HOME ECONOMICS AND EDUCATION 621 



from the bacteria though the changes are chiefly due to the action of 

 ferments normally present. It is not easy to draw the line between 

 the harmless ripening processes and the bacterial changes classed as 

 decay. 



The food may become dangerous even before it shows outward 

 signs of decomposition, for the bacteria may give off substances 

 known as ptomaine, some of which are very poisonous. It is not 

 known under what conditions these ptomaine poisons are developed 

 in foods ; we know only that they are the result of bacterial action. 



Disease Germs and Polluted Water. The so-called germs of 

 typhoid fever, diphtheria, and tuberculosis are bacteria, and as they 

 may be conveyed by means of water or food this danger is a very 

 real and serious one. Science has shown us that insects, especially 

 flies, may carry bacteria to our food. They should, of course, be 

 excluded from our homes and kept away from our food supplies. 

 Dust, too, may be very dangerous, and should be avoided as far as 

 possible. Another possible source of danger, frequently overlooked, 

 is the presence of pet animals in the kitchen. Rats and mice are dis- 

 agreeable pests and no one wants to eat food they have touched as they 

 are known to carry disease. 



The food brought into the house should be clean and of good 

 quality. Clean shops and markets and sanitary bakeries are a ne- 

 cessity. With cold storage goods it is important that they be used 

 very soon, especially poultry and fish. Poultry, meats, and vege- 

 tables should be carefully selected and carefully protected from 

 contamination. 



Ice chests and refrigerators are valuable aids in keeping food, 

 but must be carefully attended to, cleaned and scalded, as there 

 are bacteria that grow at low temperature. Ice is not always free 

 from dirt. A cloth folded about the piece of ice tends to protect it 

 from outside heat and catches any dirt frozen in the ice. It should 

 be scalded after each using. All cooked food should be cooled as 

 soon as possible before being placed in the ice box. Butter may be 

 kept from taking up the flavors of other food by keeping it in a 

 tightly covered receptacle. Milk requires more access of air, but in 

 a clean ice box in which no strong-smelling food is kept milk 

 should remain uninjured in flavor for twelve to twenty-four hours. 

 If vegetables or other foods of pronounced odor are kept in glass 

 jars with covers or in covered earthenware receptacles there will be 

 fewer odors to be communicated. Portions of canned food should 

 never be put into the ice box in the tin can. Such food does not of 

 necessity develop a poisonous product, as has sometimes been 

 claimed, but experiments show that ptomaines are particularly 

 liable to develop in such cases. Casting out this somewhat remote 

 possibility, the tinny taste acquired by such keeping is enough to 

 condemn the practice. 



Refrigerator ice is often dirty, and may bring in putrefactive 

 or even typhoid bacilli, for most bacteria are not destroyed by freez- 

 ing. On this account no food should be brought into direct contact 



