It is evident that as individuals we may each do something to prevent the spread of germ diseases, especially in our homes. We may keep our bodies, especially our hands and faces, clean. Sweeping and dusting may be done with damp cloths so as not to raise a dust; our milk and water, when from a suspicious supply, may be sterilized or pasteurized. Wounds through which bacteria might obtain foothold in the body should be washed with some antiseptic such as carbolic acid (1 part to 25 water), which kills the germs. In a later chapter we shall learn more of how we may coöperate with the authorities to combat disease and make our city or town a better place in which to live.[23]
[17] Experiments on conditions favorable to growth of mold should be introduced here.
[18] An experiment to show conditions unfavorable for growth of molds should be shown at this point.
[19] See Goff and Mayne, First Principles of Agriculture, page 59, for formula of Bordeaux mixture.
[20] For directions for making a culture medium, see Hunter, Laboratory Problems in Civic Biology. Culture tubes may be obtained, already prepared, from Parke, Davis, and Company or other good chemists.
[21] Perform experiment here to determine the value of different preservatives. Use sugar, salt, vinegar, boracic acid, benzoic acid, formaldehyde, and alcohol.
[22] Experiment to determine the most effective disinfectants. Use tubes of bouillon containing different strength solutions of formaldehyde, lysol, iodine, carbolic acid, and bichloride of mercury. Results. Conclusions.
[23] Teachers may take up parts or all of Chapter [XXIV] at this point. I have found it advisable to repeat much of the work on bacteria after the students have taken up the study of the human organism.
elementary