276 NATURE STUDY REVIEW [7:9— Dec, 1911 



2. Sunshine. 



3. Exposure to air. 



f. Stomach and intestines. 



1. Digestion experiments. 



a. Effect of chewing. 



b. Starch to sugar. 



1. Effect of acid environments. 



c. Mix food in test tube. 



d. Sugars and proteids in water for fermentation. Draw 

 conclusion. 



e. Digestion of proteids. 



2. Foods. 



3. Tea and coffee, alcohol, tobacco. 

 Hygiene of environment : 



a. Air 



1. Cultures. 



a. Room in morning, noon, night. Ventilated and unventi- 



lated room. 



b. After dry sweeping and moist sweeping. 



c. Draw conclusion. 



b. Water and milk supply. 



1. Cultures. 



2. Trace to sources. 



c. The house fly, mosquito, etc. 

 1. Cultures. 



Control of bacteria : 



a. Antiseptics, poisons, acids, cold, absence from air, cleanliness. 



Helpful bacteria: 



a. Use in manufacture in clothing, cheese, butter, etc. 



Prepare a flat bottle with the culture medium. Catch a house 

 fly and let it walk about on the culture medium. Observe results 

 from day to day. Such a demonstration is more eloquent than 

 days of talking relative to the harmfulness of the house fly. 

 Avoid letting air into the bottle. 



Bacteria are so closely related to the health and happiness of 

 the individual each class should spend at least two weeks of its 

 school life in their study. 



Be sure that the bacterial cultures are applied in the direction 

 of conduct. 



