106 LABORATORY EXERCISES. 



1. What conditions seem to favor the growth 



of bacteria? 



2. What conditions seem to hinder the growth 



of bacteria? 

 G. Practical questions in bacteriology. 



1. Why are fruits cooked before canning? 



2. Why should fruit-jars be filled completely 



before screwing on the cover? 



3. Why do fruit- jars sometimes burst long 



after being filled? 



4. Why is grass dried before it is put into the 



barn? 



5. Why are milk, meat, etc., put in the refrig- 



erator in summer-time? 



6. Why should the prohibition against spit- 



ting in public places be rigidly enforced ? 



7. Why should sweeping be done so far as pos- 



sible without raising a dust ? 



8. Why are hard-wood floors more healthful 



than carpets? 



9. Why should the teeth be brushed often? 



10. Why should the refuse be removed from the 



streets every morning early, especially in 

 summer-time ? 



11. Why should sink-drains be carefully in- 



spected ? 



12. Why should wounds be carefully cleansed 



and dressed at once? 



13. Why are typhoid fever, diphtheria, and 



other infectious diseases often better 

 treated in hospitals? 



