EXERCISES 457 



Disinfectants should be separated from medicines, so that they may 

 not be swallowed by mistake. 



440. Exercises. 



1. Give some of the objections to smoke in the air of cities. 



2. If you remember that plants and animals build up complex 

 materials out of simple foods, what does the work of bacteria and 

 ferments seem to be? What, then, is the function of bacteria in the 

 economy of Nature? 



3. What are the objections to the making of clothing in " sweat 

 shops" and in houses where families live? 



4. What effect has the density of the population upon health and 

 the length of life? 



5. Suggest how it is possible that the city may be made more health- 

 ful than the country. 



6. To what danger are men exposed who work in factories where 

 metal articles are ground or filed? 



7. What is the advantage, to a city, of a hospital for persons having 

 contagious diseases? What does your town or community do with its 

 smallpox patients? 



8. Some people contend that rats and mice, like flies, are scavengers, 

 and are therefore useful to man. Are they economical scavengers from 

 the community's point of view? 



9. Suggest how a house may be placed so as to get the greatest 

 possible amount of winter sunshine. 



10. Give the objections to having unlighted clothes closets in a 

 house. 



11. Medical books state that the period of isolation for scarlet fever 

 should be six weeks; what is the practice in your community? Is it 

 possible for a child in your community to go to school while another 

 child in the same house has scarlet fever? 



12. Ask a physician or health officer about the number of cases of 

 infectious diseases in your town in the course of a year. Can you find 

 any reasons for the change in number from month to month? 



13. Is inoculation ever used to protect animals from disease? Give 

 instances. 



