly in cool or tepid water, they can at last become quite clean without losing their delicate flavor and consistency. As long as a particle of grit is present there is of course possibility of contamination by living organisms. They should be washed, therefore, until the wash water is clear. This is a rule which applies to all food that is to be eaten raw. With cooking such caution is not absolutely necessary. Potatoes, etc., are washed before boiling for esthetic reasons only.

The worst cases of food poisoning, known as ptomaine poisoning, are mysterious in character, and are not entirely preventable. Chemical substances not usually formed in simple decomposition are responsible. They may be present alike in raw, cooked, or frozen foods, and in fresh and preserved foods. In some cases there is abundant evidence of extreme decomposition. The use of rotten eggs in cookery by bakers has caused severe ptomaine poisoning. Cold storage meats are sometimes responsible. Fish poisoning, especially with shell fish, may be due to some unknown disease of the animals themselves (although fish very readily undergo decomposition), and personal susceptibility is often a factor. The numerous cases of ice cream poisoning are usually due to mistakes of amateurs who do not understand the proper requirements of the art. Although we do not understand and cannot always foresee ptomaine poisoning, it is the more important that no step be neglected which will contribute in theory to securing clean food. Most cases occur in prolonged warm weather in which decomposition is favored. Sound, fresh food, thoroughly cooked and eaten at once could hardly cause ptomaine poisoning under any conditions.

The articles which the ordinary careful nurse must think of in this connection are preserved foods of all kinds, shell fish, and milk products, the latter being of most significance, because milk, fresh cream, ice cream, etc., are often given freely to invalids. The care of milk, drinking water and other kinds of food is considered elsewhere.

Special care of food in respect to fly pollution has become necessary since we have learned of the part played by this insect in causing typhoid fever, cholera, dysentery, etc. Both the feet and the excrement of flies are sources of contamination. Dealers in food-stuffs in the main take but little pains against protecting their wares from fly contamination. Cooking and careful washing of food to be eaten raw, are our principal safeguards in respect to food as it reaches the house. There is the added danger that food when ready for consumption will be freshly contaminated. To obviate this, doors and windows of kitchens and dining rooms must be properly screened, and flypaper and similar precautions employed. If typhoid is epidemic in a neighborhood, it is well to avoid raw food entirely, just as we avoid unsterilized water and milk. Plies are much more likely to abound in neighborhoods where manure, garbage, etc., are allowed to accumulate, and are more dangerous than ordinary dust.

Dealers usually are at some pains to keep their supplies free from dust, though their methods are not always sanitary, e. g., the use of the feather duster for fruit. Dust from the streets of cities abounds in germ life. Vegetables and certain fruits in clusters which cannot be wiped (grapes, currants, etc. ) are most likely to be dusty. Washing successively in a number of waters will usually remove the dust; but in the tropics where many diseases are dust-borne it is not considered safe to eat raw grapes at all. Whether washing is sufficient depends on the character of the dust and the degree of exposure to it.