Food study

CONN. " Bacteria, Yeasts, and Molds in the Home ", sections on Bacteria and Yeasts. 1. Give instances in which bacteria are beneficial. 2. Why may there be more spores on the fruits and vegetables SWEET PICKLED PEACHES 25 growing in a very dry season ? Why would such fruits be harder to can successfully ? 3. Why, in making cucumber pickles, is the brine reheated at intervals ? 4. How should garbage cans be cared for ? 5. What are the best means of disposing of garbage ? 6. Why should all foods and dishes be covered carefully when sweeping or dusting is going on ? SWEET PICKLED PEACHES A. PREPARE SWEET PICKLED PEACHES. Use one peach. 5 peck peaches 1 pint vinegar 2 Ibs. brown sugar 1 oz. stick cinnamon Cloves Scald the peaches, peel them, and stick them with three or four cloves. Cook until tender a few of them at a time, in a syrup made by boiling together the sugar, cinnamon, and vinegar. Put in jars. B. Class Experiment. CONDITIONS FAVORING GROWTH OF MICRO-ORGANISMS. Try the following experiments, using petri dishes, or saucers covered with tumblers or sheets of glass : 1. Place a piece of bread in each of two dishes. Leave the first piece of bread dry; moisten the second piece with water. Expose both to the air for five minutes in a room where people are moving about. Cover, and keep both in a dark place (as, for example, in a cupboard) for two days, and observe the results. 2. Place a piece of bread in another dish and moisten it. Expose it for five minutes in a room when no one but yourself is present, and do not move more than you can help during the exposure. Keep this dish also in the dark for two days and compare with the second dish in (1). 3. Put pieces of bread (moistened) in four dishes, and expose all at once for five minutes in a room with people moving about. a. Keep the first in a warm room. b. Keep the second in an ice-box. c. Keep the third in the sunlight as much as possible. d. Keep the fourth in a dark, warm place. Examine these at the end of two days. If necessary, let them stand longer. What effect has dryness or moisture, warmth or cold, light or darkness, on the growth of mold ? Account for the difference in (2). CONDITIONS FAVORABLE TO THE GROWTH OF MICRO-ORGANISMS Food might seem to be the first condition necessary to the growth of micro-organisms, and so it is ; and yet they seem able to live for a fair length of time without food. They blow around in the air, or are transmitted by water, in neither of which elements are they fed. Under these circumstances, it is true, they are not growing or multiplying, and may even be in the spore state, but once the organisms reach available food, they begin to grow and reproduce with wonderful rapidity. Water, as well as food, is necessary, but different organisms vary somewhat in regard to the necessary amounts. Bacteria and yeasts require a goodly propor- GROWTH OF MICRO-ORGANISMS 27