464 Our Surroundings 



The strongest natural defense of the body against disease 

 germs is the work of the white corpuscles. 



Immunity from a particular disease may be natural or ac- 

 quired. It is natural when inherited, and acquired when it results 

 from having had the disease or from having had some preventive 

 treatment. 



Sanitation treats of methods of making our surroundings 

 healthful. 



FACT AND THOUGHT QUESTIONS 



1. Discuss the importance of health. 



2. Why is keeping physically fit an aid in avoiding contagion? 



3. Mention errors in diet. 



4. Name several diseases caused by bacteria. 



5. What defenses do our bodies erect against disease? 



6. Is there any danger in the entrance of just a very few disease germs 

 into the body? 



7. Name diseases caused by protozoa. 



8. What is meant by natural immunity? 



9. What is meant by acquired immunity? 



10. What is meant by sanitation? 



11. Describe sanitary methods of sweeping and dusting. 



12. Name some of the effects of disease. 



13. Define: (a) vaccination, (b) inoculation, (c) serum. 



PROJECTS 



1. Make a list of precautions that should be taken to avoid disease. 



2. Describe the sanitary equipment of a well-arranged dwelling house. 



OUTDOOR OBSERVATION 



1. Observe and list unsanitary conditions around buildings and in open 

 fields and suggest remedies. 



REFERENCES 



Infection and Immunity Sternberg 



Bacteria in Relation to Country Life Lipman 



Primer of Sanitation Ritchie 



Principles of Health Control Walters 



